Resin for patterns

[pkastagehand]

I remember reading about casting resins for making multiples of a pattern. For example, if I make a wood pattern for a locomotive wheel. But instead of putting one wheel on a match board, ramming it up 6 times and consequently 6 pores when I want 6 of them or making 6 wood patterns, I've seen where one can make a negative of the pattern then cast multiple positives from it using resins with little or no shrinkage, mount those on a match plate or whatever it's called, gate them, etc. and get 6 wheels in one pore.

I can't find names for those products either for the positive or for making the mold for the negative. And sources for same. So far my searches have been a lot of general casting/foundry supplies that are not what I am looking for.

Any ideas?

Paul

 

[Tin Falcon]

take a look at smooth on plastics.

Smooth-On Casting Supplies

These guys have a huge product line for just about any application you can cast a replica of something or someone even your wife or girlfriend.
Tin

 

[canadianhorsepower]

I can't find names for those products either for the positive or for making the mold for the negative.
Paul

Hi Paul

You can make your mold with any material you want. The material
you will use will only change the life of your mold, after a few pore
you're mold could be ruined.

The best thing is to use balsa wood for the original wold, easy to work with and cheap. Spray A LOT of sealer and mold release agent and leave space for
air vent. Then pore your fiberglass This will become your mold master. Polish it to the best you can and use mold release wax. then when you did your final
multiple wheel mold use a lot of PVR mold release wax and keep your temperature to 70 F as close as possible. Any higher or lower temp no one can tel what the reaction will be
good luck

 

[aonemarine]

Go to YouTube.com and look up trainman4602. He has a video showing how to do this....

 

[pkastagehand]

Go to YouTube.com and look up trainman4602. He has a video showing how to do this....

Thanks everyone for ideas. Now that I see this response I'm thinking I know where I originally saw info about this process. I know the site trainman haunts at times...or one of them. So many forums, so little time to read.

Paul

 

[fltenwheeler]

BCC Products

BC8002 is what trainman4602 and I use.

Tim

 

[littlelocos]

I've used two different combinations of materials with differing results

Favorite: Freeman 1035 / Freeman Repro One
Also Used: Smooth-On PMC-744 and Smooth-On Task 18

The Freeman materials have a lower viscosity and don't have a tendancy to form and collect bubbles on the surface of the model; however the Repro-One is TOUGH on tools if you mill or drill it.

The Smooth-On materials are thicker and I had trouble with bubbles on the surface of the wood models. The Task-15 is aluminum-filled and machinable, but is quite thick compared to the Repro. It also forms bubbles. It also takes overnight to set up. Repro sets up in under 2 hours.

Some of the bubbling issues could be corrected by vacuum degassing, but I don't have the equipment for that.

In both cases, I have used Smooth-On Super Seal as a first coat and sealer on the wood model and wood molding frame and then applied Smooth-On Universal Mold Release.

For better finish over wood, clear lacquer such as Freeman Foundry Kote gives a smoother finish.

I use Foundry Kote to finish the matchplates as well.

Processes for my Essex Caloric and Parsell & Weed patterns are logged at
www.facebook.com/littlelocos


Hoping this is a help to you,
Todd.

Littlelocos Model Engineering
www.littlelocos.com

 

[pkastagehand]

I'm planning for a future gage 1 locomotive build and want to replicate a wheel pattern once decided on. All good information from those of you who have done it already.

Paul