timjs

Can anyone tell me exactly what this material is? I'd like to get some bar stock of it and just make my own insulators from now on. Thanks

Roelof

Teflon or also called PTFE is a material that can withstand high temperatures and is also a good temperature isolator.
It is only bad to glue

timjs

I have some PTFE bar stock and that was my plan first, but at this wall thickness, it doesnt have any strength. (thinking about the pinch bolt)
Whatever material the original parts are made of, is nice and stiff even at such a thin wall thickness.
Any idea what it is?

andreas78

From the looks it could be PEI, Polyetherimid, or PSU (Polysulfon), both are a bit translucent. It's probably hard to get those. PEEK might be a bit easier to get. At least in Germany it is, don't know how the situation is in the US.

Andreas

Roelof

Probably you have the white stuff? That is the softest of them all. The black one is harder.

timjs

Looks like you're correct, it's probably one of those two. They look very similar to the part.
I only have white, but come to think of it I also have acetal which might work.

andreas78

Keep us posted about your findings, I just bought a new insulator, but I'm interested in this topic, too.
Andreas

timjs

Thanks for reminding me.
We'll find out soon enough.

stephen_bess

Replacement OS insulators are cheap, and they shouldn’t need replacing except when they’ve gotten old and/or were messed with a lot from frequent carb changes or adjustments. DIY is always fun tho.

timjs

All my stuff is old, man! They're all crumbling.

Also I tried ordering the insulator for my 11K carb three times from 3 different vendors. Each of them said "in stock" but eventually refunded the order after a few weeks, and blamed Horizon for poor inventory management... I don't know. I ended up waiting 3 months then ordering again, and that time one showed up.
Then I got the idea to make my own.

I did receive the plastics by the way. Theyre very similar materials, and likely either would work fine. Would be trivial to whip up some insulators in the lathe when I need to. Judging just by color alone, it appears the stock part is made from polysulfone.

andreas78

Nice! I had the same experience here in Europe (Germany), these insulators are often sold out, but eventually I found one lately.
For the installation, OS states to use epoxy to glue it to the carb. I am lucky to have some special epoxy at home which is used for gluing strain gauges, which are made from Polyimid (Kapton). It is very thin, like CA, but seems to do the job quite well.

Andi

timjs

Cool beans. I usually don't glue mine, I find they're a very tight fit, basically an interference fit and the plastic stretches over the carb. Maybe some are more loose and I'd probably end up gluing them like the instructions say. When I go to make my own, I'll shoot for that interference fit, though.

I paid about 20 bucks (USD) for that one insulator in the picture. I could make my own for about a dollar each now, so that's neat. I'll probably never ever need that many though!