weld fill in for re-drill

[arrow]

So I drilled the hole too big. I have to start again and fill in the hole to re-drill. Is there a rod that makes this easier as it may be my imagination, but it seems weld metal is awfully harder than mild steel?

 

[AaronS]

I'll be following because I have to do the same thing on a Jeep.

 

[jix]

Drilling in a weld is quite tricky..Martinsite (weld fill) is hard, it is brittle. The weld may crack and break out. I( would use a welded on backing plate, if feasible, and drill that hole in the new metal... but I am not a welder. Jut someone who has tried this kind of a repair by filling a drilling. not satisfactory if stress or vibration are a factor. TIG might work.

 

[bcp]

What size hole, in what, for what? What stresses? Does it have to look pretty, or just work? Can you replace the hole and bolt with a stud?

Bruce

 

[toneill]

Heat the area up red hot, weld your hole shut, then let the area cool very slowly. When the area your welding is not preheated it draws the heat out of the weld causing it to cool quickly thous hardening it. To harden steel you heat it up rad hot and cool it rapidly by quenching.

 

[roadhunter]

If you are concerned with the weld being hard material you might consider brazing the hole with something softer.

Or just use washers.

 

[mikehaugen]

Drill/mill it larger and use a bushing?

 

[arlen4720]

I know exactly what you are talking about, and have been down this street a few times. I learned that stainless mig wire comes out just right for re-drilling. I haven't had to use a stick welder for this yet, so I can't make a recommendation for what stick to use. I would get some rods suitable for stainless and experiment.
Braze ends up being too hard too

 

[MinnesotaDaveChalmers]

In mild steel I have not had any problem just welding with mig or stick, and re-drilling.
Stick has been with 6013 and 7014.

Have not had to use my tig for it yet, but it uses essentially the same wire fill as my mig.

My friend who does machining work just welds the inside of wallowed out giant holes and mills it out smooth again - nothing special as far as I know.

 

[Big Barn]

It's important to completely fill the hole then grind flush so that you can properly centre punch your hole location for your pilot drill.

Terry

 

[Katahdin]

I've done it with a Mig welder so I could fit a M151 shackle mount to my Jeep TJ. It came out pretty well. I just filled in the hole using an aluminum plate for backing. The molten steel mig puddle doesn't stick to the aluminum.



Worked great. There's also a few youtube videos that cover this sort of thing.

I don't recall any problems drilling the new hole.

 

[Capricious]

Heli-coil?

 

[LD1]

I am also curious as to the application.

But never had any issues re-drilling or machining a mig or stick weld if just mild steel to start with.

A copper plate on the back of the hole and fill it in. Grind the top flush then re-drill.

If a drill is all you have, you MUST fill the hole completely. IF you have a mill. No need to completely close it off. Just a bead or two around the outside and mill it out.

 

[Scooby074]

As said above.. I just mig the hole full then grind, and redrill with a sharp bit. A copper, brass, aluminum etc pad behind the hole can help, but usually I just mig it up without it.

 

[oldtimer 66]

One other tidbit. It was mentioned in one of the other threads. Make sure the hole is oversize. You may want to make it even slightly larger. The method here is to drill only in the weld metal. If you are re-drilling partially in the parent material and partially in the weld material the drill bit will walk one way or the other. I have never had the weld material and the parent material match and have the same machining properties. As per another thread if you are going to mill the hole then don't worry about it. Later.

 

[arrow]

This was nothing critical. It just bothered me that it did not match the other side on the tractor bucket area. It was purely cosmetic and I have a peculiarity that if I do something wrong, I should pay for it by punishing myself with the hard way and do it right. I stupidly grabbed a bit that I thought was the same size as the other hole I drilled 2 days before. As it was going through about an inch of metal, it was time costuming to stand there with a 3/8" hand drill and I have a "patience" issue. When I went to tap the hole, the tap was just swimming in there. Could I have drilled another hole? Yes. . Was I carried away and angry with myself for being a dolt? Yes I was. I needed a fix that made the first mistake disappear. As I do not have a mig, it seems that the 6013 appears to be a suitable rod. Thanks to all for the tips. As it is an inch deep, I'll probably weld it in from both sides. I'll make the hole larger, torch it up tomorrow, stick the 6013 in there and close it up. Then I'll grind it down, punch it, then re drill.

 

[Big Barn]

This was nothing critical. It just bothered me that it did not match the other side on the tractor bucket area. It was purely cosmetic and I have a peculiarity that if I do something wrong, I should pay for it by punishing myself with the hard way and do it right. I stupidly grabbed a bit that I thought was the same size as the other hole I drilled 2 days before. As it was going through about an inch of metal, it was time costuming to stand there with a 3/8" hand drill and I have a "patience" issue. When I went to tap the hole, the tap was just swimming in there. Could I have drilled another hole? Yes. . Was I carried away and angry with myself for being a dolt? Yes I was. I needed a fix that made the first mistake disappear. As I do not have a mig, it seems that the 6013 appears to be a suitable rod. Thanks to all for the tips. As it is an inch deep, I'll probably weld it in from both sides. I'll make the hole larger, torch it up tomorrow, stick the 6013 in there and close it up. Then I'll grind it down, punch it, then re drill.

Haha. Quote 'a patience issue'. I'm stealing that one, Lou.

Terry

 

[AGRIMAN]

Heli-coil?

If its not to far oversized, that's what i would do.

 

[mikehaugen]

If this hole is going to be tapped, I think that is going to present bigger problems than drilling

 

[arrow]

If this hole is going to be tapped, I think that is going to present bigger problems than drilling

Oh great.... So I take it weld metal doesn't tap well?