Weld it up or no

[jimmyleetn]

I probably have a tail pan that's in the top 90th percentile of south eastern trucks that haven't been restored yet. I did find these pitted up areas one has two holes through it. I'm plenty capable to fix it but I'm not sure what I should do. Should I just weld up the pinholes and the deep pits or should I just cut that out and replace it. I know it's rusting from the top down because there is still paint underneath. I'm just going to buy some 13 gauge steel to replace it if I have to cut and patch it. I guess basically I just don't want to do work that's not necessary. Of course I'll paint all this up where it'll never rust again once I'm done. What should I do, weld it as is or cut, patch, and then weld it?

 

[Mdjunior]

I’m no professional welder, but you probably have not much more time involved cutting it out and patching

 

[Blue85]

1st question is why did you cut that open?

As far as the tail pan in concerned, it's way less work to sandblast what you see than to cut out portions, weld and move forward. Assuming you'll put new floor metal in, this is neither a structural nor a cosmetic issue, only one of which will repel corrosion longer. I have more faith in factory sheet metal than a bunch of welds and random stock. Sure, put a few spot welds in to close the holes, then seal up on both sides. It's less of a rust magnet then many inches of new cutting and welds.

 

[jimmyleetn]

1st question is why did you cut that open?

As far as the tail pan in concerned, it's way less work to sandblast what you see than to cut out portions, weld and move forward. Assuming you'll put new floor metal in, this is neither a structural nor a cosmetic issue, only one of which will repel corrosion longer. I have more faith in factory sheet metal than a bunch of welds and random stock. Sure, put a few spot welds in to close the holes, then seal up on both sides. It's less of a rust magnet then many inches of new cutting and welds.

Answer to your first question. On the driver's side I knew it was rusted under there because the bed was started to lift their from all the scale and I could see where those two holes were started to form and spread. It was more of an exploratory cut than anything. If it wasn't bad I was gonna paint it with rust encapsulator and weld it back together. Those sharpie marks are so I can line the old panel back up to weld them back in. That area is notorious for rusting out so I figured now was the time to take a peak and perhaps treat it so I don't have to go in there down road. Once I saw what was on the driver's side, I decided to do an exploratory cut on the passenger's side. I can see all the of the tail pan from underneath pretty easily now that the fuel tank is gone and those were the only areas that looked like the rust monster might be hiding underneath.

I don't have access to a sandblaster unfortunately and that truck ain't driving no where for awhile. I went ahead and ordered the 13 gauge sheet metal to patch the tail pan. I measured the thickness with the calipers to determine that gauge. Making a patch for that won't be hard, I was just really hoping to skate by without doing anymore floor work because it's so time consuming. I finished both sides of the front floor, new striker patches with captured nuts I fabbed myself, and one outer rocker back in July so I'm plenty confident in my abilities, but I am tired of doing floor work. I'm soaking the bed panels I cut out in a rust remover (much like evapo-rust) overnight. They were in usable shape so I don't have to buy a patch that won't fit for beans. Anyways, guess there's more floor work in my future.

 

[Blue85]

Harbor freight sells small sandblasters cheap. At least ask yourself how you will address the underside of the welds (sand, prep, prime, paint).

 

[jimmyleetn]

Harbor freight sells small sandblasters cheap. At least ask yourself how you will address the underside of the welds (sand, prep, prime, paint).

UPOL #2 weld thru primer is what I've been using to keep the underside of my welds and seam protected, but I'll have to take a look at Harbor Freight's sand blaster. The big problem is I don't have a compressor big enough to run high scfm tools.

 

[joshuak]

If sandblasting isn't an option, I've had decent luck removing surface rust like that with phosphoric acid. Sometimes takes a couple applications and some elbow grease, but its worked for me.

https://www.homedepot.com/p/Klean-S...l-Prep-and-Rust-Inhibitor-GKPA30220/100406369

 

[ktmoutfront]

Harbor freight sells small sandblasters cheap. At least ask yourself how you will address the underside of the welds (sand, prep, prime, paint).

For the small amounts and short time needed, a small compressor in short blasting times will do the trick. I use mine frequently. So much cleaner then grinding and wire wheeling. But the sand everywhere kinda sucks. I only use it outdoors.

 

[Blue85]

Yeah, running a sandblaster continuously takes a big compressor, but anything can run it for some amount of time. Then you just wait for it to recharge. Something like the $30 Harbor Freight gun will need to be refilled pretty often anyway. If you can borrow another compressor or air tank you can connect them together for increased capacity.

 

[bp71k5]

The harbor freight pressure pot blasters work ok too with the same limitations.