Welding advice needed...

...For a semi critical application.

I need to fabricate camper tie downs for my new truck (2009 F350). I'll be modeling them somewhat after the Torklift mounts

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but I can't really use those due to apparent clearance issues with the tiedown locations on my camper.

My plan is to use 3/8" plate for the frame plates for the front mounts, and the remainder of the mounts will be made with 2.5", 2" and 1.5" x

3/16" wall square tube and 2" x 2" x 3/16" angle. I'll be doing an all welded configuration since I'm not setup for bending plate (yet) or square tube. I'll be TIG welding with 70S2 filler unless there is a need for a different filler.

Is there anything in particular I have to watch out for in this semi-critical application other than the obvious penetration? Any post heat treat, peening, stress relief type stuff?

Thanks,

Pete C.

Reply to
Pete C.
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Yes, that is the general idea (I included the link in my first post).

I got the installation instructions for the models that "fit" my truck, and after some measurement and test fitting of the camper I determined that the standard unit won't quite work based on my tie down locations.

The mounts I will fabricate will follow the same overall design, with the front receivers mounting to existing frame holes with a 3/8" think plate. The 2" square tube receiver will aim out towards the outside of the truck. The brace on the receiver tube will be a piece of 2x2x3/16 angle connecting up to another piece of the same angle which will span two of the bed cross tubes and attach via existing holes there. The receiver location needs to be mid span between the bed cross tubes, not in-line with one as the Torklift unit seems to be.

The question is if I need to do anything special beyond good full penetration TIG welds with 70S2 filler I have on hand with this being a semi-critical application. Unlike most of the stuff I weld this will see extensive vibration, shock loads, etc. I call it semi-critical since there is redundancy with four anchors and it isn't directly load carrying.

Thanks,

Pete C.

Reply to
Pete C.

It's under the truck where no one other than the guy doing the brakes or exhaust will see it. Just use 7018 stick. 1/8" Electrodes should be fine. It will be faster welding, and strength will be more than adequate for this. Just make sure that you are getting good welds before you tackle the final weldout on your brackets. Weld a couple of coupons and break em open. Drew

Reply to
Drew McEachren

I'm the guy who does brakes and exhaust (and most everything else).

I don't do stick, I do TIG almost exclusively.

I will test a couple scraps of the same materials.

Reply to
Pete C.
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I'm with Drew on this. 7018 stick. When I read the first post I couldn't think of any reason you would use Tig rather than Mig or stick.

Reply to
RoyJ

The reason is simple - I do pretty much all TIG. This isn't production, time isn't a factor, what is a factor is that my TIG welding skills are much better than my stick welding skills.

Again, does anyone have any info on any post weld treatment that may be needed?

Reply to
Pete C.

No. Tig welding mild steel with 70S2 wire requires no post weld heat treat or stress relief, and offers no disadvantage over 7018.

Reply to
Tim

Well, the first bracket is done and the paint on it is drying. That's one heavy bracket. The welds seem to have gone well.

Reply to
Pete C.

I hate three words. Should, probably, and seem.

You'll know when you put max stress on them a few dozen times. But if you know how to TIG, I'm sure you paid attention and got penetration and fusion at the proper points. If you're Tigging vertical, my guess is that you know what you're doing.

Steve

Reply to
SteveB

Well, there was no TIGging vertical, this was all welded on the bench in the most convenient position and bolted to the truck with grade 5 hardware. At any rate, the mounts are back from a 3,400 mile round trip with plenty of shock loading and whatnot and so no signs of any distress.

Pete C.

Reply to
Pete C.

Reality is always a good test. Glad everything went well.

Steve

Reply to
SteveB

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