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Is there a special type of screw which should be used when making a fiberboard box?

I use stainless steel screws.

gemhuyck wrote:Is there a special type of screw which should be used when making a fiberboard box?

Vermiculite box, I assume. Screws probably wouldn't work that well with fiberboard.

Any decent stainless screw would work, I use a Phillips flat head, Stainless steel 18-8, #8 x 1-1/2".

Make sure you pre-drill a hole before using the screw.

Where is fiberboard sold! I went to the friendly friendly men homedepot,no luck!
Does. It have another name?

Try a refractory supply or commercial boiler repair shop.

Tony

The primary source for vermiculite boards is Jim Wiles at Southern Service company in Charlotte NC, 704-341-5577. There are different grades of boards, categorized by density (insulating value), and different manufacturers.

Bert Weiss wrote:The primary source for vermiculite boards is Jim Wiles at Southern Service company in Charlotte NC, 704-341-5577. There are different grades of boards, categorized by density (insulating value), and different manufacturers.

May I ask, which size and density is best to buy? T. Y.

S.TImmerman wrote:May I ask, which size and density is best to buy? T. Y.

You usually want a higher density board, around 600. If you go much more than that, the price climbs quite a bit.

Last time I purchased from him, Jim didn't carry Skamol boards any longer. The European (German) board he does carry is metric, around 39" by 24", in various thicknesses (one inch or two inch is probably what you want). My experience has been that the German board is better than the Skamol.

The lower the density, the greater the insulating value, and the lower the strength (read crumble prone). Screws work better in denser boards. So you need to pick a point where you balance strength, and insulating value.

Bullseye sells vermiculite boards that they deem worthy of holding screws. I forget exactly which one they use, but I'll guess it is the one in the middle.

Last I knew, Jim has access to both the Skamol and the German boards. He likes the German boards, but I have heard opinions that the Skamol is good for certain apps.

Bert Weiss wrote:Bullseye sells vermiculite boards that they deem worthy of holding screws. I forget exactly which one they use, but I'll guess it is the one in the middle.

Unless they've changed, Bullseye carries the 600. Specifically, Skamol's V-1100(600) board. The 600 refers to the density, which is 600kg per cubic meter (37.5 pounds per cubic foot). One board weighs around 19 pounds.

I've been using the Vermiculite (1") board from Bullseye for the past 7 or 8 years as a kilnshelf in my coffin kiln. (approx. 24" x 36"0). I purchased 2 at the time not knowing how long it would last. Here I am 8 years later having never had to put the 2nd one in service. It has proved to be an excellent product. I have raised it off the kiln floor with about 40 spacers (3/4" kiln shelf cut up blocks 2" sq.) NEVER WARPED!! I may cut the other one up to make casting boxes.
I recommend this product.

You will want the type of screw that has deep threads and a narrow shaft and not a 'wood screw'. You don't need strength so the shaft can be skinny. There are lots of these screws out there now, they used to be referred to as not needing to predrill.

I want to thank everyone for helping. Sorry it took so long to say thank you, I have been out of the country for 3 weeks.