Crusty Body Joints

[PaulyWally]

Hi All,

 

I'm currently looking at (another) 1966 Mustang. I know nothing about body work. Actually, I know nothing about a lot. So I'm hoping some of you can help me out. I saw some questionable "stuff" around the body joints in the trunk and under the back seat. Please see the attached photos. It isn't hard (like a weld joint). If I push my fingernail into it, it has the consistency of 20 year old dried caulk. And I can pick it off with my finger. The best example is probably the picture of the trunk. I included another photo I found online that shows a trunk floor sanded to (almost) bare metal. It obviously has much cleaner joints.

 

Anyone see anything like this before? Or know what it might be? The owner claims it's rock-solid besides the surface rust. So when (and if) I go to see the car again, I will likely ask the owner to pick that junk off so I can see the weld joints.

 

Thanks in advance!

 

P.S. I'm also including a pic of the driver side door frame. Looks like it might be there under the paint as well... or just the paint cracked around the weld joint. Difficult for me to tell.

[TerryB]

Take a look at this, it’s a Cougar which is really a fancy Mustang.  This is what a well sorted automobile will look like. Mr. Harwood is a regular on this site.

 

https://www.harwoodmotors.com/vehicles/inventory_details.php?id=1370

[PaulyWally]

11 minutes ago, TerryB said:

This is what a well sorted automobile will look like.

 

Yeah. That's a very well-done vehicle. If I could afford such a vehicle, I would certainly buy one that nice. Unfortunately, my budget says otherwise.

 

I'm trying to get into the most solid car I can within my budget. I know work will need to be done. And some of it I can do myself. But the last thing I want is hidden body/frame issues. All the panels seem solid. I just don't know what to make of those joints.

 

The car I posted actually has quite a bit going for it. Most of the interior and upholstery is in excellent condition. And the paint and exterior chrome is in good shape. Not show-quality, but she's a looker from 20 feet. Aside from that, the body is straight, doors/trunk/hood open and close smooth, and the windows operate.

Edited August 2, 2021 by PaulyWally (see edit history)

[joe_padavano]

The material in the photos is dried seam sealer, applied at the factory over spot welded lap joints. Over the last half century, the sealer shrinks, moisture gets under it, and you sometimes may get some rust. The sealer needs to be scraped off, any rust addressed, and the metal re-primered. Once that is done, apply new seam sealer. There are many newer products on the market today, especially two-part epoxy style seam sealer.

 

[TerryB]

3 minutes ago, PaulyWally said:

 

Yeah. That's a very well-done vehicle. If I could afford such a vehicle, I would certainly buy one that nice. Unfortunately, my budget says otherwise.

 

I'm trying to get into the most solid car I can within my budget. I know work will need to be done. And some of it I can do myself. But the last thing I want is hidden body/frame issues.

 

The car I posted actually has quite a bit going for it. Most of the interior and upholstery is in excellent condition. And the paint and exterior chrome is in good shape. Not show-quality, but she's a looker from 20 feet. Aside from that, the body is straight, doors/trunk/hood open and close smooth, and the windows operate.

Yes, I know all too well about budgets.  The last picture in your set, the white door opening, would be cause for concern for me.  Seems like body work was done and now it’s not too sound.  I just wanted to show how a good body job would appear.  Mustang designers were not charged with making the car last 50 years so finding one with as few of problems possible for X dollars takes a lot of looking.  All the best in your search!

[PaulyWally]

1 minute ago, TerryB said:

The last picture in your set, the white door opening, would be cause for concern for me.

 

That's the one that bothers me the most too. I wasn't even going to post it... but it seemed like there might be something similar going on underneath the paint.

 

Joe's post above makes me feel better about the situation. At the least, I won't feel like a jerk for asking the owner to scrape some of that off so I can see the weld joints. He seems like a good, straight shooter. And I think he might just oblige. But I certainly won't ask him to scrape off that door frame joint. I think asking the guy to ruin the paint job would certainly be a jerk move.

[Rusty_OToole]

Years ago I worked on a Mustang that had a bead of seam sealer applied at the factory to various weld seams. In some spots the sealer missed the seam by 1/4". They were not that precisely made when new. Random blobs of sealer on the floor would not bother me. They are supposed to be hidden by the carpet or trunk floor mat.

[F&J]

1 hour ago, TerryB said:

the last thing I want is hidden body/frame issues.

Then you must get the car up high enough to do an underside rust/rot/ or "patched rot" inspection.  Early Mustang buyers always look at the front and rear "torque boxes" which are in front of rear tires and behind front tires.  It can be see in some YouTube videos.  Basically a metal pan that reinforces the undersides of the unibody structire, and could be rotted if the car came from the rust belt.   Also look for very noticeably "rust swollen" seams under the car where panels are lap welded together when new. 

 

I would not ask the seller to peel up the old dried factory tar, as most cars, even solid ones, will show surface rust from metal staying damp there for decades due to cracked tar.  The underside of car is most important.  Get a local vintage car guy to help look under there?

 

One more rust area often overlooked on early Mustangs:  Water going down through the ventilation vent louvers behind the hood at windshield can cause rot on a tray down in there, and then water from rain or washing the car will get the underdash floor and adjacent carpet wet.  It's not easy to fix.   But this is also from rust belt cars. Ask him if it gets wet there from washing the car.

 

You never know, you could have a super rock solid car there, rather than worrying about minor surface rust under old seam sealers. 

 

Most older car gurus will know in just minutes of looking under the car, to know if it's patched up junk or a very uncommon rock solid survivor that came from a dry area.    If it really is a no rot, not patched up early Mustang, don't hesitate too long on purchase if price is ok to you.

[PaulyWally]

58 minutes ago, F&J said:

...rather than worrying about minor surface rust under old seam sealers. 

 

There's a lot of surface rust. I'm not worried about that. I clean surface rust off bolts on my motorcycle all the time.

 

The owner said it's a west coast car, and I have no reason to doubt that (in my limited knowledge). According to the VIN tag it was built in San Jose and assigned to the San Jose sales district. He said he bought it from someone in Idaho. I was pounding on panels inside, out, and under. I also stood up in the back seat and jumped up and down. It felt very solid. I'm just paranoid there might be a hack-job of a joint repair underneath the sealer. That's me though. I've been burned too many times by people that mis-represent their stuff to sell it.

 

Very good info from your reply though. Thank you. I don't really know any classic car guys in my area. Perhaps I'll put some feelers out and see if someone will take $100 to drive out with me to inspect it.

[Rusty_OToole]

Any good mechanic can inspect brakes, steering, exhaust etc especially if you find an old timer who worked on them when they were just another used car. While it is up on the hoist have a good look underneath, you will soon see if it has been patched up, or covered in undercoating to hide rot and repairs.

[Frank DuVal]

Your third picture concerns me. The seam sealer blobs is typical, not an issue. But where you have circled some rust in white is where the rear  leaf spring attaches to the unibody/frame. I have repaired Mustangs where the leaf spring had broken through that spot and was now inside the trunk!😲 It is repairable, just costs money. But, if it is indicative of more rust problems, then more money..... Like the  4th picture, that area will be an issue at some time in the future. If kept in a dry environment, might be a long time before it shows.

[Rivguy]

That door opening has evidence of a couple of problems. It looks like seam sealer or even regular bathroom caulk was applied over a rusty area. The front edge of the quarter panel was spot welded onto the door striker post. The factory applied sealing was not that extensive and over the years moisture will cause some rusting around that joint, front and back. You can see into this area a bit by removing the rear panels under the rear windows.

 

Inspecting the car from underneath will tell the story. The front and rear subframes can be seen and any damage , rust, or unprofessional repair work will be evident. The factory fitted things together with OEM brackets attached to these subframes, not with layers of steel plate welded on as reinforcements. 

 

Anything and everything can be replaced and repaired on these early cars. But it is easier and cheaper to start with a better car. These cars were built with very light construction, and areas like shock tower mounting welds will often have broken over time causing wheel alignment problems. 

 

If this is the same car with the poorly performed V8 swap I read about in another thread, than there a lot of red flags. You might be better off buying a structurally good car that needs paint and interior that can be added over time as funds allow. Best of luck with your search.