Where did the spot welds go

I'm drilling the spot welds in the floor of my 75 Duster. The front passenger side the indents are there but the drivers side I cannot find any spot weld indents The only ones I see on the drivers side is above the floor seam to firewall gap on the firewall. AM I blind I see I have to drill the ones on the outside of the trans tunnel and along the sides of the tunnel in the engine compartment It looks like I will have to remove the heater box also. The pictures of the spot welds are from the passenger side

"Wire wheel" the hell out of the area you think the spot welds should be. You may be able to find them.

Run a chiesel or gasket scraper between the panel where you can and you'll find them.

Are you changing out the main floor pan? If so it's a *****. I have done 2 of these. Use a cutoff wheel on the "floor pan side" to cut loose the floor where it meets the firewall leaving a flat spot welded strip attached to the firewall sheetmetal. After you get the rest of the floor out of the way you can assess this thing from inside the car. Use a sharpened putty knife with a good handle and hammer it inbetween the strip of floor pan flange that's left and the firewall this will pucker up the first weld you will find.

Use a ball rotary file on an inline air grinder and carefully grind all around the perimeter of the weld to weaken it, then cut thru it with the putty knife and hammer and on to the next one. When you get to the left and right corners it will be harder to access the lip to drill it. You dont want to drill the spot welds on the sides of the metal you intend to keep if you can help it. In my pic you can see no holes drilled on the firewall side, and how it gets tight at the framerail area. It took several hours with a ball rotary file, hammer and putty knife to carefully get the strip of firewall metal out. When I am changing out a floor pan I only keep in one piece. The critical stuff that I have to transfer to the new pan like console shifter mounts etc. This way I have a way to measure to transfer it all. Once I got the dimensions off the console, and took pix, I scrapped the tunnel.

The rest of the pan use a cut off wheel to get it out of the way in smaller pieces being mindful to not cut into the frame. After that you have strips of metal covering crossmembers and outboard seat brackets. You can sit inside on a small stool and peel the rest out with the method i described. Its messy sucky work, but the results are well worth it.

Notice in pic #2 the inline air grinder to the right of me, and the floor strips peeled up with ground in circular rings from the ball rotary file on grinder. Wear rubber gloves and safety glasses because of the metal splinters it gives off. Do not use a 90° angle grinder with a rotary file it will kick back at you like a rented mule. Slowly grind around the perimeter of the spot weld on the side you want to remove. Do not grind the center of the weld as the metal is thinner from the 2 pieces being squeezed together. When you see a puff of brown, or notice a thin brown rust line that's separating the 2 pieces of metal then that's deep enough. Is this time consuming? You bet it is !! Will it help prevent you from drilling too far and damaging the metal you need to keep? Absolutely. It took me roughly 10 hours to get to where the car looked in the last pic, but I have done enough body parts replacements, not just the 2 barracudas. If your swapping the whole pan, give yourself a few days. And go slowly as to not damage the pieces your trying to keep.

Man!
Im tired just reading about that!

Matt nailed it! Follow his advice, and just take your time. Also note that he had on ear muffs.......a die grinder or air chisel inside of a car will KILL your ear drums!

I just gotta disagree here.

I've done 6 a-body full floor pans and 2 b-body full floor pans in the last 8-10 years. It's one of the least "it's a *****" jobs you can do on these cars. The "it's a *****" part of the equation is the OTHER damage you may uncover during the process.

As far as the OP:

Wire brush (not grind/sand) those spot welds, they will show their faces.

Yep its time consuming trying to get it all out. Be careful to not damage what your keeping, otherwise you will have to do repairs on it. I work Aviation sheetmetal repair on commercial airliners for a living, I also instruct people learning how to do that for a living. My philosophy I use all the time is "DO NO HARM" in other words carefully dissassemble the "patient" for the repair that needs to be done without creating any additional damage In addition to what has to be fixed. I find myself saying that in my head when I am taking apart spot welds to remove sheetmetal in an automobile. In the case of the main floor of this car, I had to remove all of it from the firewall to the rear framerail tie bar for replacement. In this case it was to reverse a hacked in aluminum mini tub job, and remove some horribly welded in spring relocators. Only took a few months of weekends to get it to the last pix. It's really nice working with clean metal. The open framerails were all sandblasted and epoxy primered prior to the first floor piece getting installed

DemonChronicles said:

I just gotta disagree here.

I've done 6 a-body full floor pans and 2 b-body full floor pans in the last 8-10 years. It's one of the least "it's a *****" jobs you can do on these cars. The "it's a *****" part of the equation is the OTHER damage you may uncover during the process.

As far as the OP:

Wire brush (not grind/sand) those spot welds, they will show their faces.

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I agree, Yes they will show their faces, however some do not. I find using a rotary file thinning the metal out around the edge of a spot weld gets it apart without damaging the metal you want to keep. You stick your putty knife in close to the spot weld to put tension on it. And lots of times you can rotary file around the weld and it will pop loose on its own. Spot weld cutters are ok too. I have a Blair cutter kit, and I do use it, but can damage the metal underneath if not real careful. A rotary file can too, but you have a bit more control, and spotweld cutters cannot fit into every spot when removing the welds. I find you need a combination of spot weld cutters, rotary files, putty knives and home made chisels etc. to get it all apart without screwing up the metal you need to keep. I agree with what you find underneath. I had to unFuck some relocated spring boxes, and fabricate my own framerail pieces after I removed them.

moparmat2000 said:

I agree, Yes they will show their faces, however some do not. I find using a rotary file thinning the metal out around the edge of a spot weld gets it apart without damaging the metal you want to keep. You stick your putty knife in close to the spot wekd to put tension on it. And lots of times you can rotary file around the weld and it will pop loose on its own. Spot weld cutters are ok too. I have a Blair cutter kit, and I do use it, but can damage the metal underneath if not real careful. A rotary file can too, but you have a bit more control, and spotweld cutters cannot fit into ever spot when removing the welds. I find you need a combination of spot weld cutters, rotary files, putty knives and home made chisels etc. to get it all apart without screwing up the metal you need to keep. I agree with what you find underneath. I had to unFuck some relocated spring boxes, and fabricate my own framerail pieces after I removed them.

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Agreed.

I will add that using a Blair cutter (I use this tool extensively over rotary files) is a "feel" type process, and once you get about 5-10 done, you get a feel for it.

But like you said, its more of a combination of both these methods that get the job done.

The one thing I like to tell some getting into metal work, is do a full floor first. For two reasons:

1.) It's not a difficult process, t's a long and tedious process, you'll certainly learn some patience doing one.
2.) It's a huge panel that, once done, offers a huge visual "bang for the buck" that leads to confidence in tackling other metal work areas.

Current project - 18 months ago



Current project - taken this morning



Completed floor work (mini-tubbed, left side seat crossmember relocated)

DemonChronicles said:

Agreed.

I will add that using a Blair cutter (I use this tool extensively over rotary files) is a "feel" type process, and once you get about 5-10 done, you get a feel for it.

But like you said, its more of a combination of both these methods that get the job done.

The one thing I like to tell some getting into metal work, is do a full floor first. For two reasons:

1.) It's not a difficult process, t's a long and tedious process, you'll certainly learn some patience doing one.
2.) It's a huge panel that, once done, offers a huge visual "bang for the buck" that leads to confidence in tackling other metal work areas.

Current project - 18 months ago

View attachment 1715597171

Current project - taken this morning

View attachment 1715597172

Completed floor work (mini-tubbed, left side seat crossmember relocated)

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Excellent job you've done there!
And a lot of good advice too..........

Thanks guys I'm going slow. I'm making templates of where the bottom of the rear seat brackets go so I won't have to wonder where their proper placement is. I've made a coupe of mistakes by drilling all the way through that I will have to fix. I've got the sides drilled and across the back of the pan drilled. It appears that I will have to take the quarter window out when I get ready to fit the new pan. Even after I get the old pan out I will have a ton of clean up work to do. I guess it's my OCD kicking in but I just can't leave the other stuff dirty and rusty

There are many ways. One I would not recomend is an air chisel which I have used quite a bit. But with that said I know how and when to use it. I can seperate some panels with only damaging the side I don't want. If I'm Blair cutting and cant find a weld like yourself I separte lightly with an air chisel set low enough so the spot weld will pull a slight dimple. With an 1/8" drill bit I drill through the metal that's going away (not all the way through. Then I use the dimple drilled to keep my blair cutter from walking around and only cut through one layer (panel being removed).
Hey Moparmat2000 your bring back memories of when I did mine.

Post #10 I love that jig, did you make it ?

Kendog 170 said:

Post #10 I love that jig, did you make it ?

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I did indeed.

I was planning on making a standard type frame jig like the AMD Installation Center uses, but a local manufacturing company was just going to throw away all this steel (after a single use). So I took it off their hands and built this jig from it all instead.

Havent tried it yet, but i think it will work very well. May take a lot of the sheet metal in the process. I use it for cleaning up welds and it has done it very well

Kendog 170 said:

There are many ways. One I would not recomend is an air chisel which I have used quite a bit. But with that said I know how and when to use it. I can seperate some panels with only damaging the side I don't want. If I'm Blair cutting and cant find a weld like yourself I separte lightly with an air chisel set low enough so the spot weld will pull a slight dimple. With an 1/8" drill bit I drill through the metal that's going away (not all the way through. Then I use the dimple drilled to keep my blair cutter from walking around and only cut through one layer (panel being removed).
Hey Moparmat2000 your bring back memories of when I did mine.

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Sorry dude, but these are memories of unfucking a minitub mod I'd prefer to forget. Memories? more like a ******* nightmare! This car was a hacked up mess. This guy who modified it won the "yon golden hatchet" award. The best part is the way they cut the transition pan. What was left along with the outer framerail flanges was then beat down against the framerail sides. I had to peel that off, straighten the rail lips, repair torn rail flanges in spots, then hammer and dolly them flat. No rust thru though on the framerails, that was a plus.

I think I'm going to cut the floor near the fire wall then drill the spot welds from the backside or at least try to for the spot welds that are attached to the firewall or cut enough of the floor pan out so I can get to those welds and slowly work at them

moparmat2000 said:

Sorry dude, but these are memories of unfucking a minitub mod I'd prefer to forget. Memories? more like a ******* nightmare! This car was a hacked up mess. This guy who modified it won the "yon golden hatchet" award. The best part is the way they cut the transition pan. What was left along with the outer framerail flanges was then beat down against the framerail sides. I had to peel that off, straighten the rail lips, repair torn rail flanges in spots, then hammer and dolly them flat. No rust thru though on the framerails, that was a plus.

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Damn man, I've seen some hacked up stuff, but this one is right up there.

Pictures of the front pass side and drivers side floor pan. First pic is a small piece of what was used for the drivers side floor pan

Damn....a stucco floorboard! Oh well, just think how good it will look when the new floor pan is in.

Dam that was bad.That was a nightmare !