Can you use sand to thicken EPOXY?

Even sawdust would work.

 

The bottom line is what's it's intended use; as a fairing compound or a structural element. As a fairing compound you can use anything you want, though physical properties do come to bear if you have to sand or other wise shape it after cure. As a structural element, you have more possibilities and again physical properties will come to play, under loading, the various types of strength and stiffness, weight, etc.

Is it just a fairing or will it need to bear some load? Light load? Under fabrics? How much (roughly) load?

Since you don't seem to care much, I'll assume it's a fairing compound, in which case yes, cooking flour works great, though can be heavy and absorb a good bit of resin. Salt, sugar, poppy seeds, whatever you like, though (again) each will bring it's set of physical issues and properties to the table. Considering the cost of most filler materials, it begs the question why not the "usual suspects"?

 

Yeah I think Talcum is only 3 dollar per kilo. Is that cheaper than flour --Dunno. cant be far off.

 

I don't know Frosty, I go through a lot, I mean an awful lot of flour. You know, I have to roll the other half around in it . . .

 

The only time I've used sand with epoxy was building a pretend beach fire on plywood for my daughters pre-school class. It worked great!

-Tom

 

In that sharp, hard corner you can lay strands of roving pulled from woven roving, or strings pulled from glass cloth. Lay them lengthways, along the corner. A few rovings will fill in the hard corner and leave a "fillet" that the next layers of mat or cloth can conform to without leaving long air bubbles along the corner. The glass strengthens the sharp corner so it is less likely to chip when using the mold.

 

Why spend the money for epoxy to fill a gap on a plug?You could go to a supplier of materials for car body repairs and buy polyester filler that you could use instantly and every mix will be the same,not to mention easily sanded.You could also use modelling clay or plasticene,if I understand the situation you describe.

 

If that's the case, filling a gap between the plug and the flange before glassing the mold, modeling clay works well.

I thought since he said the fiberglass cant quite bend to the exact shape, that he was past that and was laying up the mold.

And if that's the case, another way to get glass into the sharp corner is to cut mat to the correct shape. The first layer on the plug would butt tight to the flange, the second piece would be on the flange and would butt up tight to the plug. The third piece would be on the plug, butting up tight to the flange, the fourth would be on the flange butting up tight to the plug, etc.

 

Car filler is crap and expensive . I make my own with polyester resin and talc, sands better, goes off faster, doesnt shrink, water proof, accepts any paint and I can mix some up as quick.

 

Ive never had any luck with using any additives to form a thick enough paste to make a radius that the fibres will conform to (but then i am a amateur). Ive found the only way i can get it to work is by painting on the gel coat and then using a car body filler to take the edge off with a lolly pop stick or my finger. Once it is dry i then glass over it and ive never had any problems

 

More filler material Leon and it'll get thick enough. Of course it helps to use a thixotropic agent, such as silica or cotton flock.

 

Thanks PAR, I did use Cotton flox but i found the amount i had to use to get a thick paste and the price it was for me was too expensive over a 5kg tub of filler for £14.

Ive used polyester resin and talk to make a thick resin for fill gaps in floors but once again it never got thick enough to a point i could say " yer that would work" haha

Thanks

 

Never had that trouble, I can get polyester resin as thick as tar if use enough talc. At a guess I would say maybe twice in volume talc to resin and if you leave it a while it will go thicker. If you leave it a week you'le need some more resin it.

I had found that I need much more hardener with resin made filler, Ive been cought out with that, fortunately a hair dryer saved the day even though day time temps is 80 to 90 degrees year round.

 

Thanks frosty,

The thickness i would need it would be need to be able to stick on a vertical surface of a mould and not slump down. Ive got some talc on order so will have a play around and may leave it to firm up a bit like you said.
Thanks

 

No.. the answer would be yes..