I want to make a mold using epoxy, instead of tooling PER.
I understand from what i have read that i need to add a filler to the epoxy. What is a good filler/s to add to epoxy to make a tooling “gel coat”? In what ratios do i add the fillers? This mold will be used many times over.
Thanks
epoxy companies make epoxy tooling gelcoats, you would be better off buying it then making it. also epoxy molds should be vacuum bagged.
Is that because epoxy is relatively flexible as compared to cured poly? Hard to get the air out?
First time Ive heard this, so just curious.
I’m still ears open… for how to mix up tooling epoxy. Buying it ready mixed is very expensive, unless someone knows where to buy it other than Fibreglast. They want $40 a quart.
If anyone knows the ratio of silica gel and carb o sil or whatever ingredients get added please let me know. thanks.
fibreglast sucks, they are the biggest rip off ever. get your materials from northern fiberglass if you know whats up. they carry huntsman resins. Richmond bagging supplies and BGF fabrics. as far for vacuum bagging epoxy molds, you want to do this to achieve the strongest, highfiber low RC, low air content possible, also less chance of voids and blemishes. and if your are going to be post curing your parts you dont want air pockets witch will expand and ruin your surface. If you want to make your own surface coat you can mix cabosil in. make sure you mix it very well no lumps, you can also use aluminum filler. degas the gelcoat before apply to your surface. epoxy gelcoats DO NOT get sprayed. you should never spray any epoxy gelcoat or epoxy
Thank you Hojo 
I’ll look into that company you mentioned. thanks.
yes, you should, those guys are cool shit. and by the way, if I was you, since your making a epoxy tool, you should get high temp epoxies with a tg around 250-300 degrees, so in the future if you want you can do prepregs. there shouldnt be much cost difference between them
How do you buy their stuff from hojo? I’m caught in a web loop flipping from their site to their suppliers sites. Richmond Aircraft seems to carry the broadest range of materials but I can’t find where to buy them? Maybe you can’t do it online. 
There is a distributor called northern fiberglass, they distribute richmond aircraft, huntsman and BGF products. this is there website: www.nfgsales.com .
you need to call them, they will connect you with a sales rep for your area who will take care of you. actually if you look under contact, and click sales staff you can find your rep there, if your lucky you will get dick hewett, he knows his shit
Cool. Thnx. Good suppliers are few and far between up here. I usually have to go south of the border to buy materials. Being able to order online helps a lot.
yea, but oredering online you usually get raped on prices. northern has got great products, awesome surface, and the reps know what they are talking about, unlike other big distro’s, but i wont mention names
Yeah I think you did already earlier! 
What this world (and god forsaken stupid frozen country) needs is a decent online reseller that has a full range of products at reasonable prices. Hey! Maybe Walmart will start selling some of this stuff eh?
Seriously it’s tough out here in the boonies. You have to sort of “hunt & peck” for materials. I’ve tried some common h/w store stuff and some materials from the wifey’s fabric retailer that actually work pretty well as peelply’s. For now e-Bay is 'bout the only place I can pick up some small quantities.
Eventually we’ll need larger quantities of films, plys etc. for our boat and will have to go to the larger resellers.
[QUOTE=KnottyBuoyz;15044]Yeah I think you did already earlier!
Ha, I was thinking of a different large distro when I said that, actually, I dont think fibreglast pushes too much weight. They called me at work one day trying to get our business, they were quoting fake carbon for more then the price that we pay for real carbon fiber. unreal
Here in the UK it seems to me that online sellers with flashy websites,commonly charge prices about 30% higher than small independant distributors.
I found my current supplier through a guy that makes parts for me, and who has been running a small one man laminating business for many years.
Airtech sells tooling epoxy, both high and low temp (high-temp obviously if you are cooking your parts for pre-preg or post curing in mold)
As I always say, check out compositesworld.com/sb (CW’s Source Book) for stuff
I don’t know prices.
Mixing is standard, 100 part A, xx part B, by weight (get a cheap scale)
Fillers, are NOT needed, unless you have lots of vertical surfaces that might sag off, then you just ad cabosil or whatever till it gets a bit thick, OR let it sit in the cup till it starts to gel (and I mean, JUST…else you are trying to work with fast curing epoxy goo)
Come on name names. Compone? Uscomposites?
I tried contacting nfg through their site one time and never got a return. So I left it at that. Do they make you jump through hoops to do business with them. Compone made me fax forms and follow up forms…
Bryan Duffey is your area rep. He was my rep when I lived in maine. He’s a good guy. give him a call, or email him
Bryan P. Duffey
bduffey@nfgsales.com
Phone (603)-926-1910 ext. 13
Cell (617)-803-1143
ps: you don’t need fillers in the epoxy, unless you have a large vertical surface that sags. Then, just add teaspoon at a time until it is seemingly thicker.
unless you are spraying…then I guess you won’t have sag.
yea, but this guy wanted to make his own gelcoat from epoxy resin, so he would need to thicken it up with a filler