Tools & Fabrication - Basic Fab question

When welding a plate to the floor, ie- plate for cage, do you remove all the paint from in between the two surfaces?

If you do it this way is there concern about future rust issues?

Or do you use a weld through primer?

Thanks-
John

you have to clean the metal if you want a quality weld. I use aircraft paint remover and .023" wire to weld them. I would not clean it with a grinder cause the metal is pretty thin to begin with. Wire brush it and paint it good after welding and you shouldnt have rust isses.

What about rust between the two (after welding)?

Yeah, you want the metal as clean as possible when welding, or else the weld will turn out like junk. You can also try a grinder with a sanding disk on it so that it will take very little material off.

I don't think they got your question...He means like if you take a 4x4 piece of plate, and are welding it to the floor boards, should you remove a 5x5 section of paint? Or just the area near where welding will take place, leaving say a 3x3 section still painted that will be underneath the 4x4 piece of plate. Dunno if that helped or not, sorry I cant actually help you with your answer.

-Will

Will is correct...will rust ever start between the two pieces if all the paint is removed?

Wouldn't the weld be airtight?

Will is correct...will rust ever start between the two pieces if all the paint is removed?

Removing all the paint is not necessary, only the paint in the area where the 2 surfaces are being welded together needs to be cleaned to bare metal for good weld penetration. After welding, prep and paint the area just welded, it's simple stuff.

Just clean the paint off where you will be welding, not underneath it. Clean the edges of the top plate and the surface your welding on.

I've had no problems with just cleaning around the edges of the plate, but if you're concerned then weld through primer is probably the best way to go.

If you weld all the ya round the seams it wont. You need oxygen and moisture to create rust. If the whole seam is welded there is no way for moisture or oxygen to get in.

Just where the weld is will be fine...and be sure to have all surfaces clean (sanded/grind)

you have to clean the metal if you want a quality weld and if you use a seam seal after this will help with a good paint