Question for our metal fabricators!!!

[rwhite692]

I shoot for almost no significant gap when making patch / filler panels...Maybe .010" all around... You just don't want the filler piece to be tight in the hole when "cold", since it can bind/distort when it expands when you start welding on it...

You also want to dial in your heat and wire feed such that your weld bead lays out almost flat, as opposed to being a big "log" of welding wire bead that is sitting way up high that you will have to grind a lot down. As GW already said you don't want to be trying to hammer and dolly to manipulate weld sites.

To avoid distortion make many small tacks to get things in position, carefully grind those tacks flush, then clean all of it and prepare for the actual welding...Do about an inch of bead length at a time, let it cool, keep a wet rag nearby to help cool off the nearby areas...