Advice on filling this gap?

JeepFreak21

NAXJA Forum User
Location
Cameron Park, CA
It's 3/8" mild steel and the gap is 3/16" wide. I chamfered both edges on both sides and I'll be using a Millermatic 175 (MIG).

33myioo.jpg


So... one pass per side? Two passes per side? Should I try cut a piece of material to stick in there or just fill it with weld?

Any advice is appreciated!

Thanks,
Billy
 
the hardest part is going to get a bridge between the t wo pieces so u have something to start your weld puddle with, per sonally i would run a bead on both pieces to build it up to help close the gap, i would also tack the loose pieces to a solid piece on metal as it is going to pull, draw real bad, unless u flip back and fort between sides as u weld hth
 
Why not do a lap weld with another layer of material? Is clearance a problem?
Tack weld another piece of material (fairly thick sheet steel or thin flat stock) on one side or the other (hammer it straight), then a piece of filler for the middle. You can actually use steel rod for this or a long bolt (built in bezel). Short welds (passes) no more than 3/8"-1/2" at a time. One end, then the other, one side then the other, check for straight (maybe use a vice) let it cool down between passes.
Grind off the backing material and repeat with the other side.
Depending on function, maybe heat it up red, hammer it straight and dump it in a pot of used oil. Or let it lay on the garage floor until cool.
You have to take function into consideration, just how strong does it have to be. If it cracks and fails, will it be catastrophic?
One bad thing about MIG, is the welds are universally fairly hard and when they are harder than the surrounding material, things can stress in strange ways.
My MIG welds rarely (never) fail, if it does crack, it is often where the weld meets the original material, right at the edge. Weld failures are most always from vibration or expansion and contraction. The only exception being is if you dump your work into water when hot, it may crack most anyplace and stresses the work in odd ways.
 
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What's it for?
In the picture, I see one bolt hole, are there other bolt holes on the left side, out of view? If so, how do you plan on maintaing in the tolerances while you weld, because they will likely change as you fill the gap. The practice of bolting something like this to a jig will help maintain proper tolerances, fwiw.

Without any more info, you could run a bead on each side of each piece to narrow the gap.
 
What's it for?
In the picture, I see one bolt hole, are there other bolt holes on the left side, out of view? If so, how do you plan on maintaing in the tolerances while you weld, because they will likely change as you fill the gap. The practice of bolting something like this to a jig will help maintain proper tolerances, fwiw.

Without any more info, you could run a bead on each side of each piece to narrow the gap.

It's a caliper bracket. I plan on bolting the one in the picture to one that hasn't been modified through the caliper mounting holes and then either tack welding both sides to something or c-clamping them down.
Thanks,
Billy
 
Why not do a lap weld with another layer of material? Is clearance a problem?
Tack weld another piece of material (fairly thick sheet steel or thin flat stock) on one side or the other (hammer it straight), then a piece of filler for the middle. You can actually use steel rod for this or a long bolt (built in bezel). Short welds (passes) no more than 3/8"-1/2" at a time. One end, then the other, one side then the other, check for straight (maybe use a vice) let it cool down between passes.
Grind off the backing material and repeat with the other side.
Depending on function, maybe heat it up red, hammer it straight and dump it in a pot of used oil. Or let it lay on the garage floor until cool.
You have to take function into consideration, just how strong does it have to be. If it cracks and fails, will it be catastrophic?
One bad thing about MIG, is the welds are universally fairly hard and when they are harder than the surrounding material, things can stress in strange ways.
My MIG welds rarely (never) fail, if it does crack, it is often where the weld meets the original material, right at the edge. Weld failures are most always from vibration or expansion and contraction. The only exception being is if you dump your work into water when hot, it may crack most anyplace and stresses the work in odd ways.

I don't have much room to overlap material, but maybe temporarily would be good.

This is a caliper bracket, so it needs to be strong, but way the forces will circular around the edge (if you know what I mean), so that works to my advantage.

Should I consider preheating/postheating the weld area?

Thanks for the advice,
Billy
 
An old shade tree mechanic's trick is to lay it on a piece of copper. You can then puddle the weld. The weld won't stick to the copper.
 
Thats because you young wippersnappers are still wet behind the ears. :laugh:
 
An old shade tree mechanic's trick is to lay it on a piece of copper. You can then puddle the weld. The weld won't stick to the copper.

that's sweet to know!

Billy, I was gonna recommend welding it on top of another plate with a bunch of passes, cleaning between each one really well and then grinding the plate off the back..
kinda a pain, but it works exceptionally well for big gaps like that.
 
that's sweet to know!

Billy, I was gonna recommend welding it on top of another plate with a bunch of passes, cleaning between each one really well and then grinding the plate off the back..
kinda a pain, but it works exceptionally well for big gaps like that.

How thick do you think the plate should be if I do it this way?
Thanks,
Billy
 
An old shade tree mechanic's trick is to lay it on a piece of copper. You can then puddle the weld. The weld won't stick to the copper.

Yup. Professional metal fabricators have a tendency to keep a chunk of copper around for this reason. I have a couple. :)

I would use the copper backing plate, or tack a thin strip of plate in the middle of the bevel.
 
Thats because you young wippersnappers are still wet behind the ears. :laugh:

Thats why us youngins neeed to ask old guys all the questions before they catch an ice drift out to sea :wave1:.
Thats one of many tricks I learned from an "old" guy.
 
just do like 1/8th
something you can weld to and get good penetration on the bottom of those two pieces.
and also something else I'd do is when you grind the back plate off go ahead and use your grinder and make a slight groove to get any pits left over and go ahead and refill it.
 
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