bubbling/boiling problems....help needed please

[★★Terri★★]

I have been happily beading with the tank of gas I got last year with no particular problems.  But now I have a new tank and it's all gone wrong

Hot head and regulator set up still the same - flame is quite obviously bigger and stronger and melting glass much, much quicker.

I am getting a lot of bubbles forming - especially with effetre ivory - which are swelling up and then bursting.  Have had this happen a couple of times before - but not on every bead and lots of them.  When it burst it the crater goes all the way down to the mandrel.  I have coaxed and nudged the glass to fill the holes but...........why it is happening.

I have tried working in different parts of the flame - but it still happens.  I turned the pressure down a bit on the regulator which seems to have made the flame a bit less violent, but the bubbles are still happening.  I also seem to be scorching glass as well.....dark grey and red patches on Copper Green, Caribbean Sea and SIS seems to be fuming rather than melting/seperating. 

Any ideas?

[Redhotsal]

I get bubbles in ivory too and it's usually because I haven't heated up the bead release on the mandrel enough. There's trapped gas in the bead release and because the ivory is so "floppy" it covers the bead release before the gas can escape. If you heat the release first all along the area where the glass is going to go you will minimise this problem somewhat. You'll find this is more of a problem on longer beads.

It does sounds like you are scorching the glass somewhat though - a new tank of gas may well give a much higher pressure - despite the regulator. Is it possible to turn the flame down at the torch itself? It will probably help - although it does sound as if you are doing the right things - turning the torch down and working higher in the flame.

[★★Terri★★]

I thought about the bead release - and have been heating it throughly all along the coated area.  I have a new batch of bead release that I made last week and modified the recipe slightly so thought that could be the cause.  I had a few mandrels already dipped from the old batch so I tried those and got the same problem.

It was the beads with a longer footprint that I had the most problems with.....but it's happening in donuts as well.  It happens in most the glasses I tried - eff white, clear, ink blue, and ivory.  Was not so noticable in Sedona, Caribean Sea and Copper Green but they scorched.  Bah!

Will try turning the regulator down a bit more......not really any control on the hot head.

Thanks Sal.......reassuring to know that I was thinking along the right lines.

[jammie]

Hmmm, I get this with blues, I have a hothead, I seem to have the opposite problem and can't get my flame hot enough. My reg is turned full and so is the hothead    You can turn the hothead down a little though you're right it doesn't seem to make much difference. Can you keep the bead really high in the flame or even just behind it, or keep taking it out of the flame, is it maybe in the flame too much, that's what I'm doing when I boil my blues.

[Les]

Some blues just seem to boil, no matter how you treat them.... mostly the turquoises, both trans and opaque.... Well mine do anyway

[jammie]

That's good to know in an oh poop then kind of way, Les. 

[ScarletLeonard]

Not had this happen to me, seems odd that the tank has made a difference unless it happened the first time you hooked up to bulk too.

Have you unhooked the torch and given it a good clean out, I usually cover the holes and then blow hard into the top and all manner of things seem to come loose if I haven't done it for a while. If you have things trapped it could be like you were working with tinfoil around the holes.

[Les]

And I ALWAYS seem to get that awful grey scum on my turquoise beads, especially the Dk. turquoise, no matter how I adjust the fuel mix ... that's why all my turquoise beads are etched, lol

[♥♥Tan♥♥]

Les do you find you don't notice the grey scum until they are out of the kiln? Thats when I notice it so it must be kiln strike related?

I had lots of bubbly glass the other day, exactly as you have described Terri, all sorts of colours and the bubbles were definitely coming from the very core so I surmised it must be bead release related.

I wonder if it sucks up damp even if its been on the mandrel a while

[★★Terri★★]

Could be the release...........thinking about it I added whiting which is to promote porosity, this time and didn't last time.  Perhaps it's just too porous and holding moisture even when the madrel has been heated.  I will make up a new batch tomorrow without and try again.

It didn't happen with the last tank of gas.......I was almost a complete newbie then and would most definately remember that happening.  I have used ivory since I started bead making and have always favoured it as I find it so easy to work with.  If it had done this to start with I would have given up.