input on this weld

[dyn88]

under cut is when a portion of the base has eroded away into the filler. this is often cased by to much voltage and not enough wire feed on mig.

[BradJacob]

It's hard to tell from the photos, but it looks like a bit of undercut. If so, this creates stress risers which can cause welds to fail. My eyes see it more on the top part than on the bottom part of the bead. It may not be a problem in this situation, but in the interest of good welds, you want to avoid undercut at all times. The solution is more filler.

INTP,

what do you mean by "undercut"? Is this when two joined pieces of metal are of different sizes and you try to "bridge" the gap between the two edges?

[INTP]

If you're welding 1/8" you should never need more than one pass. This is missing the point. Welding is about fusing the two pieces together, with just enough filler to avoid weak spots (including undercutting). Even with multi-pass welds on thicker material, the additional passes are not there to add strength, but rather to add filler to a thick part, where it would be difficult to get full penetration in a single pass.

The term being used here "over-welding" implies that more beads are better. It could very well be the opposite. A second bead on top of a bad bead is not going to add anything. And it's really hard to melt the lower beads by adding a bead over top of them, especially with MIG. Multiple beads without adequate fusion do not make good welds.

A weldor must know what undercutting is. It will be better for you to get this from a qualified weldor, face-to-face, than getting it from an internet forum. You need someone to show you how to evaluate your welds and know when you're making common mistakes like undercutting, cold-lapping, etc.

[WelderBob]

Take half the bead from center to the same width of the original bead out to the left and to the right. Bi-sect the angle then lay a third (fourth including the original pass) between the two and be done with it.

[fun4now]

undercut

ummm not shoure i understand. i uses a smooth strate bead then put a slow hot S weaveover the top. i was thinking i might have overwelded if anything.
atached is a diagram of how i welded it the green weld was overlaping itsself but i drew it apart to show the patern i was taking

as for adding strangth i'm not shoure it will need more i only widend it by about 3" on each end but ill look at it agin to see about beefing it up a bit
hummm another excuse to weld some more yep i like it already

[INTP]

It's hard to tell from the photos, but it looks like a bit of undercut. If so, this creates stress risers which can cause welds to fail. My eyes see it more on the top part than on the bottom part of the bead. It may not be a problem in this situation, but in the interest of good welds, you want to avoid undercut at all times. The solution is more filler.

[dyn88]

very nice work. now that you have xtended the width of th front axle you may want to consider additional support, beacause the original was designed for less of a load than the wider one. Just a thought. Looks nice.

[fun4now]

ummm i think i get it
by melting in i get good fusion but would get beter hold by surounding the plate.
right

James over welding is as bad as under welding. I guess if you were to use 1/4" when you only needed 1/8" you would not need that much weld, if you needed the strength of 1/4" then go to the edge.

Does this make any sense? Scott

[fun4now]

roling over

roling over the edge is beter than melting into it?
my brother keeps telling me i over weld stuff so i been trying to use just enough to get a good bond if more is better i'm all for watchin some more sparks
i needed to extend the front end of my riding mower as i turn it into a yard truck, i fliped the rear wheels around and picked up a few inches so i thought i would widen the front as well ( another excuse to weld )
just finished ataching the extended front end togather about 3" on each end
here is a finished pic

tryed using the 14" chop saw to ct it LOL after 5 min. i went to the plasma cutter (beter sparks ) and had them bolth cut in about 2 min. gota love that plasma

[arcdawg]

im sure that its the best weld on that tractor !

just watch the craters at the end of the weld

thumbs up bud !!!

dawg

Well James, The weld is definetly good, never going to come apart. The only thing I would watch for is to try to have the weld roll slightly over the edge of the material, really more of a concern with aluminum. The picture looks like it has'nt but pics can be deceiving. Nice job. Scott

[Paul Seaman]

Looks good for the intended job.
peace,

[fun4now]

i'm making some extentions for my yard truck added some 1/8" to the square tube not shoure if you can tell in the pic but the top plate cups where it started to melt away at every riple of weld
i think it looks good would like some feedback, i think the melt away is good right ? covers penitration yes/no ?
i used a MM135 4v/ 4 1/4ws
i put a pice of the tube and plate on top in pic