Thread unlocking chemical
 

Does anyone remember the name of the product used to release the cores on tuning components. I’m working on a Trio 9R and they are covered in what looks like white paint. I have tried heat, acetone and IPA but none appear to soften it. I have had N-heptane recommended but I don’t think it’s available in the small quantities.

I remember back in the day RS components used to make a product. I think it was like paint stripper but I cannot find it or remember the name of it.

Any recommendations

Thanks regards Chris

Re: Thread unlocking chemical
 

Cellulose thinner will dissolve cellulose/acrylic based paints etc, repeated dabbing with a cotton bud dipped in the cellulose thinner will soften/dissolve it.

poppydog

Re: Thread unlocking chemical
 

That’s a good idea Poppydog

I didn’t try that and have some in the garage.

Thanks regards Chris

Re: Thread unlocking chemical
 

Wickes paint and varnish remover, which I think is based on benzyl alcohol and is totally wonderful.

B

Re: Thread unlocking chemical
 

I’m fairly Sure the stuff I bought years ago smelled like paint stripper and cost 10 x the price for a tiny bottle

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Of course, paint stripper these days "ain't what it used to be"!

Re: Thread unlocking chemical
 

Which is a very good thing, and we should all be very pleased that is the case.

Of course, asbestos, cadmium, carbon tet and benzene ain't what they used to be. Which is to say, in common use causing serious health problems, very often to lowly paid workers, and killing off just about anything that had lived in the rivers and canals. Gee, those were the days ;)

B

Re: Thread unlocking chemical
 

Absolutely agree 100%.

Steve.

Re: Thread unlocking chemical
 

So all we need now is to find something that does none of those bad things and actually works at its intended purpose.

The agents we used to use have gone away, but the need hasn't.

David

Re: Thread unlocking chemical
 

Probably dichloromethane (methylene chloride) then. Toxic in multiple ways, environmentally unfriendly and banned in consumer-grade paint strippers since 2010, but useful when suitable control measures are in place.

Re: Thread unlocking chemical
 

Dichloromethane was used in refrigeration many decades ago.
I still have a tin of Radiospares carbon tet in my outside workshop!

Back to original request.
For unseizing or dissolving or removing anything when cleaning or dismantling, my usual army of ipa, nail varnish remover, meths, lighter fluid, Humbrol liquid poly, liquid acid flux and heat ( to name a few!) is at hand as my usual go to.
I have a part tin of what upvc installer gave me, as used for cleaning up. That is handy.
Rob

Re: Thread unlocking chemical
 

Thanks for all the replies. I have been speaking to a few people on here regarding my Trio 9R and nobody has reported issues with stuck cores I must just be lucky! They are all solid in the coil box even the capacitors. The mechanical filters have no issues. It maybe it doesn’t require alignment but I would like to find out etc.

Thanks regards Chris

Re: Thread unlocking chemical
 

Nope, plain old chloromethane.

Re: Thread unlocking chemical
 

Yes, Merlin. Chloromethane (Methyl Chloride) was used in very old domestic refrigerators back then.
That is the one that I was thinking of! No "Di"
Dichloromethane is also a refrigerant, R30, (Freon 30) and my confusion may be due to this being used in water chillers many years ago when my dad worked on refrigeration in a dairy at Leicester.
Rob

Re: Thread unlocking chemical
 

In order of desperation, left to right,
Attachment 204486
Based on my own perception and not any knowledge of chemistry. Please feel free to educate me, particularly on the relative merits of ethyl acetate vs acetone nail products in the workshop.

Re: Thread unlocking chemical
 

Studying the pictures in first post, I would be tempted to try a hot soldering iron tip as close to the paint as you can get. I don't know how much heat you already tried or whether a hot air gun or soldering iron tip?
Then, if it were MINE i would try more force on the screwdriver!
Whether you test a coil or trimmer first, I would go for a trimmer as more readily obtainable. Breaking the slot on a coil screw will be more troublesome.
You say "maybe it doesn’t require alignment but I would like to find out etc. "
It looks so nice and tidy, I would see if it really needs alignment?
Rob

Re: Thread unlocking chemical
 

THere is always something which will remove any locking compound on a coil slug. The critical part is finding something which will not ruin the coil former.

If all the safe agents have been ruled out, then you're going to have to find a replacement coil assembly, or at least a former and slug you can rewind as a replica.

Moral: Never throw away coils and IFTs, you never know when you're going to need parts of it.

David

Re: Thread unlocking chemical
 

You can always search Google for data on solvent properties as based on the "Kauri Butanol" scale (KB), for example this paper https://cool.culturalheritage.org/by...r/solpar3.html shows that xylene and toluene have high KB numbers, but it does not include the solvents you ask about. If you find a table or graph showing our usual suspects, please post it.

The downside of comparisons like KB tables, is that there is a "horses for courses" element to this; what softens/dissolves one material very well make not be so good for everything.

B

Re: Thread unlocking chemical
 

I did try heat from a soldering iron. Short answer I snapped out one side of the screw driver slot. Lesson learned!

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I used have some upvc cleaner from the same source. I think it is methylethylketone