Welding Tips and Tricks

I've only done a little bit of stick welding with a cheapo welder from Harbor Freight. I mainly burn 6011 or 6013 on mild steel. Now, I have a delima. My 05 Altima has a very common problem where the floor boards rust completely out. Mine are so bad, the only thing between my feet and the road is a thin piece of plastic and some carpet. I need to cut out the rusty spots and weld in new, clean metal and I'm not sure the best way to do it. I've tried 18 ga with my stick but it just burns right through it. I also have access to a Lincoln flux core machine from work but I've never used a wire feed. It's a 110v machine and it's very small and portable. I'm sure I could get the hang of it with a couple hours of practice. That's what I did with my stick welder. If I can do this with the Flux core machine, what would be the best method? I've seen where the patch is overlapped with holes drilled and spot welded and I've seen where the metal is cut to exactly fit the opening. I think the overlap would be easier but not sure if it's the right or best practice. Thanks for any suggestions

Welcome, cyberphreax,

For your experience level, equipment available, and the location of the repair, I HIGHLY recommend doing the overlap, drill, and spot. You can use automotive seam sealer after, to make it air/water-proof. It's less work, offers you better results (a little rosette weld with a 110V FC machine is more do-able then a butt-weld or a full lap-weld.

Look at how the seams on your door are put together, especially at the bottom where no one sees it, and you'll see it doesn't take that many welds to make one hell of a tough connection.

Steve S

Thank you Steve. I really appreciate your input. What kind of seam sealer would you recommend? I have some rubberized undercoating in a rattle can that I was going to spray on the outside. Would that be Ok for the inside too?

There's an automotive product, available at any auto store with a real paint/body department, literally called "seam sealer," that is tough as hell and made just for this purpose. On the outside, though, you'd still topcoat with the undercoating to protect the exposed metal, therefore:

A good rubberized undercoating should serve nicely on it's own. I'd suggest doing the outside first, using a putty knife to mash a first coat in the gap, then hit it with a second coat. One or two coats without additional work for the inside should be plenty to keep a spilled beverage from getting under the lap.

Good luck, and don't be shy about putting up some pictures as you progress. Perhaps someone will spot a detail or give a suggestion to make it easier/better.

Steve S

Welcome to the forum.

Welcome!!