I'm looking to get the rear that I'm building all cleaned up so I can paint it and get it all set up. I'm mainly looking to get all the surface rust off. I've had a couple things hot tanked at a machine shop and they looked brand new afterwards, but didn't have any surface on them to begin with like the rear. I think I recall seeing hot tanking remove rust to but can't really remember. I know most of you will just say "why not have it sandblasted?" Well I'm considering it, but hot tanking would be easier for me, and I THINK a little cheaper. Anyone have any experience with hot tanking surface rusted parts? Tom

If it uses acid then it might cause a problem with the bearing fit. You must be sure that the bearing bore does not get damaged. If it removes rust then it might also remove some good metal too. As little as .001 inch can cause major problems with bearings. If the bore for the pinion bearing races is increased by .001 inch then the races will no longer have a press fit and will be loose in the bore.

If you decide to have it sandblasted then be sure that the seals and bearing races are still installed so the blasting doesn't damage the bore for these parts. Keep the cover on it too.

Yeah, point noted. I thought about that myself, but figured that any process they use on bare engine blocks ie cam journals, and main journals, and wont mess with those, it should be fine on a rear end.

there may not be a hot tank big enough for the rearend. if you sand blast it, pull it out,leave it together, power wash, then blast it, wash again, tear apart

You are right about the cam bearing bore and other parts of the block. It should be safe for the rear end housng too.

Hot-tanking facilities are becoming harder to find,
thanks to EPA reg's. If you have access to one that's
still operating, good-on-them.

As an alternative, I've had good luck w/ electrolyzing.
The re-action process only involves FeO2 (rust), not
Fe (iron). In a nutshel: submerse the treated part
into a solution of water & washing soda, fix electrodes
around (but not touching) the part, then connect part
& electrodes to a 12v battery charger. (Proper polarity
is imperative, and my cheatsheet is not at hand. There's
a detailed write-up out on the web somewhere.)
The obvious problem is a suitable container for a diff housing.
(If you're married/co-habitating, don't even THINK about
the bath-tub. ). Electrodes should be considered
expendable, and foundation re-bar works very well.
End solution is non-toxic, and can be poured out in
the yard.

Good luck,
kk

PS
I shopped around and got mine blasted for $50, which was
to cheap to consider anything else.

I've done heads & block this way, with excellent results.

I power-washed mine, then scrubbed and scrapped and washed it with Simply Green several times. I painted it with POR-15. Several years have passed and it still looks fine.

JamesC