Here are some pics of One and Two part molds for On30 roofs for rolling stock, a flat car and a small log. I am scratch building in 2 scales at moment On30 and S standard gauge.

So far I have Kitbashed 5 box cars(On30) and scratch built 3 cars 2 in S and one in On30(the On30 has had a mold and I have cast hald a dozen of them so far.

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Nice, great work

If you put the molds in a pressure tank when you make a casting, you will eliminate or minimize the bubbles in the castings. Many people use a paint sprayer bucket.

dave1905 Wrote:If you put the molds in a pressure tank when you make a casting, you will eliminate or minimize the bubbles in the castings. Many people use a paint sprayer bucket.

I have also heard that de airing in a vaccume jar does the same thing, they also say a light dusting of talc in the mold also helps bubbles come to the surface and pop.

I am collecting stuff ro make a spincasting machine to help avoid any voids by useing centrifugal force to draw material in to the molds.

I noticed that now several suppliers are selling powders to coat molds with to give the look of metal to the detail surfaces of a casting.

Practice and low viscosity resin help.

Here's a flatcar I cast:



The deck is a separate part from the frame, and is made up of scale 2"x6" boards...which are correct for this car. Some minor air bubbles were present, but I filled them with the trusty super glue and baking soda combination. You can't see them now.

Michael

NKP_174,

Nice work it will be a while to I am that good at it.

What is the mix ratio of super glue to baking soda?

I need to try this... someday!

I've got about 4-6 flat cars I want to make. But I am told for that few it's easier to just scratch them all in an assembly line.

Kevin, I agree with that recommendation. That's not enough to justify the cost and learning curve of resin.

There isn't really a super glue to baking soda ratio. Just fill the void with superglue and then add baking soda to it. Usually, an air bubble leaves at least a thin layer on the surface. I recommend filing flat car decks from the bottom before removing them from the molds to protect the thin surface as the void is filled.

Keep up the good work!

dave1905 Wrote:If you put the molds in a pressure tank when you make a casting, you will eliminate or minimize the bubbles in the castings. Many people use a paint sprayer bucket.

I have heard this a few times now and went looking for a pressure pot and they were kinda expensive however Harbor Freight has a 2 1/2 gallon one on sale for $79.99. At that price I am willing to try it. It beats trying to make a spincasting setup. If I get one will post the results in this thread.

Well I got the pressure tank/paint bucket today and will test it out soon as I can get to it as I am in the middle of a job hunt and have slowed down my hobby pace a bit.

Well here is the lattest casting and molding I have done, still have not setup pressure chamber due to a bad gauge waiting for replacement as the face of gauge was bent up and a loose screw as well rattling around(can you say mfg. defect?). Anyway here is what I have been up to today.

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