Kiln shelf lining advice needed

[rowli]

Hi everyone, I have looked through many, many interesting ideas on the forum, but none of them quite answer my query. Hope someone can help. I work in the main with Bullseye glass spending some experimental time on float.
I line my kiln with with 'thin fire' paper, and it always works well. However, I am sure I have read somewhere or someone has told me....., that you can either put dry builders plaster, or dry plaster of Paris on your kiln shelf, up to a few mm thick. .

You can then either have your glass have a smooth texture or whatever texture you create in your dry plaster shelf mix. Has anyone ever tried this, or would anyone like to recommend this to me, or maybe a similar material to place on my kiln shelf.

[Pat from Canvey]

When I used to make stained glass windows, I used to put whiting on shelves inside the kiln to act as a base for firing stained glass paints and silver stain. I also experimented with making shapes from the whiting so that I could slump flat glass over them. Have a look at http://glass-suppliers.com/glass-process-3/process-3-3271.html Whiting is calcium carbonate and if I remember correctly. I mixed it to a thick paste with water and allowed to dry. I had free standing steel shelves specially made inside the kiln with a lip so that I could get a good depth of whiting and make sure it was totally flat otherwise the glass would deform to the shape of the whiting layer which was about 5mm thick.

[flame n fuse]

Yes, you can use plaster of Paris either as powder, or you can pour it over a clay mould and then slump glass into it. For the latter you can make nice shapes in the clay - impressed shells, seedpods etc. Wear a face mask with dry powder. For a smooth finish Bullseye shelf primer is good - you can polish it up with a dry cloth after applying it. I find that thinfire is good for small pieces but less good for large - tends to 'drag' and give a rough texture in places.