The Stovebolt Site Forums The Shop Area Paint and Body Shop Fender Patch panel forming

Working on a patch panel for the tail of my Right Rear fender. Pretty big rustout, so I cut a 6x13 inch piece of sheet metal and went to town with a mallet and sandbag. It's getting there, but still a ways to go. I may have to put a v-notch in it and weld that back together to get it to curl around the rear of the fender. It's my first attempt at forming a compound curve and I may have gotten too much curl in the short dimension.
Pics:
Rusty Fender
Sandbag forming
More hammering
Fitting up

Also did a few other patches to that fender to fix the rust that grew behind the crown brace. Also in flikr - hit < after viewing the photos linked above.

That looks very good for your first time! Take your time when you weld so you don't warp it and you be proud you saved a original fender.

Nice job on the hammering, but I would suggest using the V-notch as a last resort only. Do some research on stump shrinking, the corners you show there could easily be formed using this process.

Thanks for the compliments, guys.

Robert, I haven't given up on the hammer forming yet. I have looked at a couple of videos on stump shrinking, but finding an oak stump in the middle of winter in Alaska might be a chore. I do have some birch logs, and might give one of those a try. They're not as hard as oak, but are still pretty hard wood.

Wow that fender is rusty! I thought that I had brought back some nasty ones. You got me beat. I have a TIG welder which allows me to neatly weld together smaller pieces which are easier to form into shape.

Yeah, this truck started it's life as an Alaska Road Commission truck. It has/had road tar all over the underside of the fenders, and evidence that someone drove it with broken tire chains. So the chains knocked off some of the tar, letting rust get a toehold. I think it also worked on Seward Highway road project along Turnagain Arm east of Anchorage, so probably had some exposure to salt water as well.
I have experience with rust-outs from back in the 60's working on my Model A's, but original parts for those were easier to come by.

Finally got hold of a suitable log to try out stump shrinking. Actually worked pretty well. I managed to get my patch panel formed to match the fender contours.
Patch Panel in place
rear section
front section
In that last photo, the log can be seen in the background. I still need to roll the front edge, but was thinking to wait till it's welded in place before forming that segment.
Does anyone have a recommendation on how to weld it in? I was thinking of tacking it in place in a few spots and then cutting the old metal away. The lower brace also needs replacing, but will do that after the patch panel is in place.

Lookin good; take some more pictures of your stump if you can.

I'd recommend forming the patch before you weld it in place.
Robert / MP&C has a great writeup with some procedure and pictures. (I am assuming you are asking the procedural questions about "how" to weld it in - otherwise MIG,TiG,and Oxygen / acetylene welding will all work).

Brad

Thanks, Brad

Actually, I was planning on forming just that last roll at the wheel opening after at least tacking the patch in place. My thought was it would be easier to match the existing roll that way. The main part of the patch lays close to the contour to what remains of the existing metal.

My question was more directed at whether I should cut a big gaping hole in the fender the shape of the patch or use some of the remaining metal to hold the fender shape till the patch is tacked in place, then cut out the rest of the rusty old stuff.

I do have MIG and O/A capabilities.

I'll try and get a pic of the stump posted up. I cut it out of a white spruce log that I tracked down. The bowl is about 2" deep - used a skil saw to cut it, then finished up with a chisel. It's not that pretty, but does the job.

Back when body men actually repaired things, we had a tool that fit an air hammer to put a 1/2" wide flange onto a body panel, stepped down just enough for a patch to fit flush. It made welding patches much simpler. I've still got one stashed away somewhere, but I'd rather have a root canal without novocaine than do body work!
Jerry

I have seen upsetting tools like you're talking about, but a plier affair.

Sounds like you've burnt out on body work. Some of us haven't. Of course I've never done it for a living. It that were the case, I'd probably be living under a bridge somewhere, as slow as I am.

Looking at your pictures, and taking into consideration the rusty/banged up condition of your existing metal, I would form the patches to closely match the contour of the existing panel and trace the outside edge of your patch and cut out the existing metal for a tight fit. Then you can butt weld it a spot at a time, spaced out the length of the panel to prevent warping.
Carl

Before I saw your post, I decided to go with the huge gaping hole in the fender, but I did weld in a scrap between the bottom stiffener (that will also get replaced after welding the patch in) and the metal to remain at the wheel opening. That helped keep the fender in shape instead of having it flopping in the breeze.
Here's some more pics.
metal shrinking stump
Stiffener
Cutting out the bad stuff
Gaping hole
Clamped in place for welding

I hear you on that one. But... slow is the way to go with sheet metal, so carry on.

As far as matching the existing curve, I would say to try a flexible shape pattern to make a profile, but I do not know how to explain it very well, or if it would be appropriate in this case.

Also, that stump looks like a purty one to me. Keep posting your progress; it's cool to read along.
Brad

Nice work using the stump, that patch looks as good as anything you can buy..

Thanks, Robert

Coming from you, that means something. I could have bought a patch for $100 + shipping but would have missed out on all the fun and experience making one from scratch.

More progress on the fender.

inital welding
welding mostly completed
Welding wheel opening edge
Wheel opening forming using a bit of heat
New lower stiffener - not much left of the original

About 8 hrs worth of work.

very cool! i just brought home a truck in the same condition, and this gives me some hope.

Congrats on the truck. Just about anything can be patched. Plan on LOTS of hours.

Another patch on this fender. After this only the front patch at the running board to go, then get it blasted and weld in the mounting flange backers.

Click here one more patch and hit the left scroll arrow to follow along on the progress on this one.

Here's a few shots of the last patch I did on this fender. This is a Jim Carter patch for the front of the rear fender. All that's needed now is to finish grinding a few welds, then get it blasted and weld in the mounting flange backers.

Rusted out running board mounts
Bad stuff cut out
Patch tacked in place
Finished patch

Awesome job. Come do mine!

LOL, you don't have time to wait that long. That was 6 hours of work yesterday.
But thanks for the comment.

So you spent 8 hours on the first one and 6 hours on this one. That's a 25% increase in efficiency. Next thing you know, you'll be banging these out in 45 minutes!!

Keep up the great work.

Yeah I'd be ecstatic if it was 45 minutes each. LOL.
Thanks

I am working on same area of rear fender. A body man suggested that instead of trying to make one big patch panel make 3 or 4 panel to help deal with compound curves. So far have 3 smaller panels completed working on 4th to finish complete panel. I know this requires much more welding and grinding but my skill level with hammer is not up entire panel. Old Norse

I used Jim Carter's front patch panels and was happy with the quality and fit. I had pretty good success with forming that rear tail patch shown in the photos. It was my first attempt at compound curve forming and the stump shrinking worked out well after I had got most of the curve done using a nylon mallet and sandbag. Just keep hammering and fitting. The panel is a bit lumpy from the hammering, but that will come out once I work on it a bit once welded in place. The hammering isn't that hard. I'd give it a try rather than the multiple smaller patches. Welding and grinding is more work than hammer forming, IMO. And there's more possibility that you will warp the fenders with more welds.
Good luck.

Klhansen, one of your photos shows a magnetic holder for patch panels. Where did you get that?

If you're talking about the triangular shaped gizmo, that's a standard welding supply magnet. Any welding supply place should have them. They're also available at Harbor Freight, http://www.harborfreight.com/4-3-4-quarter-inch-multipurpose-magnet-holder-1938.html but they have to be shipped by ground, because they supposedly screw with aircraft instrumentation unless packaged in a shielded container. So I wound up buying mine locally.

I can't prove this, but have been around for many years in this resto thing, and have seen that lately the metal used in patch panels from the vendors has been changed to the proper stock gauge. 20 years ago (true 5 years ago too) when you ordered a floor panel it was of lighter gauge than original. Last week I ordered the same thing and it is obviously thicker and completely meets the stock criteria. I am still skeptical of its fit, but time will tell. Since Butt welding is really the cleanest, best way to weld in patch panels, use only the part of the new panel that you need and use butt weld clamps to do the work.

For those of us who have been doing this for awhile, it's nice to see the vendors finally listening to the restorers in a simple decision to use the correct metal gauge!

Worked on another patch panel for the rear of my LR fender today. Still need to work on the rolled edge where it curves back to the bottom of the fender.
I had attempted to weld the cracked sections back together using Oxy-Acetylene, but decided to cut it out and go with another hammer formed patch panel, because the welds looked like bird s***, even after some grinding.
crap that I cut out
Click on the left arrow to follow the progress.

Kevin, after you used the sand bag and forming hammer, how did you planish the final finish? I was thinking of getting a planishing hammer from Harbor Freight. I can get one for $62 with my 20% off coupon!

Basically, I planished with a body hammer and all-purpose dolly. Still a work in progress, being a little dimpled yet. I got a planishing bit to go into an air hammer and tried that on another panel, but it was way too hard to control it and the dolly. For $62, a HF planishing hammer might be worth looking into. Looks like the stand is another ~$25, which might be good unless you already have something you can bolt it on to to be able to control the fender while you're planishing.

Good luck with whatever you wind up doing.

For someone without the mechanized tools for metalshaping, much can be done still with simple hand tools to limit the damage done to the panel. For adding stretch, pounding sporadically into a sand bag will quickly add "walnuts" to the panel, where a less aggressive method of methodical, precisely located overlapping strikes will limit the size of the walnuts, and more importantly the DAMAGE we need to fix. As with most anything we accomplish in our restorations, match your efforts to the tools within our disposal. If you don't have a planishing hammer, don't beat the panel to death that it can't be completed without one.