I've always said we should be using butt welds, and trimming panels as tightly as we can get them. Some recent shop work helps to show that process, so hopefully this will help out someone with patch panels.
The owner of the Biederman truck we had done all those rust repairs and fabrications on also has a 51 Ford F7 with a Rollback body. He was driving it down the road a few months back when the Delco Remy voltage regulator on the firewall malfunctioned and resulted in an electrical fire. The heat caused some of the filler on the outside of the hood above the fire to delaminate, showing up as circles in the paint. As we sanded these defects out it was noticed that an abundance of filler (+1/4") had been used. The more we looked, the more filler we found all over the hood. In an effort to yield some weight savings, the entire outside of the hood was stripped..
This revealed more defects that the last shop saw as fixes, but they won't leave my shop like that.... Rather than butt weld in the proper thickness metal, a piece of about 16 gauge is slipped behind the rust hole area (from dirt accumulating between brace and hood skin) and MIG welded around the perimeter. I think we can improve on that..
To start our repairs, a body sweep is used to capture the lower flange profile. Note that a profile cut out of construction paper/cardboard works as well.
Verifying the panel thickness. Despite this being an early 50's truck, despite this being a BIG truck, yes, the outer sheet metal here is STILL only 19 gauge.
The affected area was cut out using an air body saw, use what you have available. Note we have no corners in the cut to help improve consistency in weld shrinkage on either side.
The flange bend line is traced from our profile template/body sweep, and bent using tipping wheel on the bead roller (since it's not a straight bend). Here test fitted to the hood..
An Ice Pick (something everyone should have if doing this type of work) is used to mark the area of the cut and more importantly, the cuts for the flanges.
Next we trim the panel on the band saw leaving 1/4" extra around our marks. Next, we use offset snips and trim the flanges to the lines scribed. And ONLY the flanges.. Then the panel is re-fitted with the flanges flush with the original, and RE-scribe the round line, this time with more force to see the mark better.
Note the scribe line has moved closer toward the flange as we located the panel correctly with flanges flush..
Flanges and outer surface are both aligned to the original first and I use TIG to tack on the exact corner on both ends to maintain this alignment.. Side note.... tacking only one end and working around to the other may shrink as you go, pulling other end down where it no longer aligns. So in this case, align both ends, tack both ends, and then progressively work your tacks side to side toward the bottom of the circle.
Note here the flange was left long on our replacement. Trying to weld it in place already trimmed to fit will invariably cause the edge to burn back, making it more difficult to weld this seam all the way to the edge. Leaving the flange on our patch long makes the outer part serve as a heat sink where this burn back effect is less of an issue. Once the welds are dressed, trim the excess using offset snips..
Thanks for another awesome tutorial. Good tip about nailing down the corners at the flange before welding anything else.
That original patch was a POS, for sure.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Boy, that original fix was one butt-ugly patch job! Yours looks much nicer, and I'll bet little if any body filler will be needed. Some of the body men our family shop employed back in the late 1940's and early 50's considered it to be a matter of personal pride to use no filler (lead) and metal-finish their work well enough to use only primer and paint to finish the job. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Boy, that original fix was one butt-ugly patch job! Yours looks much nicer, and I'll bet little if any body filler will be needed. Some of the body men our family shop employed back in the late 1940's and early 50's considered it to be a matter of personal pride to use no filler (lead) and metal-finish their work well enough to use only primer and paint to finish the job. Jerry
And for a dollar and a dime a day, I'll bet.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
Thanks for the metal work lesson. Your level of precision is far beyond my abilities, but I have learned many helpful procedures from your contributions. Thanks for taking the time to post!
The weld seams are then planished and dressed. Next, the front of the hood had a stress crack adjacent to one of the rubber bumpers. To stabilize the hood prior to cutting out this area, the brace is clamped back in place..
All trimmed and welds dressed, the hood bumper hole is re-drilled in the new patch. Then we notice a bit of filler closer to the nose of the hood (arrow). Let's remove that while we're here to see what carnage lies in wait.
The low area needs to be bumped up, and with little room for swinging hammers, a new tool is in order. Using the South Bend "milling machine" a die is made for the outer portion..
Using a pair of C-clamp vise grips (there goes another pair) the die we made will be welded to one side, the opposite is giving a bit of a trim to better fit in the confines of the slight gap available on the inside..
I missed the action shots, but the clamping of the vise grip is used to raise the low areas. Then dressed out for a much better "filler free" lower edge for the hood.
With Mike having completed the dies to duplicate the ribs in the hood brace we did a test run on a piece of 16 Ga cold rolled steel. First upper die addresses middle rib only, way to much drawing going on to expect this out of one set of dies...
Now to fine tune our dies for the hood brace. Looking at our original profile template, the first upsweep (red arrow) and second upsweep (yellow arrow) are both nearly vertical as compared to the opposite side.
So a new die was made for the top, this time out of aluminum. The phenolic is somewhat easy to cut out but does have challenges in making crisp bend details, so lets see if the aluminum helps out..
Next run, this time we'll do two panels in case they work... First pass to draw the metal into the center rib...
This is about 8 passes, each progressively deeper. The circle fixture to the right in the picture (white base) is used as a back stop to keep our rib centered.
This is about 9/16 of depth, so quite a bit of draw.. Next, the new top die is added and goes through the same 8 progressive passes.. Note in the next picture the vertical upsweeps are both nearly vertical. Success!
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Progress on the hood, the bead details in the brace are offset on the ends to match the hood opening flange. So we use a Vernier protractor to find the angle, and transfer that to our panel. This is where the transition of the taper starts..
The bend line is transposed from the original. As this bend is slightly convex, it was started using a tipping wheel on the bead roller to a 45* angle, and then finished on the mag brake.
This is why this is the best website on the planet right here. Thanks for the contribution. Steve
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
Time to get the hood brace end welded in place. The overall measurement had been taken prior to cutting off the old one, down to the 14 gauge outer plate as a reference. So the new end is trimmed to match this dimension, then held in place with rare earth magnets. The center (inside) rib is aligned and tacked using the TIG....
Working outward, the panel surfaces are aligned and tacked as we go. Note the "batwings" left on the outside of the new brace end (yellow arrows). This will act as a heat sink when we make the outer tacks. Had these been trimmed to match prior to welding, the edge will have a tendency to burn back from the heat.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Starting on the other end of the hood brace, this one not as rotted as the other but has issues just the same. One of those "while we're here" things....
The ribs are trimmed and ends rounded.. A piece of flat 16 gauge is trimmed to fit..
A question from the class, Robert. What are you using to dress up the welds on the concave parts such as the opposite side of your last picture? Using even a 3" cutoff wheel makes it highly likely that I would bugger up the opposite side. I've resorted to a Dremel with a small grinding wheel for tight spots, but dang, is that slow. Thanks
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
I have a ball end die grinder about 1/2" diameter that I use in there. Still pulling them slivers out!!! I'll get a picture of all the implements of destruction when I'm in the shop this weekend.
Yep, that's what I was referring to. I know what you mean about slivers. I got self-studded shoes after using a sheet metal nibblers. Those little crescent shaped slivers were terrible. Took about 10 minutes per shoe to dig the little buggers out of the soles before I could go in the house. Thanks
Last edited by klhansen; 04/04/20204:12 AM. Reason: my keyboard can't spell
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Looking at the back side, you can see where a few holes were welded closed the last time it was painted, and the severe pitting and new holes that we have. A testament to the fact that what shows is always the tip of the iceberg. Although better than the passenger side, this is definitely one of those "while we are here" things. Do it right, do it once. (grinder marks were mine)
With our new replacement all one piece, the next step is to bend the flange that spot welds to the hood skin. A tipping wheel in the Fasti-werks bead roller makes quick work of it. The bend line was transposed from the original and an initial pass under the tipping die marks the crease line a bit better, Then successive passes are made, lifting slightly with each pass. This is done until the beads interfere with the tipping die.
Then the partial bent flange is clamped in the magnetic brake for the remainder of the fold. This brake allows us to use a die on either side of the bead details, where a full die may inadvertently push in on the beads.
Looks like we may have enough bead stock left for another couple of ends.
I guess you'll need to find another truck to fix. I imagine your pile of "we may need that some day" metal far outstrips mine (and I come from a long line of packrats).
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Then it gets trimmed to our scribe line and the end media blasted in prep for welding. Our new end is test fit and trimmed until we get the right distance to our reference marks. The "batwings" give us a heat sink at the edge for less chance of burning back the edge at the weld.
We have a few more spots to fix from cracking and fatigue, namely the holes on the underside for the rubber hood bumpers. We've already repaired three, and from the looks of it, need to take care of the remaining three..
18 Gauge x 1/4" plugs were TIG welded in to fill the existing holes, and a copper backer gives us a bit of a heat sink so the cracks/fatigued areas don't blow a big hole on us..
Welds were dressed on both sides of the sheet metal, and new holes drilled slightly in farther from the edge to help slow down the reappearance of cracks.
Next, I'm sure everyone has seen how these hoods can oil can, show low spots, and try to flop around while driving down the road. Part of that is abuse over the years, fatigue, etc. Any low spots invariably result in a loss of support of the hood and will show oil cans or loose areas.
A good tool to check the crown of the hood is a long straight edge in the form of a 36" rule. If you don't have one, most hardware stores sell aluminum flat bar for a few dollars that will make a good profile template. For this style hood, lows are bad, straight is better, and a slight crown in the center crease along the entire length of the "flat" area of the hood is optimal.. This gives the support to help eliminate those oil cans and floppy hoods.
When we started there was an obvious area about 12" forward of the rear edge, dead center, that appears low, and was easily pushed downward. In order to better define the center crease and provide the support needed, we will use a sand bag (a rather large one) and lightly hammer from the bottom side into said bag with a purpose built "punch".
In order to keep the back portion of the hood down against the bag for support, we used our latest "metalshaping" tool to hold the front of the hood up, an engine hoist..
The crease was checked for low spots prior, and the bottom marked. The "punch" is dragged along the centerline and tapped as you go. Flip the hood over, check crown, remark as needed, repeat. We got to a good straight/slight crown and the oil can disappeared. Pushing along the entire center crease was a nice tight support now..
