Getting Started FAQ - by Drew Fritts

Lampworked Marbles: A Getting Started FAQ
by Drew Fritts

I'm frequently asked questions about getting started making lampworked marbles, so I started saving the questions and my responses in a file. The following is the resulting FAQ (Frequently Asked Questions) sheet.

Q: Where should I buy my supplies?

A: The politically correct answer to this question would be to list lots of suppliers and let people choose. However, here's what I tell people:

1. Call Frantz Bead Co. (1-800-839-6712) and request both of their catalogs: Glass Catalog and Tool & Supply Catalog. Much of their catalog is also online at http://www.frantzartglass.com

2. Call Arrow Springs (1-530-677-9482) and request their Catalog of Flameworking Tools & Glass. Much of their catalog is also online at http://www.arrowsprings.com/

Anything that you need to get started in flameworking you can get from either of these two companies. Both are very good at answering questions about equipment and glass. They also have very competitive prices. Several of the suppliers that you will find on the Internet have minimum purchase requirements, don't have competitive prices, or require that you jump through hoops to set up a wholesale account with them before they will sell to you. These are the two suppliers that I use exclusively because they have great service and they have no minimum purchase requirements.

Q: What torch should I get?

A: There is no simple answer to this question because it depends on what your goals are and how much money you're willing to spend. Assuming you're going to be working in soft glass like Moretti/Efettre or Bullseye, not Borosilicate glass like PYREX® or Northstar, here are the three most common situations:

1. You have very little money to spend OR you're not really sure how long marble making will hold your interest... Look at Hot Head torches and Hot Head Kits in each of the catalogs that you requested above. The Hot Head is very inexpensive and the MAPP gas cylinders that it uses can be purchased at a local hardware, home center, or stained glass store that stocks bead making supplies. This will allow you to start making small marbles or beads with a minimal investment.

There are several trade-offs with this less expensive option. However, they are all situations that can be dealt with as long as you're aware of them going in.

a. MAPP gas will tend to discolor or devitrify some colors of soft glass. (See the table below)

b. It takes longer to work the glass because the flame is not as intense with this type of torch. Therefore, making marbles larger than 3/4" is extremely time consuming and frustrating.

c. MAPP cylinders cool as the torch runs. When run for extended periods of time, as in making several marbles, they tend to get frosty on the outside. As the tank gets cooler so does the flame. At this point the tank must be allowed to warm back up or a warm tank must be attached.

2. If you have some money to spend and are pretty sure that hot glass will hold your interest for a while... For the money, a beginner can't go wrong with a Minor Burner by Nortel. This is an "oxygen / propane", surface mix torch and will therefore work the glass much faster and cleaner than the Hot Head. It doesn't have the "frosting" problem that the Hot Head has, and can easily make marbles up to 1 1/8". Marbles up to 1 1/2" are possible, but take quite a while.

This setup will cost a bit more than the Hot Head setup because, in addition to a more expensive torch, you will also need oxygen and propane regulators, hoses and flashback arrestors. You will also need to rent an oxygen tank. This can typically be done on a yearly or monthly basis. Where I live I rent my tanks from my local welding supply company (my tanks are "M" size and hold 125 cubic feet of oxygen) for $35 per year, and it costs me about $17 to have a tank filled. That's enough oxygen for about 20 hours of torch time using a Minor Burner.

My propane tank is off of an old gas grill that someone was throwing out, but you can get them at any home center. You can use the ones that you just exchange for a full one whenever it's empty, but I find that to be more expensive, and I like knowing how the tank has been treated. My 20 lb. tank costs about $7.50 to fill, and that lasts well over 100 hours.

3. If money is not a big issue and you want to start out with a setup that you won't outgrow for quite a while... My best advice is; do some research on the more expensive torches. Talk to as many experienced lampworkers as you can to find out what they have tried and what they're using now. Many times you can try out different torches at classes, seminars and shows. Ask for advice about high-end torches on any of the glass-related forums on the Internet, they always receive a lot of responses.

I personally believe that you should buy as large a torch as you can afford, for several reasons. This medium (hot glass) has a tendency to make people want to keep growing and trying new things. Also, as you become familiar with handling the hot glass, you will be able to do larger and larger work. And, finally, you can almost always make a smaller flame on a bigger torch, but the reverse is not true.

You will still have the same costs for regulators, hoses, flashback arrestors and tanks, but your torch cost can easily swing from around $450.00 to well over $1,000.00.

Q: What supplies will I need?

A: There are several things that you will need to buy. Some that you can scrounge, and some that you can make yourself.

1. Absolutely buy a pair of protective glasses. If you're only going to be making beads and small marbles out of soft glass, get a pair of rose didymium glasses. They cut the sodium flare so that you can see what you're doing in the flame. More importantly, they keep you from burning your eyes with ultraviolet radiation! They also keep bits of glass from getting into your eyes when your glass rods "spit." Both suppliers listed above carry some fairly inexpensive pairs of rose didymium glasses.

If you want more selection in frames or sizes, need prescription lenses, or are going to be using borosilicate glass, I highly recommend that you go to the Auralens Products Co. web site at: http://www.auralens.com/ and read their product descriptions. They also have a Frequently Asked Questions page that is very good.

I used didymium glasses until I started working at the torch full time. I then upgraded to AUR-92 lenses for better UV protection and enhanced RGB color transmission. There was a big price difference, but there's also a big difference in the way my eyes feel after a day at the torch, too. You only get one pair of eyes - don't go cheap on them!

2. Buy a pair of tile nippers for cutting your glass rods. You can get them from either of the sources listed, or at your local hardware or home center. Get the cheap ones with the flat, straight jaws, not the ones with the roller-type blade jaws. Nippers are well worth the small investment.

3. Get yourself a pair or two of long tweezers - preferably stainless steel. I have two pair that are about 10" long. I picked them up at the dollar store. One has smooth, rounded jaws and one has pointed serrated jaws. I use the smooth jaws for picking off bits of molten glass because the glass doesn't get stuck to them like it does to the serrated jaws. I use the serrated ones for picking up preheated rods or parts off of my hot plate because of the nice narrow tip and good gripping capability.

4. Make yourself some marble tweezers out of an old coat hanger - the thick brown kind not the skinny white ones. For pictures and descriptions see the marble tweezers on my web site at: http://frittsartglass.com/articles/Tweezers.html.

5. Buy a graphite marble mold. I highly recommend the kind with multiple mold holes. Mine originally came with holes for 4 different sizes of marbles (3/4", 1", 1 1/2", and 2"). I added holes for 1/2" and 5/8" myself using core box router bits in a drill press. Don't do this without practicing on wood first. Read my article on making wooden molds (see the next question). It's the same process.

6. Watch garage sales for a hot plate. I got mine for $5 and use it for preheating murrine, strips of dichroic, and pieces of glass rod. Mine is actually the heating base from a two piece crock-pot and has covered heating elements. However, if you get the kind of hot plate that looks like the coiled heating element from an electric stove, go to a metal supply company and have them cut you a square of 1/4" thick steel to place on the heating element. It can be several inches wider than the hot plate, thus providing a nice, wide, flat surface on which to set your preheat items.

Q: What kind of molds should I use?

A: I use both graphite and cherry-wood molds. I do all of my initial shaping in my graphite molds because they don't burn out. When I'm ready to put the final surface on the marble I switch to cherry-wood molds. I highly recommend that beginners make 50 to 100 marbles using only a graphite mold before they ever use a cherry-wood mold. Remember that every time you put a red-hot marble into a wooden mold, the mold hole gets just a little bigger. It doesn't take very long before your 3/4" cherry-wood mold is now a 7/8" mold.

To cut down on the cost of molds I recommend that you read my article in Glass Line Magazine entitled How to Make Cherry-Wood Molds. It's also online at: http://frittsartglass.com/articles/Articles.html.

Q: Where can I get information on how to actually MAKE a marble?

A: Here are several good sources of information on lampworking in general as well as marble making.

1. Read the articles written by Robert Mickelsen and posted on his web site at: http://www.mickelsenstudios.com/articles.htm. Although none of them deal directly with marble making, the information you can glean from them about lampworking is invaluable.

2. Read the articles written by Brian Kerkvliet for Glass Art magazine. They can be found on his web site at: http://www.inspirationfarm.com/GG/articles/articles.html and there are several about bead making, lampworking and marble making.

3. Buy Gerry Coleman's video on "The Basics of Making Marbles". It's about $45 including shipping, and it's well worth it. He shows basic technique and walks through making about 6 marbles from start to finish. Both of the sources listed above carry it.

I usually tell people to watch the video and then Email me so that I can tell them about a couple of techniques that I use that are different than Gerry's. However, rather than trying to respond to Emails from this article, I'll discuss them here. I do so only after saying that it is with the deepest respect for Gerry and with great appreciation of the fact that he is the only person I know of that has made any attempt to show his marble making techniques on such a wide scale.

a. I recommend that beginners NOT try to use PYREX® rods for their punty rods. The likelihood of leaving a bit of the PYREX® rod imbedded in the marble is very high for a beginner, and if a piece of PYREX® is left in a soft glass marble, no matter how small the bit of PYREX®, the marble will most certainly crack, if not explode. I always tell beginners to use rods of the same type of glass that the marble is made of for their punties. I tell intermediate and advanced lampworkers to use 1/8" diameter bead mandrels because they don't soften in the flame and they provide better control. However, they take experience to master and are definitely not for beginners. For information on using bead mandrels as punties, see my Glass Line article "BULLSEYE MARBLES" in the February/March 1999 issue, Volume 12, Number 5. It's also online at: http://frittsartglass.com/articles/Articles.html.

b. I recommend that EVERYONE use marble tweezers (see the question on supplies) when knocking off the final punty, burning off the punty mark and placing the marble in the annealing oven. In my opinion, cherry-wood molds are awkward to hold the marble in during these processes. The marble tweezers I make allow the marble to be held securely at different angles to the flame and keep you from burning the holes in your expensive cherry-wood molds any more than you have to.

Q: Do marbles have to be annealed, or can I cool them in a crock-pot like I do with beads?

A: In my opinion, all beads and marbles should be properly annealed. I can tell you from experience that marbles larger than 3/4" that are cooled in a crock-pot of vermiculite will almost certainly crack or explode. It may be months later, but they WILL break. If you want to test your marbles or beads to see if they are going to crack, put them in a plastic bag and place them in the freezer overnight. If they are still in one piece in the morning then they have passed the test and will not likely break due to improper cooling.

Q: What do you use for annealing your marbles?

A: I have a fairly large kiln that I use for both annealing my marbles and for doing fusing of platters and bowls. It's a little overkill for an annealing oven, but at the time I bought it I couldn't afford two kilns. The one I have is the Jen-Ken PFG-18. It has a computer that controls firings (and annealing) and a built-in digital pyrometer. I bought my kiln from Marty Daily at Centre de Verre. His web site is http://www.cdvkiln.com/ and he's very good at answering kiln questions.

Realistically, ANY kiln that will maintain between 850° F. to 1000° F. will work for annealing. You just have to be able to maintain the proper temperature for the glass you are using, for the length of time that it's thickness requires. Annealing is both an art and a science and is far beyond the scope of this article. However, my fairly conservative rule of thumb for annealing marbles is this:

For marbles that are 1" in diameter or smaller, I soak them at a specific temperature within the annealing range for that glass for at least 30 minutes for every 1/2" of diameter. Therefore, for example, I soak a 1" marble for at least 1 hour.

For marbles larger than 1", I soak them for at least 45 minutes for every 1/2" of diameter. And the larger they get, the longer I leave them soaking.

Soaking my marbles for a long time is not usually a problem because I do it full time. Therefore, I make my larger marbles in the morning and they sit in the annealing oven all day. I make my smaller marbles at the end of the day and then simply set the controller to hold for the amount of time necessary to properly anneal the last marble I put in the kiln.

Q: I put my marbles in my annealing oven and they got flat spots (or they picked up the texture from the floor of the kiln). What's up?

A: It's most likely one of three things:

1. You're putting them in before they are cooled enough to stay round.

2. Your kiln is too hot, possibly because your pyrometer isn't reading accurately or you kiln has hot spots.

3. Your annealing temperature is too high for the length of time you are letting them soak.

To keep from putting them into the kiln while they are still soft, simply hold your hand above the marble so that it is in the shadow. Wait until the red glow disappears from where you just burned off the punty mark. Then set the marble in the kiln gently with the punty mark pointing up. Don't drop it in or roll it in. If you still get flat spots, you might need to check your pyrometer and your annealing schedule. Remember that annealing temperatures are stated in ranges, not specific temperatures. If you're going to be putting marbles in the kiln throughout the day, you'll want the marbles to anneal at a temperature near the bottom of the annealing range. That way they can soak longer without running the risk of picking up the pattern of whatever they are sitting on in the kiln.

When deciding on your soak temperature, be sure to consider radiant heat versus ambient heat within the kiln. Moretti's annealing temperature range is approximately 935° F. to 965° F. but, whatever you put in the oven is subjected to the radiant heat from the elements whenever they come on. Therefore, your marbles will pick up and store a lot of heat directly from the heating elements that the pyrometer doesn't register. The pyrometer only registers the ambient temperature at a certain place in the kiln. It doesn't tell you the actual temperature of the marbles.

All kilns are different due to shape, size, element and door placement. You'll just have to experiment with yours. When working with Moretti, I actually have to set my kiln at 850° F. to have the actual temperature of the marbles stay in the lower end of the annealing range all day.

Q: What glass should I start with?

A: Soft glass is the easiest to heat and the least expensive. Unfortunately, some colors discolor or devitrify if you're not careful and can be discouraging for beginners.

Here's a list of Moretti colors that I use frequently. I marked with an asterisk "*" the ones I think you should try first, based on ease of use while providing a good color selection. Notice that I use both large and small rods of several colors. This is because I use them as the base glass for the marble and it's much easier to get your initial gather of glass if you start with bigger pieces. However, there's a caveat... You should pre-heat the large pieces (anything wider than 8mm) on a hot plate or they will often explode when you put them into the flame. You can bring them into the back flame without pre-heating and warm them up back there before bringing them up into the working flame. However, with 11mm to 14mm rods, you spend at least a minute in the back flame, burning gas and oxygen, while you could be working.

For starting out I would recommend that you stick with the standard size rods (the ones that don't have a size marked are usually between 5mm and 8mm) until you get used to them and until you start making marbles larger than 3/4".

The Item Numbers are Frantz Bead's Item Numbers:

TRANSPARENTS:

*91-004-A Clear, 5-6 mm I use this for punties and encasing.

*91-004-C Clear, 10-11 mm I use this for encasing.

91-004-M Clear, 13-14 mm I use this as base glass.

91-012 Lt. Topaz Works well in the flame.

91-016 Dk. Topaz Works well in the flame - Root Beer.

91-020 Lt. Grass Green Works well in the flame - Lt. Yellow Green.

91-024 Dk. Grass Green Works well in the flame - Dk. Yellow Green.

91-026 Lt. Teal Works well in the flame.

*91-030 Dk. Emerald Green Works well in the flame.

91-036 Dk. Aqua Beautiful color. Gets scummy in a pure propane or MAPP flame. Use an oxidizing flame and don't allow it to cool too much before finishing the marble. If it cools and is then reheated, it will boil badly on the surface. If that happens, the only way to get rid of the bubbles is to super heat it until they go away. Sounds weird, but it works!

91-038-A Pale Aqua, 5-6 mm Works well in the flame - I use for encasing.

91-038-C Pale Aqua, 10-11 mm Works well in the flame - I use for base glass.

91-044 Dk. Purple Works well in the flame, Amethyst, not true purple.

91-056 Dk. Blue Works well in the flame.

*91-060 Cobalt Blue Works well in the flame.

91-082 Lavender-Blue Very pale, can be used for encasing.

*91-064 Black I use this for punties for black-based marbles.

*91-064-B Black, 8-9 mm I use this as base glass Very forgiving in the flame.

91-069 Electric Yellow Beautiful color but gets cloudy if not encased in clear. Strikes to brilliant yellow
from very pale yellow. Does not strike back to pale.

91-072 Orange Beautiful color. Strikes to orange. It will strike back to clear while you are working it if you heat it and then cool it quickly. To strike it back to orange, heat it slowly in the flame and let it cool off slowly.

91-076 Red Beautiful color as long as it doesn't get too hot, in which case it turns muddy brown. Strikes to red. It will strike back to clear while you are working it if you heat it and then cool it quickly. To strike it back to red, heat it slowly in the flame and let it cool off slowly.

PASTELS:

*91-204 White I use this almost exclusively for white.

91-204-B White, 8-9 mm I very seldom use this - it spits (explodes).

91-204-M White, 13-14 mm This explodes even after preheating.

91-212 Pea Green Nice yellow-green color, but must be encased or it bleeds into other colors.

91-214 Nile Green Nice light green color but must be encased or it bleeds into other colors.

*91-216 Grass Green Nice medium green color but must be encased or it bleeds into other colors. Tends to reduce (get a scummy metallic sheen) in pure propane or MAPP. Will turn yellow glass brown if
used next to it without encasing one of them in clear.

91-218 Petroleum Green Nice blue-green color but must be encased or it bleeds into other colors. Tends to reduce (get a scummy metallic sheen) in pure propane or MAPP. Will turn yellow glass brown if used next to it without encasing one of them in clear.

*91-220 Periwinkle Works well as long as it doesn't get too hot. It will boil and make surface bubbles if not careful.

91-224 Lt. Sky Blue Boils and scorches easily unless encased in clear.

91-228 Dk. Sky Blue Will reduce (get a scummy metallic sheen) even in an oxidizing flame. Encase it in
clear or pale aqua.

91-236 Dk. Turquoise Will reduce (get a scummy metallic sheen) even in an oxidizing flame. Encase it in
clear or pale aqua.

*91-240 Lt. Lapis Nice glass but can turn gray in pure propane or MAPP if left too long in one spot, Bright
Blue.

91-242 Md. Lapis Nice glass but can turn gray in pure propane or MAPP if left too long in one spot, Dark
Blue.

91-246 Lapis Cobalt Works well in the flame, Navy Blue.

91-252 Dk. Gray OK to work. Turns darker the longer it's heated.

91-272 Violet Works well in the flame but can reduce (get a scummy metallic sheen) in a pure propane
or MAPP flame.

91-276 Dk. Ivory Has interesting reactions with several other colors. Can be used to your advantage for
effects, but can also ruin a piece quickly.

SPECIAL:

91-404 Lt. Lemon Yellow Translucent lemon yellow - Works well.

*91-408 Md. Lemon Yellow Nice Canary to Mustard yellow - Works well.

91-412 Dk. Yellow Yellow orange - Works well.

*91-416 Bright Acid Yellow Bright opaque yellow - Doesn't bleed into other colors at all.

*91-422 Orange Translucent orange - Works well.

91-428 Lt. Red Orangish Red - Works well.

*91-432 Md. Red Bright red - Works well.

91-436 Dk. Red Closer to Burgundy - Works well.

91-456 Gold Pink Great color, very expensive, works poorly, but if you want pink in Moretti, it's all there is!
Encase it in clear to keep it from bleeding into other colors or scorching. It can be encased in Dk. Blue (91-056) to get a very nice Barney-purple. I have never tried using it in a pure propane or MAPP flame, but my guess is it would reduce (get a scummy metallic sheen) or scorch. It's a very, very soft glass.

Other: The dichroics are all extremely expensive and hard to work with. You must turn your heat down so that you don't burn or scorch the dichroic coating, and you should encase it in clear once it's applied to the marble. I don't recommend trying dichroics until you've made at least 100 marbles and are good at encasing without bubbles.

1129 1/4" Dichroic Strip Blue Very Nice Color.

1129 1/4" Dichroic Strip Green Very Nice Color.

1129 1/4" Dichroic Strip Dark Red Sensitive to too much heat.

1129 1/4" Dichroic Strip Aqua Very Nice Color.

1129 1/4" Dichroic Strip Purple Very Nice Color, Dark Blue-Purple.

1129 1/4" Dichroic Strip Gold OK , very dark gold or light orange.

1129 1/4" Dichroic Strip Copper OK

1130 1/4" Dichroic Strip Pink Nice, Very Pale Pink.

1130 1/4" Dichroic Strip Magenta Very Nice Color.

1130 1/4" Dichroic Strip Silver Very Nice color.

1130 1/4" Dichroic Strip Aqua-Silver Very Nice color.

ABOUT THE AUTHOR

Drew Fritts is a full time glass artist and has been working with hot glass since 1994. The Marble Gallery on his web site displays over 100 of his contemporary art glass marble styles, some of which are limited edition sets.

This article was originally published in GLASS LINE Magazine, June / July 1999, Volume 13, Number 1

Lampworked Marbles: A Getting Started FAQ by Drew Fritts

Email me with any questions or comments...

Lampworked Marbles: A Getting Started FAQ
by Drew Fritts