Devit after borax solution?

[Cliff Swanson]

I made some pattern bars and cut them into slabs using a tile saw. I was careful to place the cut slabs into water immediately upon coming off the saw, and I cleaned the cut faces with a toothbrush adn clean water before letting them dry. I've read that devit can be a problem with pattern bars, so I mixed up some borax solution (1 cup distilled H20, 1 tsp 20 Mule Team Borax, ~1/2 tsp Klyrfire) and dunked some slabs in it. Actually, they soaked for about 5 mins while I did something else. The bars from which the slabs were cut are S96 opal red and black, and S96 opal cobalt and black. I set up a test firing involving 2 slabs of each color, one of the red slabs and one of the blue slabs were soaked in borax solution, and the matching 2 by color were not. I tack fused all 4 slabs to a piece of S96 clear, processed at ~1325/10 min in an Aim 8x8" kiln. Neither the treated nor the non-treated red/black slabs devited, but the cobalt/black was another story. The non-borax slab developed blotchy devit on the sawn surface, and the borax-treated slab has just a slight haze...actually not objectionable. There is no devit over the black part of the design in any of the red or blue slabs.

In the experience of those of you who use borax solution, are these results typical? Is there variance in devit development with different colors? Does the amount of time a piece of glass is soaked in borax influence devit develpment or is a quick dunk and dry all that is required for it to work correctly?

Cliff

[Tess Farley]

I spray the borax on with an airbrush and let dry before firing. So far no devit. Since glass isn't absorbant, I don't think soaking would help one way or the other. What you want is a coating of borax on the glass. If you don't have an airbrush, you could use an empty hairspray bottle.

[Rick Jarvis]

In our studio we are always messing around with the borax vs Superspray devit issue within spectrums line. As pattern bars have undergone similar firings as my work I dare comment. I wish I could say I have a definitive answer...Reds Yellows Blacks seem never to have a devit issue and are never initally sprayed. Other Colors either S96 or not can develop devit when the glass has been pushed. <I use mostly cullet and some say thats why I have devit issues, although I am not convinced of that...I think its the temps and kiln gods but thats another story>

Borax and superspray solve most devit problems but only careful note taking will reveal the better choice. For example I use a very heavy coat of borax on amber but that is a disaster on a S96 dark green which requires two light coats of superspray. Needed or not I sandblast before refiring and wash both with soapy water followed by alcohol. I have not been able to identify all the variables and control them but most of the time you can mess with the anti devit spray of choice and refire till you are happy. Good luck and if any one ever figures this out let me know

Rick

[charlie]

you just need a thin coating of borax, and soaking doesn't do much good since it probably sheets off when you remove it from the soak. also, drying it is not good either.

i find spraying it on with an atomizer works well. you have to put a little bit of dish shoap inthe water (just a drop or two) to lower the skin tension so that it doesn't bead up.

i've also found that the cobolt blue can devit even with borax. i seem to have the most trouble with that color than any other.

[Dani]

What Charlie said, and I do consistently get a bit of hazing on red edges. I'm certainly glad to read that folks other than I routinely use overspray to control devit on non-devit glasses! LOL.

[chuck666]

Cliff,

I sandblast the final surface after I've tack fused the elements together and do a 1350º, 20 minutes of fire polishing as the last operation. With that technique, you always have a fresh surface for the fire polish and never any devit.

Chuck of AZ