Request Input, Terminal Cancer On Subframe

[TonyC]

Hi, all,

This post is not for me as I do not have this problem. It's on behalf of a John Blaney, a member of "The Late Slabside Club" group on Facebook. I guess my instinct to help out prompted me to reach out here, because I know there are very few experts on our cars in that group.

Backstory: John has a '69 non-Mark Continental he's trying to get up to driving status. He says he's nearly there, but he came across something that concerned him: Cancer on one of the subframe rails. The pictures he shared with me concern me as well; pictures are below. From the third picture, I think he may have that issue on both rails, though the right one looks in far worse shape. He wants to know if he can patch that with 1/8" steel. Personally I think that, if that can be addressed, he'd have to have that whole rail removed and replaced...that is, if it can be done. He says that is the only cancer on the underside of his car, that the rest of the platform is still intact.

I've never seen that kind of cancer in that spot before, and I've seen more than my share of cancer on organ donors in my time. I'm curious to ask if anyone here has seen this, and what they did or would do about it. I don't like the idea of scrapping the whole car because of that one spot; but on the other hand, it is a structural point that's affected. I have already told him not to even try rolling that car anywhere, lest the spring collapse on him should the rail break. To me, that does not look like something mere patch-welding will fix, but I have no experience in cutting and welding. Any ideas on this?

---Tony

[LithiumCobalt]

Going to be some pretty beefy material for the spring mounts. If there is that kind of rot I highly doubt the rest of the car isn’t also compromised. May not be able to see it necessarily or someone may have patched along the way and gooped it with black tar, but slim to none chance it’s exclusively that area.

[frasern]

My '68 parts car was parked in a puddle for many years, and is clearly junk, however, I took it for a 50 MPH run across my field, crossways to the furrows, and the spring mounts held, and they are a lot worse than those. Still, that body is weakened, I would not spend a ton of money on it.

[1Bad55Chevy]

Thats a relatively simple fix.

1. Buy a complete trunk from a rust free car in a salvage yard.
2. Remove frame rails from the new trunk section with a spot weld cutter
3. Remove rusted frame rails from car by drilling out the spot welds
4. Weld in New frame rails

Not sure if they have the ability to pull that off or not but it isn't very complicated. If they really wanted to stiffen the car up they could fabricate sub frame connectors and basically make it a full frame car.

[Mike]

The last pic shows holes further back also so it's not just the frame rails that has problems. Did he post pictures of the rest? You usually don't have one area that bad and the rest good especially when it's rusted through like that in an area that isn't prone to it.

[LithiumCobalt]

Thats a relatively simple fix.

1. Buy a complete trunk from a rust free car in a salvage yard.
2. Remove frame rails from the new trunk section with a spot weld cutter
3. Remove rusted frame rails from car by drilling out the spot welds
4. Weld in New frame rails

Not sure if they have the ability to pull that off or not but it isn't very complicated. If they really wanted to stiffen the car up they could fabricate sub frame connectors and basically make it a full frame car.

Cutting out rusty metal, drilling out spot welds, cutting parts off of a parts car and welding them onto the other car all the while maintaining rigidity to avoid tweaking the body is easy and simple?

[1Bad55Chevy]

I guess complexity is all relative to your knowledge base.

I have never put floors in one of these cars but I would assume it cuts and welds like everything else. I have done Camaros, Novas, and Mustangs all of which are uni bodies. When you cut the floors out of a vehicle it doesn't move around and flex like you think it would because all the strength in a unibody car is in the rockers not the floors.

If you know how to weld and can do basic metal fabrication this is something you could pull off in your garage without an issue. The issue I see with this car is there is probably A LOT more rust in it than just this. If you could source panels you could rebuild it.

[TonyC]

Thanks for the input so far. I do agree that there could be worse issues that John either may not know. So far, though, it seems that the input matches my own takes, that patch-welding which he's thinking of will not suffice. I like to think repair can be done, as Chevy has suggested, but it would require a certain level of skill in cutting and welding which I'm not sure the OP possesses.

---Tony

[LithiumCobalt]

Problem with these cars is that a lot of times the rust doesn’t look bad until you start cutting and then you realize it goes a lot deeper than you think. Unless there is some sentimental attachment, it almost always make sense to find something nicer condition. Even doing all the work yourself, you’re still left with a cobbled together car that will never be worth as much as a less rusty version would be

[frasern]

Rust is like an iceberg, 4/5ths is hidden. My take is use and enjoy the car as is, but find another one to restore.

[TonyC]

Right; with that kind of rust in that area I agree. I'm glad Frankenstein never had that issue.

I'm not sure how far he's able or willing to go on this repair. He does already own the car, so it's not quite so easy to just walk away and look for a better example. I suppose an alternative to keep it going for longer might be to resort to the rear-suspension mods used on balloon conversions...but the structure will still be compromised, maybe to the point of the Pinto Effect should he ever be anal-probed.

---Tony

[Dan Szwarc]

This is very severe in a critical area for the rear of the vehicle. He could easily spend half of what the car is worth to do it right.

He needs a local welder/restorer to do a hoist inspection and just quote it out. Bail at 50% of vehicle value.

I have a Conv chassis in my yard in better shape. If anyone wants to come to Michigan to cut off the ass end of the car, no charge, I’d be happy to let him.

[1Bad55Chevy]

I think the thing to remember with this vehicle is in its current state its best used as a parts car. With that being said if you attempt to fix it on your own the worst case scenario is you "ruin" a junk car. Dan brought up a solid point about cutting the ass end off his vert! You could easily brace the roof and cut the entire back off the car and weld on another ass end. All you do is level the chassis using a lot of jack stands, brace the roof with a good amount of 1x1 steel tubing, cut the bottom of the C pillars and the through the rockers all the way across the width of the car. This is basically how most salvage rebuilt cars are put back together and put back on the road today. You could also fabricate some sub frame connectors while you were doing all of this and have something much stronger than what rolled off the assembly line.

if this was my car I would save it in a way that most everyone here would hate. Chop all the floor out of it and mount it to a 2x3 frame like a drag car. Pretty much build it like a rusty rat rod! If he is looking to sell for cheap I might be a buyer!

[Dan Szwarc]

For reference, here's the rails on my 67 chicken carcass. It's suitable for convertible or sedan soup, but not much meat left for a meal.

[TonyC]

John is practically your neighbor; he lives in the Chelsea/Ann Arbor area. Maybe I can convince him to register on the Forum so he can reach out to you directly.

---Tony