Cutting Fiber board for molds

[jim burchett]

I got a large piece of 1" fiberboard to use for mold making. I'm finding it very difficult to get a clean edge on this material Is ther a secret I dont know? I have already fired the pieces before i try to carve them is this proper or should I try it the other way? Any help will be appreciated :

[Lisa Allen]

Try carving before you burn them out. From my experience, they are less fragile and less prone to crumbling before they are fired. Also, use a really sharp exacto blade.

Lisa

[All Fired Up]

I had the same problem. I am in the sewing business and we use a rotary knife alot. I used it on the fiber board and it worked outstanding. Here is a link:

http://shop.store.yahoo.com/cinemasuppl ... -6984.html

[Barbara Muth]

that's just the regular what I call rotary scissors for cutting fabrics?

[slats]

I also received a hugh piece of board..never used it before. Would like to cut out a big ring (drop ring) to make a sink. Do I have to harden this and how do I go about it?

[All Fired Up]

that's just the regular what I call rotary scissors for cutting fabrics?

That's exactly what it is. Cuts it like butter.

[Bert Weiss]

I also received a hugh piece of board..never used it before. Would like to cut out a big ring (drop ring) to make a sink. Do I have to harden this and how do I go about it?

I simply cut it with a razor utility knife. It doesn't much matter what angle you cut to, square, beveled in or out. Prefire it and go. I generally use some dry powders on it to help seperate. I like alumina or plaster.

Bert

[slats]

Bert, how long and how high to fire? Do I have to use hardener? before or after? Sorry for all the questions, just never used it before..Thanx

[Bert Weiss]

Bert, how long and how high to fire? Do I have to use hardener? before or after? Sorry for all the questions, just never used it before..Thanx

I have never used hardner so I can't comment on how it works.

I recommend prefiring the board up to the top process temp you plan to use it at.

[Tony Serviente]

I've used a colloidal silica hardener on fiber batt, and applied it before firing. Worked well. Never used it on board.

[charlie]

i've used it on board. it works well. it's more solid and the edges don't flake off unless you bang it on the side of the kiln. damhikt

[Liam]

for rigidizing do a search in the archives for
fiber rigidizer
or fiberdizer
Anything with fiberdizer-n-go is good
Liam