Reefer floor repair

What you’re describing is called “brazing”
YouTube to learn how, it’s not hard, just got to do it right and set the metal evenly and keep it really clean prior.

if you’re bad spot is aluminum you can braze with aluminum brazing rods and a matching aluminum plate (cut to fit space). Make sure they’re the same type of aluminum grade.

you can put some steel under the spot to avoid burning the insulation (aluminum won’t stick to steel) , but aluminum dissipates heat really quick so you could “spot” braze it if you’re afraid to burn under.

KEEP IT CLEAN, or the aluminum will have bubbles inside the weld that will crack

 

i would try to figure out a way to cool the underside while applying heat on top, but I’m normally over cautious.

maybe a waterhose fastened to a saw horse with a vice grip and zips? Lol

 

If the floor is cracked from flexing, welding it won't fix a thing. If something hit it and gouged a hole you can weld that back up.

You don't have to worry about the foam, unless you put heat directly to it.

 

If you get the Hobart 210MVP with the spool gun and correct gas bottle, welding the inside of a trailer is a breeze. It welds it like a champ. Make this your dedicated aluminum rig. The spool gun is best because the aluminum wire is soft. It is fast and does not heat up the insulation unless you are welding a long stretch. It is pricey, yet, once you get it dialed in, welding aluminum is like zipping up a coat.

 

This is true. I tried the rods back in 2012 or earlier. Just would not work for me. I bit the bullet and purchased this Hobart mig. At the time, Northern was running a special on the 210MVP with the spool gun for $899. The bottle was another $300. It is a dedicated aluminum welding unit. We have probably used it twice. Once on a floor crack from a forklift fork. Once on a hood bracket for a whopping total of about 8 inches worth of weld. Yet, like I stated, once dialed in, that puppy flat out welds.