WarmGlass.com

Need some advice. New to it

I used to use Thinfire paper when fusing my glass but got like mucky lines around the fused glass. Looked into it and change to using primo primer instead but the glass on the bottom side has rough and sharp edges which I never got with using the paper.

I apply 5 coats of the primo, drying each coat but not sure how to get around this


Thanks

I don't know about the Primer, but to get around the murky edges, have you noticed that this only happens when you have a ground edge?
Either don't grind, or manually polish the edges before firing.
Use a very find grit to do the final grind and it should be fine.
The other Jim

First of all you don't have to dry the shelf primer between each coat. I usually do about 6 coats all at the same time alternating brushing direction each coat.. then dry (sit out in sun, or sit on top of kiln when your firing something else) Once it is dry run your dry hand over gently to reduce brush ridges.
Needles at edge are usually caused by not enough glass volume... Get yourself the Warm Glass Fusing (Brad Walker) book .. a lot of your problems will be addressed!

Thanks for responses

In relation to the mucky lines they show a fine line round the whole piece straight, like an outline . Not always around the whole thing. They come out nicely formed

With the kiln wash, there are no lines so don't think it's a grinding thing.

Can't understand why the paper would cause this issue and kiln wash doesn't

Thanks

Because the paper fumes are trapped in the microscopic bubbles caused by the voids left by the coarse grinding head.
Kiln wash doesn't have any fumes to get trapped.
The other Jim

Even if they are freshly cut pieces not grinded but cleaned before being put in the kiln

Thanks

I stopped using fiber paper and my issues stopped. Now, if for some reason I have to use paper, I simply vent the kiln while firing.