Why does my kiln wash keep cracking?

[NRichards]

Hello,

I hope one of you lovely people can help.

I'm having major issues with my kiln wash cracking before i even fire it.

The last one i managed to smooth and risked a firing, fuse was good but the wash had severly cracked and needed replacing. So i scraped all the old stuff off and cleaned the shelf as usual and decided this time to make a fresh lot. I started the application, leaving each coat to dry (naturally this time) and before ive finished its all cracking and peeling up. This has been happening the last few times and i'm beginning to wonder if my tub of kiln wash is defective.

Does anyone have any ideas?

Thanks
naomi

[Sarah A]

I don't really have any idea why it would be cracking.  How think is it when you put it on?  I always make mine watery, about the consitency of single cream and put around 8 coats on straight on top of each other.  It dries and looks powdery and have never had any probs with it cracking.

ETA what make are you using?  I use Bullseye. 

[Zeldazog]

I'm same as Sarah, quite watery, brush on several layers straight after each other - on a clean shelf, the first few layers absorb and dry pretty much straight away.

[NRichards]

Interesting, I've always thought you had to leave each coat to dry before applying the next.

I think I must have inadvertently been making it up too thick as when I added more water it seemed to work. I'm going to try coats straight after each other next time.

I also use the Bullseye one.

Thanks for your quick responses as always.

[Flippopotamus]

I bought some so-called Bullseye from an ebay seller - it came in plastic bags and looks right - goes on pink, fires to white, but cracked badly on first firing every time.  I bought some more genuine Bullseye from Warm Glass and the problem went away.  Maybe it's a case of fake Bullseye (would anyone really bother?) or perhaps it has a shelf like like old cement and loses performance with age?
Flip

[NRichards]

Hiya, thanks for that. As I bought it from Warm Glass I think maybe it could be a case of shelf life as it were. I wasn't as meticulous about letting each coat dry and it wasn't as bad by any stretch but it definately doesn't last as long as it was.

Thanks

[awrylemming]

Blimey, does it have a shelf life?  I have an unopened tub here that I'm never going to use, better get it up in the sale/swappy board 

[NRichards]

It might be worth asking a supplier to confirm. I might do this when I have a little more time and not so stressed with work. I'm just thinking it might be that as it wasn't that bad when I first opened it.

[Warm Glass UK]

It shouldn't be shelf life - the rate of turnover at BE and here is high so it doesn't sit around long! Each batch is kiln tested to ensure consistency from run to run. It sounds like it's a bit thick to me which is the most likely reason for cracking. Have you checked out the Application of Shelf Primer PDF on our site here: http://www.warm-glass.co.uk/bullseye-shelf-primer-400g-p-324.html

Give us a call if you are still struggling, Pippa

[Warm Glass UK]

PS. There isn't a specific shelf life for this product but most plaster-based products will start to deteriorate after about 12 months. Keeping it in the sealed tub it comes in will help as it will stop moisture getting into it. Pippa