Welding holes closed...

[trapin]

I have to weld 4 holes closed on my subframe. They resulted from a bad Guldstrand Modification (the drill bit walked on me). What is the best technique for doing this? I have a Miller 135. Thanks.

[rohrt]

Use a larg piece of copper on the backside and start welding. Weld dosn't stick to it.

[astroracer]

Are you going to have to redrill the holes? Just welding them closed will make them even harder to drill. I would have to see the area you have to work with but you may want to consider cutting the area out and welding in a new piece to give you room to drill...
Mark

[Camaro Zach]

if you don't have acess to the backside to back it up with copper then just use your standard settings for the thickness of metal and start filling the hole in a circular pattern untill its completely full. Grind smooth and redrill. If that doesnt work then i would do what mr. astroracer said.
Zach

[trapin]

Mark...can you explain why they would be harder to redrill after welding them closed? Is the material that gets deposited during welding more difficult to drill through?

I'll post a pic of the area in here when I get home from work today.

Thanks.

[astroracer]

The weld is a lot "harder" then the virgin steel. If the new hole is half on/half off the weld it will be near impossible to keep the bit centered due to the softer parent material allowing the bit to walk. If you had access to a Magdrill the ability to maintain the bit on center would be improved. Another problem is incomplete welds, air pockets or voids which will grab the bit.
Not that this is impossible to do but the inconsistancies and harder material make drilling it more difficult.
Mark

[mikey]

You could partially weld the hole shut. Then use a pointed carbide burr in a die grinder to ream it out to the proper size and location.

[EFI69Cam]

The weld is a lot "harder" then the virgin steel. If the new hole is half on/half off the weld it will be near impossible to keep the bit centered due to the softer parent material allowing the bit to walk. If you had access to a Magdrill the ability to maintain the bit on center would be improved. Another problem is incomplete welds, air pockets or voids which will grab the bit.
Not that this is impossible to do but the inconsistancies and harder material make drilling it more difficult.
Mark

The weld is harder than the hinges on the gates of hell.

[trapin]

I'm going to weld the holes closed and just leave it. I plan to upgrade my spindles to the tall ATS/AFX spindles in the near future. Then I won't need to do the Guldstrand Mod. Thanks guys.

[toxicz28]

The weld is harder than the hinges on the gates of hell.

What do you use to weld? 10018, hard facing, or tool steel???

[Siroadrnr]

pilot holes, pilot holes, pilot holes!!