Me again! I've started working with float glass and have found that it loses its clarity after slumping. I don't dislike the finish (a bit cloudy but actually quite nice) however I keep hearing about devit spray that can be used to prevent the cloudiness. Has anyone heard of this or used it before? How does it work? I've seen a homemade recipe using borax, washing up liquid, distilled water http://www.glass-fusing-made-easy.com/devit-spray.html . Can it really be that simple? I know the best thing to do would be just to try the recipe but I would be interested in your thoughts.
Is that the same as this (second item down)
http://www.tempsfordstainedglass.co.uk/acatalog/Devit_Spray_and_Liquid_Stringer_.html
I was advised to use this on fused glass that has been ground at the edges - it helps to remove the "tide" mark from the grinding! I clean the edges and then paint on with a fine brush and fire polish!
I didn't find this much use, you're better off buying an ultra violet tester to find the tinned side. They don't cost much and always worked for me
Quote from: Trudi on February 10, 2013, 05:11:25 PM
Is that the same as this (second item down)
http://www.tempsfordstainedglass.co.uk/acatalog/Devit_Spray_and_Liquid_Stringer_.html
I was advised to use this on fused glass that has been ground at the edges - it helps to remove the "tide" mark from the grinding! I clean the edges and then paint on with a fine brush and fire polish!
Thanks Trudi. It's similar but it fires at a higher temperature I think. As I'm still experimenting I think I will start with homemade recipe and see what happens. Nothing ventured, nothing gained.
Quote from: firedinglass on February 10, 2013, 05:25:11 PM
I didn't find this much use, you're better off buying an ultra violet tester to find the tinned side. They don't cost much and always worked for me
I read that it takes some doing to use it correctly and to be very, very careful with your eyes. It kinda put me off a bit tbh.
If you correctly identify the tin/air sides does this prevent clouding at the slumping stage?
The Devit A solution from Tempsford glass has crushed glass in it and woks well, apparently the homemade one is a bit questionable as the glas is needed to coat the area....however the solution needs to be stirred with the paintbrush every time you apply it to suspend the glass or the results can be disappointing. Mind you, I havn't tried this with float glass.
Quote from: Angie on February 10, 2013, 07:56:28 PM
The Devit A solution from Tempsford glass has crushed glass in it and woks well, apparently the homemade one is a bit questionable as the glas is needed to coat the area....however the solution needs to be stirred with the paintbrush every time you apply it to suspend the glass or the results can be disappointing. Mind you, I havn't tried this with float glass.
Thanks Angie.
I think I'll try this out and let you know how I get on.
The tin side of float glass is more prone to devit this can be minimised by not maintaining high temperatures for long periods and by crash cooling. I have used a hand held UV tester for years with no problems but I don't look straight into the lamp but it is very low powered. An old school way of testing is to put a small drop of water on to clean glass if the droplet becomes irregular then that is the tinned side. if it stays as a neat drop its untinned. Its not foolproof but with a bit of practice it works ok.
Quote from: Glyn Burton on February 10, 2013, 09:29:55 PM
The tin side of float glass is more prone to devit this can be minimised by not maintaining high temperatures for long periods and by crash cooling. I have used a hand held UV tester for years with no problems but I don't look straight into the lamp but it is very low powered. An old school way of testing is to put a small drop of water on to clean glass if the droplet becomes irregular then that is the tinned side. if it stays as a neat drop its untinned. Its not foolproof but with a bit of practice it works ok.
I think I need to persevere with testing the sides using alternative methods. I've also heard that it's possible to tell by licking the glass!
The problem seems to be at the slumping stage. I used my usual slumping schedule which, in fact, didn't cause the piece to slump as much as I'd expected or wanted. So it looks as though I will have to either increase the temperature or hold for longer. Do you generally retain the clarity even after slumping?
:)
Quote from: Glyn Burton on February 10, 2013, 09:29:55 PM
The tin side of float glass is more prone to devit this can be minimised by not maintaining high temperatures for long periods and by crash cooling. I have used a hand held UV tester for years with no problems but I don't look straight into the lamp but it is very low powered. An old school way of testing is to put a small drop of water on to clean glass if the droplet becomes irregular then that is the tinned side. if it stays as a neat drop its untinned. Its not foolproof but with a bit of practice it works ok.
Just what I was going to write, in all my years of fusing this is what I used and had no problems with devitrification :)
Also maybe you need to look again at your slumping schedule and don't soak for too long