Torch Type - Make a difference with how glass behaves?

BurningScentsations · #1 2005-11-04, 12:21pm

I've been wondering how much of a difference does the type of torch you use affect the properties of how the glass behaves?

I saw a demo last weekend of encasing (Thanks Mary!) using Lauscha (the glass I use) that made it look so easy. I went home, turned up the flame on my torch since I don't think it was hot enough, but still could not get it liquify from rod to bead and continue applying the glass in one stroke.

Does the type of flame affect the way the glass is worked or am I just missing something fundamental? I've added more heat, but the glass will not melt quickly enough to make encasing work like that for me.

Also, the glass does not melt into the bead as nicely (or quickly) as hers did either.

Would a better torch (maybe Lynxx) make a difference or is it just that I am out of practice with encasing?

Thanks,

Lloyd

MikeAurelius · #2 2005-11-04, 1:09pm

Very definately. Surface mix torches are different from pre-mix torches which are different from propane/air torches. Even between "brands" they are different.

Glass behaves differently because the chemistry and temperature of the flame varies from torch to torch.

Cosmo · #3 2005-11-04, 1:21pm

Yes, like Mike said, the torch definately makes a difference.

Your encasing problem, however, may or may not be related to the torch.

You mentioned that you couldn't get it hot enough to encase the bead all in one stroke. That may be technique, or just not enough heat. However, that is not the only way to do it. Some people (myself included) encase just like winding glass onto a mandrel, a little at a time. That may work for you better than the "all at once" technique. Just make sure the bead you are encasing is cool (almost to the point where you think it's been out of the flame too long) before you start encasing it, and get the encasing rod really hot.

BurningScentsations · #4 2005-11-04, 2:52pm

Quote:

Originally Posted by Cosmo

Yes, like Mike said, the torch definately makes a difference.

Your encasing problem, however, may or may not be related to the torch.

You mentioned that you couldn't get it hot enough to encase the bead all in one stroke. That may be technique, or just not enough heat. However, that is not the only way to do it. Some people (myself included) encase just like winding glass onto a mandrel, a little at a time. That may work for you better than the "all at once" technique. Just make sure the bead you are encasing is cool (almost to the point where you think it's been out of the flame too long) before you start encasing it, and get the encasing rod really hot.

Cosmo,

I have encased this way in the past where I make several passes and get the whole bead covered, but inevitably there is a bubble or two left in the glass.

I do encase larger beads going horizontally down the side of the bead and that works better for getting rid of the air.

However, when I saw the demo this weekend, the glass was so smooth and pliable (it's usually stiff and stubborn when I try it) that I couldn't believe it was the same glass.

I did try turning up the heat, but still could not replicate this phenomenon. If I get too much heat, then the glass scums up or bubbles and the bead is ruined. During the demo, it was like the laws of physics were completely different! I always imagined encasing that way, but didn't think it was possible. Since more heat did not seem to help, I thought maybe the different torch might explain what I saw.

I will try again this weekend with more heat and see if I can come any closer.

Thanks for your help,

Lloyd

jokersdesign · #5 2005-11-04, 8:31pm

I had this same problem. A local teacher in town used a Nortel Minor, the same torch I used to use and he could make much larger beads with soft glass and boro and could liquefy clear rods used for encasing. When I tried on my torch at home to encase clear rods they would liquefy but get stiff before I got around the whole bead.

I too thought it was the area of the flame I was working in and or my technique. One day the studio teacher let me torch for free in his studio for 3 hours and I found out I could liquefy rods and do the same things I’ve seen him do on his torch and encase beads with ease all the way around.

I then went home and tried for many hours to do the same with no success. I turned the heat up on my torch and still no change and even got fewer successful results. I then started to think the issue was my torch and thought of buying a new Nortel Minor torch.

Well months went by and I never did buy a new torch. Then one day I jumped at buying a GTT Lynx instead of a Nortel Minor. The Lynx is a much hotter torch and it did make liquefy rods and encasing beads so much easier but I still experienced the same issue encasing, only with not as much difficulty with the Lynx.

Over a period of 2 weeks I found out the problem was not with my technique, not the torch, not the area of flame I was working in, but it was the ratio of GAS to OXYGEN PSI I was using.

My propane regular only has number dial increments in 10s from 0-10-50 so I have guess where 5 PSI is. I know many times it’s probably over 5 PSI. It’s probably many times at around 7 PSI or more. One day I ran out of tanked oxygen and switched to the 2 oxygen concentrators and connected them to the torch. I could not get a hot oxidizing flame no matter what I did and glass was slow to melt (felt like a hothead torch).

I then looked at my propane regulator and realized that it was set at 6-7 PSI and then realized that my oxygen concentrators output is 8 PSI.

So basically my gas to oxygen ratio was almost 1/1. I lowered my gas to 3-4 PSI to give me a gas to oxygen ratio of 1/2 and my torch was a whole new torch. Much hotter like it should be and felt like I was using tanked oxygen. I still continued to have encasing problems with liquefy rods and heating large gathers of glass at a time.

I then read a post saying most torches should be running a gas to oxygen ratio of 1 to 3 or more. I went to many torch manufactures websites and called others and all the manufactures have recommended gas to oxygen setting of 1 to 3 or more. I then tried my torch at 4 PSI and turned my oxygen concentrator up to 12 PSI for the 1 to 3 ratio. WOW!!! Talk about a major difference. I can liquefy clear rods for easy encasement. Before I could only make small marbles and can now make over 1” marbles on a minor. Boro was slow and it was hard to get striking colors to come out, now its no problem.

So this may not work for you, but it’s worth a try. I’d try turning down the gas and turning up the oxygen to get at a 1 to 3 ratio and see what happens.

Cosmo · #6 2005-11-04, 8:55pm

Quote:

Originally Posted by BurningScentsations

Cosmo,

I have encased this way in the past where I make several passes and get the whole bead covered, but inevitably there is a bubble or two left in the glass.

I do encase larger beads going horizontally down the side of the bead and that works better for getting rid of the air.

However, when I saw the demo this weekend, the glass was so smooth and pliable (it's usually stiff and stubborn when I try it) that I couldn't believe it was the same glass.

I did try turning up the heat, but still could not replicate this phenomenon. If I get too much heat, then the glass scums up or bubbles and the bead is ruined. During the demo, it was like the laws of physics were completely different! I always imagined encasing that way, but didn't think it was possible. Since more heat did not seem to help, I thought maybe the different torch might explain what I saw.

I will try again this weekend with more heat and see if I can come any closer.

Thanks for your help,

Lloyd

What kind of torch are you using now?

BurningScentsations · #7 2005-11-05, 12:31pm

Quote:

Originally Posted by Cosmo

What kind of torch are you using now?

Currently, I'm using a Nortel minor.

Your suggestion is a solution I wouldn't have thought of. I set the propane to 5 PSI and my Oxy Cons to 8 (4 each).

I will definitely try adjusting the gas to oxygen ratio.

Thanks for the tip, and I'll let you know how I do tomorrow.

Lloyd

Mr. Smiley · #8 2005-11-05, 2:05pm

Try turning your propane down to 3... then lower if that doesn't help. You're at about 8-9 PSI if I'm not mistaken with those oxycons. Having two just doubles the volume, not the pressure.

saxon · #9 2005-11-05, 2:50pm

Hi there. I have been reading this with a lot of interest. I have a premix national , my jewelry torch, with a mulit orafice tip, tanked oxy and propane. I have a LOT of trouble burning up soft glass , muddy colors, white forget it. What would you suggest for settings for this set up. I have turned the propane down to 3 from 5 after reading this. Boro is new for me and works but takes a good while and the colora go poop. a lot. Thanks
Saxon

saxon · #10 2005-11-05, 2:51pm

Sorry *colors * get poopy. S

Rebekah · #11 2005-11-05, 3:05pm

I'm so confused. Must not read technical stuff.

So my propane is way too high? I have two oxy cons and a minor. Brent! PM me! LOL Rebekah+big technical words=burning house down.

Rebekah

Whimsey · #12 2005-11-05, 8:34pm

I think I am confused also.....I have an airsep that I bought from suncoast beads, and was told to set it at 3 1/2. So what should my (left ) guage be set at? At the torch (nortel minor) should the oxy be open all the way? Now I am second guessing the way I learned and windering if I am doing things right.....

Wilma

R4GlassStudio · #13 2005-11-07, 12:03pm

There are yet some more factors....... Great info above!! The only thing that needs to be reviewed again is technique. What I have seen in the past, sounds like it could be part of the problem here as well. When you are heating the end of the encasement rod... are you spinning it? Also,is the end of the rod waving when you spin it. A simple thing, but someone that can spin a rod evenly and keep it in the flame without waving.... can work more than twice as fast. One hint aside from practice, is to hold rods and mandrels with your hand closer to the flame, not by the end. (not too close, LOL).
Ron Jr.

MikeAurelius · #14 2005-11-07, 12:22pm

Weasel and Rebekah - here is what we are (basically) recommending:

If you use Tanked or Liquid Oxygen: Set your propane at 5 and your oxygen at 15.

If you use an oxygen concentrator: Set your propane at between 2 and 3 PSI. Oxygen concentrators typically supply about 8 PSI and 92% pure oxygen, so you have to adjust your propane pressure downwards in order to achieve the 3 to 1 "target".

If you have a higher pressure concentrator/generator, divide the delivery pressure by 3 and further reduce it by about 8% (for example, your concentrator/generator delivers 15 psi, divide 15 by 3 to get 5, then multiply by .92 to get 4.6 PSI, set at about 4.5.

Remember that the pressure you first set on your regulator is not always your "running pressure". After the torch has been operating for about 10 minutes or so (leave the torch on and) check the regulator - you'll find that it has crept up by at least 3-4 PSI. Simply back off the regulator "T" handle until the pressure drops slightly below your desired setting, the slowly tighten the "T" handle to bring the pressure up to where you want it set.

BurningScentsations · #15 2005-11-09, 9:53am

Hi,

I just wanted to thank everyone for their help on this issue. There's a lot of great info and I know I learned a few things.

I have adjusted my Propane setting and am getting good heat and not having any real problems. My encasing still needs some practice, but that will come in time, I hope.

Thanks again,

Lloyd