Cleaning (welding related)

[Damn True]

Ok, so I plan to finish the welds on the front subframe of my '68. As it sits now it is sorta stitch welded and there are a ton of gaps.

I understand than any effort put toward cleaning the metal prior to welding will be rewarded by much better looking and more sound welds. But I ask you this:

What would be the best way to clean the area where the two pieces of material are overlapped or right in the crevice of the lap? No way to get a grinder or wire brush in there.

[Matt@RFR]

Torch, laquer thinner, compressed air, in that order.

[crashbox455]

matt-

can you explain the process more specifically? i'm about to tackle the same thing.

[Matt@RFR]

You would play the torch over the lap joint to burn off all the grease, grime, dirt, boulders and small children that may have found their way into the joint. Take care to not heat the steel too much; not much over 200º-300º and it'll be fine. Wear a respirator!

Then do your best to get the laquer thinner (or MEK, Acetone, etc.) into the joint itself.

Shoot the compressed air into the joint to assist the laquer thinner in carrying away all the bad stuff (especially those small children, they don't weld so good).

It won't be perfect, but it's about as good as it'll get without taking the frame rails completely apart.

Ofcourse you would grind, sand or wire brush everything you can get at. Do this after you do the above though, so anything that gets boiled or washed out of the joint won't spoil your previous cleanup.