Overlapping seam rust prevention

[Stefan S]

I’m adding some reinforcement to the bottom lip of my cargo trailer. It can drag.

The cross member is 3”X 1” channel 11g or 1/8th.

My plan is to weld 3/16” 1x1 angle to the bottom going the full width of the trailer. My concern is rust between two pieces. I’m considering 3 options and wonder what everyone thinks is the best.

1. Seal the seam with weld
2. Use a paintable caulking sandwiched between pieces and weld for connection only
3. A weld through primer On both pieces.

What has worked for this group?

Thank you!

 

[iajonesy]

I'd say weld it on with stitch welds and then use some good automotive seam sealer on it.

Mike

 

[rsanter]

I'd say weld it on with stitch welds and then use some good automotive seam sealer on it.

Mike

This

 

[Hammer1963]

Weld through primer is a good choice provided that you keep the direct area of welding clear of the product. The biggest problem is the moisture created by the sandwiched welding. That's where the weld through primer shines. I cannot stress enough that you need to keep the weld areas free from the primer. Plug welding or spot is a good choice, followed by a urethane seam sealer and etching primer before top coating. DO NOT apply the seam sealer over the etching primer.

 

[bigguns69]

As stated, stitch weld the seams, use automotive seam sealer for the remainder of the joints.

 

[joe_padavano]

Another vote for seam sealer. The weld-through primer will be burned off near the weld locations anyway. The trick is to epoxy prime the mating surfaces then grind it off where you plan to weld. Minimize the heat as much as possible and use seam sealer.

 

[Stefan S]

Thanks all! I’m gonna hit it with 3m weld through anti corrosion coating then stitch weld and seam seal as suggested.

Thanks for all the tips!

 

[ng8264723]

Why not use epoxy primer after you weld the piece and leav tape on the seam. Peel the tape and then use panel adhesive. It will then all be covered

 

[MP&C]

Trailer "skid" wheels under the frame rails at the rear..

 

[Stefan S]

Trailer "skid" wheels under the frame rails at the rear..

These are going on after!!

 

[scale]

i am in the same boat...kind of.
I lap welded some small patches into my truck bed after cutting out some rust holes.

Now im lost.....
Do i put seam sealer on the bare metal before priming or do i get a good self etching primer and seam seal over that? I have read it both ways. Just above in this thread it says not to apply it over the primer. Other places have said.....of course you prime first and then seal. WHich is it?

Also guys seem to say you want a good epoxy primer. Where the hell do you get that stuff that isnt in huge contiainers and $100? I need about 24 inches of coverage. I cant seem to locate any epoxy based primers in the big box stores thus far. I was thinking of just throwing down some rustoleum self etching automotive primer.....then a bead of seam sealer.....then paint. I am probably over thinking it. Of course whatever i do will be wrong in the eyes of 3/4 of folks on the internet and because i didnt use snap on tools it will probably fall apart ....etc etc. You know how that goes. Just looking for the best recommendation. It isnt a classsic car restoration....its an old truck bed....so im trying to not over think it