Help With Welding In Flanged Repair Panels

Guys,

I'll soon be welding in rocker panels from Classic Enterprises. They have the offset flange for a lap weld. Old metal is already trimmed and the panel is fitted, ready for welding. Any advice for a novice welder and body man? I have a MIG with 75-25 gas, unsure of wire size. So far I've patched in floor panels with not-so-awful butt-welds. I need to do a better job for the "money shots".

Thanks,
Chilly

Thanks,
Byron

 

Do NOT hurry or you will warp the panels. Tack it in place, then tack in between the tacks letting the previous ones cool. Then tack, let cool. Repeat until all the tacks come together to form welds. Also go slow when grinding down the welds. You can warp the panels just as easily by getting the metal too hot from grinding too heavy and/or too fast.

Edit: I'd also suggest using some scrap the same thickness to get your welder set up properly and do some practicing before welding on the real thing.

 

I like an angled die grinder with sanding discs for knocking down the welds. I use .023 or .024, I think it is, wire and take my time, as Nick said. I tack a spot, then move to a spot as far away from that spot as possible for the next tack and, keep working like that. Not sure if that's the professional method but, it seems to have worked for me thus far.

 

Yup, Nick and Dave have good advice. I use .023 wire. I also make use of wet rags and compressed air to keep it cool. Don't let your tacks get bigger just because everything is going good. Take your time.

 

I would avoid the wet rag or compressed air. That might cause warping to. Just take your time and skip around.

 

All the above and make sure your metal is bright and shiny. No paint, primer or rust. When you blow a hole through take a piece of filler wire and manually insert it into the hole and mig weld it in with pulses.

 

Thanks for tips. I have 0.30 in the welder right now. Maybe I'll run to store for lighter wire.

All floor patches are in, welded from bottom with butt welds. Figure on touching up welds from the top. Hat channel having the body mounts was rotten on ends so cut that out and prepped area for installation of replacement. Front floor panels and transition step are also in. Last big body welding tasks are rockers and replacement of entire rear panel. Then primer, filler, paint. Getting close.

Chilly

 

figure out the size of your wire, and get as small of wire as possible, bigger wire usually means hotter, and burn through on sheet metal.

 

.023 wire and slow spot welds they should be cool enough to touch before you weld any more. the flanged edge will help with the burn through. patience is the key...

 

Been finishing hat channels and floor pan, ready to tack in a rocker. Should I rosette weld from the inside of the flange every few inches, then weld the outside of exposed seam? Or simply weld the outside of the seam? Without rosette welds will contraction of seam weld sort of fold the seam creating a shallow valley?

 

Bumping this very old thread because I am about to do the same thing this week and have the same question, as I have also never done this before.

The Classic rocker replacement panels flange laps up behind the factory steel - I get the approach of tack/move/tack along the seam on the outside - should I do the same thing on the back side too?

Held over roughly (the new steel will be behind the old steel after I cut along the line)

 

Grant, I’ve never welded a flanged panel.
There is a tool for flanging and punching holes for rosette welds. Hopefully someone with more skill will chime in. My rocker panels from Midwest military are not flanged so it’s a butt weld.

Looking at the panel in the photo it looks almost as if the flange should be on the other side. Maybe it’s a an optical illusion? Because you mention the panel will be in the back or to the inside.

if that’s the case I’d weld on the outside as shown in that short video I posted below, which isn't a rosette weld that requires a hole.

go easy on the grinding and avoid a flap wheel in this case as they can really take off to much metal. A sanding disk is better.


Flanger And Hole Punch Combination Tool

edit: I use an Eastwood weldthru primer that would be good to spray in that overlap area.

 

Yeah for a professional photographer I took some bad pictures! Here are three other angles:

Looking at the Classic replacement panel side-on:


Showig the lap with a piece of scrap in place for where the factory body panel would be:



And holding up a piece of scrap looking at the "back" or inside of the joint:


Interesting idea to add a flange to the edge of the factory metal...guessing Classic just expects most folks to weld the front "valley" and grind flush, but leave the raised lip on the back?

Edit - or are you meant to trim most of the flange off just leaving the ~45 degree valley?

also here's a Good primer on Rosette welds: How to Make Perfect Rosette or Spot Welds with your MIG Welder | Eastwood Blog

 

I think welding just the flanged panel to a non flanged is totally acceptable.

In fact the fit up you show in the second photo looks good. I wouldn't worry about adding a flange to the Jeep steel.

keep in mind I'm a newbie to all this too, so take my advice for what it is

 

Yeah that is what I think too, but I would love to hear from some of our more experienced fabricators

 

If you leave the flange on the inside, you need to fill and cap it off some way. If moisture get in, there will be know way for it to get out.

 

Keep the flange on the inside, it is designed (shaped) to work with a flat piece of sheet metal. Weld the outside a tach at a time and skip around to keep cool. Do some and go work on another area, and come back. In my opinion: leave the flange on the inside(don’t cut it off), and use a two part seam sealer on the inside to seal the open seam from water and mud. Oh, and zinc weld-through primer on the weld location helps reduce corrosion in the future. Be very carful when using a flanged repair panel as a template. It is very easy to forget to adjust the mark and cut off too much on your tub. Good luck with your Jeep!

 

I have a tube of SEM Sprayable seam sealer, do you think that is a good product?

 

Sem makes some good products. Obviously, the key is to make sure moisture stays out. I know Sem has a few different options for sprayable sealers. One style more or less would be similar to a caulking gun. Another sprays the sealer to look like cottage cheese. If the latter, us an acid brush (small paint brush) to make sure the seam in your flange is filled first, then you can go back over with with cottage look. This will almost hide your flange.
I actually plan to use the Sem tint-able spray in bed liner (if they still make it), inside my tub to cover up some flanges. Just my thoughts, others may differ.