Help Needed With 1/2 Tub (1 Viewer)

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I'm wanting to separate the rear tub on my 79 and maintain what's needed to attach the replacement.
Specifically what I need to know is there a good way to get it separated. If this doesn't make sense look at my picture of the inside seam. Any ideas would be appreciated in that I don't want to eff it up.
Thanks.
 
A 3/4 tub separates at the A - pillar, which is a much easier place to split the tub.
 
reddingcruiser is correct. It will be MUCH less work involved moving up to the A pillar as opposed to the B pillar you have in the pics. A 3/4 tub will have the front floors and rockers. Splitting at the section you have shown would be only a 1/2 tub, and going by the pics your front is as bad or worse then the back.
 
OK, I just realized I had a brain fart. I have a HALF TUB not 3/4 so I do need to separate at the point pictured.

Title edited.
 
OK, you're about to have some fun. If you haven't already, you need to invest in:
  • a high quality bit to drill out spot welds,
  • a sawzall or similar reciprocating saw,
  • a 4 1/2" angle grinder and s**t pile of cut-off disks
  • 4 1/2" flap disks (or sanding disks w/backing plate), 80 and 100 grit
  • 4 1/2" coarse and fine wire wheels
You'll need to pull the seats, gas tank, electrical wiring, tire carrier, body mounts, roll cage, etc. Most spot welds are typically easy to see, but you can use a wire wheel or sanding disk along body seams to make them more visible. drill out every spot weld you can find, and you'll need to cut the tub top rail free from the B-pillar at the weld joint. When you come to a tough spot, any metal you have to 'sacrifice' you'll want to do on the side that's getting replaced and sometimes it's just easier to hack out sections of the 'old' tub (1/2 or 3/4 tub) to make it easier to work with the space available. Work from one end to the other along seams. When drilling or grinding to separate layers you can usually see a rust stain or color variation between layers, work slowly and use this to avoid removing too much of what you need to keep.
 
Thanks @reddingcruiser. I was sort of thinking along that line. Sounds like you have been down this road before.

If you own enough FJ40's, you'll end up splitting some seams and removing body sections. I'm a regular pro at removing and replacing rear sills.:mad:
 
Remember to drill out spot welds from the side that will be easiest to reweld and grind from. It can be a little harder to drill them out this way, but it’ll pay off big time during reassembly.
 
Remember to drill out spot welds from the side that will be easiest to reweld and grind from. It can be a little harder to drill them out this way, but it’ll pay off big time during reassembly.

Noted. Any other tips are welcome before I tear into it.
 
Get this kind of spot weld cutter:

https://www.amazon.com/Blair-11096-...d=1519427079&sr=8-5&keywords=spot+weld+cutter

DO NOT get this style:

https://www.amazon.com/Zinger-Cutte...&sr=8-1-spons&keywords=spot+weld+cutter&psc=1

The cheaper ones don't last long and are much harder to use. The nicer kit (first link) is better mostly because it has a spring-loaded drill bit as its center, so it drills a little divot and exaggerates your center punch mark. So the bit doesn't wander much. The cheaper model uses a spring-loaded pin in the middle, and it's really hard to keep it from wandering. Plus the hole saw style teeth break off easily.

I can't recommend the above spot weld cutter kit enough. you'll save money over the other in the long run.
 
Get this kind of spot weld cutter:

https://www.amazon.com/Blair-11096-...d=1519427079&sr=8-5&keywords=spot+weld+cutter

DO NOT get this style:

https://www.amazon.com/Zinger-Cutte...&sr=8-1-spons&keywords=spot+weld+cutter&psc=1

The cheaper ones don't last long and are much harder to use. The nicer kit (first link) is better mostly because it has a spring-loaded drill bit as its center, so it drills a little divot and exaggerates your center punch mark. So the bit doesn't wander much. The cheaper model uses a spring-loaded pin in the middle, and it's really hard to keep it from wandering. Plus the hole saw style teeth break off easily.

I can't recommend the above spot weld cutter kit enough. you'll save money over the other in the long run.

I think that second style works fine. The cutter has two sides so you can swap it when teeth break it gets dull, and I prefer not drilling all the way through with a pilot drill bit. Besides, you can get them at harbor freight for just a few bucks so you can just toss em when they get dull.

I second using a wire wheel to expose the spot welds a little better.

Also, make sure you weld some bracing in before removing any body panels. Weld in the bracing across the b pillars and then diagonally from b pillar to opposite side a pillar.
 
Make sure all 4 corners are level b4 u weld in the half tub. I think you'll find a fair amount of rust in the front floor section so may be easier to fix with half the tub off
I’m also replacing the front floor section and the support below it. Should be interesting.
Thanks for all of the input.
 
Hi mtrdud,

Have been working on 1980 for quite a while. The up to 1978 body build style is way easier imho to work on than the 1979 up body build style.
On your picture of the left door pillar, you see where the half moon cutouts are on the inside. On each one of those there is a spot weld. You don't really want to mess those pieces up. I would suggest you strip the paint of the outside of were the welds are with paint stripper rather than anything mechanical. That way you can see the spot weld marks. I would also suggest you drill right through each weld with a ⅛ drill. Then take your 5/16'' Blair drill bit with a ⅛ pilot in the ⅛ drilled hole and drill out the spot weld on the outside of the rear quarter. That way you can re-weld the ⅛ holes in the door pillar before you put the new panel back on withe plug welds.You could do that with the welds that go across the floor panel to the other door pillar. You will have a series of ⅛ holes to fill but they are easy compared to anything larger.
Take you time taking it a part and take pictures or use pencil line drawing for some parts. It also depends if you are doing a restoration type rebuild or something less.
Good luck on you venture.

Thanks jb
 
Jb, thanks for the insight. I think I understand your reasoning about those half moon tabs. This is a build basically for myself. It won't be of restoration quality but I would like it to turn out decent. A 3/4 tub probably would have been easier but I'm not known for taking the easy route. I think it's an inherited trait.
 
I think that second style works fine. The cutter has two sides so you can swap it when teeth break it gets dull, and I prefer not drilling all the way through with a pilot drill bit. Besides, you can get them at harbor freight for just a few bucks so you can just toss em when they get dull.

Have you tried the cutter I'm recommending? I bet if you did, you'd be gushing over it too. It cuts WAY faster, doesn't dull anywhere close as quickly, and doesn't wander all over the place. The drill bit in the middle is spring loaded and doesn't drill all the way through. Once the larger diameter cutter engages, it cuts much faster than the center bit and ends up surpassing it by the time you've drilled out the weld. It takes about 5-10 seconds to drill out a spot weld. It would take me a minute or so with the other bit, mostly because it refuses to stay put while drilling- it keeps jumping out of the center punch mark.

Yes, you can flip the cheaper ones over, but I found that they only last for 4 or 5 cuts before they're missing teeth or are too dull to use. I went through three of those kits before I bought the other one. I've probably drilled out 50 spot welds without dulling the first bit.
 
I haven't done anything on it yet. Got sidetracked over the weekend.
 

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