Trash Shelves; the next chapter

[Jerry]

Well the folks from Evenheat came through; sort of. They admitted their shelves were warped and did their best to find someone who was making shelves that weren't warped. The sad part is everyone they know in the business has the same problem. All they could do was send my supplier a credit in my name, and I get to keep the shelves. This means that there are a lot of companies out there getting their shelves from out of the country that are substandard, they know it and don't seem to care.

In the midst of all this I sent Paragon an email asking them where they get their shelves and they said that theirs come from the same place as Evenheat gets theirs. All our American jobs are in central America where the labor is cheap and the quality contorl doesn't exist.

So, I'm in the market for kiln shelves from another source; Brad, what do you have?

Jerry

[Bob]

Jerry,

I suggest going to a pottery supply shop with a straight edge and a piece of paper. Take all the kiln shelves that have unblemished tops ( no scratches/ gouges) and check them for flatness. If the paper slide easily between the straight edhe and te surface of the shelf then don't take the shelf. I find that only 20% of shelves pass the test. t I haven't had to replace the shelves for years. Touch wood.

Cheers,

Bob

[charlie]

So, I'm in the market for kiln shelves from another source; Brad, what do you have?

Jerry

if it were me, i'd attempt to flatten them. it will take some effort, but you're no worse off if it fails.

scribble all over 2 of them with a soft pencil. put some sandblasting grit on top of one of them, maybe 100-150 grit. invert another shelf and make a grit sandwich. move the top one over the bottom one. every now and then rotate the top one 45 degrees. you'll be able to tell when they're flat when all the scribbling is gone. the last to go will be the low spots. keep adding grit because it will tend to work itself out on the edges.

with luck you'll get 2 flat shelves. they may wind up 1 concave, 1 convex. after all, this is how you make telescope lenses/mirrors.

to do this correctly, use 3 shelves. you'll wind up with 3 flat ones.

[Tony Smith]

Marty from Centre deVerre suggested using a widebelt sander. Most commercial woodworking shops have these. Not sure how they would feel about running mullite shelves through their sander, but Marty says it works well.

Tony

[Jerry]

Well guys, I appreciate your guidance. The nearest pottery shop is just over 3 hours away. I don't need any plaster, silica or clay just yet, but the next time I visit them, I'll be armed with a straight edge and a piece of paper; thanks for that one.

As to grinding the shelves, I'd thought of that especially since they are mine for free, so to speak. The weather is still nice in Maine and I have a belt sander so I may try that tomorrow. I've got a load of glass coming in fairly early and need to get it ready for a large project that gets picked up on Wednesday, but after all that, the day is mine, or what ever is left of it, so the grinding belt may come out then.

As far as the blasting grit goes, that sounds like a great idea except I don't have any. Do you suppose that the folks that make headstones use something that would work? There's a couple of them around if they've got something usable.

I've done two firings on one of the warped shelves using 1/4" shelf paper and gotten away clean. These are both large, square platters dropped through a mold such that they have a 16" square drop in the middle; it's for a wedding cake. I need 6 of these in three different sizes and decided to save the largest two for last; that's tomorrow and Sunday assuming things don't get too crazy.

So wish me luck with the warped shelf and if there's anymore to the story, I'll tell it.

Thanks again,
Jerry

[charlie]

there is no way you're going to flatten them with a handheld belt sander. what tony was referring to was a wide belt sander, at least as wide as the shortest dimension of your shelf. a custom cabinet place will have one, usually 20" is the minimum width.

sandblasting grit can be found at headstone makers. that's what they use to do the engraving.

thick paper should work, but it'll get expensive after a while.

[DonMcClennen]

Did you check out the shelves offered by Bullseye?

[Lynne Chappell]

The pottery supplier near me thinks I'm a little off my gourd. I come in with my level and paper and go over every shelf he has. If I can get the paper under the level I pass on that shelf. Remember to check across more than one direction. Fiber paper will get you by in the meantime, that's what I had to do while I was waiting for his next shipment - from England by the way. They make the best shelves and I think that's what Bullseye is selling. They're not mullite, I think they're a type of alumina product.