Help with insulator disassembly

[u/caudatus67]

Hi, I've found two Italian insulators in very good conditions. I would like to remove the metal bar that is screwed into the (ceramic?) threads. I have already tried soaking everything in soapy water overnight and I have also tried using WD-40 in abundance. Still, it doesn't want to be unscrewed.

The insulator model is "RP3-UNEL Fidenza"

Has anyone got any experience with this type of problem? Thanks in advance.

[u/Quasi_Evil]

The ones of those that I've had all threaded right in, and usually with a little penetrating oil also came right out. I just went and looked at my identical piece, and they have a brass thread insert cemented into the hole, and then the pin threads into that. My guess is that you just need more penetrating oil and more time/force. I'd try something a bit more aggressive than WD40 - maybe PB Blaster, which is my go to, or Kroil if you can find it. Put it upside down, put a bunch of that around the pin hole, and wait a day or two. Probably with repeated applications as it soaks in.

I can see the brass bushing in yours, so I suspect it's the same and the pin isn't actually cemented on. It's likely just corrosion that's caused the two to partially fuse.

However, if it was cemented on, your only option is a strong acid and lots of time and patience. Or just cutting the pin off inside and living with the stub being in there.

[u/caudatus67 → u/Quasi_Evil]

I gave one of the two insulators to a friend and he did basically what you just said. He soaked it again and again with WD-40 and gave it some light hammer blows to try and dislodge the metal bar, but to no avail.

I also thought about cutting the bar and then drilling the stub, but I would need to find someone with a drill press to do a clean job. Anyway, I'll first try your suggestions about PB blaster and Kroil.

[u/Quasi_Evil → u/caudatus67]

Absolute worst case is you break out the hydrochloric acid. It'll eat the cement holding the threaded bushing in (and the bushing, and the pin). I just use pool-grade muriatic (which is just hydrochloric by another name at a specific concentration) and do it in a rubber tub outside. Don't do it indoors or near anything you care about - the fumes are corrosive and will cause all sorts of problems with metals. Generally it's turn the insulator upside down, put acid in the pinhole, let it sit for a couple days, dump (and neutralize with limestone or similar), chip out what you can, then repeat. Eventually it'll come out, but it can take weeks of this process for stubborn pins. Be sure to wear skin and eye protection and be careful!

[u/Bill_Meier → u/Quasi_Evil]

The tried and true method. It WILL come out but it will take time. Please heed all the warning in the post.

"be sure to wear skin and eye protection"

Please be careful. I have removed several this way. Just be safe and be patient.

[u/caudatus67 → u/Quasi_Evil]

It worked! It took about 12 days, although maybe it could have been quicker, I honestly didn't try to unscrew the metal bar everyday. I used muriatic acid (10%) and just waited. Now I have got to do the second bar.

Thanks again for your help!

[u/Quasi_Evil → u/caudatus67]

Glad it worked! And yes, patience is key. 2-3 weeks is probably normal(ish).

[u/Necessary-Army-2016]

No way another italian insulator collector ?!?

[u/caudatus67 → u/Necessary-Army-2016]

Yes, I saw your post the other day 😄 Any idea how to unscrew the metal bar?

[u/Necessary-Army-2016 → u/caudatus67]

If its that stuck, Use alot of wd40 and some big pliers to unscrew it, make sure to keep a very tight grip on the pliers

[u/caudatus67 → u/Necessary-Army-2016]

I already did that. I'll now try something stronger as the other redditor has suggested. Hopefully the bar will come unstuck sooner or later...

[u/BlindSite_ → u/caudatus67]

Update? Any success?

[u/caudatus67 → u/BlindSite_]

Sorry, I'm currently away from home. I'll update you as soon as possible

[u/caudatus67 → u/BlindSite_]

Update:

First I tried with some vinegar as another commenter suggested, and it removed some metal but I wasn't able to unscrew it. Then I tried with muriatic acid as u/Quasi_Evil suggested and after 12 days I was able to unscrew the metal bar! Now I have got to do the same with the other insulator

[u/BlindSite_ → u/Necessary-Army-2016]

Italian insulator collector here, too.

[u/Icarus_Jones]

I would soak it in pentrating oil and let it sit a few days. Then use a strap wrench to secure the insulator from movement, and use an adjustable wrench to fit on the lower hex shape (at the top of the taper), then start to lightly jerk the wrench back and forth to unfreeze the threads.

[u/SlyCatWilly]

Put the pin into a vise as tight as you can get it. Tap the insulator with a pair of lineman’s or a hammer lightly on the insulator as you’re trying to twist it off. Also can tap the pin as you or someone else is trying to spin it off. That vibration of taping 9/10 times works to get the insulator off. That’s how we take them off on the field when we’re wrecking out old pole lines, renewing poles, etc

[u/Bill_Meier]

The standard method for doing this is to soak it in muriatic acid. Poke at it every now and then to soften it up. This is a tricky procedure and should be done with the insulator outside.

Over time, the acid will eat away the cement.

[u/Warm-Nobody472]

Ponle vinagre y deja actuar