Quick cheap resin casting?

[jcbigpaw]

I am missing one wheel and tire for a pending project. I remember seeing an article many years ago that showed how to do an easy resin copy using (I think) black silicon and 5 minute epoxy or something like that. I just need to copy one part once in a great while so don't want to invest $50 in resin casting materials that are just gonna sit and go bad. Anyone have any ideas? I appreciate your help as always

[Casey]

Are both the wheel and tire so obscure that making a copy of each is your best option?

[Ace-Garageguy]

google "silicone caulk mold making". Five minute epoxy thickened with talcum powder will work for your part, as will JB Weld in some cases. Complete mold-filling and air bubbles whipped into the epoxy while mixing can be tricky problems.

[jcbigpaw]

I can either track down another wheel or use something else if need be. I was just curious because this was in the back of my mind. I do wish I could copy a part once in a while but not often enough to make the investment. I may just take the dive and step up to duplicating my favorite engines etc. lol

Edited August 17, 2012 by jcbigpaw

[Casey]

It's really not that expensive to be honest. For around $100.00 you can have everything you need to make parts, provided they are smaller things like wheels, engine halves, etc. You can buy mold rubber which sets in a few hours, and you can be casting later that day if you're in a hurry.

I have seen articles in SAE long ago which used silicone caulk as a mold to copy nameplates/emblems and to repair a broken A-pillar.

[Danno]

Uhhhh ... don't forget or overlook the series of articles Gregg Hutchings {you've heard of him, right?} has been presenting in the past several issues of Model Cars Magazine {you've heard of that, haven't you?} with Art Anderson's encyclopedic knowledge and consultation.

Very informative and extremely helpful, the series provides just about everything one needs to launch a whole new skill set ~ resin casting.

Resin casting of small parts is not that difficult. The hardest part is learning the basic steps ... and Gregg's articles lay it all out.

[Steven Zimmerman]

You can get everything you need from Hobby lobby for about 45 bucks. If you take a friend, and you both use a 40% off coupon, you can drop that to about 28 bucks,that's resin, hardener, mold making material, and mold kicker. Doesn't get much cheaper than that !

[Art Anderson]

I actually made my very first silicone RTV molds from Silicone II sealer. Used 30-minute epoxy to make a set of wheels and tires for a USAC Offy dirt car. it worked very well (1984) even though it took some time to figure out exactly how to make open face molds that would sit flat. As for the air bubbles that got stirred into the epoxy, I learned from a friend, that the CO2 in my breath would pull them to to the surface, so I simply breathed out across the top of the still-liquid epoxy glue, and it worked!

Art

[Ace-Garageguy]

I actually made my very first silicone RTV molds from Silicone II sealer. Used 30-minute epoxy to make a set of wheels and tires for a USAC Offy dirt car. it worked very well (1984) even though it took some time to figure out exactly how to make open face molds that would sit flat. As for the air bubbles that got stirred into the epoxy, I learned from a friend, that the CO2 in my breath would pull them to to the surface, so I simply breathed out across the top of the still-liquid epoxy glue, and it worked!

Art

That's the best tip I've heard all year.....going to try that this weekend, and THANKS !!!

[jcbigpaw]

That sounds Ike what I remembered Art and the time frame is right too. Did you do a tech article back then? Lol

[MoparWoman Jamie]

I always used engine silicone to make small parts, it's about $6.00 in stores. I just brushed on some vasoline ($1.00 at dollar store) on the part I need to make a copy of and then I just put the engine silicon on the part easy and made sure it was covering one side, if it was a two side mold, I would just cover the part in the engine silicon and then stand that whole thing up on one side and then later cut the resin vent and breather hole in the top of the cast after I had cut the mold half way down the middle and got the part back out. Best thing about engine silicon is that you don't need to use any release agent on the cast before you do a copy of the part with the resin. Engine silicon doesn't hold the resin or bond to it like the other mold casting stuff does.

[tsroark]

I have had good luck with cheap silicon caulk mixed with a little corn starch and glycerin for larger casts. You can also add a couple drops of acrylic paint in place of glycerin. The corn starch and glycerin help distribute moisture through the caulk so the entire lump dries, and you end up with a 100% cure no gooey center. Don't use to much additive or detail will suffer. You can get a small kit of resin for about $12 from hobby lobby with a 40% coupon.

[tedd60]

For those who use this,  can this type of silicone mold making  (cheap silicon caulk mixed with a little corn starch and glycerin) be used to make 2 piece molds?

 

Thanks