today's work

[He Who Shall Not Be Named]

[trout]

Would you elaborate on why the mold is put in the refrigerator?

[He Who Shall Not Be Named]

Would you elaborate on why the mold is put in the refrigerator?

The Plasticine backing clay is too prone to clinging at room temperature and sticks to the RTV flange portion of the tool half. Lowering its temperature permits easy removal from the flange without having to resort to scraping and a lacquer wash to remove sticking clay.

[Subculture]

An article I saw once said that Play-doh was originally a product used for removing coal dust from wallpaper called Kutol. Post WW2 people switched to gas heating, and the market dwindled for Kutol, however the maker recognised that the original product was often used for recreation, and rebranded it as product for play rather than utility.

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[He Who Shall Not Be Named]

[He Who Shall Not Be Named]

[He Who Shall Not Be Named]

[RCENGR]

Fascinating. Do you microwave the mold to warm it up or is that something to do with moisture? I don't see any air vents in the prop mold like I see you make in the resin molds. Are they not necessary or did I just miss them?

[JHapprich]

Hey, David! What type is that new hull you are making?

Jörg

[He Who Shall Not Be Named]

Fascinating. Do you microwave the mold to warm it up or is that something to do with moisture? I don't see any air vents in the prop mold like I see you make in the resin molds. Are they not necessary or did I just miss them?

That's right, I heat the rubber to about 200-degrees F. That way the molten white-metal (95% Tin, 5% Antimony), when poured is more apt to fill all cavities before freezing. This results in a good shot, right out of the gate.

Moisture is delt with by dusting the tools cavities with Talc before tool assembly.

No need for a vent network with these tools. Provided there is sufficient pressure head (tall sprue), the force of the heavy molten metal will momentarily distort the tool flange plane enough to 'burb' out displaced air. Same thing happens in high-pressure injection molding; no need for a vent network there because of the slight tool burping as the molten plastic is injected into the tool.

Some shots to show off metal forming rubber tools, cintrifugal and gravity pour types:

[JHapprich]

This reminds me of a dental technicians workshop! Always fun to have molten metal flying around! Mr.Merriman, how are your arm's doing? Hopefully, only supercicial burns!

[He Who Shall Not Be Named]

Hey, David! What type is that new hull you are making?

Jörg

1/96 Type-21. This should be about the fifth one to date. For me and some buddies.

[JHapprich]

Ah, yes. A fine smaller boat!

[He Who Shall Not Be Named]

This reminds me of a dental technicians workshop! Always fun to have molten metal flying around! Mr.Merriman, how are your arm's doing? Hopefully, only supercicial burns!

I got the occasional burn. But nothing to write home about.

About 20 years ago, Ellie got the big prize for metal burns:

While spin casting some metal, the tool unseated during the pour and slung molten metal in a disc pattern, hitting everything at that height in the shop. Ellie was about ten feet away and got some of that spread right at tit level.

She was not amused!



A trooper. I had her back on that machine in no time.

David