air holes in SS bowl molds

[Mark Selleck]

I've got some new "molds" to play with, and I'm not sure how many holes I should put in them to allow air to escape during a slump. The first is a 20" SS bowl with a flat bottom. I would guess just a couple of holes in the very bottom would be sufficient. The other is a little tricky, at least it offers more likelihood of problems. It is a SS bowl that, the best I can describe it, would create a very large doughnut if it was filled with dough and baked. The center of the bowl has a raised cone shape that rises to a height level with the perimeter of the bowl. I'm planning to put a disc of glass over the form with a hole in the center of the disc, thus resulting in a doughnut-shaped "bowl". My question is: How many holes should I space around the doughnut depression? Suggestions? Thanks for any help.

[rosanna gusler]

i put 3 or 4 holes in the bottom where the wall meets the bottom. the holes should be in the last place you think the glass will touch when slumping. that ss bundt pan sounds cool. tell us how it works ok? rosanna

[Ron Coleman]

Just some thoughts on hole locations.

Put the holes where the glass isn't going to be when the slump first touches down on the bottom.

For a flat bottom mold I would drill the holes near the edge where the bottom and sides join, right where the last bit of air will be trapped as the slump finishes.

For the dounut bowl I would think at the lowest point at the bottom. You might also try to guess where the coolest part of the glass will be in the kiln and locate the holes there. Top elements really help with evenivity.

Also, when drilling stainless, start with a good sharp drill bit, center punch the hole location to keep the bit from skating around, and don't tease the metal, drill it. Stainless tends to work harden and going slow and drilling holes with a dull bit can give you a hard spot that just won't drill no matter what you do short of annealing the metal.
Ron

[Marty]

And a drop of oil where you're drilling will help.

[Mark Selleck]

Thanks for the input. I'm going to try the SS "bundt pan" with some scrap glass first. I'm not sure what I'll end up making with it, but it was too interesting to not get it. I'll take some pics when I get a result worth sharing.

[Tony Smith]

Mark,

Bundt pans typically have steep, almost vertical, walls. You may find that the mold traps the glass and that you'll have to remove the mold at elevated temperatures. Just a possibility. Let us know how it turns out.

Tony

[Mark Selleck]

Tony, I used the term "bundt pan" as a somewhat descriptive term, but the piece I have is similar only in that it has the center elevated "cone" shape. My pan/bowl is from a piece of restaurant equipment, a meat chopper. I saw the bowl on a chopper at an auction, then was able to find one at a used restaurant equipment supplier, after going through a couple of dozen aluminum and otherwise shaped pieces. I'm not sure how it's going to work out, but I'm about ready to try it. Results soon.