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Crash0637 11-01-2017 10:21 PM

Body work advice needed
 
I am replacing the lower front fenders with patch panels. The drivers fender is where I started, it is the worst. I decided to go ahead use the entire patch panel. After welding it up I realized that I didn't quite get the angles right nor aligned perfectly. Started comparing it the the passengers unmolested side and noticed a problem.

Not sure if I should just hammer and dolly out the low spot or if I need to cut in reliefs or if I should cut off patch panel and start completely over.

I have done some bodywork before, however this is my first major replacement. I caught my error, I want to make it right, just not sure which direction to go in.

Help and advice is greatly appreciated!.

https://ibb.co/nwP7OG
https://ibb.co/ffbnOG
https://ibb.co/mCQE3G

mongocanfly 11-01-2017 10:31 PM

Re: Body work advice needed
 
3 Attachment(s)
here's your pics...

mongocanfly 11-01-2017 10:33 PM

Re: Body work advice needed
 
I'm no bodyman by a long shot but id try hammer and dolley...if that doesnt work you may need to cut it loose and redo it..
maybe Martin will be along shortly and give you the right pointers...

MARTINSR 11-01-2017 11:11 PM

Re: Body work advice needed
 
Ok, I have to assume your welds shrunk and that is what brought that down. Did you cool the welds? (BIG NO_NO) When you do the metal shrinks and gets harder.

Even if you didn't cool them, the metal still shrinks at the weld as it cools so that is what you need to do.

If the back side looks as smooth as the front side you can "planish" the metal along the weld thinning and thus stretching it out, that could get you back to flat. You planish it by putting a dolly behind it and striking the metal "on dolly" to thin it.

One thing I never understood for years, and it's so damn simple. If you end up with something like this, EVERYTHING that caused it is at the weld. If you had a big warped piece, I remember trying to fix the warp out a long way from the weld. That is SOOOO wrong, the weld is what did it, thus at the weld is where you correct it.

Brian

northern 49 11-01-2017 11:47 PM

Re: Body work advice needed
 
I would start with Martin's advice, but I would also hang the fender on the truck and check your door gap. A lot of these patch panels don't have the same shape as the original, some fit really well, others not so much. When doing sections like this I like to hang the fender on the vehicle and tack the new section in place. This way I can set the gap as straight as possible.
Also, take your time welding and check for warping as you go and carefully hammer and dolly as needed.
Happy metal working!

MARTINSR 11-01-2017 11:52 PM

Re: Body work advice needed
 
Quote:

Originally Posted by northern 49 (Post 8073548)
I would start with Martin's advice, but I would also hang the fender on the truck and check your door gap. A lot of these patch panels don't have the same shape as the original, some fit really well, others not so much. When doing sections like this I like to hang the fender on the vehicle and tack the new section in place. This way I can set the gap as straight as possible.
Also, take your time welding and check for warping as you go and carefully hammer and dolly as needed.
Happy metal working!

Good point there, you are right on, you want the BIG picture.

Brian:metal:

e015475 11-02-2017 12:32 AM

Re: Body work advice needed
 
What you have there looks pretty much par for the course based on my limited experience. As MARTINSR says most of the deformation is locked up in the weld.

The next time you weld a patch in you might think about planishing the weld while it is still hot and alternate between welding and planishing till you've got it welded up. It seems like it is a lot easier to weld and planish if you're welding with gas instead of MIG. The MIG wire seems like it a lot harder too.

I've never been able to get the low spot out after welding by just planishing the weld and I usually have to stretch the metal a little past the heat affected zone too, then work up the low spot with a 'hammer -off'.

I find if I use a slapping spoon and a dolly, I don't have to have quite so much precision hitting the dolly and its a little easier than using a hammer and leaves the surface smoother during the stretching. I spray a light coat of flat black on the area I'm stretching so you can see everywhere you've hit with the spoon - just 'connect the dots' to get a nice even stretch.

Follow a round of stretching with a spoon and a dolly on the heat affected zone with some 'hammer off' hammer and dolly work to bring the metal up to contour.

It usually takes me a couple rounds of planishing, stretching and hammer-off dolly work to sneak up on the weld depression so very little filler is needed.

But there's always bondo when you're tired of screwing with it.

MiraclePieCo 11-02-2017 03:21 AM

Re: Body work advice needed
 
Quote:

Originally Posted by e015475 (Post 8073563)
But there's always bondo when you're tired of screwing with it.

Bondo - good enough for Coddington and Foose. It's highly unrealistic to expect to avoid filler in bodywork. An article I read in Street Rodder magazine claimed that there were probably less than a dozen show cars in the country without some level of bondo.

e015475 11-02-2017 08:14 AM

Re: Body work advice needed
 
It seems like doing metalwork follows the 80-20 rule like a lot of other things - you'll spend 80% of your time getting the dent to move the last 20% into contour.

For all but a few that have the time/money to throw at metal finishing a panel, bondo is a necessary evil- it's just a matter of degrees. Do you want 1/4" of filler or something as thick as a piece of paper?

If I'm really ambitious I'll work it until the remaining imperfection can be covered with featherfill (which is really just bondo you can spray from a primer gun), but I usually stop when a skim coat of bondo (maybe with a little resin honey to smooth it out) will cover my sins.

The OP's work looked pretty good to me. He probably fell into the same trap that I did when I first attempted it - you weld it up and when you're done it looks worse than when you started. Took me a while to figure out that cutting the old piece out and welding a new one in is the easy part and most of your time is spend undoing the damage you caused with weld shrinkage. The lesson learned for me was to do everything possible to minimize shrinkage because that takes work out of the back-end of the process and ultimately saves you time.

e015475 11-02-2017 10:07 AM

Re: Body work advice needed
 
There's a good tutorial on weld planishing over at the garagejournal.com website in the Forums under 'Fabrication & Techniques'

Look for a poster called 'MP&C' which is McCarthy Paint and Customs.

It is a very long post, but the relevant topic of welding and planishing starts here-

https://www.garagejournal.com/forum/...182565&page=26

b-mac 11-02-2017 10:49 AM

Re: Body work advice needed
 
I too have experienced OP's problem.

My question is, what do you experts think about a lap weld in this situation? I usually butt weld like OP, due to the simplicity. But could he have flanged the lower piece in, and used a series of plug welds? Or is that worse because of the strength or potential for rust?

If we were doing this repair with epoxy instead of a welder, like is often done today, it would just be lap, or series of laps. But I guess the epoxy protects the seam from rusting.

_Ogre 11-02-2017 12:56 PM

Re: Body work advice needed
 
1 Attachment(s)
Quote:

Originally Posted by MiraclePieCo (Post 8073590)
Bondo - good enough for Coddington and Foose. It's highly unrealistic to expect to avoid filler in bodywork.

i have to agree with MPC; in a perfect world you'd fix it or cut it out
my trunk had a similar pucker in the weld when i sectioned it and no access to the back side
it was my first attempt at welding 22 gauge and my welder is fluxcore :D
i filled it and moved on, 32,000 miles later i still can't see the filler
that and i learned from my mistakes

i'd also follow northern49's suggestion to hang the fender and check the fit

northern 49 11-02-2017 02:33 PM

Re: Body work advice needed
 
There's no Bondo on anything I have ever done...I use Evercoat..haha.
Sorry had to be a smartass.

northern 49 11-02-2017 02:40 PM

Re: Body work advice needed
 
Evercoat's Rage Ultra is what I would recommend. Very nice to sand.

b-mac 11-03-2017 09:52 AM

Re: Body work advice needed
 
Quote:

Originally Posted by _Ogre (Post 8073831)
i have to agree with MPC; in a perfect world you'd fix it or cut it out
my trunk had a similar pucker in the weld when i sectioned it and no access to the back side
it was my first attempt at welding 22 gauge and my welder is fluxcore :D
i filled it and moved on, 32,000 miles later i still can't see the filler
that and i learned from my mistakes

i'd also follow northern49's suggestion to hang the fender and check the fit

You did all this with a FLUXCORE WELDER?!!! WTH?!

MARTINSR 11-03-2017 10:08 AM

Re: Body work advice needed
 
Quote:

Originally Posted by b-mac (Post 8074400)
You did all this with a FLUXCORE WELDER?!!! WTH?!

I know really? The dude is a stud for sure!

Brian:metal:

mongocanfly 11-03-2017 10:22 AM

Re: Body work advice needed
 
reminds me of as a kid watching my dad weld up a cracked truck fender with his old AC stick welder with 6010s....and its still holding

_Ogre 11-03-2017 06:15 PM

Re: Body work advice needed
 
3 Attachment(s)
not to hyjack this thread...
but i love to hear the welder snobs say ''you can't use a 120v fluxcore to do that''
i say move over and let me show you how it's done :D

95% of truk was welded with my lincoln weldpak100
mustII, boxed frame, x-members, motor mounts, trans mount, hydroboost bracket, spring pads, all the bed fabrication and 2/3 of the sheet metal patches were welded with that bad boy

all the curves on the bed were fabricated with 2.5'' muffler pipe and flat stock :D

_Ogre 11-03-2017 06:19 PM

Re: Body work advice needed
 
1 Attachment(s)
uno mas :D

my56chevytruck 11-03-2017 07:42 PM

Re: Body work advice needed
 
my .02 worth is as some have said, if you didn't work the weld while you could, then do the bondo thing. or as northern 49 has said, use Evercoat. Start light and bring it up gradually. I learned that the wrong way, lol

BIGglaSS 11-04-2017 01:50 AM

Re: Body work advice needed
 
Lots of good advice here.

Crash0637, that is sunken from welding. If it was butt welded, you should be able to work it back out by stretching the heat affected zone (HAZ). If you cut the angles wrong, you will have to cut it back off to re-align it. Also, grind the bead off the back side before hammering.

ALL welds shrink. It doesn't matter if you cool it or hammer while hot. They ALL shrink. The secret is keeping the HAZ as small as possible. ALL welds shrink = ALL welds have to be stretched.

Learning to work a weld takes a lot of practice and experience.

There are only 5 rules of metal shaping. You can CUT, WELD, SHRINK, STRETCH, or BEND metal.

Also, never lap weld on a visible surface panel.

my56chevytruck 11-05-2017 12:27 AM

Re: Body work advice needed
 
Thanks Ogre, I've done all my welding with the fluxcore welding. Still holding and no ones the wiser.

Advanced Design 11-05-2017 08:11 AM

Re: Body work advice needed
 
Quote:

Originally Posted by mongocanfly (Post 8074420)
reminds me of as a kid watching my dad weld up a cracked truck fender with his old AC stick welder with 6010s....and its still holding

Now that would have been a trick...

roger55 11-05-2017 09:06 AM

Re: Body work advice needed
 
Welding seams in the middle of a panel will always need planishing due to shrinkage.
I show many examples of that in my build thread. If you have time, browse through it. I took many photos of my patch panel work and I had several.

mongocanfly 11-05-2017 03:16 PM

Re: Body work advice needed
 
yep Doug...dad was a decent welder back in the day....it was on his 57 IH 4x4....I think they stamped those things outta 1/8" sheetmetal...I didn't know what he was doing at the time but he had a copper bar he backed it up with when he welded it...
on a side note I'm secretly trying to resurrect his 57 IH 4x4 without him knowing....it hasn't run in 30yrs...I've already got a donor truck hid at a friends and am in the process of "stealing" his old one....ill be doing a build thread in alternative section soon...dads 83 so I've got to hurry...


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