Butt welding help

[Caboose]

Would you add more weld or a skim of filler? These are tiny pin holes on cab door skin for the more experienced out there what would you do any help appreciated thanks in advance.

 

[StuF]

Clean surface back to metal, unless thats weld through primer?
Personally would reweld to close the holes, grind back to a smooth surface and see how it looks
Metal is always better than filler in my view

 

[radish]

get a piece of copper pipe behind it, it helps it from blowing the holes open

 

[davidoft]

are those holes where its been repaired before ? or rust holes?

 

[Caboose]

Thanks StuF, yes that's weld through primer I'll tack closer to holes.
Thanks radish I have an old copper cylinder outside so I can cut a piece to go behind door skin..
Thanks davidoft those holes are where I have welded but haven't got as close a I thought with the next weld

 

[chug]

what I do is lots of small tacks along the length, grind back but not all the way yet, then add more tacks building onto the previous into the gap between the panels.
Repeat until its fully welded, 9 times out of 10 this won't leave any pin holes.

 

[Caboose]

Cheers chug I shouldn't of grounded them back all the way

 

[subheatadey]

The trouble wit grinding welds if your not cafeful on all ready thin metal is you can be left trying to weld something with the consistency of tin-foil. Sometimes it best to cust your losses and cut back to good metal and put a freshh piece in.

 

[cunning plan]

get a piece of copper pipe behind it, it helps it from blowing the holes open

Please could you explain how this helps? :?:

 

[sparkywig]

get a piece of copper pipe behind it, it helps it from blowing the holes open

Please could you explain how this helps? :?:

The flattened piece of copper pipe is held tight against the rear of the weld, prevents blowing through and the weld doesn't stick to copper.

 

[radish]

get a piece of copper pipe behind it, it helps it from blowing the holes open

Please could you explain how this helps? :?:

The flattened piece of copper pipe is held tight against the rear of the weld, prevents blowing through and the weld doesn't stick to copper.

What he said

 

[KateLovesPurple]

Yep, as above.

I use a short length of 22mm pipe, flattened apart from one end, which is then rammed on to a short length of broom handle so it can be held easily.

 

[Caboose]

Cheers subheatadey, cunning plan, sparkywig and radish thanks for all your help, I do have a piece of copper pipe flattened I'll use it when I address the pin holes. The panel that's going on is an old repair panel from another door both cut back to good metal, So no thin parts.
Appreciate all the replys thanks again.