what is the pattern mold made of ? painted wood? If I made a pattern mold like this, would you be interested in doing the rough casting part? If so PM me some $ details. Then if you liked it you could keep it and produce em for your own profit.
It's funny you mention this... I've been tossing around the very same idea, I actually even wrote up a rough draft of a post for the "Online and local shops" section
I was going to wait until I got some more projects done so I can show more examples of my work before posting it, but if you or anyone else would be interested in a "casting service", I'd be all for it... I'll be getting into aluminum here shortly too, I've got some finned engine covers next on the list.
To answer your questions :
Yes, patterns are generally made of wood, though other things can be used (clay, machinable wax, etc.) For this pattern in particular, I used 1/8" hardboard (used mainly for cabinet backs ) for the emblem part, regular 2x4 construction lumber ripped down for the splash well and runner, and 3/4" mdf (medium density fiber board) for the backing board. Most everything was covered with a couple coats of automotive sand-able primer , wet sanded, top coated with 2 coats of clear enamel, then wet sanded again with 1500 grit paper to leave a very smooth finish.
As far as using a pattern made by someone else goes, I am not opposed to the idea, but I could see some potential problems with it...
You may already know this, but just in case you don't, and for the benefit of others that may not, there are many things to consider when making a pattern; first and foremost, it must be able to be pulled cleanly from the sand. A pattern must have a very smooth and even finish, it needs to have draft as well (usually at least a 3-5* angle). You can see in my mold photo that some of the sand broke away from the edge of the pattern, this is because my pattern has no draft on the outside edges. I did ease the edges a bit and I thought that by being only 1/8" thick I could get away with zero draft... not entirely. I lucked out
this time and am able to get these to pull well enough to end up with a decent casting. Other things to take into consideration are runner and gate size, gate placement, shrinkage of the metal upon cooling and ways to combat it, etc.
All that said... yes, if you could provide me a good pattern to work with, I could definitely mold it and pour it for you. For a one-off piece, the runner and gates can be hand cut in the sand, I can work that out on my end with no trouble. I made the pattern pictured here the way I did because I will use it over and over again. The incorporated back plate, splash well, runner, and gates are just to speed up the molding process, they are not absolutely necessary.
As far as what I would have to charge for a "contracted" casting job, it would depend on a number of things, but mainly time and materials. The castings I'm offering here for example take about $10 worth of materials start to finish and 4 - 4.5 hours to mold, cast, shake out, and get the edges cleaned up enough to start doing the final sanding on the entire piece. If you could provide a good pattern that I think I could sell duplicates of, I could definitely cut you a deal on time and materials.... there's all kinds of variables/possibilities.
Anyway, if you (or anyone else here) wants something custom cast, give me as much info about the piece(s) as possible, and I can give you a much better idea of what it might cost.
Jesse
