just had a quick question, i know some of you guys do this, what can i use for a mold release,cant seem to find any around here at the hobby stores, thanks
I use Stoners urethane mold release. I believe that there are different releases for different mold materials. They say silicone does not need it (esp. the higher end silicones), but if it will extend the life of the mold, I would use it. Try www.alumilite.com - email them for a price list. There are several places that sell it that are closely priced. The stoner site is high IIRC.
I was picking up some 1Shot in **** Blick Art Supply about 2 hours ago, they have a good selection of casting materials. Hobby Lobby does too. From what I understand, you can use vegetable oil or baby oil as a release (don't take my word for it).
what are you trying to replicate? How many do you want to make? Will you offset some of the costs by selling some repro's? The moldmaking materials are not cheap at all. The bulk stuff from the link I posted is cheaper per unit weight. Yuo'd be surprised at how much you'll need. You need to calculate the volume of your piece plus a min of .5 inch all around. Look at the link I posted and they have some info there.
Use silicone molds and you will never need a release agent. If you are using a rigid mold that is coated with tooling gelcoat then all you need is a good Carnuba wax finish on it. Coat the mold with the paste wax, let it haze over, polish with a clean soft cloth...repeat three times.
just messing around with a couple hood ornaments and shift knobs, 3 dimensional, ive done some metal casting but never this resin stuff, can you sand this stuff to? and then maybe polish it?
Wet sand it then use a plastic polish. An antstatic polish is best. If your using a buffer be careful you can burn it with the friction. pogo
anyone ever do a tech on this, i got most everything i need, just trying how to do a seamless 3d mold, im a visual person, need pics
wes, next tech week I'll try to put something together. After searching the net for hours, this is the best one that I found for pics and descriptions for resin mold-making: www.danperezstudios.com/workshoppages/molding_casting.htm BTW, I know that you don't need mold release for silicone molds, but in the molds I made with some long bolt holes, it made it MUCH easier to extract the casting from the mold vs. no release or baby powder (and I'm sure it will extend the life of the mold). Hope this helps! Also, the alumilite resin is machineable. Again, check their site and forum, as it has lots of information!!
i went to the **** blick here in town today, they ****! michaels had more than they did,im gonna order a catalog. So i started messing around last night, i found about 20 old lightbulbs that are perfectly round, thought i would try that to give me a seamless round shift knob. I scored the part of the lightbulb that screws in and broke it off, leavingme with a seamless orb with a hole to pour the resin in, I tried mixing some flake into the resin, then poured into the gl*** bulb, this morning, the resin inside had shrank ust enough to pull away from the bulb so all i did was break the bulb and i have a nice round sphere. Except the are what i guess i would refer to as Wrinkles in the casting, the bottom came out pretty smooth, but the top has weird wrinkles, what am i doing wrong here, probably not using the rigth stuff dosnt help, but i thought i would give it a try. I can sand it smooth, but then ill ruin the flake, so i guess ill just paint this one and clear it. But i would like to suspend some flake inside the resin. Any tips for this? It seems to all fall to the bottom, maybe let it set up more before i pour it into the mold?
wes, the wrinkles are where the resin has a free surface, at the top right? Is this the clear stuff? If so, to get it bubblefree, you may have to cast it under vacuum. To get the flake to stay suspended, you should experiment with the pot life of the resin (the time it takes for it to start to change to a solid or thereabouts) and wait as long as possible before pouring. Depending on where the wrinkles are, you can wet sand the stuff and buff it out, just don't get it too hot. Did you see the alumilite site? Again, I would recommend to read all you can to help yourself out here. Secondly, there is a forum there that is monitored daily, so your questions will reach those that deal with resin as their job. edit: should have said vacuum instead of positive pressure.
PVA works real good. It's a water based solvent you spray on your mold surface. It dries sort of similar to a thin layer of plastic food wrap. We buff the mold with hight temp. mold-release wax (we use high-temp because fibergl*** resin gets REALLY HOT when it starts to kick), then spray the PVA. The PVA generally sticks on the finished peice once the mold is released. Then you just spray it water and the PVA disolves. It has greenish tint so you can see it. I have been involved in popping some nostalgia funny car bodies, currently we've used this process very effectivley 5 times. LOOK! http://www.ww2racing.com/smith-sattelite.html We've had a few spots that had "wrinkles". We suspected the we had to much hardener in the resin for that peticular ambient temperature. A little less hardener, and the next body was fine.
i got a little tip for you for getting the bubbles out when you pour resin. pro resin casting is done with vacuum to get all the air out of the mold, i made a cheap way of doing this when casting small parts. you need to get yourself a wine pump (a small hand pump for vacuuming air out of a open wine bottle) and a plastic soda bottle. take the plastic bottle and cut the bottom off as straight as possible, then when you pour the resin into the mold, put the bottle over top (of the mold) and seal the open end of the bottle to your work surface (duct tape works good for this) so now your mold is inside the bottle. the wine pump comes in 2 pieces: the pump and the bottle cap, put cap on the top of the plastic bottle, then put the pump on the cap and pump away untill you see no more air bubbles coming up through the resin. This sounds pretty odd but it works.
I tried doing one today and sat it on my drier while running and it looks like its pretty bubble free, il ;let ya know about the wrinkles once it cures.
another variation of the Washing Machine Boogie I've never been in Michael's, I'll have to check it out. **** Blick has what I need usually, but I'm mostly buying paint and brushes.
i was really bummed out about blick, the catalog has everything, but i went into the store which is huge, and all they had was the clear resin. My girlfriend toldme michaels had, they also have the modl making materials and the dyes to tint it.
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