68 Firebird 428

Had a couple of hours after work to address the shrinkage. It has highs and lows in the HAZ and about 2-3 inches away from it. The panel is supposed to be flat front to back, and a low crown top to bottom.

I set a 36” radius bottom die in the planisher that I made a couple of weeks ago, lubed up the panel where the work will be done, and fit the panel in there. The rear brace was able to pull out just enough to clear the lower planisher arm. I concentrated the blows on the weld front to back for about a minute.
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I’m trying to be careful not to over stretch the area so I pulled it out to inspect with a straight edge, and could see it needed more. One more 1 minute round and most of the distortion was removed. It still has a way to go but it’s amazing how fast the panel started to shape up. The rear had a high spot and middle was a large low, so I used a hammer with a 12” radius head and a dolly to move the high into the low with hammer off dolly hits (hammer on the high & push the dolly from behind on the low). It seemed to work. The straight edge showed that I’m moving in the right direction.
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A close upof the planisher welds. I need to get better at my welding, and learn to use only the amount of filler necessary to control the chemistry of the puddle. It seems to me I will have to grind the filler down some. Tomorrow I’ll fine tune the highs and lows, and will need to hammer and dolly the areas the planisher could not reach around the rear flange and wheel opening details.
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Worked on the fender yesterday in the afternoon. Ground down the extra filler rod on the weld seam, worked it by hand with the hammers, dollies, and flippers I have.

I incorrectly kept stretching the weld seam on the return leading to the wheel opening jogs. It sunk before I realized what I was doing. This provided a learning opportunity for me. I have a few old books from the 70’s on principles of sheet metal repair work I dug into to study hot shrinking. I’ve done it before, but found it easy to overshrink. I wanted to wrap my head around the concepts, and afterwards realized it is just lowering the yield point of the metal to be shrunk with heat, striking it with a hammer immediately, and because the surrounding “cool” metal will not yield as easily, the hot metal upsets and shrinks. That’s fine to understand, but experience is the other 95% of the equation to expect success. Knowing where to heat, how much heat, how big of an area to heat, how much hammer force, when to quench if even necessary are all in the experience department. So I started slowly, and used my acetylene torch with #2 tip to heat to dull red a 1/4” spot in the middle of the low on the reverse. It was 3 secs if that, and whack with a body hammer from the backside, and it upset. I did some very light hammer on dolly to level things and to my surprise the low was gone. No quenching needed. It cooled to touch in 30 secs. I used a flipper to finish it out
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I used the flipper, hammer, and dolly to get the profiles correct from the measurements I took before I started. Flat front to back, flat top to bottom below the weld, and a48 radius above the weld to the mid fender body line.

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DA sanded the area and called it a day. It will obviously need filler work, and the rear edge radius of the patch panel is different than the original. I will wait till I mount it on the car with the door to adjust gaps and other issues I’m sure will be waiting for me.
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I need to trial fit the fender before I plug weld the brace back in, as I suppose if something is off I’ll be cutting that brace back out to move stuff around. Plus I have a new door skin to put on, and that will probably change alignment too.

First I had to tackle the door skin. I chose to punch holes to plug weld in the same spots the factory did their spot welds. I’ll line it with adhesive dampener later. This is the first door skin I ever replaced. I used a body hammer, door skin hammer, and an old rubber sand block as the dolly. Arms got a good work out. I made some mistakes I should note. 1 I hammered the flanges over too tight, the idea was to hammer them over and fit to the car and have some wiggle room to move the skin a bit for fine adjusting before I plug weld. I got it too tight and it is locked in place. 2 I wasn’t getting a consistent factory radius at the edges, it was too thick. So I used a metal dolly which worked to correct the problem, but it had a radius’ed face which marred the surface slightly. I switched to a dead flat dolly and that problem went away. I had to keep cutting the corner folds to prevent the flanges from touching. Next time I’ll measure and cut 1-45 degree notch.

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Next I fitted it to the car on new hinges. I screwed around with it for a few hours to get the bottom gap consistent, lower front edge lined up with front of rocker panel, and the fender to quarter gap and flush the best I could. It needs a lot of work on the quarter to door alignment and gap. The gaps I can handle, but getting the door and panel flush will be a challenge. When the top and bottom are flush, the middle body line protrudes 1/4” out on the door. I also need to strip the paint off the quarters to see what kind of body work is under there to before I make a decision on how to adjust this.
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I need to see what the fender looks like mounted too. I welded up the original brace with the new patch piece, and temporarily tacked it to the fender near where the bolt is, to hold it in place so I can mount it. If the brace needs adjustment, I only have to break 1 small tack.

The plan is to test fit, make adjustments, before I weld up all the plug welds on the brace to fender flange.
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Fitted the fender to get an idea where more work needs to be done. Quickly discovered the lower patch needs more form top to bottom. It’s dead flat now and the rocker and door have a radius as you can see in the profile gauge. I’ll have to pull it off and see if I can shrink the two side flanges to get the form top to bottom to match the radius gauge.
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Before I weld anymore of the fender bracing back fully, I just tacked it in place and installed the fender. I had to mess with it for a couple of hours to get it somewhat lined up to the door.
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I noticed the radius of the fender lower patch is different that the rest of the fender when I was welding it on, looks like I will need to correct that. I sprayed some primer there to see the contrast. Gaps will need some work too.
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Before I get started on gaps and welding door skin plug welds, I want to skin the drivers door, mount it, patch the fender and mount, and install the hood to see how it all fits together. I can then figure out where to do my work to get it all right.

Picked up a used door skinning tool on EBay for $180 shipped. It did a fast and clean job on the drivers door.
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Time to mount it and get working on the fender.
 
Last year I studied with Fay Butler and took his principles of shaping metal 3 day seminar. I quickly realized this man is a genius, and has probably forgotten more than I’ll ever know. He taught me how to tig weld (Specifically sheet metal), and explained to me what is going on at the atomic level when welding. I had been arc and mig welding since I was 10 but In one day learned I knew nothing.

Well I still know very little, but I will work at applying what I’ve learned here.

I clean everything with acetone until the no more grime shows on the towels. The metal, the filler rod, electrode, etc.
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He suggested I purchase these gas lenses for my torch. The argon shielding gas envelopes the weld puddle much better, reducing oxide formation.
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Next after careful registration of the panels, I tack from one end to the other, using filler rod to control the chemistry of the puddle (deoxidize)
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Next I make a backing shield using aluminum heat tape and stove door gasket to trap the argon (that is heavier than air) that seeps through the seam, and shield the back side from our atmosphere to reduce oxide formation. The oven gasket keeps the tape from burning, and I tent it up to keep it off the weld.
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Then I weld from one end to the other using filler rod (ER70S-6). Fay can weld from one end to the other non-stop like a robot, and the welds planish to invisible with no grinding. I’m not that good. I had two blow through holes, used too much filler in some areas, and need to start and stop numerous times. All of which will create more work for me, but hey I’m learning and enjoying the process.
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Inside after backing tape is removed.View attachment 19689
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I clean the adhesive left behind with Acetone, and clean the welds, wire wheel the hard oxides off and clean again. I need to grind down areas i overused the filler rod, and can then start addressing the shrinkage. I’m glad that inner brace is out of the way.
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A helpful tip for tig welding that I learned when tig welding body panels is to use 0.30 mig wire. It melts much much quicker than 1/16" rod which will reduce over heating the panel being tig welded. What I do is cut 3' feet long pieces of mig wire. Then on one end of the wire I make a small loop. I insert the looped end of the wire in a drill, and the other end I put in a vice. I then twist the wire for 20-30 seconds. This will make the wire stiff like normal filler rod so it's easy to handle and not flopping all over the place when used.

What tig welder are you using?

I'm enjoying your thread and restoration. Keep up the good work!!!
 
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