Resin

Most people just buy the casting resin. Never heard of anyone making their own from a bunch of chemicals.

Dave

Resin is obtained as a two part liquid, which when mixed is catalyzed to form a solid. Different compositions are available with different pot lives. You also have to ensure that large air bubbles are not trapped in the resin when pouring (hence vent channels in the mold). You also have to decide what material (rubber is usual) that you will make the mold from. There have been several articles on making and casting small parts in resin in FSM. Resin can be obtained from several sources; e.g., MicroMark. Tom Dougherty ( snipped-for-privacy@aol.com)

Hello Dave. You can buy a kit of casting resin at many larger hobby and craft stores. It's a 2-part system and the kit contains a bottle of each liquid along with some small plastic measuring / mixing cups and some wooden mixing sticks. I haven't bought any in a couple years but as I remember, it's not too terribly expensive.

The important thing is to follow directions for mixing the two parts exactly. If you add too much of one of the parts, it hardens so fast you don't have time to get the air bubbles out of the mixture. If you mix too much of the other, it may not completely harden at all (I've "been there-done that" on both accounts).

Normally, you take the master (the part you want to copy) and cast up a mold using RTV - RTV is a rubber that is also a 2-part compound of the rubber and a hardener. The mold-making process, itself, can be either simple or complex. For some parts, a simple 1-piece mold will work fine. For other, complicated shape pieces, a 2- (or even more) part mold may be required in order to remove the finished piece without destroying it in the process.

Once you've poured the mixed resin into the RTV mold, it takes a relatively short amount of time to harden; during which time you have to try to remove any air bubbles that are trapped in the liquid resin. Some smaller pieces will harden in a matter of seconds while larger pieces will take longer. You can tell when it's hardened by the change in color of the resin from a rather transparent to an opaque.

Bottom line is; the actual casting process it quite simple but the TECHNIQUES of planning and making the mold, correctly mixing the 2-part resin and RTV compounds, removing air bubbles, etc, can take some time to master. I would suggest you try to get a book or two from your local library on the subject and get "schooled up" on the subject before actually trying it. Then, start with something small and simple to practice on and develop your technique before tackling anything more complicated.

Good luck with your casting project.

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One of the better casting resins is available from Vagabond:

Their "website" is not that helpful, but it does provide contact information. They will send you rates for different quantities of two-part resins. I have found their products to be much more superior to Alumilite or the Synair resins. Like all resins, however, they do have a shelf life and react unfavorably to humid conditions (like getting humid air back into the resin containers).

Lee

in article snipped-for-privacy@posting.google.com, Dave Hall at snipped-for-privacy@hotmail.com wrote on 7/10/04 4:39 AM: