Separating rusted-together telescoped square tubes

Don, very interesting as usual. I have a question. If you made a bracket suitable for an air hammer to "pull" your puller, do you think that the air hammer would finally free inner rectangular tube from the rust?

A jackhammer might, but not an air hammer I have at hand. If several hard blows with a 2 lb hammer wouldn't move it at all then the impulse from a small airhammer certainly wouldn't have either. Ratatatat can accelerate rust busting only if minimum shear force to bust rust is reached.

Further, air hammers push rather than pull. Making a bracket suitable for push rather than pull would have been considerably more of a project. It didn't take me an hour to make my pull grabber.

Running sideways?

I've used that approach to jerk loose stuck trailer hitch receiver tubes: set up slack chain from ball to tree, start driving toward Fargo, very soon there will be a loud noise accompanied by either a very sudden stop or success. My experience has always been success.

But my truck doesn't run sideways.

Seeing the pictures of the truck/chain/tree I assumed a running start in the truck would have been the venue...you disappoint me.

I just assumed there was 100' of chain coiled by the base of the tree. You could probably get up to 30 by then.

Way to go, McGyver!!

Don Foreman wrote in news: snipped-for-privacy@4ax.com:

Good job Don, The only thing I would suggest is a coil spring between the pins, this would help prevent them from thinking about popping out of the holes, and make insertion simplier.

Nice work. One thing to consider though. The fit of the inner tube may be T-I-G-H-T when you coat it with a primer and a two part paint. We had that problem with some boat trailer hitches in the old shop. Ended up sandblasting them and using the E-Coat tank after giving them a coat of zinc.

Don't attempt that with the newer generation of factory tow hitches from GM or Ford, They WILL bend and damage the frames.

I used a 2-part zinc-chromate epoxy primer. The caliper sez there's at least .030" minimum clearance all round, but we'll see how she goes tomorrow when the paint has cured for 24 hours or so.

If it's a problem, I'll blast 'em clean and zinc plate 'em.

What is an E-coat tank?

Might I suggest a nice slathering of Never-Seeze, or some other anti-seize compound as you assemble?

Ecnerwal, what do you think about using LPS-3 or some similar rust preventative for this application. After reading this story, I applied LPS-3 to my ball/lunette coupler on the areas that go insidethe hitch tube.

Electrostatic coating tank.

We had three of them. The way they work is the main tank is connected to the positive side of a high voltage power supply. The part is grounded and hung so it can be dipped into the tank. The paint itself is a VERY thin mix (almost at the viscosity of water). When the part is dipped in the charges insure that the paint coats ALL the surfaces at once. Then the part drips off the excess and gets baked. We used it on Garden Way parts and some GM stuff.

Beats doing nothing. Rust is the problem, it's just that if parts stay together a long time (say, long enough for grease to dry up) the anti- seize stills leaves something to help get it it apart again. LPS3, being waxy, should stay put pretty well, but I'd personally reach for one of the several containers of anti-seize I own, because I simply hate fighting with parts that are stuck, and I really hate ever doing that more than once on the same part.

That sounds like it would work to paint the inside of tubing, something I've long wondered about. I'm getting ready (steel gets here tomorrow) to make a fair sized gantry from square steel tube, and as it will spend a lot of its life outside I wonder about how to prevent rust on the inside of the tubing. I know about hot-dip galvanizing, but that isn't perfect either (high cost, large lumps, unpredictable thickness, difficulty in masking) so if this would work I'd like to learn more about it.

Grant

Nice photos...

Because I've never owned a pickup or a camper I gotta ask this:

What holds those pieces in place (when they're not rusted in.) and keeps them from falling out onto the road when the camper isn't tied to them?

Jeff

It works fine if ya just do it every couple of years. I let my camper mount tubes go for too long. My receiver tubes don't get stuck because I change balls now and then, and squirt 'em when I do.

Thanks! I'd not heard of that before.

Are they bent together ? - subtle little from a heavy load and a bounce ?

That might be the issue.

Have you heated the outside receiver ?

Martin

Mart> Warning: metal content.