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epoxy ammo molds

Posted: Sun Sep 16, 2007 4:32 am
by trae08
hi i have a few questions about epoxy and making ammo molds for epoxy to be poured into.

1- if i made a mold out of metal coated it with an oil and filled it with epoxy, after the epoxy cured would i be able to get the epoxy ammo out of the mold without destroying the mold?

2- what would be better for a piston? hot glue or epoxy?

3- whats the best type of epoxy to use for both of these applications listed above?, i know JSR talked about marine epoxy in his epoxy how toos but is that the best for spudding purpose?

i think i had a few more questions but i dont remember what they were so for now these will do...


thanks for your help.

Posted: Sun Sep 16, 2007 4:52 am
by spud yeti
I am no proffessional at epoxy casting, but from my knowledge I give you:

1- yes, they are both non-natural materials, and therefor should not join into one another, but be sure to use some good lube (KY lube etc) that is water-based for best results

2- I think that epoxy is a better material for the slide aspect, but hotglue does not shatter, unlike epoxy, and it is cheaper. My final vote would have to be hotglue with a foam inside (sorry JSR :D )

3- Apparently marine epoxy is great because of its consistency which is light, so all the bubbles raise out of it and leave a good mold. I am not 100% sure of this though.

I hope I have helped, but as I said, Im not the pro with epoxy, and so you should probably wait for someone like JSR to reply :D

Posted: Sun Sep 16, 2007 5:10 am
by jackssmirkingrevenge
I think that epoxy is a better material for the slide aspect, but hotglue does not shatter, unlike hotglue, and it is cheaper.
So hotglue is definitely better than hotglue then? ;)

I've never had an epoxy piston shatter on me even at 400 psi, though of course I always used an appropriate bumper. I think epoxy is a better idea because it can be sanded down to a smooth friction free finish, though having never worked with hot glue I can't really compare.

I think marine epoxy is worth buying for contruction purposes (though I wouldn't throw it away as ammo), it might seem expensive at first but you use very little per propject (unless you're into monster 3" cannons) - whatever you chose to use, it must set hard and strong, usually the longer they take to cure the stronger the result, and must be liquid enough to flow into your mould. It's a good idea to include some reinforcement for load-bearing areas, such as wire or nylon mesh.

Posted: Sun Sep 16, 2007 5:12 am
by trae08
spud yeti wrote:
2- but hotglue does not shatter, unlike hotglue, and it is cheaper.
ok thx for your help.. yea ill see what JSR has to say. and im confused by the part of your post that i quoted...


edit ok thanks JSR what i plan on doing is making molds and pouring in some epoxy then putting something on top of it.

as for building guns with epoxy i dont really make to complicated of guns to need it. but on my next rifle im making i will be using it to join brakeline with copper.

Posted: Sun Sep 16, 2007 5:18 am
by jackssmirkingrevenge
Ideally if you're making a piston, use the tube you intend to fit it in as a mould, and the same goes for projectiles, use a section of barrel pipe.

Posted: Sun Sep 16, 2007 5:27 am
by spud yeti
Note, I edited my above mistake. Sorry.
I agree that epoxy is nicer for shaping purposes, so perhaps my vote has swung due to JSR's persuasive skills [/sarcasm] :D J/K

Posted: Sun Sep 16, 2007 6:45 am
by trae08
oh and with the marine epoxy any idea which one is the hardener?

Posted: Sun Sep 16, 2007 7:06 am
by jackssmirkingrevenge
usually the one which you have to put less of, what options are you looking at?

Posted: Sun Sep 16, 2007 7:10 am
by trae08
i got one like this except one is white and the other is black. it says put the same of each but i was wondering which one is the hardener

Image

Posted: Sun Sep 16, 2007 7:16 am
by jackssmirkingrevenge
here's the data sheet:

http://www.paintz.co.uk/datasheets/04pc11data.htm

The only issue I can see is that it's a paste, not a liquid, so you might have problems getting it to flow into your mould.

Posted: Sun Sep 16, 2007 7:24 am
by trae08
oh sorry that picture was just an example of the tube it came in. i have a different kind then that tho. mines loctite.


edit: http://www.loctiteproducts.com/products ... 9&plid=473

thats exactly what i have

Posted: Sun Sep 16, 2007 11:35 am
by frankrede
trae08 wrote:oh sorry that picture was just an example of the tube it came in. i have a different kind then that tho. mines loctite.


edit: http://www.loctiteproducts.com/products ... 9&plid=473

thats exactly what i have
Thats still a paste, just different brand

Posted: Sun Sep 16, 2007 11:56 am
by spud yeti
Whilst we on epoxies and pastes vs resins I have this:
I know that epoxy resin works well, but has anybody tried fibreglass resin, or do you think it would work; because it is a load cheaper!
I have used it for my surfboard and a few molds, so I was just wondering.

(sorry for the slight thread hijack, I didnt think this warrented a new thread though)

Posted: Sun Sep 16, 2007 12:34 pm
by jackssmirkingrevenge
spud yeti wrote:I know that epoxy resin works well, but has anybody tried fibreglass resin, or do you think it would work; because it is a load cheaper!
Fibreglass resin is usually epoxy, n'est pas? I don't see why it shouldn't give excellent results.

Posted: Sun Sep 16, 2007 1:48 pm
by spud yeti
Thats really decent because I can get 450mls of it for R45 (about $6) which goes a long way. I think I may experiment with it a bit.