Author Topic: Guidance on bringing car down to metal  (Read 527 times)

Zach

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Guidance on bringing car down to metal
« on: July 18, 2023, 08:52:45 PM »
Hello, I recently acquired a very rusty and ugly 71 Mustang(not a bird, shoot me), I have a build thread somewhere, "1971 Mustang Mach 1 Restoration". Good practice before I restore the T/A. I am looking to get opinions and guidance on ways to strip the car down to bare metal, remove surface rust, find bad metal, and just overall clean up the body so I can start doing rust repair on a clean body. I will need to do pretty much every inch of the car as well, inside, outside, under, on top. After grinding I will spray with a primer but I will save that for another thread.

Media blasting is the first thing that I was looking into, I have a friend who might be able to get me in otherwise places charge an arm and a leg where I am located, it would also be a hassle to transport the car. Garage has a slight incline which makes it really hard to roll the car out to work on it so I resort to getting the garage and the t/a dirty. Could always buy my own dustless adapter, or something and blast it myself at home Just am unsure how difficult that would be to not mess it up.
The next avenue I started to venture was hand grinding/sanding, I am quite patient and don't mind putting in a bunch of physical labor to save money, but this also brings up a lot of questions I do not have knowledge on. Curious what people on this forum have used regarding this route, angle grinder, polisher, D/A, strip and clean discs, sanding disc, brands, etc, etc. My current idea was to get a big polisher and put some 7 inch strip and clean discs on it. Polisher seems to do a good job, just have to be worried about warping and gouging, plus it means I will have a buffer for when I finish paint.
Using paint thinners/strippers seems to be another option but doesn't seem like the best solution. They look to be pretty messy and tend to get pretty expensive when you start buying gallon after gallon. Will most likely avoid this depending on what people say.

Overall, I am thinking I will be choosing a polisher, unsure what kind, with strip and clean discs and see how that turns out. I will need to find something for tight areas as well, angle grinder can barely get in some places. But, I would love to hear suggestions and guidance. Being 19 I have little experience and research the heck out of everything before I start something.
Thanks.
1977 #s W72 400 4 Speed Trans Am
1971 351c 4 Speed Mustang Mach 1

ryeguy2006a

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Re: Guidance on bringing car down to metal
« Reply #1 on: July 19, 2023, 07:10:38 AM »
I like your thought process, but I don't think that a polisher will be up to the task of cutting paint. It's not meant for a lot of resistance, so I think you would be best to use a dedicated D/A sander.

After spending hours upon hours D/A sanding all the panels on my 76 T/A, I'll tell you that it gets very tedious and boring. One thing that I've learned as I've been building cars is that time is money. I had the same thought process as you when I was first building cars. I have lots of time on my hands and less cash, and can afford to put in more labor rather than spending money. That said, a perfect example was when I re-did the floor pans in my 1968 Camaro. When I bought the car it same with 4 lower pan patch panels, so I thought it was a no brainer to weld in the panels and save a bunch of money. Well after about 2.5 months of cutting, welding and grinding I was finished with the floor. Hindsight, I would have been way farther ahead on my timeline if I had just spend the money to get a full floor pan and spot welded it in like the factory. Not only would my timeline have been better, I think that the end results would have been much cleaner.

Just passing along my experiences, hoping to save you some effort in the long run. Look forward to seeing what you do with the car. Coyote swap??  :lol:

1976 Trans Am LS1 and much more...SOLD
1968 Camaro LSA, T56 Magnum, and much more...SOLD

Current Project: 1955 Nomad LC9, 4L80e, C5 brakes and etc...

5th T/A

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Re: Guidance on bringing car down to metal
« Reply #2 on: July 19, 2023, 10:06:24 AM »
My personal experience goes back to 1980, things have changed a lot since I started doing any body and paint work. I started by using a Sears electric reciprocating hand sander that used square sheets of paper. Fortunately I had a good friend who owned a body shop who set me straight. He told me to buy a Detroit National DA sander. Air powered and used 3m adhesive to hold the paper to the pad. I purchased the DA and could not believe how much more efficient it was.

I haven’t tried one for body work, but I am guessing a modern electric orbital sander would probably come a lot closer to the performance of a DA. As Road King suggested.
I am pretty sure most body shops are still using air tools. Having said that it’s hard to get into all the nooks and crannies, especially underneath with a sander.

Personally I like the idea of dustless blasting or similar processes. Just make sure you have someone who is experienced in auto body work or they will destroy your sheet metal. In my more ignorant days I sand blasted the underside of a hood to remove the rust. Ended up ruining the hood as it stretched all the metal I hit from underneath. Experienced automotive guys use a much softer media.

I will add you are smart in doing all the research you can first instead of just diving into your project. Once you get started be patient. It will always take longer and cost more than anticipated. If you can hang in there you will get a lot of satisfaction of doing this yourself.
1980 T/A with a Pontiac 461

Gone but not forgotten;
1973 T/A 455
1975 T/A 400
1978 T/A W72
1982 T/A cross fire injected

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2013 Honda CB1100
2010 Yamaha Vmax
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Zach

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Re: Guidance on bringing car down to metal
« Reply #3 on: July 19, 2023, 10:43:47 AM »
I like your thought process, but I don't think that a polisher will be up to the task of cutting paint. It's not meant for a lot of resistance, so I think you would be best to use a dedicated D/A sander.

After spending hours upon hours D/A sanding all the panels on my 76 T/A, I'll tell you that it gets very tedious and boring. One thing that I've learned as I've been building cars is that time is money. I had the same thought process as you when I was first building cars. I have lots of time on my hands and less cash, and can afford to put in more labor rather than spending money. That said, a perfect example was when I re-did the floor pans in my 1968 Camaro. When I bought the car it same with 4 lower pan patch panels, so I thought it was a no brainer to weld in the panels and save a bunch of money. Well after about 2.5 months of cutting, welding and grinding I was finished with the floor. Hindsight, I would have been way farther ahead on my timeline if I had just spend the money to get a full floor pan and spot welded it in like the factory. Not only would my timeline have been better, I think that the end results would have been much cleaner.

Just passing along my experiences, hoping to save you some effort in the long run. Look forward to seeing what you do with the car. Coyote swap??  :lol:

Appreciate the response, main reason I don't get a snadblaster and do this myself is cause I know it is tricky doing sheet metal of various thickness and rustiness. Since this is my moms car, its technically her budget and my labor, but whatever money I can save will be used on other things. Tedious is ok with me if it means a good final finish and not have to worry about it. Coyote swap would be really fun, but nothing beats an old period correct engine in my eyes. Although, this 351 might get stroked out to 408 with a big cam. Still a ways away from tire burning upgrades, need to get through body work.

My personal experience goes back to 1980, things have changed a lot since I started doing any body and paint work. I started by using a Sears electric reciprocating hand sander that used square sheets of paper. Fortunately I had a good friend who owned a body shop who set me straight. He told me to buy a Detroit National DA sander. Air powered and used 3m adhesive to hold the paper to the pad. I purchased the DA and could not believe how much more efficient it was.

I haven’t tried one for body work, but I am guessing a modern electric orbital sander would probably come a lot closer to the performance of a DA. As Road King suggested.
I am pretty sure most body shops are still using air tools. Having said that it’s hard to get into all the nooks and crannies, especially underneath with a sander.

Personally I like the idea of dustless blasting or similar processes. Just make sure you have someone who is experienced in auto body work or they will destroy your sheet metal. In my more ignorant days I sand blasted the underside of a hood to remove the rust. Ended up ruining the hood as it stretched all the metal I hit from underneath. Experienced automotive guys use a much softer media.

I will add you are smart in doing all the research you can first instead of just diving into your project. Once you get started be patient. It will always take longer and cost more than anticipated. If you can hang in there you will get a lot of satisfaction of doing this yourself.

I have a 60 gallon air compressor on the way so if I need to use air tools I will, although electric does outperform depending on price points in some tools. My only concern with sand paper is if old lacquer and rust will gum it up quickly. The car has the original paint, primer, and a new paint job, along with rust everywhere. Being able to say all the labor was done by me will be pretty rewarding. Thanks.
1977 #s W72 400 4 Speed Trans Am
1971 351c 4 Speed Mustang Mach 1

roadking77

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Re: Guidance on bringing car down to metal
« Reply #4 on: July 20, 2023, 05:17:41 AM »
This is gonna sound crazy, BUT a single edged razor blade will peel the paint right off the car. I have seen where guys have done a car in relatively short time. My experience with the sander is that the paint will not gum up on the paper. It will wear out though. I like the diablo stuff from home depot for the rough work, only because thats what I use in my shop. Start coarse and work you up to finer stuff.
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Re: Guidance on bringing car down to metal
« Reply #4 on: July 20, 2023, 05:17:41 AM »

Zach

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Re: Guidance on bringing car down to metal
« Reply #5 on: July 20, 2023, 11:52:53 AM »
This is gonna sound crazy, BUT a single edged razor blade will peel the paint right off the car. I have seen where guys have done a car in relatively short time. My experience with the sander is that the paint will not gum up on the paper. It will wear out though. I like the diablo stuff from home depot for the rough work, only because thats what I use in my shop. Start coarse and work you up to finer stuff.

I’ve heard about the razor blade stories too, however there is about 3 layers of paint and primer already on the car, including the original lacquer and a bunch of surface rust and holes. My only issues that I have with sandpaper is that it will get gummed up immediately and be useless since there is so much it has to eat. I tried out my grinder with the strip discs and man do they shake bad, I might try a da for something more stable and less aggressive.
1977 #s W72 400 4 Speed Trans Am
1971 351c 4 Speed Mustang Mach 1

5th T/A

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Re: Guidance on bringing car down to metal
« Reply #6 on: July 20, 2023, 01:28:07 PM »
While I haven’t done body work for years, I too like the Diablo sanding disks for projects around the house. When you buy in large quantity 50 or a 100, I don’t remember, the price is reasonable and it holds up well.
1980 T/A with a Pontiac 461

Gone but not forgotten;
1973 T/A 455
1975 T/A 400
1978 T/A W72
1982 T/A cross fire injected

Two wheel toys;
2014 Harley Ultra Classic Limited
2013 Honda CB1100
2010 Yamaha Vmax
1982 Yamaha Seca 750

FormTA

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Re: Guidance on bringing car down to metal
« Reply #7 on: July 20, 2023, 06:04:55 PM »
Here is how I would attack it. I would get myself some aircraft stripper and apply it to one panel at a time. Let that work for a little bit. It will turn the lacquer into a liquid so you can use a bond spreader to whipe it off and the wipe the panel with a rag and then some acetone or something. Let it dry up and hit it with 80 grit sandpaper on a random orbit sander. I have found that an electric sander is sometimes better than using air and working your compressor to death when a cheap random orbit sander can do it. Using the aircraft stripper gets the paint that gums up the paper off so it really speeds things up. Just don't go crazy and apply it to too many panels that you can strip right away. You don't need to create panels that will rust because you can't get to them. After you have a panel or two done or at least you are at a semi stopping point I would hit them with a coat of epoxy primer (after correctly prepping them) to keep flash rust off.

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Re: Guidance on bringing car down to metal
« Reply #7 on: July 20, 2023, 06:04:55 PM »
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