I have travelled a lot this last month visiting with in-laws and then taking an elderly Aunt to see her best friend from college. They definitely had some interesting stories to tell and I enjoyed being able to share some time with my Aunt!
Now I am back and working on some new projects. While gone, I noticed several people searching for information on how to prepare a stainless steel mold with kiln wash. So I thought I would share my experiences here.
The preferred method by others I have read is to heat your stainless steel mold to about 500 degrees and then carefully take it out of the kiln and apply your mold kiln wash like Primo Primer (the purple color one). You will need to repeat this process several times until you have completely covered all of the stainless steel with primer.
I have had good luck with this method as far as the primer lasting for several uses of the mold. However, the disadvantage is that it is very messy. Because the mold is hot, the primer spatters and makes a mess of your immediate area. I use my hake brush to apply the primer, but the bristles stick to the hot mold and it is hard to spread the primer evenly. The right way to do this is to use a sprayer to spray on the primer but alas I haven’t invested in one yet.
The next method is to use boron nitride. I have tried several and will have to admit that my favorite and to me the only reliable one is MR-97. I use this on all of my stainless steel molds except for my vase draping ones (more on this next). It comes in an aerosol can and you basically spray it on making sure you have completely covered the mold. Be careful though not to be too heavy-handed. You will also need to remove this each time after firing and reapply as it is not a multi-use method. Use a brush to remove and then just wipe clean with a cloth.
With my vase draping molds, I do apply a coat of the MR-97 to the stainless steel mold. But then I also place a piece of Bullseye Thin Fire shelf paper between the glass and the stainless steel mold. I do this because I was having difficultly with these molds with the boron nitride actually sticking to the glass and I wasn’t able to remove it without some sort of abrasive. I am guessing that for this type of mold, the glass is not just gently slumping into or over the mold, but it is stretching down the mold as it slumps and it pulls the boron nitride along and embeds in the glass. So why apply the MR-97 at all since it is actually pretty expensive? This is my just in case the glass slumps farther down the mold than expected and the fiber paper didn’t quite cover all the stainless steel.
One side note regarding MR-97 is that if you take the kiln above 1400 degrees using MR-97 on a mold, MR-97 tends to stick to the glass and will be difficult to remove without an abrasive. So I have adapted several kiln schedules to hold longer at 1400 degrees or less and this seems to work great. If even after using a lower temperature you still have MR-97 residue left, try soaking in vinegar and it should come off.
Check out the spoon rest I created using a stainless steel mold I bought in a kitchen store using the MR-97 mold release.
As always, everyone’s experiences are different. Hope this gives you some help though on what works for me.