ways to weld body holes?

[oregondime]

so i finally bought a welder. havent touched one in 3 years. ive been trying to figure out the best way to weld up the holes. ive welded up a few small holes by cutting a patch, mounting it behind, tacking it and filling it in on the outside then grinding to make it flush.

 

whats the best technique for doing a butt weld without blowing through?

just how close should the gap be?

 

im really curious on how people have been welding up the running strips (510) as well..

[jesusno2]

well if you can get behind the hole with a peice of copper brass aluminum (non ferrous) metal that works great for a backer the weld will not stick to it. and you can just fill with weld. if you cant get behind it clean the area down to bare metal. set your welder as low as it will go. and tack all around the hole to build up the metal. then slowly keep working your way around it slowly moving inward every tack until filled. then sand smooth and repeat.

 

 

 

 

lol i just noticed this post could get very sexually crude in a hurry! such as, "bigger holes are hard to fill and require alot of time and patients!" lol.

[72240z]

I agree with jesus? lol

 

With the butt welds you should be stitching at a lower setting and the gap should be as little as possible. I try and be flush on all sides.

You want to go from side to side tacking (stitch welding) one so you dont blow through with a super hot bead and two so you dont warp the hell out of the area.

 

Hope that helps.

 

This is from my build thread as an ex.

Edited October 19, 2009 by 72240z

[MikeRL411]

whats the best technique for doing a butt weld without blowing through?

just how close should the gap be?

If you truly want to butt weld, the gap should be as narrow as you can get it. Use a "backer" strip tack welded to both sides of the patch and the fender. Fill the gap with weld turning the fender so that you are welding upwards from bottom to top to get proper fusion between passes and let it cool. Then comes the hard part! Grind the backer strip and tack welds off. If there are gaps in the back, fill them with weld. Now grind smooth on front and back, clean like you have never cleaned steel before, prime and paint. You have to remove all traces of the backer strip or you have just created natures preferred nest for rust.

[72240z]

Ya but you should note butt welding a straight bead on a datsun body is almost always going to result in warping no?

 

Non bodywork I agree 100% though/

[thisismatt]

On the rocker panels of the 510 you can get to the back of every hole, albeit not with a welder. But, you can fish a panhead or wood screw through from the back and then weld it in from outside, holding the screw tight against the inside with some pliers gripping the shank. Then cut off the shank and grind/sand smooth. The screw head will give you backing to weld to without blowing through the sheetmetal.

[oregondime]

On the rocker panels of the 510 you can get to the back of every hole, albeit not with a welder. But, you can fish a panhead or wood screw through from the back and then weld it in from outside, holding the screw tight against the inside with some pliers gripping the shank. Then cut off the shank and grind/sand smooth. The screw head will give you backing to weld to without blowing through the sheetmetal.

 

 

i like that idea, ill have to try that with the fenders