Ford obviously knew these cars leaked like seives otherwise why put so many drain holes throughout the car if it wasnt to deal with water infiltration
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Summer deadline - 72 Mach 1 Build thread
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The only way to correctly open up the cowl is to remove the front wind screen and drill the 1 million spot welds that hold the cowl cap on. This will give you full access to the cowl. Before going this route I would suggest climbing under the dash with a bright light and remove the two air box vent assemblies that bolt to the bottom of the cowl. These are the typical problem areas and will tell you the extent of the issue. If you have AC going under the dash is not an easy task.
baz70
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that reminds me of a question that's been bugging me. what do the drain holes on the floor pan do ? they are plugged up with a cover, or screwed in with a metal plate as in the rear of the front seat, is the idea to release the covers when you discover a leak, do they magically open when there is water ingress ? puzzled.....
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The drain holes are part of the manufacturing process. When the body is bucked and completely assembled in bare steel the bodies were dipped in a primer tank to cover the bare metal. As the body rose from the tank this allowed for drainage of the primer from the body back into the tank
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I am reading your thread and it is a very similar situation that happened to me. When I bought my car the PO didn't know (or didn't disclose) any rust issues. I believe him. He was an old man and the rust was covered by a very bad restoration body work done 10 years previously. The floors were repaired with fiber glass and that's why they sounded "solid". The rest is history. I have repaired the floors, trunk, cowl and battery apron. I didn't know how to weld before I started all this and tackled the floor by myself. I did one side at a time to help keep the car in shape. Here is my long floor thread for reference: https://www.7173mustangs.com/thread-muscletang-needs-new-floor-pans-advice
In regards to the cowl you can inspect a lot through the vent openings and from the interior with a flexible camera (endoscope. I got a cheap one that I connect to my phone (similar to this, https://www.amazon.com/BlueFire-Android-Endoscope-Phones-Function/dp/B013HZCYXK). Well worth it! Here is my method of cowl repair. By no means it is a rotisserie repair, but I avoided removing the "one million" spot welds. If no one really looks inside the cowl, they will never know how it was done. Here is a link to that thread: https://www.7173mustangs.com/thread-my-method-for-cowl-repair
As you are learning things are going to take 2 to 4 times longer than planned. When I started the floors I thought it was going to be one winter, but it ended up taking me 1 1/2 years. Then came the trunk, the cowl and the battery apron. The more you inspect the more rust you find!! I have replaced pretty much every moving part little by little over the last four years. The last batch is the rear end which I am working on as I speak. This is my build thread for reference: https://www.7173mustangs.com/thread-muscletang-mod-project-thread-1971-m-mach-1
Feel free to ask me any questions. I think you are in the same boat I was in four years ago..... and a few(+++) thousand dollars ago.
In regards to the cowl you can inspect a lot through the vent openings and from the interior with a flexible camera (endoscope. I got a cheap one that I connect to my phone (similar to this, https://www.amazon.com/BlueFire-Android-Endoscope-Phones-Function/dp/B013HZCYXK). Well worth it! Here is my method of cowl repair. By no means it is a rotisserie repair, but I avoided removing the "one million" spot welds. If no one really looks inside the cowl, they will never know how it was done. Here is a link to that thread: https://www.7173mustangs.com/thread-my-method-for-cowl-repair
As you are learning things are going to take 2 to 4 times longer than planned. When I started the floors I thought it was going to be one winter, but it ended up taking me 1 1/2 years. Then came the trunk, the cowl and the battery apron. The more you inspect the more rust you find!! I have replaced pretty much every moving part little by little over the last four years. The last batch is the rear end which I am working on as I speak. This is my build thread for reference: https://www.7173mustangs.com/thread-muscletang-mod-project-thread-1971-m-mach-1
Feel free to ask me any questions. I think you are in the same boat I was in four years ago..... and a few(+++) thousand dollars ago.
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baz70
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Tony, thanks for all the tips, will definitely reach out with questions, good to know someone has been on the road and paved a way forward like you, i don't believe seller lied and think the 2 years in which the car was in probate and parked up is where the bulk of the rust occurred. Plus the fact I've had the car for 9 years and never once lifted the carpet puts the onus on me to have addressed the issues earlier. Some parts of the car are in amazing shape so it is a little inconsistent. I dont think i will need any external panels to be cut and welded although i haven't taken out the windshields/screens to inspect, mind you nothing will surprise me now.
Re cowls, i did exactly that, inspected through the openings and it did look like surface rust which is why i was concerned by the floor pan rust, i like the endoscope idea and will look to buy it.
I will check out your build thread.....
baz70
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Interesting, thanks, I've learnt something new today !
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The same with my car. Some parts are in great shape while others were terrible. Hopefully I have taken care of most of the terrible spots.
baz70
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not much progress during the week, battery apron removed and repro panel trial fitted. i don't like the repro, so much for CJPP "Classic" part. If anyone knows that i can get a less wrinkle free panel let me know from where and i will re-order. I also have the original panel and it was not wrinkled, had some dings from transit which i need to hammer out. also original panel was stamped, anyone know what the stampings signify and have these been reproduced by anyone ? thanks!
so far about a third done on battery apron, need to wirebrush rust, plug holes, trial fit and fettle, remove EP coat, prime, spot weld (need to find a spot welder from someone to reproduce factory style spot welds..... ironically that is going to be my most difficult task. I'm not buying one !
i cut off the fender support panel that goes over the battery apron and under front panel, will reweld later.
so far about a third done on battery apron, need to wirebrush rust, plug holes, trial fit and fettle, remove EP coat, prime, spot weld (need to find a spot welder from someone to reproduce factory style spot welds..... ironically that is going to be my most difficult task. I'm not buying one !
i cut off the fender support panel that goes over the battery apron and under front panel, will reweld later.
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baz70
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hmmmm, found a nasty rust hole on the shock tower, not sure what is backing it up..... unless someone says otherwise i will "cut and butt" it.
initial view of passenger side cowl below : in a previous post i asked whether it was feasible to cut the section above to get access to the cowl and then repair as necessary. difficult to tell if its rusted through. dumb question but what's the purpose of the cowl. its not something i hear mentioned in relation to European cars bit always part of the Mustang discourse....
flip a coin generator
initial view of passenger side cowl below : in a previous post i asked whether it was feasible to cut the section above to get access to the cowl and then repair as necessary. difficult to tell if its rusted through. dumb question but what's the purpose of the cowl. its not something i hear mentioned in relation to European cars bit always part of the Mustang discourse....
flip a coin generator
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Your picture shows the cowl's hat. The cowl takes the fresh outside air through the vents and then through the hat into the cabin. The hat is there to allow water to drain around it and not into the cabin.initial view of passenger side cowl below : in a previous post i asked whether it was feasible to cut the section above to get access to the cowl and then repair as necessary. difficult to tell if its rusted through. dumb question but what's the purpose of the cowl. its not something i hear mentioned in relation to European cars bit always part of the Mustang discourse....
It appears that you may have only surface rust. Mine had a lot of rust where the hat attaches to the cowl. I suggest you try to get pictures of inside the hat, behind the hat and from inside the cabin. The inside hat pictures you can take by extending your arm through the cowl and the pointing your phone inside the hat. Sometimes taking a video is easier. From the cabin, remove the glove box, unscrew the heater box from the hat and remove the foam in the area. This should give you enough of an opening to see the hat from the cabin. You may have to use the flexible camera I suggested in an earlier post. The area behind the hat you should be able to access through the drain hole on the fender side.
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baz70
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so. progress has been demonstrably slow this week, although I've got a lot done. removed driver side seat platform, can reuse this I think.... cut into tunnel when trying to remove welds though, hey ho will need to add to the welding job list. Still undecided on whether to remove complete floor pans or patch the damaged sections. I'm leaning over to complete floor pans this week.
Removed all interior rear plastic trim panels and rear seat sections including fold down seats so it gives me more space to work in and less panels to damage during welding. Have started cleaning chrome edges and will need to re-dye black carpet as faded but otherwise rear seats/fold downs look good.
Moving backwards, sanded trunk floor, found pinholes in 4 sections. I don't fancy putting in a new floor so will patch weld in sections. Removed rear lights, electrical light wiring, rear panels. Lights are good will need the black trim sealing edges, and rear black panel has some damage will need to epoxy fill, sand and paint.
There is a metal surround with 4 screws attached to the trunk floor for fuel tank filler pipe. this was quite rusty. I had to separate it from the rubber gasket. anyone know if this is reproduced ? I Couldn't see it on CJPP.
will post pics when imgbb is back up....
Removed all interior rear plastic trim panels and rear seat sections including fold down seats so it gives me more space to work in and less panels to damage during welding. Have started cleaning chrome edges and will need to re-dye black carpet as faded but otherwise rear seats/fold downs look good.
Moving backwards, sanded trunk floor, found pinholes in 4 sections. I don't fancy putting in a new floor so will patch weld in sections. Removed rear lights, electrical light wiring, rear panels. Lights are good will need the black trim sealing edges, and rear black panel has some damage will need to epoxy fill, sand and paint.
There is a metal surround with 4 screws attached to the trunk floor for fuel tank filler pipe. this was quite rusty. I had to separate it from the rubber gasket. anyone know if this is reproduced ? I Couldn't see it on CJPP.
will post pics when imgbb is back up....
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Missed this one in the past.
On the drain holes. No 71 - 73 ever got dipped in primer they got two coats of spray on primer. That is why they rust so bad.
Yes the cars had to go through a wash tank to remove the oil from the stamping process and would have also gone in a phosphate tank to etch the metal so the primer would stick. So the drains are there for that reason.
If you go to the Ford Facts book that Ray posted it tells the paint process.
In today's world they do e-coat the primer on but it still does not get in close spaces not enough flow of material. The tank with the e-coat is only about 20% paint the the remainder is just water.
On the BMW X-5 it had huge holes in it to allow the liquid to get in also and prevent the body from floating off the carriage. The mustang sat on a carriage all the through the build process. The larger diameter holes in the frame rails were the locator pins on the carriage were.
Here is a link to a music video made on the mustang assembly line you can see car on the carriage in it. You can see how they painted the hoods and fenders off the car also.
I know it is way too late now but I encourage everyone to always look at the car yourself or just do not make the purchase. Pictures lie and so do the sellers. Hope the link works does not look right is on youtube of course.
On the drain holes. No 71 - 73 ever got dipped in primer they got two coats of spray on primer. That is why they rust so bad.
Yes the cars had to go through a wash tank to remove the oil from the stamping process and would have also gone in a phosphate tank to etch the metal so the primer would stick. So the drains are there for that reason.
If you go to the Ford Facts book that Ray posted it tells the paint process.
In today's world they do e-coat the primer on but it still does not get in close spaces not enough flow of material. The tank with the e-coat is only about 20% paint the the remainder is just water.
On the BMW X-5 it had huge holes in it to allow the liquid to get in also and prevent the body from floating off the carriage. The mustang sat on a carriage all the through the build process. The larger diameter holes in the frame rails were the locator pins on the carriage were.
Here is a link to a music video made on the mustang assembly line you can see car on the carriage in it. You can see how they painted the hoods and fenders off the car also.
I know it is way too late now but I encourage everyone to always look at the car yourself or just do not make the purchase. Pictures lie and so do the sellers. Hope the link works does not look right is on youtube of course.
baz70
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some pics of trunk floor....
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baz70
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I had one of those moments last weekend when i surveyed the shell of my 72 and wandered wtf have i got myself into....
hey ho, ok so this weekend the rear has been dismantled and weld work commenced.
first job was a small cut and butt of a tail light edge on the rear panel. I'll do more next week just getting back into the swing and dusting off the welder.....
Priority is rust removal and prevention. I use kurust to coat cleaned areas preventing rust from spreading then red oxide primer to keep at bay until decision on respray. Plan of attack is preservation of as much original parts and sheet metal before replacing complete parts and panels.
Putting off the biggest job (floor plans) till later on.
hey ho, ok so this weekend the rear has been dismantled and weld work commenced.
first job was a small cut and butt of a tail light edge on the rear panel. I'll do more next week just getting back into the swing and dusting off the welder.....
Priority is rust removal and prevention. I use kurust to coat cleaned areas preventing rust from spreading then red oxide primer to keep at bay until decision on respray. Plan of attack is preservation of as much original parts and sheet metal before replacing complete parts and panels.
Putting off the biggest job (floor plans) till later on.
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baz70
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a thought....I dont think it was factory (someone can correct me) but PO had horrible silicone like sealant around light panel fixings and this worsened the rust as it seeped behind. I think the less of this the better, good paint and primer and let the car breathe rather than silicone sealing / undersealing everything.... your thoughts ?
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I thought the same thing when I started my project. The more I looked the more I found aaargghhh!!
First thing I did was the floors and cowl panel then trunk floor, quarters etc
Best to get the most difficult areas done first I reckon
With the tail lamps as far as I know they had a thick rubber gasket and no sealer but perhaps someone can confirm
Agree in some areas it is best just to treat and apply epoxy primer, 2K primer and paint and make sure your drain holes are clear
In some areas such as roof drip rail mouldings rather than use tape I found it better to use strip caulking
You might get away with patching your trunk floor but be aware the metal will be quite thin and difficult to weld so might have to cut a fair bit away to find good metal.
First thing I did was the floors and cowl panel then trunk floor, quarters etc
Best to get the most difficult areas done first I reckon
With the tail lamps as far as I know they had a thick rubber gasket and no sealer but perhaps someone can confirm
Agree in some areas it is best just to treat and apply epoxy primer, 2K primer and paint and make sure your drain holes are clear
In some areas such as roof drip rail mouldings rather than use tape I found it better to use strip caulking
You might get away with patching your trunk floor but be aware the metal will be quite thin and difficult to weld so might have to cut a fair bit away to find good metal.
baz70
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Managed to weld repair the shock tower section that had rusted out. Rust was caused by blockage of drain hole. There are way too many panel sections on this car ! Will grind down welds and then move onto completing the battery fender apron panel replacement.
I know the perfectionists won't like it but it'll be finished up like it was never welded, more important for me was preventing further rust in the recess and clearing the drain hole that the factory folks seam filled.
I know the perfectionists won't like it but it'll be finished up like it was never welded, more important for me was preventing further rust in the recess and clearing the drain hole that the factory folks seam filled.
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baz70
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Here's a view of the current state of rear section, with surface rust sanded down and ready for kurust and then red oxide primer. I am going to remove windshield for easy access and to avoid damaging it.
How have folks treated rust behind the rear quarter panel in the gaps seen in this pic ?
I don't want to have to remove the quarter panel sections to access as it looks like surface rust but then again the floor pans looked pretty solid before i removed the paint....
How have folks treated rust behind the rear quarter panel in the gaps seen in this pic ?
I don't want to have to remove the quarter panel sections to access as it looks like surface rust but then again the floor pans looked pretty solid before i removed the paint....
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I just removed my tail lights and cleaned the trunk of my 73 Mach 1. When the guys at the factory sprayed paint in the trunk they got very little if any where the tail lights went. The flange with the studs that hold the tail lights in was in the way of spraying the paint. I used a brush and put POR Paint Over Rust around where it seals.
Daniel Carpenter makes a much better seal that the Ford original. I have a couple sets of NOS Ford gaskets but ordered the DC from National Parts Depot. It is molded from better material and more dense.
Like someone else stated I use the 3-M strip caulk on the roof rails and also around the tail lights. I do not wash my Mustangs with a hose or pressure washer and try to stay out of rain. Every time you do wash you feed the rust inside the quarters, cowl, tail lights and all the places with no primer or paint.
The trunk floor is one of the most important parts of your car structure. I think you should think about replacing it. I have seen the leaf springs actually come through the floor at the rear mounts due to rust damage. I believe you will find that replacing the whole front floor pan will be much faster and easier than putting the patches in. They never match in form and very difficult to get a good butt weld. Most people overlap and end up with lots of sealer to close them them.
I have seen my friend put floor pan in from firewall to tail lights in two days. They were not patches.
Any project on a Mustang tends to snowball out of control because you keep finding more issues. You being far from the supply of parts makes it tough and expensive also.
Daniel Carpenter makes a much better seal that the Ford original. I have a couple sets of NOS Ford gaskets but ordered the DC from National Parts Depot. It is molded from better material and more dense.
Like someone else stated I use the 3-M strip caulk on the roof rails and also around the tail lights. I do not wash my Mustangs with a hose or pressure washer and try to stay out of rain. Every time you do wash you feed the rust inside the quarters, cowl, tail lights and all the places with no primer or paint.
The trunk floor is one of the most important parts of your car structure. I think you should think about replacing it. I have seen the leaf springs actually come through the floor at the rear mounts due to rust damage. I believe you will find that replacing the whole front floor pan will be much faster and easier than putting the patches in. They never match in form and very difficult to get a good butt weld. Most people overlap and end up with lots of sealer to close them them.
I have seen my friend put floor pan in from firewall to tail lights in two days. They were not patches.
Any project on a Mustang tends to snowball out of control because you keep finding more issues. You being far from the supply of parts makes it tough and expensive also.
