Anyone with welding experience please advise <img src="/forums/images/graemlins/confused.gif" alt="" />

Grind them away....Notch the parent material joining surface....pre-heat with a butane torch....then weld away at the highest setting on the 135.

I have a Lindy 135 that I use for some things...but for applications such as this I prefer to use my friends MM210....hands down. If you have to use the 135, pre-heat is your friend....and it's no fun either. You'll end up with more penetration, however, you'll also get a more uniform crystalline structure (less of an HAZ). I personally don't like to pre-heat...as I feel like I'm messing with the parent material too much, but when you look at the big picture....that's all you're doing with more voltage on a bigger welder.

Not sure if Pre-Heating is recommended by those who are "certified". I would consider it a last resort. However, it is better than putting out welds with a lack of heat.

Max

Ok I'll chime in. It looks to me that the metal wasn't very clean when you welded it and that you didn't get very good penetration. But IÆve seen worse. Yes a second or third pass would help especially if you get good penetration with the extra passes. The welder you used may be too small. Find someone with a 220 volt DC welder to fix it for you. Prep the metal with a stiff wire wheel right before you do any more welding, it should be shinny clean before welding.

Bandit Well ,,,ya ,,,you could try some more passes 2 more at least,,,,,,,,,but really,,,you need a larger welder,,,and when you are done it should look like Vee shaped fish scales (single pass only)and looking at the brown haze on the metal,,,,do you know if that was a flux core welder,,,or does it have a gas tank kit ,,,,if its flux then again you need to clean slag (brown crud) every time you make a pass. I`ve welded some thin stuff (sheet metal) and some thick plate around the farm,,,the 3/8 and 1/2 inch plate sucks up the heat,,,,any time you see the weld Mound up when you welding in a corner its too cold,,,it should look like a nice curved transition from one metel to the other..1/4 wall is pushing it for a small welder.it just takes practice,,,and learning how to move in each position, with small zig zag or circle 8`s...

madsquirel Thanks for the explanation. The welder is MIG using a 25% mix (non-fluxcore) and that was a single pass. I thought with MIG the weld will end up convex (mounded up?) whereas with stick it will become concave (fillet).

I am going to paint it and bolt it on as is for now without adding the hitch receiver and avoid using it as a recovery point. I'll just keep it on as a bumper. Then after I do a body lift I will remake the brackets using a stronger welder. Think I will be okay?

What about the welds on the tubing? The tubing is 1/8" thick while the welder is capable to 3/16ths. HERE IS A LINK TO THE TUBING WELDS. I understand where the tubing is welded to the 1/4" plate I will probably need to grind and reweld, but are the other welds (tubing-to-tubing) okay? <img src="/forums/images/graemlins/confused.gif" alt="" />

Thanks again for your advice; you are incredibly helpful.

Well Bandit,your bumper shouldnt fall off going down the road for now, and if you get smacked in the rear it will only be pushing it together, I would think its fine.,,

The tube welds should be ok, but what you could do is slow down the wire speed and move in a wider zig zag to get the smooth fillet shape you want,,,you should have the same shape weld regardless of stick or mig welding.

And when you are welding different thickness metals spend more time around the thicker metal, it needs the heat to penatrate , the thinner stuff will melt faster,,,either do this by slowing down as you pass the thick metal,,,or just move your whole zig zag closer/over the thick metal...also I made a reply for directions to Johnson vally in the other post.

Thanks for the tips; you've been very helpful and I appreciate the guidance.

dido what you said on the thick stuff i start from the thinker metal to the thinner i also use the 220 stick welder for it and save the flux core welder for the thin stuff but either way the welds should be /look the same when i do use the flux welder on heavier metal i turn down the wire speed and turn the setting to high i put some cross bracing on my custom bronco's bumper i finished up this past weekend and got it so hot i bubbled the piant on the other side of what i was welding too
but prep work is a must for a good weld on a sid enote i noticed that you angled the corners front to back instead of bottom to top i cut mine on a 45 degree to help with the bumper hanging up on anything i'm gonna use the same style on my toy when i get the flatbed done

I am going to have more 2x4 running forward to the wheelwell that will join at that 45 degree cut. I thought about angling the corner with another cut, but this way is about as simple as it gets.

Today I finished bolting everything up and I jacked the truck up from the bumper. It flexed enough to take up the 1/2 inch gap I had between it and the tailgate. The tubing didn't seem to bend visibly, just the plate. I trust it to hold up as a bumper until I remake the brackets.

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Look at the flat plate on the other side of the weld if you want to see if you got good penetration. You should be able to see discoloration where the metal was heated on the back side. Usually if you see that, you've got a pretty strong weld.

Also, if you are welding thick steel to thin steel you should point the mig gun more in the direction of the thicker steel. Instead of running the gun straight into the 'V' made by the joint, angle it a little more toward the thicker material. This will help direct the heat more into the thicker metal.

And when you are using a mig gun you want to 'push' the weld. Let's say you are welding from right to left. Angle the gun tip to the left, and zig-zag the pattern from one metal to another. Above all, be patient and go a little slower than you think you need to.

If you want to be a better welder, practice a lot on scrap metal, and try different things until you get a nice weld. Good welding takes practice. You might also want to take a welding class at a tech school.