Heat & rust stuck parts??

[geezer32095]

What is it? the expansion of the "female" part that makes things come unstuck? Or something about heating the rust? Today I was trying to get a rusted up turnbuckle to unwind on my TPH, & after much penetrating oil & trying to break it loose with an 18" pipe wrench I took it to my bench vise and applied some heat with a bottled propane torch and was able to get it started loose with the aforementioned pipe wrench. (the biggest thing I have) then some more oil & working it in & out got it going fairly good. At least to adjustable with a reasonable wrench now. I really didn't think the little propane torch would do anything for it but then what do I know?? I am NOT a mechanic,nor really so inclined. I prefer wooden things, not so greasy.

 

[Wrenchin]

Yes,female side expanse so when heating something up try staying on outside,once it's loose or out,use never cease it will keep it from rustin,and easier to remove next time i use it on everything,nuts,bolts,pins,ex....

 

[NT304]

I was told once by an engineer that when you heat the parts, both parts expand. Then as they cool and both parts contract they loosen.

 

[3930dave]

Most of the time, 2 parts in contact won't cool/contract at the same rate - most of the rust gets fractured from this relative movement during heat cycling.

Oxy Acetylene torches are impressive, but many folks don't realize how much you can do (freeing things up) with a simple propane torch.

Acetylene is more expensive to buy, and if you aren't somewhat familiar with their performance, oxy/acet torches can create bigger problems than you started with - as it is fairly easy to get things too hot for too long with them.

I have both torches, but often reach for the propane one when getting stuff unseized.

Rgds, D.

 

[flusher]

Most of the time, 2 parts in contact won't cool/contract at the same rate - most of the rust gets fractured from this relative movement during heat cycling.

Rgds, D.

Right---differential thermal expansion/contraction is the key to breaking rust welds. IF you can get the heat applied to the right spot. Sometimes this requirement is what causes problems and then you have to think of other alternatives.

 

[EddieWalker]

I just heat it all up as hot as I can get it and hope for the best. Sometimes it works, sometimes I break off the bolt.

Eddie

 

[3930dave]

Right---differential thermal expansion/contraction is the key to breaking rust welds. IF you can get the heat applied to the right spot. Sometimes this requirement is what causes problems and then you have to think of other alternatives.

Agreed - sometimes I get out a Freezit type spray too, for a bigger differential. :thumbsup:

Rgds, D.

 

[3930dave]

I just heat it all up as hot as I can get it and hope for the best. Sometimes it works, sometimes I break off the bolt.

Eddie

Some days, you get the bear, other days the bear gets you...... but at least the bolt is off.

Well, the top half anyway .

If you continue working on "fun" stuff like this, you come to regard it as "character building". Either that, or an excuse to invent some new expletives !

My recent bit of "fun" was getting the original temperature sensor (ECT for the 'puter) out of a 1989 aluminum head. Nerve wracking, but got it done successfully.

Rgds, D.

 

[geezer32095]

Thanks guys the heat/cooling - time difference is something that I would never have thought of.. Makes sense tho..




Sometimes U R the windshield && sometimes U R the bug

 

[flusher]

I just heat it all up as hot as I can get it and hope for the best. Sometimes it works, sometimes I break off the bolt.

Eddie

That's my usual approach also. But I'm always worried that I'll hear the snapping noise that means I've cracked and expensive casting

 

[3930dave]

That's my usual approach also. But I'm always worried that I'll hear the snapping noise that means I've cracked and expensive casting

Ummm..... that reminds me......

My comment about heat followed by Freezit spray has an implied assumption that you have a pretty good idea that the part in question can handle those drastic Delta T swings. Typical low-cost castings may not survive these fast temperature changes.

I'll only go to Freezit as a last resort. I usually escalate as follows:

1) Heat.

if that doesn't work, then:

2) Heat + water spray.

if that doesn't work, then:

3) Heat + Freezit.

Rgds, D.

Edit - on the other side of the equation, when I'm taking my time on disassembly (ie. non-commercial, personal) work, I'm really getting to like soaking parts in red Rust Check. (As opposed to the green can product - which is a good product too, but for other reasons).

Rust Proofing Products in the United States & Canada

Rgds, D.

 

[bumperm]

And for the best penetrating oil to loosen rusted or corroded parts, a 50/50 mixture of Acetone and ATF beats all the commercial products such as Kroil or Liquid Wrench. You do have to shake it before use as it phase separates.

bumper

 

[GManBart]

Most times we're looking at a male object and a female object. The circular female object has more surface area, and when heat is applied, it expands more/faster than the solid male object. Sometimes different metal types enters into it as well, but usually it's just a matter of surface area and how that influences expansion rates.

 

[3930dave]

And for the best penetrating oil to loosen rusted or corroded parts, a 50/50 mixture of Acetone and ATF beats all the commercial products such as Kroil or Liquid Wrench. You do have to shake it before use as it phase separates.

bumper

That is a very popular homebrew. I've also had some success using ATF by itself. You just need soak-time, with any liquid.

Rgds, D.

 

[diesel lover]

Most of the time, 2 parts in contact won't cool/contract at the same rate - most of the rust gets fractured from this relative movement during heat cycling.

Oxy Acetylene torches are impressive, but many folks don't realize how much you can do (freeing things up) with a simple propane torch.

Acetylene is more expensive to buy, and if you aren't somewhat familiar with their performance, oxy/acet torches can create bigger problems than you started with - as it is fairly easy to get things too hot for too long with them.

I have both torches, but often reach for the propane one when getting stuff unseized.

Rgds, D.

X2!
I too have tons of experience with removing broken bolts and loosing seized parts. I'm a heavy duty truck mechanic. The person who started this thread was using the right approach with a pipe wrench!! A pipe wrench will grip an object well because as your turning the wrench the teeth work to grab onto the object. Same with channel lock pliers, Irwin grip locks and similar products. Vice grips can round things off because they have straight teeth. We have lug nuts on trucks that won't come off on a daily basis. They cannot come off with a 1 inch impact. Soaking with pentrant oil is always the first thing. The farmers trick I grew up with was soaking and soaking. (A can of pb blaster is much cheaper than broken parts).
Oxy act torches with a rose bud tip are the best but that is not always an option! I constantly use map gas and a really nice torch head. Mapp gas is just a little hotrer than propane. Works very well! Found out deep creep works very well with heated/ expanded female parts! This is also true of atf/ atf and acetone. Always heat only the female part if possible. By the way harbor freight has a nice 24 inch aluminum pipe wrench for 20$. I have a Lowes 24inch for 20$. Be safe!

 

[diesel lover]

Just as well when heating stuck objects to loosen them, if you fear they are brittle heat up and turn 1/16 of a turn and back to where you started. Then 1/18 and back and so on. This back and forth motion helps to seperate siezed objects with out breaking them. Been there done that.

I'm very impressed with TBN and wanted to say how thankful I am to find great information from you guys. Love to learn new things. Quite a knowledgeable group here!