Heat-resistant epoxy and similar materials (for a tube adapter)?

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Hah, beat me to it. Not for the transmission tube level radiated heat, but great for simple DIY repair. Indispensable in my garden machine workshop for threaded heads, bearing castings &c.
 
Ah yes, German steel distracted me. So no conductivity, what about the insulators used when the steel was affordable, are they no longer functional? If not,machined metal with neoprene gaskets should suffice?
 
@k brown I was just responding in a lighthearted manner to your comment about not using conductive epoxy (eg the stuff for wood should be safe). Sorry if I wasn't clear :)

Edit: that stuff might be a practical option for filling in a tight space that needs some shielding, though! Obviously when there's no chance of ever needing to get back in there. I need to get a fresh batch (of the original) and when I do I'll mix some up and measure the conductivity.
 
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Let me briefly summarise my experiences.

For an adapter project like the one I did here (rather "cold" preamp tube on a gutted tube base), a substance that is quite liquid and hardens strongly is ideal. It shouldn't be too liquid either, which would otherwise complicate mould making. The hot glue is ideal, the temperature stability is more than sufficient for this tube, absolutely no problem.

I will build two more adapters, for which I will look for a suitable plastic (or metal?) tube that will serve as a mould and "cladding" at the same time. This will reduce the amount of post-processing work enormously and significantly improve the look.

Another project could be an adapter with a built-in load resistor to replace a very rare tube for microphones 😎 . But you definitely need heat-resistant fill material for this, hot glue is absolutely not suitable for this kind of experiment. .

Stay tuned!
 
I will build two more adapters, for which I will look for a suitable plastic (or metal?) tube that will serve as a mould and "cladding" at the same time. This will reduce the amount of post-processing work enormously and significantly improve the look.

Forgive me if I missed any reasons why not (I often do!), but could you just use an octal tube base?
 
Forgive me if I missed any reasons why not (I often do!), but could you just use an octal tube base?
These octal tube bases are great, I also have some, ideal for building adapters!

The problem is, German steel tubes also have 8pins but a different layout, hence my DIY version. (Edit: They are rarer and, as far as I know, are no longer produced)

https://www.tubecollection.de/ura/stahlroehren_d.htm

also check this thread:

https://groupdiy.com/threads/diy-adapter-to-compare-modern-tubes-with-the-ef12k.85883/

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Urethane potting compound like MG 8800 would work I guess?
Or any other urethane casting resin, possibly less heat tolerant. Comes in a range of colours so you could colour the "ultimate series" red and the recycled green? :cool: ;)
Viel Spaß!
Thank you!
MG8800 also looks good. I think there is now something for every need in this thread.(y)

The idea with the colors is actually very good:cool:, I bought some glue sticks at LIDL this week (they were on sale), including different colors and properties. The next one will be red, for a 1620/6J7 to EF12k adapter, very stylish...they also had some with glitter flakes in them, but they were the only ones I didn't buy.😅
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I am such a Parkside fanboy! 😬 That's what happens when you live very close to LIDL. They should sponsor me!
 
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Hi guys, really good German steel tubes are slowly becoming unaffordable. That's why I've been experimenting with DIY tube adapters for some time now, which works pretty well.

View attachment 135918

My question is, which material is suitable for electrically insulating my adapters? A little more mechanical stability would be another goal, although the basic construction is already surprisingly stable.

What would you use to mould the base adapter? Epoxy? Or is there perhaps even a material for the hot glue gun that can do the job?
this probably sounds insane, but i would use a thick solvent silicone, like a thick caulk for this. not joking. i've done it before, and it works shockingly well. i used sil-bond 4500. an evaporative caulk is ideal for this, since there is no melting temperature, since it's not a thermoplastic. as soon as it sets hard, it can easily take hundreds of degrees.
 
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There are a ton of "silicone stuff in a squeeze tube". From experience, if it really stinks....maybe like vinegar....those fumes will totally corrode switch and connector contacts.

Bri
Yes! It Depends on material compatibility with the solvent. You need to check that and select the silicone with the appropriate solvent
 
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