Is this the proper way to weld a patch?

[Shield Arc]

I did some fillet weld break tests a few years ago. I was shocked that Lincoln's L-56 Mig wire came out the best.
Here are the results.
6013 broke with only 3-blows of a 4-pound hammer.
6011 = 8-blows.
7014 = 10-blows.
6010 5P-Plus = 10-blows.
Tig = 13-blows.
7018 cold never seen the inside of an oven = 18-blows.
7018 right out of the oven = 23-blows.
L-56 = 29-blows.

 

[Sodo]

the only thing I don't like about the above "patch" is the continuous welding....if it was to crack for some reason the crack would eventually (in theory) keep traveling... now if it was stich weld and cracked only that leg of the stich would be comprimesed and not the entired patch....

Agreed it's like a rip-stop, but point is there's no repeated loading to fatigue the steel. Here's a scenario where cracking would be more of an issue:

- If that beam was used on a highway bridge (an application where repeated load cycles has potential of being a large number).
- And IF it was undersized to the point that it reached critical stress often (safety factor insufficient).

If a highway construction project had 5,000 (overweight dump truck) vehicles per day, (and the beam strength was slightly undersized) it could get to a million cycles after 200 days.

Back to a gantry crane usage, stitch welding would be fine, would save some unnecessary welding time and looks pro. If a guy had to do 5 of those i bet the later ones would be stitched.

I'm still curious what LD's planning to use that wicked piece of machinery for. If he's gonna test that splice better get crackin' that's gonna be a lot of overweight projects !!! Would be fun to calculate the deflection of that beam lifting (for example an L3400) and then measure the actual.

 

[Shield Arc]

Skip welding has it's place. I'll venture to say, very few members here know when to apply that method.

 

[Sodo]

Skip welding has it's place. I'll venture to say, very few members here know when to apply that method.

Agreed, most members here will weld it continuous, because "why the heck not"?
If everything's going good, keep welding! :cool2:

An experienced welder can see the areas where a continuous weld risks warp, or shrinking. In the web of that beam, the splice (almost) simply separates the flanges, and holds the web straight from buckling, certainly stitch is fine. Especially if there is a fish plate on the other side too. If someone woulda asked me, ahead of time, I'd say since the strength is not an issue, skip weld that plate (s), so there's less chance of causing a wowie in (the straightness of) the beam.

 

[jwmorris]

There are many structures that if welded complete will fail before they would if skip welded. It's not always a matter of warping.

 

[Sodo]

Agreed. These would be larger weldments. With regard to what people need to know, I'll bet nothing made on a tractor subforum is weakened by continuous welding.

Maybe "nothing" is too strong a word, probably better use 0.01% of tractor subforum projects.

 

[npalen]

Another consideration when adding gussets is the type of material used. I read an article years ago about adding gussets to truck frames and they were recommending use of the same type of steel for the gussets as in the truck frame. Many truck frames are high tensile steel to withstand the high stress repetitions. Using a low carbon low tensile steel gusset can cause failure of the gusset over time as it gets stretched repeatedly beyond it's plastic range.

 

[Oldpath05]

That patch/welding looks great to me. But on some ships that I worked on, patches wasn't done like that, all 1/4" thick and up, I-beams, T-bars and shell plates are beveled, with a 1/8"-3/8 open root, then welded with temp. ceramic backing, then x-rayed for 100% weld, 3/32-5/32 max reinforcement for keeping stress riser to a minimal.
The only stich welding, is done on 11 gauge none structural steel, kitchen area etc. and if anyone is getting cracks in the weld, check pre heat, check weld gas, check for right filler wire also clean steel helps with weld quality.

 

[Oldpath05]

Thought I could spend 2-3 weeks looking at/for torches, my son couldn't wait, had to do a repair on his pulp loader, so we went out to the welding store bought a Uniweld 30SA-16", totally different from the Victor style we had, the trigger is on the bottom and there's only 2 knobs to adjust. Hopefully I can use to the trigger being on the bottom, but does seem to be a nice short torch, one funny thing though, it makes a purring sound when lit, it's different for sure.

 

[Oldpath05]

Thought I could spend 2-3 weeks looking at/for torches, my son couldn't wait, had to do a repair on his pulp loader, so we went out to the welding store bought a Uniweld 30SA-16", totally different from the Victor style we had, the trigger is on the bottom and there's only 2 knobs to adjust. Hopefully I can use to the trigger being on the bottom, but does seem to be a nice short torch, one funny thing though, it makes a purring sound when lit, it's different for sure.

Right message, wrong thread