Absent any rust issues interfering, Ideally you would place the seam just below (about an inch to allow room for dolly from the back side) that bottom crease (under the orange) as this slight crown gets your weld in a nice area for planishing from the outside, and a straight cut horizontally would eliminate any of the puckers normally seen on inside corners. The red and green cuts are going through a substantial crown in the middle of the panel, which is going to pull inward and may require additional planishing to keep things where they should be. The downside to anything that pulls inward is the the most effective planishing is from a hammer strike from the inside or to a lesser extent, pushing outward with the dolly while striking from the outside. Which means limited room available the closer you get to the wheel well.
Given the rust issues present, the area below the bottom crease is too low. The next best option IMO would be to go about an inch above the crease in the concave valley. Here any shrinkage is going to pull OUTWARD so it will be easier to planish with hammer swings from the outside. This means your hammer face will need to conform to the shape of the valley without the edges of the hammer touching. (In much the same fashion as selecting a dolly, as close to the shape of the panel as possible without the edges touching as that will cause coining) I think I’ve shown the fabrication of a body hammer using a leaf spring eye (I’ll try to find a link) and this hammer is ideal in working such areas. Jim Kueneman’s current project included welding on near full quarter panels and I convinced him to use a similar feature just below the top of the quarter, so if you look at his thread you can see the concept of welding through that area.
I think the area above the crease (slightly higher than you show) through the center of the inward radius will be easier to address planishing efforts. If you need to go up into the wheel well flare any higher, I would almost do that as a separate piece as it will give you better options for planishing while the bottom of the quarter is open. Once that is done (and planished) then finish up with the horizontal seam across for the entire bottom part.
Here's a little more detail showing how big my AMD patch panel is. Getting in there from the back side (was hard to get a picture), I think I need to cut that lip at least 2" above the body line to have decent metal to weld to, as well as give me room to repair the lower edge of the wheel well. In a nutshell, the closer to the edge of my new panel the better.I wouldn't cut the patch panel before you find out how far the rust goes up the seam.
Absent any rust issues interfering, Ideally you would place the seam just below (about an inch to allow room for dolly from the back side) that bottom crease (under the orange) as this slight crown gets your weld in a nice area for planishing from the outside, and a straight cut horizontally would eliminate any of the puckers normally seen on inside corners. The red and green cuts are going through a substantial crown in the middle of the panel, which is going to pull inward and may require additional planishing to keep things where they should be. The downside to anything that pulls inward is the the most effective planishing is from a hammer strike from the inside or to a lesser extent, pushing outward with the dolly while striking from the outside. Which means limited room available the closer you get to the wheel well.
Given the rust issues present, the area below the bottom crease is too low. The next best option IMO would be to go about an inch above the crease in the concave valley. Here any shrinkage is going to pull OUTWARD so it will be easier to planish with hammer swings from the outside. This means your hammer face will need to conform to the shape of the valley without the edges of the hammer touching. (In much the same fashion as selecting a dolly, as close to the shape of the panel as possible without the edges touching as that will cause coining) I think I’ve shown the fabrication of a body hammer using a leaf spring eye (I’ll try to find a link) and this hammer is ideal in working such areas. Jim Kueneman’s current project included welding on near full quarter panels and I convinced him to use a similar feature just below the top of the quarter, so if you look at his thread you can see the concept of welding through that area.
I think the area above the crease (slightly higher than you show) through the center of the inward radius will be easier to address planishing efforts. If you need to go up into the wheel well flare any higher, I would almost do that as a separate piece as it will give you better options for planishing while the bottom of the quarter is open. Once that is done (and planished) then finish up with the horizontal seam across for the entire bottom part.
Not sure how easy it is to tell, but the top of the hole you see here is the top of the cutout in the previous picture. I have a wedge shaped dolly that I can get in there, however its not going to have a lot of mass. Although I can probably wedge it up against the wheel well and support it that way. I can get my finger between the wheel well and the quarter to the point that the tip of my finger barely touches the lip, so they aren't flush against each other. I need to patch in about 1" to the bottom of the wheel well around that rust hole area as well. Basically the wheel well, trunk extension and quarter all come together right there, and the junk that accumulated there and stayed wet for years rotted them all out.What is the access to that area from the inside ??
Please forgive the hijack but I feel this is a good place to ask for help in this matter.Robert as always offers excellent sound advice... When I say tack I mean just that. On and off. This is critical. You need to have the proper gap (.030-.035) between the panels and you need to be able to tack it quickly. On and off. Dial in your settings by practicing on some scrap of the same gauge beforehand.
Yes, I did.Did you change the polarity of the machine when you went from Flux wire to solid wire?
I recently had a chance to demo a hand held laser welder, and it is impressive. It does tight gap butt welding very good, so I was trying it with a gap. There was a choice between .023 and .030 wire, so I started out with .023 wire on 20 ga metal and had no luck at all when trying to make a tack or for welding from a tack with a gap of about .030-.040 . Switching from .023 to .030 and starting the tack on one side of the gap, and flicking the welding head toward the other side made the difference. It wasn't a pretty tack like it would be with a tight butt, but it worked. I think .040 would have been even better.have tried using both Flux .030 and Shielded .023 wires with the same results.