Northstar User’s Manuel & Tips

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Page 1 of 19 Northstar Use Info.docx NOTES ON THE COMPATIBILITY AND USE OF NORTHSTAR BRAND

by Robert A. Mickelsen 4/29/94

This document contains some of my personal observations and experiences with Northstar Borocolour colored glass. These are strictly my feelings and opinions and do not necessarily reflect the opinions of the manufacturer or anyone else for that matter.

Northstar colors can be roughly divided into two categories: colors that strike and colors that do not strike. They can be further categorized into several color groups: reds, oranges, and yellows; the cobalt family; transparent and multi greens; opacified colors; exotics; and what I call 'pastel' colors. These categories are somewhat arbitrary and but I list them here because it demonstrates how many of the Northstar colors are derivative of each other. I will discuss them within the context of these categories.

REDS, ORANGES, AND YELLOWS

Northstar Ruby was the first Northstar color I tried. It is a striking color that turns an intense transparent red when re-heated. This color used to have a lot of seeds and bubbles in it, but has gotten much cleaner in recent years. Just recently, Paul Trautman has sent me samples of a 'new improved' Ruby that is cleaner and less seedy than ever before. Furthermore, this new Ruby does not 'overstrike' (turn opaque brick-red) as easily as the old Ruby did, so you can work it more. Paul says he is changing all the Ruby and Orange colors over to this new technology.

Ruby (NS07) can be heated back to clear and re-struck many times without damaging or devitrifying the glass. For best results, Ruby should be worked in a neutral to slightly oxidizing flame and, if possible, placed in the oven while still clear. This will result in a very transparent red. Ruby goes very well with Cobalt Blue, Black, Turbo Cobalt, White, Green, and Aqua. It makes excellent casing material, but is only fair for frit and trailing. I generally use Dark Ruby (NS08) for those types of applications. Dark Ruby strikes almost black if applied thicker than 1/8" and annealed while still clear. It's intensity makes it great for very thin trailing and fine frit and it makes very nice twisted lip wraps. I also use it for shards because it can be blown very thin and will still strike deep red. I simulate black on larger pieces of glass by casing Dark Ruby over clear with a layer of Cobalt Blue (NS01) over that.

Northstar Orange (NS05) is one of my favorite colors, but it can be aggravating to use because there seems to be a broad variation in intensity from batch to batch. You have to be careful not to use two different rods on the same piece because, as often as not, they will not strike the same, and could ruin the piece. This variation is due primarily to continuing attempts by Northstarþ to improve their formulas. Still, the color is one of the best Northstarþ makes. The intensity ranges from a pale transparent orange to a deep almost opaque coral color. This color is clearly a mixture of Ruby (NS07) and Yellow (NS09). Orange tends to strike with a slight opalescence that increases the more you work the rod. This opalescence will appear first with the orange highlights taking longer to strike. The opalescence can be eliminated by reheating the color clear and then striking the piece in the oven, which will result in a transparent orange. Like Ruby, it Page 2 of 19 Northstar Use Info.docx can be heated back to clear and re-struck many times without any ill effects on the glass. Dark Orange (NS06) is a more consistent color. Like Dark Ruby (NS08), it is very good for trailing, shards, frit, and other applications that are very thin. Also like the ruby, the oranges have had a problem with seeds and bubbles in the past, but Paul tells me that the new technology will apply to them as well and should clear the problem up. Both oranges go well with any of the green colors and look wonderful with Black.

Northstar Yellow (NS09) is similar to Orange in its behavior. I do not use much Yellow, but I have heard that very interesting effects can be achieved by layering Yellow over other striking colors like multi-green (NS03). Yellow tends to stay pretty clear, but if it is re-heated in a reducing flame it will take on the swirly opalescence that is characteristic of yellows and oranges. This opalescence can be avoided by heating the color back to clear before placing the piece in the annealing oven. If annealed clear, the result will be very transparent yellow. The extra Light Yellow (NS34) is even lighter than Yellow. It was designed primarily for overlaying other colors. These rods are so light I have gotten them confused with my clear pyrex stock from time to time. Layering Yellow or light Yellow over Ruby will yield very pretty violet and vermillon highlights.

Amber-Purple (NS13) really needs its own classification, but I am putting it with the reds, oranges, and yellows because it is most closely related to Yellow. But Yellow it is not. Amber- Purple is one of the most unique and difficult to learn of the Northstar colors. Like Orange, this color tends to vary from batch to batch, so you don't want to use two different rods on one piece. The rods look deep yellow when you buy them, but when they are re-heated, they take on a beautiful opalescent violet color. This color is more easily viewed in direct light. If back lit, the glass will look more amber in color... thus its unlikely name. I have had difficulty in getting consistent results with Amber-Purple, but I still use it extensively. The Northstar catalogue says to work the color in an oxidizing flame and then reduce to get the purple highlights, but it is not that simple. Amber-Purple is a color that changes its characteristics the longer you work it. If used in a procedure that only involves heating it one time, it is quite easy to strike it purple. But, more often than not, you must repeatedly heat and re-heat the glass and then Amber-Purple seems to get overpowered by the opalescence in the glass. It becomes more and more opaque until it is actually a deep custard color. When it reaches this stage, it is much more difficult to strike it with purple highlights. If you encase Amber-Purple in clear glass, it is impossible to get purple highlights. Instead the glass becomes an opaque custard color, which is not bad actually, so I case it all the time! Amber Purple goes very well with Orange, Black, and Jade Green. It is intense enough to make good frit and trailing, but makes only fair shards. It is excellent for sculpting, especially if you can achieve final shape with only one or two heatings so you can strike it deep purple.

THE COBALT FAMILY

The cobalt family is the largest group of colors. No less than nine Northstarþ colors are in this family: Cobalt Blue (NS01), Irrid Blue (NS14), Turquesa (NS15), Black (NS16), Light Cobalt Blue (NS19), Dark Cobalt Blue (NS20), Turbo Cobalt (NS33), Black Hole (NS35), and Intense Blue-Green (NS38).

Page 3 of 19 Northstar Use Info.docx There are four different intensities of Northstar Cobalt Blue: Regular Cobalt (NS01), Light Cobalt (NS19), Dark Cobalt (NS20), and Turbo-Cobalt (NS33). But they all share the same general characteristics. The cobalt colors tend to be very clean and devoid of any bubbles or seeds or even striations from uneven mixing. The lighter cobalts are extremely clear and retain that clarity even when heated and re-heated extensively. The darker cobalts are somewhat prone to reducing and should therefore be heated in an oxidizing flame. The darker the cobalt, the more pronounced this problem becomes and therefore, the more oxidizing your flame should be. I use Regular Cobalt for casing and combining with other colors. It is lovely for sculpture and any decorations over 1/8" thick. Light Cobalt is also a beautiful color, very transparent, and is great for casing and sculptures, but should be used no less that 1/4" thick. Dark Cobalt is better for thinner decorations like shards and thick trailing, but is still too light for trailing or frit. It makes very good lip wraps. The darkest cobalt, Turbo-Cobalt, is a terrific substitute for black. It will not look blue until it is drawn thinner than 1/32", but has none of the drawbacks of black and black hole like bubbles and a tendency to bloom. Turbo Cobalt must be worked in a highly oxidizing flame however, or it will reduce and show grey streaks that, once they appear, are difficult to heat out.

Three colors of the cobalt family are striking colors. They are Irrid Blue (NS14), Turquesa (NS15), and Intense Blue-Green (NS38). They are all essentially variations of one another with Irrid being the lightest and Blue-Green being the darkest. They are all a combination of Cobalt and Yellow in varying intensities. Like the cobalts, they tend to be very clean colors, without any bubbles or seeds. These colors are wonderful for casing because of the beautiful way they strike. They tend to turn a kind of bluish green with lovely streaks depending on how it is applied. The opalescence makes this glass more opaque than transparent. I use these colors for casing mostly and apply decorations on top of it, but the Blue-Green (NS38) is dark enough to use as frit or trailing.

Black (NS16) and Black Hole (NS35) are difficult colors to use. I almost never use Black because, in my opinion, it is not dark enough to really be called black. It is more of a grey. The rods look pretty black, but in almost any application, it loses its intensity. It is also very prone to reduction and must be worked in an extremely oxidizing flame. It has a tendency to bubble and bloom so you have to kind of stay off of it, which can be tough to do because it is a very viscous glass. The bloom is very nasty and, once there, is all but impossible to remove or heat out. If you heat it with the flame, the bloom will boil almost instantly. Black Hole has all the same problems, but its saving grace is that it is dark enough to be called a true black. It too has a tendency to bubble when worked and will reduce and bloom in anything less than a flame that is ready to blow out. But it can be worth all the trouble. Black Hole makes some of the best frit of any Northstar color. This frit goes extremely well when applied over orange or amber-purple. It does need a color underneath it though. It doesn't look good applied to clear glass.

GREENS: TRANSPARENT, MULTI, ROOTBEER

The only other purely transparent non-striking color besides Cobalt Blue Northstar makes is Transparent Green (NS24). This glass is a pure kelly green that is not heat sensitive at all. It will, however, reduce, creating unsightly brownish streaks, so it needs to be worked in an oxidizing flame. It is also prone to devitrification if over worked so you must avoid extensive heating and Page 4 of 19 Northstar Use Info.docx re-heating. I use a great deal of this color for sculptural work and casing. It is not intense enough for thin, delicate decorations like trailing and frit. It goes well with Orange and Root Beer.

Multi (NS03) rods look so much like Transparent Green that it is very difficult to tell them apart. But when they are heated, the difference is very apparent. This color strikes, but depending on what kind of flame you use, it strikes in a number of different ways. Unlike most other colors where I want to avoid reducing the glass, I actually want to reduce Multi. The effects can range from a streaky cream color to almost a brick red. Usually, there are all ranges of these colors present together. The effect can be dramatic, but unpredictable. Multi is great mixed with other colors for bizarre effects and can be cased over in clear which tends to magnify the intensity of the colors. Multi makes good trailing material and decent frit when used on clear glass. It goes well with Ruby and Black. Dark Multi (NS04) is just a more intense version of the same thing.

Root Beer (NS37) is a color that Paul made at my urging. Some years ago he sold me some seconds of a 'failed' color, a variation of Multi that he called 'Root Beer' because of the dark caramel color. I liked it so much that I bugged him to make more. Unfortunately, the color was a result of a mistake and could not be easily duplicated. He tried many different formulas, but was never able to duplicate the original Root Beer. But, the color he came up with instead is in some ways better. Root Beer is a greenish rod that clearly contains some of the elements of Ruby and Yellow. If reduced slightly, it strikes a cool reddish-brown with deep striations. I love to case this glass around a clear rod and draw it out into a curved or twisted shape. The colors look like alabaster or marble, only in reds and browns mixed with greens. It is very beautiful! Root Beer also makes excellent frit and trailing and shards. It goes well with Ruby and Jade Green.

OPACIFIED COLORS

There are only two truly opacified Northstar colors. They are White (NS10) and Jade Green (NS11). Neither of these colors strike.

I used to hate Northstar White (NS10). I used the cathode ray-gun mounts manufactured by Corning and sold to lampworkers as square sticks almost exclusively. But recently, I have re- discovered Northstar White and now think it is a decent color. Its only problem, and the reason I used to hate it, is that it is extremely prone to boiling. You just have to be sure not to overheat the stuff. Extreme care must be taken so that the thinnest areas, where boiling is most likely to occur, do not get overheated. But, if you can succeed in completing your task without boiling the glass, NS10 is the purest white borosilicate glass you can buy. It goes with practically every other color and does not reduce or devitrify at all. By exercising care, I have done every thing from casing tubing to intricate sculptures with it. It is not intense enough to use for fine or delicate decorations, but performs adequately in almost any other application.

Jade Green (NS11) is a strange color. On the surface, it appears to be utterly benign. It melts quickly, draws nicely, and matches viscosity with clear stock better than most of the other Northstar colors. But, in the past, it has had a tendency to check. The checking seemed to occur in certain applications more than others, so was a simple matter to avoid those uses of this color. For instance, I never encased Jade Green in clear glass. It would check every time no matter how thoroughly I annealed it. Although it makes fairly good shards, I never used it that way. It didn't Page 5 of 19 Northstar Use Info.docx seem to like being stuck onto clear glass in such a thin layer. Paul has informed me that there has been a recent change in the COE of Jade Green, and it is now much more compatible than in the past. As of this writing, I have not verified this, though I plan to try some samples in the very near future. Until then, I will just keep using Jade Green for what I have always used it. You can case over clear with it, trail with it, and sculpt with it. It makes fine lip wraps. It goes well with Orange, Black, and Ruby.

THE EXOTICS

There are three Exotic colors: NS27, 28, and 29. All three are color variations of a glass so saturated with metallic colorants that it fumes and plates when heated. It makes for some rather spectacular results however, when used properly. Generally speaking, you should apply it in an oxidizing flame and then reduce it. But, I rarely bother to try to get this glass to do what I want, instead settling for whatever it wants to do. It rarely lets me down. NS27 is a little greener than the others and tends to strike with more metallic features. It also fumes to a greater degree. This glass makes great frit, but is poor for trailing because it tends to be lumpy and viscous and does not draw nicely. NS29 is redder, fumes less, and strikes with less of a metallic effect. Again, it makes great frit but poor trailing. NS28 is somewhere in between. If worked with care, the Exotics can be used for sculpting, which can yield some really weird colors. It is best when not repeatedly reheated. Exotic frit looks great on clear, Aqua, Jade, or any of the cobalt family of colors. One trick is to case over a clear core with Exotic and then traill or draw some transparent color or clear glass over that, then reduce the glass. The clear trailing will 'resist' the reduction creating some very interesting effects.

PASTEL COLORS

I have lumped the remaining Northstar colors together into a single general category I call the pastels. They are : Milkyway Blue (NS02), Strawberry (NS12), Aqua (NS17), Moss (NS21), Polaris (NS22), Pink (NS23), Peach (NS25), Lavender (NS31), Violet (NS32), and Creamy White (NS36). Within this category, the colors Creamy White, and Strawberry are similar, with Strawberry essentially being Creamy White with some Ruby thrown in. Pink, Lavender, and Violet are likewise similar, each being a variant of the other. Milkyway Blue, Moss, Polaris, and Aqua make up the rest of the pastel family. All of these colors share the common characteristic of having intentionally introduced micro-bubbles to make them more opaque. All of the colors behave in much the same way. When you are working the piece, the heated micro-bubbles are enlarged, and appear more prominent. The largest ones, however, burst, and leave only the smallest ones. They, in turn, shrink significantly as the piece cools. The result is that the piece does not end up looking all that bubbly. In fact, Aqua (NS17), Milkyway Blue (NS02), Moss (NS21), and Polaris (NS22) take on a kind of 'metal flake' appearance to them when they cool. These colors all make excellent casing material and can be used for sculpting. They make only fair frit and usually are poor for trailing because they don't draw that well. Of these colors, I use Aqua most of all. It goes really well with Turbo-Cobalt or Ruby. Exotic 27 frit looks excellent on Aqua. Aqua twisted with Turbo-Cobalt or Black Hole makes beautiful lipwrap material.

Page 6 of 19 Northstar Use Info.docx Strawberry (NS12) is the only one of the pastel colors that strikes. It turns dark red, but because of the micro-bubbles, is considered an opaque glass. There used to be a lighter version of Strawberry that I used a lot, but Northstar no longer makes it. The present Strawberry is very dark and, I think, not as 'strawberry' looking as the old stuff was. Strawberry can be used for casing or sculpting. In all honesty, I don't use it much anymore.

Pink (NS23), Lavender (NS31), and Violet (NS32) are all closely related colors. They behave in much the same way. You have to take off your didymium to tell Pink and Lavender apart. With them on, they look exactly the same! These colors also will appear very different when viewed in different kinds of light. Incandescent light, flourescent light, and sunlight will make significant differences in the appearance of these subtle colors. These colors are not very intense and although they are probably best used for highlights or small sculptural elements, I have seen them used successfully when cased over clear tubing or over a layer of White (NS10). Even though they become quite diluted when used this way, they still have surprisingly intense and beautiful effect. They do not strike and are not sensitive to atmosphere.

Creamy White (NS36) is really more of a light gray than a white, but the micro bubbles give this glass a very smooth texture, thus its name. It is excellent as a base for application of other colors and as a transluscent casing color. There does tend to be some variation between batches with the best being the glass with the finest bubbles. If you get a batch with coarse bubbles, it will be next to impossible to work. However, I have not gotten a batch like that in a couple of years.

Peach (NS25) is another color with a creamy texture due to the micro bubbles contained in the batch. This color is the closest Northstar color to flesh, and so is a good one for doing figures and body parts. It is an extremely tolerant glass, and will put up with almost as much abuse as clear pyrex stock. Milon Townsend did warn me that the seconds are vastly inferior to the firsts, and are probably not worth the money you save by buying them.

Northstar is constantly experimenting with ways to improve its formulas and I am called upon from time to time to test new glasses for Paul. Recently, he has sent me some other colors that he has opacified using the micro bubbles. These include Orange and Ruby. The opacified orange is a real breakthrough. It is lovely to work with, creamy in texture and very consistant in its striking characteristics. I hope to see more of that in the near future. Another recent innovation is the introduction of smaller diameter stock in certain colors. These rods average about 4mm, and are perfect for casing color over clear rod and especially tubing. I have used Cobalt, Amber- Purple, and Irrid in the 4mm size with excellent results. I believe it is much quicker and more efficient to case with this size than with 6mm or larger rods.

Page 7 of 19 Northstar Use Info.docx ADDENDUM - 5/96

Northstar has developed several new colors and a couple of them are really fine! Paul sent me samples of N41 (Butterscotch), N42 (Cinnamon), and N43 (Rust).

The Butterscotch is kind of a variation of Amber-purple, only without the purple. It is an opaque striking color that has a creamy-yellow appearance, hence its name. It makes great frit and trailing because of its relative intensity and silver content. It strikes to a deep caramel color with a faint metallic sheen and pinkish highlights. It seems highly sensitive to atmosphere. It is very clean and the samples I have seen do not have any bubbles or seeds in them.

The Cinnamon is only the third transparent non-striking color made by Northstar in addition to cobalt (01) and transparent green (24). It is a dark amber-cola color that is not sensitive to heat or atmosphere. About the only way you can damage it is to overheat it and cause it to boil. The rods are clean and clear and the glass stays that way when worked. It is not very intense so it is not much good for frit or trailing but will work fine for casing and sculpture. It and the butterscotch were made for each other and look wonderful together.

Rust (43) was designed as a substitute for the old Ruby (07) that is now very expensive due to the great increase in price of one of its most important ingredients. This version of Ruby lacks the vibrant intensity of (07) and, although it still does strike, it is nowhere near as red. Striking color is closer to reddish-brown. It isn't very intense, so it is great for sculpting and casing. You don't have to dilute it to work with it. It is actually quite pretty and I expect to be using quite a bit of it.

Those are my notes about the 36 Northstar colored borosilicate glasses. Every lampworker will have different experiences and therefore different opinions about certain colors. Just because I don't like or don't use a particular color does not mean that it is no good. It just means that I don't use it. I encourage you to experiment with color combinations of your own, and to share your results with others so that we can advance our industry together. Whatever you do, TAKE NOTES so you will remember what it was that you did to get that amazing effect!

Northstar Borocolour is in a continual state of development. Color formulas are changed and improved frequently. I like to think that I have had an influence on the developement of some of these colors and Paul encourages other lampworkers to give him feedback on what they like or dislike about the colors they buy from him. You can write to Paul Trautman at 9450 SW Tigard St., Tigard, Oregon 97223, or call or fax him at (503) 684-6986. You can write to me at 265 Rita Blvd., Melbourne Beach, FL, 32951; or email me on Compuserve (71042,751) or on the internet at [email protected] or [email protected].

Robert A. Mickelsen

Page 8 of 19 Northstar Use Info.docx INTRODUCTION TO NORTHSTAR BOROCOLOUR

Northstar® Borocolour® is a colored borosilicate-type glass. It is compatible with, and may be combined with Pyrex®, Kimble/Kimax®, Duran®, Simax® and any other glass with a similar coefficient of thermal expansion (C.O.E.) (32 h +2). Glassblowers and lampworkers will be able to achieve excellent results with Northstar® glass upon the first try. However, Northstar® glass has some interesting characteristics with which the glass artist may not be familiar. It is our purpose, in this manual, to explain some of these characteristics so that the glass artist may attain the most exciting effects possible. Also, some of the following notes will be of more interest to the advanced artist trying to achieve a particular effect.

Northstar® Borocolour® may be striped, layered, swirled, combed, hobnailed, encased etc. For interesting effects try covering one color with another (like Yellow over Ruby Red) or encase with clear glass. Northstar® clear or colored borosilicate frit or powder can be used over Multi or other colors for exciting variations.

. STRIKING

Northstar® Borocolour® is currently available in 54 colors in rod, 24 colors in frit and 22 colors in powder form. Some of these colors are affected by heat. We call these "striking" or "re-heat" colors for they change color when reheated (i.e. Yellow is in clear glass rods when you receive them from the factory. But when heated to the annealing temperature [about 1050°F or 560°C], they change or "strike" to their new color). Other colors may appear pink, blue, green or amber before striking. (All RUBIES are shipped pre-struck to ensure color uniformity.) The longer you strike a color, the darker the color becomes until the saturation point is reached. If, after striking, the glass artist heats the glass to the working temperature again, Northstar® Borocolour® returns to its original un-struck condition. This process of striking and reworking may be repeated many times. The transparent colors are obtained more easily if struck in an electric kiln. Work your piece as hot as possible (but do not boil) and place it in your annealing oven while it is in the un-struck condition. Striking may be performed in your torch flame as well, preferably in a neutral to slightly oxidizing atmosphere. Avoid striking the glass at too high of a temperature. Using either method observe the glass while it is being struck. It is possible to control how dark your pieces become by carefully controlling the striking time. The striking process may be performed simultaneously with the annealing process.

Please note that some colors will strike at slightly different rates. For example, NS-05 Orange will take longer to strike than NS-07 Ruby. If you have many different colors in the same kiln this could cause Ruby to become darker than you want while you are waiting for the Orange to strike. If this is a problem, you can strike differently colored pieces in separate firings of the kiln or, if you are using many different colors on a single piece, keep watching during the striking process and begin to cool the piece when you are satisfied with the effect.

The darker, more intense, striking colors begin to strike more quickly and will be darker when saturated. The darker colors are easier to strike in the torch flame, but on the other hand may become very dark if struck for a long period in the annealing oven. Some of the lightest color variations may take longer to strike in the flame yet can be held at striking temperature for long periods without becoming too dark. A higher annealing temperature will strike Northstar® glass more quickly. A slightly lower annealing temperature will strike the color more slowly. In general, a lower annealing temperature used over a longer duration is better for striking. Please avoid accidental of your pieces!

Page 9 of 19 Northstar Use Info.docx OXIDATION-REDUCTION

Another important consideration when using Northstar® Borocolour® is the oxidation/reduction balance of your flame. This is the ratio of oxygen to gas in your flame. Some colors turn out better in an oxidizing flame, other colors better in a more reducing or neutral flame. Most Northstar® colors look great using either flame. Basically, a "hissing" flame with the oxygen turned way up, almost blowing the flame out, would be considered a very oxidizing flame. On the other hand, a soft, bushy flame low in oxygen, high in gas, is a reducing flame. A neutral flame is somewhere in between. Only practice and experimentation can teach the glass artist the subtlety of this concept. In general, if in doubt, use a neutral flame. Example: Ruby Red; use a neutral to slightly oxidizing flame. Too much reduction can cause the color to become cloudy. Example: NS-16 Black; use a very oxidizing flame for Black, a reducing flame for Grey. Also, please note that the flame becomes more oxidizing as you move farther from the torch head. Again, it is suggested that the glass artist experiment with the colors. See the chart on page five for more detailed working instructions.Color Identification If you are uncertain about which color a particular rod is, just strike the end in your torch flame for a few moments. The color should begin to appear right away. With a very light color you may need to strike a piece of the glass in the oven to see the end result.

HEAT SENSITIVE COLORS

. The opaque colors-NS-10 White, NS-11 Jade, NS-16 Black, NS-27 Green Exotic, NS-28 Blue Exotic and NS-29 Red Exotic, and NS-40 Sky Blue, and NS-56 Pumpkin are heat sensitive. This means the glass must be treated with more care when heating to avoid boiling. Use either a cooler flame or put the rod in a cooler part of the flame (the edges, or as far away from the torch head as possible). The lampworker must watch the rod and if the glass begins to boil remove it from the flame immediately. Otherwise, the rod can be "bounced" in and out of the flame to prevent overheating. Also, some lampworkers report success by inserting the color into a clear tube, then collapsing the tube around the color. The color is then said to be "clad" with the clear glass. This insulates the glass from boiling so easily.

VIEWING THE COLORS

Direct sunlight is the best light in which to observe Northstar® colors, halogen light is second best. Different types of lighting will produce slightly different effects. Also notice the difference between reflected and transmitted light. In general, Northstar® colors are better viewed in reflected light.

Page 10 of 19 Northstar Use Info.docx .. THE EXOTIC COLORS

The Amber Purples:

NS-13 Amber Purple, NS-26 Double Amber Purple, NS-48 Light Blue Amber Purple and NS-49 Dark Blue Amber Purple continue to be some of the most popular Northstar® colors. A "striking" color that also reduces, the effects can range from light yellow to a deep red-amber to various shades of crimson, purple and vermilion.

To get the most exciting effects some reduction is necessary either during or at the end of making your artwork. The trick is to burn off as much of the "haze" as possible when you are finished forming your piece and do the striking and annealing in the kiln. The color should go into the kiln with the oxide "haze" burned off completely.

"Burning off the haze" is a term that means using a hot, "pushing", somewhat oxidizing flame to remove the faint layer of reduced oxide on the outer surface of the glass. This layer will form when reduction occurs and reduction usually does occur to some extent. If the glass has been worked in a reducing environment and the haze is burned off, more vermilion and crimson will be seen. A more oxidizing environment during the working process will result in purples more in the bluish end of the spectrum. Extreme reduction during the working process will result in ambers and yellows if the haze is not burned off.

When burning off haze be aware that this should be done as quickly as possible in order to avoid boiling the glass or slumping the artwork. Some practice may be necessary to train the eye to see this haze and to learn the proper torch settings. This can be subtle. You can actually see the oxide vaporize in the "sweet spot" of the flame. You will also need to experiment with flame settings to learn the best gas -oxy ratio and best location of the flame for haze burning.

The Rubies:NS-07 Regular Ruby, can be flame or kiln struck. NS-07 can become over-struck and too dark (or "livery") if struck too hot or too long as sometimes happens when working a piece in the flame for a long period of time. NS-07L Light Ruby is designed for kiln striking and it may be difficult to get a good strike in the flame. The NS-07L can be worked a long time in the flame, then kiln annealed for a great Ruby Red. NS-08 Dark Ruby will retain its color even if thinned or pulled into a stringer. NS-08 can be flame struck but be careful not to overstrike. .

COMPATIBILITY

Please test all glass colors for compatibility in your specific application before making an expensive piece or production run. Northstar® Glassworks, Inc. strives to make all of our colors compatible and easy to use. However, it is not possible to make all colors exactly the same C.O.E. Some colors may check if used in combination with other colors under certain applications.

Certain colors, the NS-11 Jade, NS-51 Sable, NS-53 Forest Green and the Exotic Colors in particular, may give the glass worker cracking problems if worked incorrectly. Those colors are best used on the outside of your artwork. If encased with a thick layer of clear, as would be the case in a marble for example, some checking or cracking could occur. Again, please test the color for your application. If you do encase these colors, use as little color as necessary and anneal very carefully.

Page 11 of 19 Northstar Use Info.docx USING BOILY COLORS

It's a fact that some glass coloring chemicals have a lower boiling point than others. This can cause a color to boil and become bubbly if proper care is not taken to control heating. NS-10 White and NS-40 Sky Blue are two examples.

Here are some techniques that will help avoid overheating and boiling of the glass.

1. Use a cooler flame, i.e. less oxygen, but note that this is a reducing flame and if your color is sensitive to atmosphere it may be affected. NS-10 will develop gray streaks if reduced heavily. Also turning the oxygen way up, making a very oxidizing, hissing flame has the effect of making the flame cooler. 2. A flame is usually cooler at the tip and edges of the flame. Work your piece in these areas. 3. Pass the color through the flame, back and forth. This keeps the glass from being overheated by staying in a hot part of the flame for too long. 4. When laying down a of color, rotate the rod as you lay it down. This presents a cooler side of the rod to the flame continually. This prevents one section of the rod from becoming overheated. 5. Clad your color with clear glass, which insulates the color from the flame. You can shrink a tube over the color or heat a clear rod and smear an even coat over the color. This can be done on the color rod before application or you can clad your artwork with clear after color has been laid down. 6. In general, if you are using a "boily" color, it is best to gradually heat the color up. This will minimize boiling.

These notes are intended as a general guide. Individual results will vary depending upon many factors including type of gas used (i.e. propane or natural gas), type of torch used (surface or internal mix), type of annealing oven used (gas or electric), and the sequence of heating and cooling. Individual batches of color may vary slightly. Northstar® Borocolour® should come to you pre-labeled for easy identification. Please be sure to store your glass colors in a manner that allows you to identify which color you are using and which colors to reorder. As with any glass material, keep them clean and remove any packing tape immediately upon receipt of the glass. Please observe all normal glass shop health and safety practices.

If you should experience a problem with any of our colors please e-mail or call technical support. We want to know what your experience is with our colors. Your feedback will help us to continually improve our products.

Remember: experimentation is the key to diversity as well as the best way to master the use of Northstar® Borocolour® Borosilicate Color Glass.

USING NORTHSTAR® FRITS & POWDERS

The term "frit" refers to granular crushed glass. Soft glass frits have been available to glass artists for a long time in many colors and several different mesh sizes. Furnace working glassblowers and European- style Lampworkers use frit regularly as a means of adding color to their work. Frit can also be used in such techniques as Pate De Verre and fusing. It is possible to crush and screen your own frit from rod. However, this is a difficult, messy and time-consuming task. We offer many of our borosilicate colors in powder and frit form. Size A frit is coarse, approximately .055 inches or 1.397 mm. Size B frit is finer, approximately .024 inches or .6096 mm. These frits and powders have been formulated for use with Pyrex®, Duran®, Kimax®, Northstar® or any other glass with a similar coefficient of thermal expansion

Page 12 of 19 Northstar Use Info.docx (32 ± 2). Using frits and powders provides the hot glass artist with a means of adding color and/or texture to artwork quickly and easily.

As with most other materials, there is no "right way" or "wrong way" to utilize frit or powder. Experimentation will lead you to discover your own unique effects and subtle refinements of technique. The basic idea is to get the frit to stick to a target object. In order for this to occur the temperature of the object must be hot enough to be soft (at least on the surface of the glass). The hotter\softer the target object is, the more readily the frit will stick to it. If the object has already been formed and slumping is not desirable it is better to heat the object just enough for the frit/powder to begin sticking (by preheating the frit in your oven, the target object can be slightly cooler and therefore less likely to slump). Successive layers can then be built up if a heavy coating is desired. A light sprinkling of frit may be used as a subtle highlight of brightly colored dots or a substantial layer of color can be built up giving a more uniform or darker look. Frit can be coated on the outside of solid or hollow objects. It can also be coated on the inside of hollow forms. Frit may be fused in completely or left partially raised for a surface texture. Different colors may be mixed for a custom look. Clear frit (NS-F-00) may be added over a colored object for effect. A sprinkling of frit may also be mixed into the body of a solid glob of glass, giving the entire glob color.

APPLICATION

After first heating the "target object" hot enough so that frit or powder will stick to it, here are some possibilities:

SPRINKLE METHOD: Frit may be sprinkled over your object either with a spoon or with the fingers. When using this method it is wise to place a clean plate or container under the work area to collect any frit that does not stick (invariably, some frit will not adhere the first time). Remove the object from the flame before sprinkling frit. Sprinkling directly through the flame is not recommended since the flame will blow some of the frit away. This is not only a waste of good frit but can cause a dust problem in your shop (see health precautions below).

DIP METHOD: Another method is to put frit/powder into a bowl or on a plate and then dip or roll the target object into the frit/powder. The piece should be rotated for an even coating. Repeat as many times as necessary to achieve the desired effect.

TUBE METHOD: Frit or powder can be fused to the inside of a hollow object by sprinkling it into a rotating tube. Using this method the frit/powder may be added either before or after the object has been heated. This method can also be used when applying frit to tubing in a lathe.

ROD METHOD: A clear or colored rod may be heated (usually the tip, coated with frit (dip method), and then applied in the usual manner. This is a very quick and easy method of adding color.

Page 13 of 19 Northstar Use Info.docx WORKING THE FRIT/POWDER IN

Once the desired amount of frit has been deposited onto the object, use a relatively cool flame to fuse the frit in. Use a cool flame because the small particles of frit, until they are mostly fused in, are little bumps on the surface of the glass, easily caught by the flame and super heated to a boil, which could cause a rough texture. A hot flame may be used but the object should be passed quickly through the flame so as to heat the frit more gradually. The exotic frits and powders can be lightly "dusted" onto the surface of your piece and then worked in for a metallic "fumed" effect.

SCREENING

If a particular size particle of frit is desired for a specific project it is possible to screen the frit. Simply find a piece of screen (any kind of screen will do, however stainless is the best) of the desired mesh and filter the frit through.

CAUTION: AVOID EXPOSURE TO GLASS DUST. ALWAYS USE A DUST MASK AND EXHAUST HOOD WHEN HANDLING FRIT AND POWDER.

SUGGESTED OXIDATION/REDUCTION FLAME SETTINGS FOR NORTHSTAR®GLASSES BY CATALOG NUMBER

.

NS- COBALT BLUE Use neutral to oxidizing flame. 01 NS- Oxidize for blues, greens. Reduce for reds, yellows. Try MULTI 03 covering with clear for interesting effect. NS- DARK MULTI Same as Multi but more intense. 04 NS- ORANGE* Neutral to slightly oxidizing flame. 05 NS- DARK ORANGE* Same as Orange. Strike in oven. 06 NS- Neutral to slightly oxidizing flame. For clearest Ruby put in RUBY* 07 oven clear, then strike. SEE EXOTIC COLORS NS- Like NS-07 but less intense, for oven striking. SEE EXOTIC LIGHT RUBY* 07L COLORS NS- Like NS-07 but less intense, for oven striking. SEE EXOTIC DARK RUBY* 08 COLORS NS- YELLOW* Oxidizing more transparent, Reducing more opaque. 09 NS- JADE Neutral to Oxidizing flame. Do not overheat. Encase with care. 11

Page 14 of 19 Northstar Use Info.docx NS- AMBER/PURPLE* Oxidize for purple, reduce for amber. SEE EXOTIC COLORS 13 NS- IRRID Oxidize for blues greens, Reduce for opaques. 14 NS- TURQUESA Same as Irrid. 15 NS- BLACK Extremely oxidizing for black. Reduce for gray. 16 NS- LIGHT COBALT Oxidize. 19 BLUE NS- DARK COBALT Very oxidizing. 20 NS- PINK Not sensitive to atmosphere. 23 NS- TRANSPARENT Oxidize. Red streaks if you reduce. 24 GREEN NS- PEACH Not sensitive to atmosphere. 25 NS- DOUBLE Oxidize for purple, reduce for amber. Must burn off "haze" for 26 AMBER/PURPLE* more brilliant color. SEE EXOTIC COLORS NS- Oxidize while working, then reduce heavily. SEE EXOTIC GREEN EXOTIC 27 COLORS NS- BLUE EXOTIC SAME AS NS-27. SEE EXOTIC COLORS 28 NS- RED EXOTIC SAME AS NS-27. SEE EXOTIC COLORS 29 NS- LAVENDER Not sensitive to atmosphere. 31 NS- VIOLET Not sensitive to atmosphere. 32 NS- TURBO COBALT Oxidize. 33 NS- EXTRA LIGHT Not sensitive to atmosphere. 34 YELLOW* NS- BLACK HOLE Extreme oxidizing for BLACK, reduce for GRAY. 35 NS- ROOTBEER* Reduce for reds, oxidize for greens. 37 NS- BLUE-GREEN Oxidize for blues, reduce for greens. 38 NS- BUTTERSCOTCH Oxidize or reduce, easy to use. 41 NS- CINNAMON Do not overheat, not sensitive to atmosphere. 42 NS- RUST Neutral flame. 43

Page 15 of 19 Northstar Use Info.docx NS- CARAMEL Oxidize for darker tones, reduce for lighter tones. 44 NS- BLUE MOON Oxidize for blues and greens, reduce for silvers and yellows 45 NS- AURORA SEE EXOTIC COLORS 47 NS- LIGHT BLUE Oxidize for purple, restrike with flame for effect. SEE EXOTIC 48 AMBER/PURPLE* COLORS NS- DARK BLUE Oxidize for purple, restrike with flame for effect. SEE EXOTIC 49 AMBER/PURPLE* COLORS NS- TEAL Not sensitive to atmosphere. Encase with care. 52 NS- FOREST GREEN Not sensitive to atmosphere. Encase with care. 53 NS- Not sensitive to atmosphere. Heat slowly to working STAR WHITE 54 temperature. NS- PERIWINKLE Not sensitive to atmosphere. 55 NS- MIDNIGHT Use in neutral to oxidizing flame for best results. 57 NS- MINT Not sensitive to atmosphere. Do not overheat, can boil. 58 NS- Use an oxidizing flame for deep red. Use a neutral flame for CRANBERRY* 59 lighter red. NS- BUBBLEGUM Not sensitive to atmosphere. 62 NS- CANARY Can boil if overheated. Over reduction can cause color to dull. 63 NS- LAVA Not sensitive to atmosphere. Do not overheat, can boil. 64 NS- Use neutral to slightly oxidizing flame. Color can dull in a CHERRY 65 reducing flame. Will boil if over heated. NS- SUBLIME Not sensitive to atmosphere. 66 NS- PARROT GREEN Can boil if overheated and can dull in a reducing flame. 68 NS- GREEN AMBER Work like double amber purple. Similar intensity. Be especially 69 PURPLE careful. NS- Oxidize for blues. A reduction flame brings out red highlights ICE BLUE 70 and causes color to darken. NS- AVOCADO Can boil if overheated and can dull in a reducing flame. 71 NS- Oxidize for blue green. A reducing flame brings out red GLACIER BLUE 72 highlights and darkens the color. NS- MILLENNIUM MOSS Not sensitive to atmosphere. 73

Page 16 of 19 Northstar Use Info.docx NS- TRANSP Reduction may yield red streaks 74 MILLENNIUM MOSS NS- INDIGO Not sensitive to atmosphere. Pull out for a deep teal green 75 AVENTURINE color. NS- ONYX Not sensitive to atmosphere. 76 NS- DEEP SEA BLUE Not sensitive to atmosphere 77 Reduce for hazy, milky color. Oxidize to keep a cleaner, clearer NS- MYSTERY color. See Newsletter 15 for complete information about this 78 AVENTURINE* color. NS- BLUE SPRUCE Neutral to slightly oxidizing 79

* denotes a striking color

HEALTH & SAFETY GUIDELINES

Like any craft or hobby, glassworking has some inherent risk of injury to the artist. As interest in lampworking has increased, it has become clear that some general information on potential health and safety risks would be useful to many people. The following information is intended to increase your enjoyment of lampworking, while adding to your awareness and helping you reduce your exposure to potential hazards. These suggestions have been prepared and reviewed by a group of experienced lampworkers.

Eye Protection Eye protection is very important in lampworking, for two reasons. First of all, glass can sometimes shatter when placed directly in the flame, and you must protect your eyes from flying glass fragments. You must also protect your eyes from potentially damaging Ultraviolet and Infrared rays, which are emitted when you melt glass in a flame. For many years, the standard eye protection for lampworkers has been "didymium" glasses, which have the additional feature of filtering out the distracting yellow glare given off by molten glass. In recent years other types of protective eyewear have become available, some of which are superior to traditional didymium glasses. The type of protective eyewear that is right for you depends on the type of glasswork you will be doing. For instance, making would give off less radiation than working a large piece of borosilicate tubing, which in turn gives off less than melting fused quartz. Also, different people may have different sensitivity. Please protect your eyes. Check with your supplier and other reliable sources for more information on choosing eye protection.

Respiratory Hazards

Melting glass in a flame produces a number of gasses and vapors which can affect your health. It is important, therefore, to ventilate your work area. At the very least, you should provide "dilution ventilation", in which a steady stream of air flows across your work area, drawing any vapors or gasses away from your face and out of the room. Windows at opposite ends of your work area, one of which has an exhaust fan, can be an effective form of dilution ventilation. Some lampworking operations may require "local exhaust ventilation", such as a fume hood, to eliminate hazardous or irritating vapors and gasses. If you find that you feel slightly short of breath or that you have a headache at the end of a work session, then you can be certain your ventilation is inadequate.

Page 17 of 19 Northstar Use Info.docx An additional respiratory hazard is posed by dust particles you might encounter in your studio. These include powdered "bead release" compounds, the dust stirred up when you work with vermiculite, and loose particles of refractory materials such as brick or ceramic-fiber insulation inside your kiln. Take care not to inhale these irritating and potentially harmful dust particles. Wear a respirator if necessary to reduce your exposure. Beware of hazardous dusts that can be stirred up when you are cleaning your studio. Wet down any questionable areas or spills with a spray bottle before wiping with a wet rag, to reduce the chances of inhaling particles. If you sandblast your finished pieces, follow all safety guidelines appropriate to sandblasting.

Cuts and Burns

These can be avoided with common sense and care. The most common minor burns occur when someone picks up the end of a glass rod or tube, forgetting that it is hot. A simple system, such as always laying the hot end of a rod away from you, can help you remember which end to grab. Arrange your work area so that you never have to reach in front of your torch to get a tool or piece of glass. Choose your work clothes carefully, avoiding synthetic fibers, long loose sleeves, shirts with open pockets or pants with folded cuffs.

Burns can be treated with aloe vera sap, cold cider vinegar, or a variety of home remedies. Treat your injuries with respect; serious cuts or burns may require professional medical attention.

Tanks and Torch

Potential hazards also exist any time you work with compressed gasses. Carefully follow any manufacturer's instructions that come with your regulators or gas tanks, and check with your suppliers for safe operating procedures.

Never move oxygen tanks without their protective cap in place. If the tank falls over, the valve stem can be sheared off by impacting against a table or other object. The pressure inside the tank may then be high enough to send the cylinder flying like a rocket, injuring you and damaging your building. Oxygen tanks should be either laid on their side and secured to prevent rolling, or chained securely to a wall so they don't fall over. Note also that oxygen regulators, hoses and fittings should never come into contact with grease or oil, which can ignite spontaneously in the presence of pure O2.

Be sure to install check valves on your fuel, gas and oxygen regulators to prevent backwards flow of gasses-a major hazard in the event of a fire or torch malfunction. Make sure that your torch is secured to the work surface so that it doesn't move if a hose is yanked. Keep all flammable and combustible materials well away from your torch. At the end of each work/play day, shut off your oxygen and gas tanks and bleed the pressure out of the lines by opening your torch valves.

Other Hazards

These can include muscle strains or other injuries from maneuvering heavy oxygen tanks or repetitive movements (such as making hundreds of beads). Take frequent breaks and pay attention to your body's signals to minimize these types of injuries. Check for accurate height of table to chair for comfortable work. Dehydration and heat exhaustion are other possible hazards to watch out for. Drink plenty of water, especially if you are working with a large flame. You may also consider applying a sunscreen to your skin to protect it from the radiation given off by the flame.

Page 18 of 19 Northstar Use Info.docx The following references may be useful in protecting yourself from the common hazards of lampworking:

Artist Beware, by Michael McCann, available from Center for Safety in the Arts, 5 Beekerman St., Ste. 280, New York, NY 10038 Contemporary Lampworking, A Practical Guide to Shaping Glass In the Flame by Bandhu Scott Dunham, available from Salusa Glassworks, P.O. Box 2354, Prescott, AZ 86302 Glassblowing: An Introduction to Solid and Blown Glass Sculpturing by Homer L. Hoyt, Crafts & Arts Publishing Co. Inc, 626 Moss St., Golden, CO 80401 The Artist's Complete Health and Safety Guide by Monona Rossol, available from Allworth Press Ventilation-A Practical Guide for Artists, Craftspeople and Others in the Arts by Nancy Clark, Thomas Cutter and Jean Ann McGrane, available from Center for Safety in the Arts "Beads from the Beginning" by Brian Kerkvliet, Magazine, November/December 1994, P.O. Box 260377, Highlands Ranch, CO 80126 "F.Y. Eyes" by Lisa M. Malchow, Fusion Journal of the American Scientific Glassblowers Society, May 1993. 1507 Hagley Rd., Toledo, OH 43612 "Glassmaking Health and Safety" by Monona Rossol, Glass Art Society Technical Journal, 1989. Reprint available from Allworth Press "Optical Radiation Hazards in Glassblowing" by Gary E. Myers, Fusion Journal of the American Scientific Glassblowers Society, August 1976

This information is offered as a starting point for your own safety research, and new information may affect the appropriateness of these recommendations. The suppliers of this information assume no liability for any injury or harm which may result from use or misuse of this information. Be sure to consult with your supplier, physician or other qualified expert regarding any safety questions you have.

Page 19 of 19 Northstar Use Info.docx