I want to cut 1/4 BE clear circles 18" in diameter for making a sink. Tried using the Patty Grey method (as I do with 1/8 glass but ..... no way)..So, I cut it on my saw. Very hard to keep it perfect circle as with a circle cutter. Is there a better way? Are there special tools for working with thicker glass. ? Also, what is the best way for slumping an 18" circle for a sink? Draping over mold? Slumping into? or drop ring? Thanks in advance. Bert, I'm waitin for ya? PS. That is why I was so interested in taking you class but you never make it here out west...
doctac wrote:I want to cut 1/4 BE clear circles 18" in diameter for making a sink. Tried using the Patty Grey method (as I do with 1/8 glass but ..... no way)..So, I cut it on my saw. Very hard to keep it perfect circle as with a circle cutter. Is there a better way? Are there special tools for working with thicker glass. ? Also, what is the best way for slumping an 18" circle for a sink? Draping over mold? Slumping into? or drop ring? Thanks in advance. Bert, I'm waitin for ya? PS. That is why I was so interested in taking you class but you never make it here out west...
Doc
Cutting circles out of float glass is a simple routine for me. It works much like your 1/8" ones. I make a tool for tapping out odd shaped cuts. Basically take a cheap flat screwdriver and heat it up red hot with a propane torch. Let it cool and grind a slight curve on the tip. Once yopu make the score, you flip the glass over and place the tool directly under the score and hit it with a hammer with the right force and the cut starts to run. Place the tool at the end of the run and hit it again to continue the run. Do this until it has started all the way around. This technique works well on transparent glasses. Opals make it a challenge.
I just had a conversation with a glass supplier who advised me that 1/4" BE is very difficult to cut with accuracy because of the glass texture. If your cutter doesn't have intimate contact all along the cut it tends to run off. The bumpy surface seems to make it difficult to get that intimate contact. For thicker glass, you want to use a duller cutter. Yoiu could buy one designed for 1/4" glass or use an old one. The sharp wheels used for cutting 1/8" BE may be your problem.
You could simple use the 1/8" glass and stack up 6 layers inside a dam made with 1" HD refractory board.
I am teaching 3 classes out west in January/February. There might be a space left in the 5.5 day sink making class on Vancouver Island, I'm not sure. A 3 day painting on glass class was just announced in Portland see the classifieds. If all the info is not still on the classifieds Email me for details.
I am considering announcing a class or 2 at my home studio in March and April. By May the bugs are a big nuisance until August.
After scoring it with your glass cutter flip it over and strike the score with a regular cold chisel. This will run the score around the circle. Then score the excess glass and again run the score through to the edge of the circle. Make sure that the circle score has been ran through all the way or when you try and run the excess off it will continue through your circle and leave you with a half circle. Start with a square that is around 20" square as you need at least an inch to do this properly. We use this procedure regularily with 1/2" and thicker glass, although it is float. My experience with BE is limited but tells me it should work in the same manner.
It's been a while since I cut circles in 1/4", but I don't recall there being any major differences in how I cut 1/8", except the pressure you need to use to run the score is much greater. What may help is to leave a greater margin along the edge of the circle, for example a couple of inches. The greater the margin, the more leverage you have to run the score, and the easier it becomes. As for slumping into or over; if you slump over you are going to get pleats, and the interior of the sink will have form marks. If you slump into a form, or into air(drop out) you'll have a nice smooth outside and a glossy inside, perfect for a sink.
Bert Weiss wrote:
I just had a conversation with a glass supplier who advised me that 1/4" BE is very difficult to cut with accuracy because of the glass texture. If your cutter doesn't have intimate contact all along the cut it tends to run off. The bumpy surface seems to make it difficult to get that intimate contact. For thicker glass, you want to use a duller cutter. Yoiu could buy one designed for 1/4" glass or use an old one. The sharp wheels used for cutting 1/8" BE may be your problem.
That's why I want to try the 6mm Artista glass. It must be easier to cut smooth glass?.
If you use one of the Silberschnitt cutters from Bohle, they can supply a removable cutting head, they have two available with different included angle;
BO 424.0 SILBERSCHNITT Easy Grip Carbide Glass Cutter
grey plastic handle - length individually adjustable to hand size - carbide cutting wheel 120° - for opalescent or hard glass - replacement cutting heads: 427.2 + 427.3
BO 427.3 Replacement Cutting Head
135° for Easy Grip Carbide Glass Cutter 424.0 and 428.0;
If it was me though, I'd take it to a glass shop and ask them to cut and polish the edges.
Rick Wilton wrote:After scoring it with your glass cutter flip it over and strike the score with a regular cold chisel. This will run the score around the circle. Then score the excess glass and again run the score through to the edge of the circle. Make sure that the circle score has been ran through all the way or when you try and run the excess off it will continue through your circle and leave you with a half circle. Start with a square that is around 20" square as you need at least an inch to do this properly. We use this procedure regularily with 1/2" and thicker glass, although it is float. My experience with BE is limited but tells me it should work in the same manner.
Rick Wilton
Rick
Your technique is similar to mine. The reason I heat the screwdriver up red hot is so it loses it's hardness. The softer steel is more forgiving to the glass surface. A cold chisel is even harder than a screwdriver.
I didn't mention my propane torch technique. After the start has been run 360º around the circle, I run around the score with a propane torch. I am looking for some snap crackle pop. The pops are the glass continuing the run through the thickness of the glass. If you do this right you get a minimum of flare.
Yes, the propane torch is a better way to eliminate flaring. Flaring and or chipping is not a concern most of the time for us, as we usually are using scalloping the edges.
It seems to me I learned most of my glass cutting techniques from you many years ago on the rec.crafts.glass bulletin board. This would have been six or seven years ago when I first started trying to make my own glass awards. Now I think I've mastered the art of cold glass awards and sandblasting. Now I'm trying to learn both hot and warm glass at the same time. I guess I'm bored of regular float awards and blasting.
I'm pretty sure it was you who gave me alot of advice years ago, so I'd like to thank you for your generousity, then and now.
Rick Wilton wrote:Yes, the propane torch is a better way to eliminate flaring. Flaring and or chipping is not a concern most of the time for us, as we usually are using scalloping the edges.
It seems to me I learned most of my glass cutting techniques from you many years ago on the rec.crafts.glass bulletin board. This would have been six or seven years ago when I first started trying to make my own glass awards. Now I think I've mastered the art of cold glass awards and sandblasting. Now I'm trying to learn both hot and warm glass at the same time. I guess I'm bored of regular float awards and blasting.
I'm pretty sure it was you who gave me alot of advice years ago, so I'd like to thank you for your generousity, then and now.
Has anyone had experience cutting circles and curved pieces from the 1" thick dalles that kokomo and Blenko produce other than sawing them. We've been sawing them as we've found that to be about the only way. Tenn. Tom
I cut lots of 1/4" (6mm) without problems. Get the Toyo thick glass circle cutter or get a cutting wheel for thicker glass if you have a Bohle cutter. I'm hoping your sink is going to be thicker than 1/4" thick. Recommended thickness for a sink is 3/4" thick. good luck
Patty http://www.pattygray.com
Hi Patty, Don't just tell me...show me....how to cut 1/4 glass..I'll signed up for your class in March at the Glass Expo and looing forward to meeting you. Question about the class while I've got your attention....Is the class for beginners or will you be going into more advanced techniques...I hope!...like making sinks raking etc. Looking forward to meeting you.
no way)..So, I cut it on my saw. Very hard to keep it perfect circle as with a circle cutter. Is there a better way? Are there special tools for working with thicker glass. ? Also, what is the best way for slumping an 18" circle for a sink? Draping over mold? Slumping into? or drop ring? Thanks in advance. Bert, I'm waitin for ya? 
PS. That is why I was so interested in taking you class but you never make it here out west...
