welding unistrut

Welding Techniques, Theory, Machines and Questions.

Moderators: Harold_V, Scott

Post Reply
Mikes578514
Posts: 2
Joined: Sat Mar 02, 2019 10:34 pm

welding unistrut

Post by Mikes578514 » Sat Mar 02, 2019 11:20 pm

I'm planning to build a rack to haul my ride on trains for my new van.

I've purchased some green 1/2 height unistrut for the rails, and some square tube for the frame. do I need to clear the green finish off the unistrut in order to weld it to the tube frame? if yes how is the best/easiest way?

Thanks

Mike

Russ Hanscom
Posts: 1556
Joined: Wed Mar 15, 2006 11:10 pm
Location: Farmington, NM

Re: welding unistrut

Post by Russ Hanscom » Sat Mar 02, 2019 11:46 pm

Yes, you should remove the coating for a good weld. if the coating is intact, you might not even be able to strike an arc through it. I use an angle grinder with normal abrasive wheel, just a light touch to get the coating off of the proposed weld area. You do not have to get off every speck, what is left will burn off, and you cannot access the coating inside the Unistrut anyway. Of course do not breath the fumes.

Mikes578514
Posts: 2
Joined: Sat Mar 02, 2019 10:34 pm

Re: welding unistrut

Post by Mikes578514 » Sun Mar 03, 2019 12:08 am

Russ

Thanks

I just braved the cold to do an experiment. I've got a air die grinder with some scotchbrite type wheels did a quick job on a 2-3" section of the unistrut

Thanks again

Mike

choprboy
Posts: 226
Joined: Sat Oct 29, 2011 11:23 pm

Re: welding unistrut

Post by choprboy » Sun Mar 03, 2019 4:27 pm

I've welded a bunch of unistrut for various frames (microwave radio/tower/building brackets/cable trays/etc.). The zinc and yellow can be welded directly, but even with grinding it is not a pretty weld (unless you grind way back), do to zinc contamination. The yellow is zinc-chromate, so its pretty bad to breath as well. Usually I grind the surface back about 1/4" from the weld edge, run a bead, grind the bead down, and run a second bead. Then try and find some cold zinc spray. The green (at least around here) is far easier to deal with as it is just paint/powdercoat over plain steel. Wire brush or flap disc the coating, weld, and repaint.

User avatar
liveaboard
Posts: 776
Joined: Sun Dec 08, 2013 1:40 pm
Location: southern Portugal
Contact:

Re: welding unistrut

Post by liveaboard » Sun Mar 03, 2019 6:57 pm

Use general purpose stick and crank up the power.
[grunt, aarrgg, wheeze, groan]

Post Reply