I need to mig weld holes in door where old mirriors used to be,do I need to put a backer or just fill hole and grind flush,Im not sure,replacing with baby west coast Ford mirriors.THANKYOU IN ADVANCE

 

Put a piece of copper on the back of the hole that you are welding.

 

WHY COPPER JUST CURIOUS

 

If the hole isnt too big, then can be welded and ground smooth. 3/8 or bigger, i would cut a piece of sheetmetal and weld that in. Just my 2 cents.

 

Use copper as a backing. The wire dosent stick to copper. Copper backing, then hole can be welded shut.

 

You can actually pick up a "copper spoon" at a welding shop for what's been mentioned above. Other than that get some tin snips and create your own fill material.

 

Alternatives to buying a copper spoon is to use a piece of ceramic tile or a short length of copper pipe...just smash down one of the ends smooth with a slight curve. EZ.

Up to a 3/8 diameter hole can be welded closed. Bigger than that? Then do as suggested above and cut out a slug.

Jr. West Coasts? Right on! I wish I had the room to use 'em but parking stalls and my 10-foot side yard makes 'em a shaky proposition. Kudos to going really retro.

 

Jr. West Coasts? Right on! I wish I had the room to use 'em but parking stalls and my 10-foot side yard makes 'em a shaky proposition. Kudos to going really retro. Thankyou,Iv'e had them quite a while,riding through the country one day saw a farm truck just pretty much shot rusted away with the mirors on sitting in the feild,I went and knocked on the farmers door and asked if he would be willing to sell mirrors,he told me anything you want on that truck you take it,so I went and got the mirrors and other small items and knocked again and gave him 20$,so thats been my plan aluminum ag flatbed and Jr.West Coast Thanks to all you welders for input.