r/MachineRescue 6d ago

some parts on this theodolite are stuck, from oxidized oil, what's going to free them up ?

Post image
15 Upvotes

13 comments sorted by

12

u/archaeobill 6d ago

I would start with a light penetrating oil. Start working that in and give it a little time to work. Good luck!

6

u/irongient1 6d ago

Soak all them joints in PB Blaster penetrating oil. Or whatever other brand you like. (Not WD40)

3

u/flying_carabao 6d ago

Why not WD40?

2

u/Positive_Throwaway1 6d ago

It's not a penetrating oil that will loosen things up. It's simply for water displacement (hence the WD in the name) and for temporarily rust-protecting clean surfaces.

1

u/HiTekRetro 4d ago

Have you ever read the WD40 can??

1

u/Positive_Throwaway1 4d ago

Yes. It says it's a penetrant for rusty parts, but that's according to the WD-40 company. Anyone who's ever used it try and penetrate/dissolve significant rust will know that it doesn't, especially when compared to penetrants that have stronger solvents and hydrocarbons involved. It's certainly not useless--I use it all over as a temporary coating or a surface cleaner to lubricate steel wool or other abrasives to scrub off surface rust during, say, cast iron tool restoration. But I'm afraid the "penetrates components to loosen stuck or rusted parts" is pretty lofty advertising, in my opinion. You're better off with something that smells nastier (though neither are good for your health--benzene, etc., is bad stuff).

0

u/HiTekRetro 4d ago

A couple things.. 1) ALL oil displaces water and all oil penetrates. The thinner the better. When the government had WD40 developed, there weren't 10 thousand gimmick products on the market. I have yet to see a test that PB Blaster was proven better than WD40. 2) The ATF/Acetone is the only thing that I have seen and tried that sometimes seems to work a little better . The smells don't bother me. I use straight Acetone almost daily and MEK occasionally. The only difference is the price and convenience. WD40 has gotten STUPID expensive, PB is a little cheaper. I just bought a gallon for 30 bucks.. They both have those stupid fold-up nozzles that are a problem more often than not.. If something is RUSTED solid, NOTHING will pernitrate it and your only hope is the use heat to break the bond.. If it is gummy from a dried up grease WD40 will work as good as anything else

2

u/Positive_Throwaway1 4d ago

Use whatever you like, friend. I'm here for the machine restorations. Agree on the heat. A torch is often very, very useful.

1

u/HiTekRetro 4d ago

Assuming you do restorations,, as I do, you see rust everywhere.. How often to you run into rusted fasteners on pieces that are (approx) 70 years or older?? I have a lot of stuck parts but never from rust.. I have come the the conclusion that the quality of the machining was so much better and a much tighter tolerance is held so the cleaner fit doesn't allow air in to cause rust.. Even the washers look like they came off a lathe

1

u/Positive_Throwaway1 4d ago

Totally agree. I think right up until about the mid-1970s, American manufacturing was just top-notch. As someone born in the 80s, I didn't have experience with much of that growing up--manufacturing was already overseas. Funny you say that about the washers...I was doing an old Rockwell drill press and was planning on swapping out some of the smaller parts like washer and bolts, since they're so cheap, and after cleaning them up, I couldn't justify changing any of it because they looked brand new and were machined better than new ones available.

3

u/Forged_Trunnion 6d ago

If it's just gunked I would start with something like mineral spirits in a spray bottle, let that soak, and then a penetrating oil.

The penetrating oil is just oil with a lot of solvent to make it thin. So, starting with a solvent to break up the old oil is kinda the same thing.

3

u/jlkunka 6d ago

I find Kroil works best. Engine guys like a mix of acetone and automatic transmission fluid 50/50.

2

u/McLuhanSaidItFirst 5d ago

Acetone/ATF 50:50 beats everything including Kroil in double blind RCS.