Penetrating oil for old bolts/studs on exhaust manifold

[Compass790]

Bit off topic here but just a warning about using a tiny TIG, some of them dont like running off a generator so find out first if you are going to do that. If you stick to mains power they tend to be very reliable & produce nice DC these days. Cheap ones can be very difficult to strike an arc.
Personally I would never try & remove a seized stud/ bolt at very low temp as they tend to be brittle enough if old. Havent tried it myself but maybe it would work if you chilled first to break the bond & then allowed to come to room temp before trying to unscrew. The most successfull way I've found is a combination of all the methods ( heating, hammering & penetrant oil previously stated but I just would elaborate by saying the best success comes with heating the stud or bolt not what it screws into.

[Bill_E]

Originally Posted by Isabella Jane

Vinegar dissolves aluminium oxide.

That's acetic acid. I would think that citric acid (lemon juice), though a slightly weaker acid would complex the aluminum and oxalic acid, an even weaker acid, would do a better job of complexing. Although it might be hard to purchase in your local hardware store. Dilute sulfuric acid with some oxalic acid might be the way to go.

BTW. I'm going to have to look into Mouse Milk!!
Bill

[donradcliffe]

Vinegar is too slow--put a couple of drops of hydrochloric acid on and watch the oxide fizz!

[UNCIVILIZED]

One word: Thermite. - It removes EVERYTHING!

[Scrimshaw4]

Not sure if this is an "Old Wives Tale" or not but an automotive mechamic once told me about a technique for removing siezed bolts where you melt a candle over the bolt head after heating the bolt. Apparently the melted wax will wick into the threads the same way solder wicks into a fluxed joint. Then use an impact wrench to back the bolt out.

[Canibul]

Impact wrenches are awesome, if you can get it just right. It's similar to a manic dwarf on methamphetamine beating the bejesus out of it with a tiny hammer.

[Cormorant]

Though be careful with all that force. I learned the hard way that stainless bolts corroded into an aluminum body (lower unit of outboard) can break if pushed a little too hard, leaving you with a much more difficult repair. . . .

[AZ-Oldguy]

Uncivilized, isn't thermite what Ozzie's put on their toast?

[wedivebc]

OK nobody laugh, this is the real deal, tabasco sauce. It works like crazy for releasing corroded bolts. Also a couple of sharp taps with a crescent-hammer.

[Lepke]

The absolute best stuff I ever used for badly rusted ferrous nuts and bolts is Kearney Rust Cutter. It is made for people working on power transmission lines and until recently it wasn't available to the general public. Now Amazon has it.
It penetrates but also dissolves some or all of the rust. After breaking loose, the nut comes off with fingers.
With other penetrating products, I've found that when loosening rusted nuts, a wrench will often twist off the stud, but an impact wrench will loosen. With Kearney I don't need the impact wrench.

[boatbrain]

I think you know this but also - don't get hung up on unscrewing the nuts - cut them off with a nutbreaker or small high speed grinding tool - that might save you a tremendous amount of time.

[leftbrainstuff]

Originally Posted by UNCIVILIZED

Anyone have some comparative tests for products which use cold in order to break things free? Like, say, Loctite Freeze & Release. Or any of the DIY methods for radically dropping the temp of frozen parts, in order to shrink them a bit & break them free?
Obviously, there's the drawback of very cold metal being more brittle, but... if the technique works.

a64pilot, THANKS for all of the informative info herein. That comparative test which you provided is great! To date, I've been a Kroil fan, but I'll give a couple of those others a try.

Freezing works well when fitting sleeves, collars and bearings to shafts. Think engineered interference fit.

If you can get a stud to dull red heat anything from wd40 or diesel works well.

If you cant apply much heat then kroil oil or mouse milk works well.

Stainless in aluminum is problematic because the corrosion expands and holds on real tight. Drilling out works well.



Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[Badsanta]

Kano kroil is incredible. Was recommended by my local machine shop. I found it to work incredibly well. I tried all the others but this one worked.

Sent from my SM-G860P using Cruisers Sailing Forum mobile app

[Canibul]

Originally Posted by Lepke

The absolute best stuff I ever used for badly rusted ferrous nuts and bolts is Kearney Rust Cutter. It is made for people working on power transmission lines and until recently it wasn't available to the general public. Now Amazon has it.

You sure about that? I just tried to see if I could order some to try it, but no go on Amazon.

Problem for me personally with these things is that none of the forwarding services will send us aerosol cans or anything with a warning label. If a local business doesn't carry it, I am SOL.

[HappyMdRSailor]

Originally Posted by captainwireman

What kind of container do you put AT/acetone in. Will it dissolve a simple plastic applicator type squeeze bottle like an old eye drops or maybe an empty mustard bottle???

No problem at all... anything PE family will do...

Kroil rocks socks, but pricey... PB Blaster is my go to...

Just a wonder... popped into my head, and I' DEFINITELY NOT a chemist... We're talking about an oxide seizing the SS/AL interface... All this talk about sulphuric make sense too... But what say you to the known dissolvers of calcium oxides??? Yes, I know the calcium isn't there, but white oxide byproduct may be similar??? Muriatic or one of the toilet cleaners that works so well on barnykeels???