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Bending again

Posted: Fri Oct 04, 2019 11:11 pm
by ekbmuts
I've posted on this topic before but here's another one.

I'm making a rope rack. I took a piece of 16ga 2" x 2" square steel tubing, 20' long. On one face, at a spacing of 6" O.C. I welded a 6" x 9/16" post perpendicular to the face. A bit like this:

_____I_____I_____I_____I_____I_____I_____I_____I_____
_________________________________________________

I did a full weld around the base of each post. And what do I now have? You guessed it: a banana.

Clearly each weld tugged at the base metal causing a fair amount of deformation.

This, in terms of the overall project, is not a big deal. I'm going to clamp either end of this 20' rope rack to a chunky steel I-beam and it will bend back.

But I'd still like to have it straight anyway.

So: WHERE do I apply heat? How much heat? For how long?

Thanks in advance.

Jon

Re: Bending again

Posted: Sat Oct 05, 2019 11:04 am
by cj737
Can’t imagine it was necessary to fully weld the bases of the posts. You have to learn to control heat input when welding. As you weld along the length of something, multiple times, the heat is accumulating in the base. Learn to be patient and let the parts completely cool. Or at least skip around so you don’t concentrate too much heat at any time in one place.

Re: Bending again

Posted: Sun Oct 06, 2019 12:38 am
by ekbmuts
cj - Of course, you're right. It really wasn't necessary to fully weld the posts to the tube. Four spot welds per post would probably have done it. But either way... what's done is now done.

I've run into this before, meaning, distortion from too much concentrated heat so I'll have to review my procedures and not get so torch-happy that I'm not thinking of the end result.

Thanks for your input.

Jon

Re: Bending again

Posted: Sun Oct 06, 2019 7:14 am
by cj737
Learning to weld is much more than controlling an arc. Metallurgy, procedures, distortion and about 1,000 other things are part of the Black art of Welding. Distortion damage happens to everyone. It teaches patience very quickly. Don’t be too hard on yourself. Some times “less” is “more”. Or at least “enough” where welds are concerned.

I did a big stainless job a few years ago. Large pallets for holding sanitary tanks. As thick as the metal was, I chased back and forth stitching here, checking plumb, stitching there, checking plumb, and so on for about 3 days to weld something that should only have taken 6 hours to actually weld. Taught me a lifetimes worth of patience that one job.

Re: Bending again

Posted: Mon Oct 07, 2019 10:49 am
by ekbmuts
Yep - if there was one thing I could improve on, not just in welding but in life, it would be that elusive quality: patience.

Working on it... ;)

Re: Bending again

Posted: Mon Oct 07, 2019 11:36 am
by cj737
ekbmuts wrote:Yep - if there was one thing I could improve on, not just in welding but in life, it would be that elusive quality: patience.

Working on it... ;)
So next time, wait 2 days to respond! :lol:

Re: Bending again

Posted: Mon Oct 07, 2019 10:23 pm
by homeboy
I have built several similar style racks like this only on a much smaller scale (mig not O/A) and I drill right thru the tubing, insert the pins to flush on the backside and a small tack on each side is all it takes. Minimal heat and distortion and plenty strong.

Re: Bending again

Posted: Mon Oct 07, 2019 10:38 pm
by ekbmuts
You know, I considered that. Drilling right through both walls of the tubing. I thought it would be more time consuming but considering the time I'm spending to straighten out my 20' boomerang, I'm probably wrong about that...

Re: Bending again

Posted: Mon Oct 07, 2019 11:15 pm
by cj737
homeboy wrote:I have built several similar style racks like this only on a much smaller scale (mig not O/A) and I drill right thru the tubing, insert the pins to flush on the backside and a small tack on each side is all it takes. Minimal heat and distortion and plenty strong.
+1

Re: Bending again

Posted: Tue Oct 08, 2019 1:40 pm
by homeboy
ekbmuts wrote:You know, I considered that. Drilling right through both walls of the tubing. I thought it would be more time consuming but considering the time I'm spending to straighten out my 20' boomerang, I'm probably wrong about that...
Only other thing I do is grind a bit of corner off the pin on the backside for the tack to give a bit of penetration if it needs to be ground flush. ;)