Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Model & Toy Steam Engines – Stirling Cycle – Flame Lickers – Small Antique Originals => Topic started by: Jim on July 30, 2025, 10:09:59 pm
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Bohm got back to me -
Hello,
we use 1.4305 Stainlesssteel,
Chemical X10CrNiS18-9,
Corrosion resistance Medium
Not resistant to intergranular corrosion
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The oldest Bohm I have is about 28 yo, no rust. I use 95% alcohol in the burner. Possible cause might be if a higher water content in the fuel combined with the heat would aid in forming rust.
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Didn't know that Bohm's heat caps were Stainless. But there is Stainless and there is Stain Less, depending on the alloy used. Check it with a magnet, as I know for marine rigging, Stainless wire-rope that will attract a magnet is considered to be very inferior at corrosion resistance!
A magnet is not interested in it.
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Didn't know that Bohm's heat caps were Stainless. But there is Stainless and there is Stain Less, depending on the alloy used. Check it with a magnet, as I know for marine rigging, Stainless wire-rope that will attract a magnet is considered to be very inferior at corrosion resistance!
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I just sent an email to Bohm with the photos, be interested (if they ever answer me) to see what they say.
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Scorched steel makes it easier to oxidize ..... and you live right near the ocean in a salt air environment.
Even here in the high and dry of the intermountain desert I find a thin layer of fine rust on the heat caps of some of my Solar Engines and PM Research Stirling Cycle Engines!
My PMR's all will get some surface rust if I don't oil the end caps after running them, but they are carbon steel.
The Bohm end cap is stainless, I've seen a slight rust stain even on 316 stainless in marine settings, but that's a fair bit of rust on that end cap.
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Scorched steel makes it easier to oxidize ..... and you live right near the ocean in a salt air environment.
Even here in the high and dry of the intermountain desert I find a thin layer of fine rust on the heat caps of some of my Solar Engines and PM Research Stirling Cycle Engines!
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Anyone else every noticed rust on the heater cap of their Bohm engines?
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