Best way to go about rust repair on vehicle?

[ketchup]

Hello all. I bought my Sprint about a year ago, with 46k miles on the clock (was an extra car, won at Burger King back in the day). Unfortunately, it lived outside in Illinois for 24 years. So while the engine and transmission are perfect, there is rust. After this past winter, the rust has gotten worse. There is surface rust that is just cosmetic, but I am worried some of it may get structurally compromising. Particularly the passenger floorboard. It has developed a hole. See pictures (clickable thumbnails).



What would be the best way to go about keeping my car on the road?  My main concern is the structural integrity of the car. I want this car to last me as long as I can; I know the drivetrain still has plenty of life left in it.  I just rolled over 66k miles and I know the engine and transmission have at least another 100k left in them.  The body has maybe a year if I do nothing.

I posted on an enthusiast site for these cars, and the recommendation was to find a rust-free body from the west coast and drop my engine into it.  I would love to do that, if I could locate one, but these cars are scarce.

Thanks!

[daverobev]

Ohh I didn't even know there was such a car in NA - I had the British equivalent, a 1986 Vauxhall Corsa, loved that car!!

I think to fix it you need to find a friend that can weld, and sandblast. You can then get as much of the rust out as possible, weld in new steel, and it should hold up..

[ncornilsen]

As a guy who's restored a couple of classic cars with small amounts of rust...  I'd say this car is terminal. By the time you cut out the rust to solid metal, there won't be much left of the car.  The rust appears to already have gotten into the structural members of the car. You car is of uni-body construction, so the rocker panels (the ones just below the door) typically are your main structural member through that part of your car. (Along with the A pillar, B pillar and associated roof structure.)

Also, explain how you won this car at Burger King? was it some kind of sweepstakes like McD's does with the monopoly thing?

[ketchup]

I didn't win the car at Burger King; the previous owner did.  I didn't ask him any details about it, but I assume it was something like what you said.  Burger King didn't get any of the options of course.  No air conditioning, cruise control, rear defroster, or tape deck.  Also luckily, no automatic transmission.  The Burger King story is always fun when people ask about the history of the car (due to low miles and high age).

"Terminal" is a very sad word.  I took the car to a body shop about a year ago (when the rust wasn't as bad; this past winter did a number on it), and the guy there told me the rusty rocker panels on my car were just cosmetic, and the frame rails I needed to be concerned about were the one going from the middle of my last picture to the left corner (I wish I knew the terminology better) and the mirror opposite on the driver's side.  Is that possible, or was he just flat out wrong?  Either way, how can I maximize the remaining lifespan of my car?  Last October right before it got cold, I sprayed some Extend rust neutralizer on any exposed rust I could find, but I don't think it really did very much for my rocker panels.  I had meant to do some body work on the car earlier in the year, but other mechanical issues kept me occupied (clutch, radiator, etc.).  I'm still driving this car every day, and I really hate to give a car with 66k miles on it (and that I just renewed the registration on) a death sentence.  How can I postpone the inevitable?

I don't suppose I can be too upset with a $1000 car lasting me a year and 20,500 miles (so far), but I would still like to wring as much life as I can out of it.

[higginst]

It sort of depends what your skills are and how much you're willing to put into this.  It also depends on your personal "risk threshold" and the degree to which your willing to "redneck" it up a bit

There are many ways to "repair" the rust.  I'm probably going to be flamed for even suggesting some of these, but I'll do it anyway.  The first step for all cut out the completely rotten part through portions (with a sawzall or with a cutting torch), and clean surrounding sound, but surface rusted metal with a wire wheel on an angle grinder (easy way) or a wire brush and/or rust dissolver (hard way).  Then you can do one, or some combination of, the following:

1) Buy replacement panels and weld them into place. You can order things like new, replacement floor pans for many models from auto-parts retailers online (like Rockauto). You can also do this buy finding a wrecker version and cutting out the replacement body section you need (as long as it is sound) and welding it in place
2) Use sheet steel and/or thin gauge flat bars, drill holes, and then pop rivet them to patch the hole(s). This is good way of doing a quick repair to things like rocker and fender panels to make it look a little better, even if you just paint the entire lower portion black. But, if you actually do a good job of cleaning all the surface rust underneath the repair first and then paint or rubber undercoat the repair, it can do a good job of arresting the rust so that the vehicle will last a few more years
3) Use fiberglass matt.  Again, this is not going to make it all that more structurally sound, but it can help to slow or stop the rust if you clean of the rust under the repair area.  It is also a better way to get a really nice looking repair in areas that will be seen, but you have to put a lot of time into the finishing and sanding for that to happen.

Now, for the really backyard, redneck stuff: You can increase rigidity and structural intergrity by adding your own "frame rails."  This is where you can get creative. My Dad and I have used square stock steel, steel pipes, steel bars, and even lumber (2x4s, 2x6s). To add support to the under carriage. Now, I know this sounds pretty bad, but if you think about it with common sense (instead of panicky "but THAT'S NOT SAFE!" thinking), you could see that all of this will only make your car in its current state safer.  Will it be as safe as it was when it was new? No. Will it be as safe as it a 2013 model year subcompact car? No.  But if you clean (sand, sandblast, grinder) of the rusted areas underneath and weld and/or drill and bolt 1" square tube steel to the key points on the frame, it will be stronger and will last you much longer.  Lumber is not as good a solution, but it gives you an easy way (most people have the skills to do some rough work with wood but not so much with steel) to add support to floor pans. You can then use fiberglass to make it a sealed repair so that no water can get at the wood and rot it.

The key to all of these ideas is that you need to be very conscientious about the rust removal and then the sealing of the new repair materials.  I know some of my ideas are not ideal and are not the best. But this is 20+ year old Sprint, so I don't think the OP is too concerned with status or safety.  But that's a good thing, right? ;)

[BlueMR2]

It sort of depends what your skills are and how much you're willing to put into this.  It also depends on your personal "risk threshold" and the degree to which your willing to "redneck" it up a bit

There are many ways to "repair" the rust.  I'm probably going to be flamed for even suggesting some of these, but I'll do it anyway.  The first step for all cut out the completely rotten part through portions (with a sawzall or with a cutting torch), and clean surrounding sound, but surface rusted metal with a wire wheel on an angle grinder (easy way) or a wire brush and/or rust dissolver (hard way).  Then you can do one, or some combination of, the following:

1) Buy replacement panels and weld them into place. You can order things like new, replacement floor pans for many models from auto-parts retailers online (like Rockauto). You can also do this buy finding a wrecker version and cutting out the replacement body section you need (as long as it is sound) and welding it in place

We've done this on my car.  Despite all the work, it was still a LOT cheaper than a new car, and cost roughly the same as a comparable used car of the same vintage (except used cars of that vintage around here still have all that rust going on!).  Not all the replacement panels were installed complete.  Sometimes it's easier to cut the existing panel and the new one to do a half and half type install.  I've had frame rail damage repaired before too.  That's not a DIY job, you really want a pro.  A pro can make something solid and reliable.  Don't chance it if you don't know what you're doing, it's just too critical.  Most of the repair costs are simple labor in stripping and reassembling the car.  If you can find someone that will work with you on that, you can save a ton of money.  I'll do all the strip down work myself, then ship it off the the body guy, along with alignment critical parts that he requests.  It comes back to me welded up with those parts installed, then I install the rest!

[Matthew]

Ketchup - I don't have any technical advice for you, but don't give up on that thing.  Sprints are great.  I have a friend who buys them every chance he gets, to lend to people or for his many kids.  He's disappointed if they die before 300k.  My wife and I borrowed one from him that he bought for $1, and we drove it across the country and back.  No problems.  Well, we did have to hit the starter with the lug wrench to make it work.

My current car is about the same vintage - 1983 Honda.  My wife drove it from Alaska to Florida a few years ago.  Those old hatchbacks are amazing!  Real head-turners too.

[GoStumpy]

That does look mostly cosmetic... but indeed terminal.

Keep driving it!

[Mountainman75]

Thirded on the terminal part.

Search Craigslist in the desert SW for a replacement with a bad motor... swap your driveline into it.

[ketchup]

It sort of depends what your skills are and how much you're willing to put into this.  It also depends on your personal "risk threshold" and the degree to which your willing to "redneck" it up a bit

There are many ways to "repair" the rust.  I'm probably going to be flamed for even suggesting some of these, but I'll do it anyway.  The first step for all cut out the completely rotten part through portions (with a sawzall or with a cutting torch), and clean surrounding sound, but surface rusted metal with a wire wheel on an angle grinder (easy way) or a wire brush and/or rust dissolver (hard way).  Then you can do one, or some combination of, the following:

1) Buy replacement panels and weld them into place. You can order things like new, replacement floor pans for many models from auto-parts retailers online (like Rockauto). You can also do this buy finding a wrecker version and cutting out the replacement body section you need (as long as it is sound) and welding it in place
2) Use sheet steel and/or thin gauge flat bars, drill holes, and then pop rivet them to patch the hole(s). This is good way of doing a quick repair to things like rocker and fender panels to make it look a little better, even if you just paint the entire lower portion black. But, if you actually do a good job of cleaning all the surface rust underneath the repair first and then paint or rubber undercoat the repair, it can do a good job of arresting the rust so that the vehicle will last a few more years
3) Use fiberglass matt.  Again, this is not going to make it all that more structurally sound, but it can help to slow or stop the rust if you clean of the rust under the repair area.  It is also a better way to get a really nice looking repair in areas that will be seen, but you have to put a lot of time into the finishing and sanding for that to happen.

Now, for the really backyard, redneck stuff: You can increase rigidity and structural intergrity by adding your own "frame rails."  This is where you can get creative. My Dad and I have used square stock steel, steel pipes, steel bars, and even lumber (2x4s, 2x6s). To add support to the under carriage. Now, I know this sounds pretty bad, but if you think about it with common sense (instead of panicky "but THAT'S NOT SAFE!" thinking), you could see that all of this will only make your car in its current state safer.  Will it be as safe as it was when it was new? No. Will it be as safe as it a 2013 model year subcompact car? No.  But if you clean (sand, sandblast, grinder) of the rusted areas underneath and weld and/or drill and bolt 1" square tube steel to the key points on the frame, it will be stronger and will last you much longer.  Lumber is not as good a solution, but it gives you an easy way (most people have the skills to do some rough work with wood but not so much with steel) to add support to floor pans. You can then use fiberglass to make it a sealed repair so that no water can get at the wood and rot it.

The key to all of these ideas is that you need to be very conscientious about the rust removal and then the sealing of the new repair materials.  I know some of my ideas are not ideal and are not the best. But this is 20+ year old Sprint, so I don't think the OP is too concerned with status or safety.  But that's a good thing, right? ;)

Indeed I am not. :)  These all sound like great ideas.  I definitely need to make friends with a welder.

Ketchup - I don't have any technical advice for you, but don't give up on that thing.  Sprints are great.  I have a friend who buys them every chance he gets, to lend to people or for his many kids.  He's disappointed if they die before 300k.  My wife and I borrowed one from him that he bought for $1, and we drove it across the country and back.  No problems.  Well, we did have to hit the starter with the lug wrench to make it work.

My current car is about the same vintage - 1983 Honda.  My wife drove it from Alaska to Florida a few years ago.  Those old hatchbacks are amazing!  Real head-turners too.

Excellent.  Yeah, these engines don't die.  I was reading on a forum about some guy that found one with 440k on it. It was smoking real bad, and then after rebuilding the head (which on these cars is nothing) it was fine.  If it weren't for the rust, I could probably drive this car for the rest of my life.

Thirded on the terminal part.

Search Craigslist in the desert SW for a replacement with a bad motor... swap your driveline into it.

This is the eventual plan.  However, finding one isn't easy or cheap.  I look every so often though, just to see what's out there.

[riggerjack]

how to remove rust. This is a video series from a 240z, but it's the same kind of design you have, unibody with frame rails.

http://www.voodoo-people.com/~daz/mull/wmv/

Watch the series and then decide how much you love you metro.

If you decide you don't love it like that, i'd pressure wash it thoroughly, to get the salt out, maybe sand blast for rust, then fill everything you can with great stuff, a closed cell foam you can get from box stores for insulation. this will expand and stop salt water from entering the body voids and staying there causing the cancer. it'll add a tiny bit to the rigidity, but breaks down in sunlight. spay paint primer and paint should help with that. this foam is flammable, but no more than your vinyl interior.

then, decorate the car in a "mirth mobile" or "post apocalyptic mad max" motif. run it til the doors fall off.

[dragoncar]

No idea, but I think it depends on your driving conditions.  I'd worry about the thing falling apart going 80 down the highway, but it sounds like you don't drive it much, and probably not very fast.  If it's lazy around town driving, I'd be much more comfortable with the "redneck" fix.  But in that case, I'd want to make sure the welder really knew their shit -- I wouldn't trust myself.

To prevent further corrosion, try naval jelly (aka phosphoric acid).

[Matte]

I would paint it with some moisture cure epoxy paint, Por15 is a fancy brand name for it, but you can get other cheaper versions of the same thing (often sold as concrete paint) and clean it to the best of your ability (10 bucks at a diy wash place) and then paint anything that looks rusty down there, to get the insides buy a cheap undercoating gun (princess auto or harbor freight (15 bucks) and spray inside.  If you want to fill in the panels and add rigidity use close cell foam in a spray can (great stuff brand home depot) and fill your rotting rocker, fill the holes with it and then cut/sand it level with the non rusted parts and apply bondo (if you care) and sand, paint with epoxy and spray bomb body color (if you care).  When I was young I worked at a car dealership that used to take trade-ins and bring them to the auction (not to the public, dealers only), that is how we prepped cars with rust holes (minus the epoxy or por15 since it was way too expensive for them), w would say with the epoxy you should get a few years before it falls apart, or if you don't use it you will be worse within a couple months. 

[ketchup]

Well, I smashed up the car, so this isn't something I'll be worrying about anymore.  I had found someone that can help me weld, and was about to order some stuff tonight.

It was raining, I applied the brakes, brakes stopped the wheels from spinning, wet road kept car moving, smashed into a Jeep.  Jeep was perfectly fine.  My car... wasn't.

[paulsilver]

I hope you're OK after the accident, ketchup.

Seeing the earlier part of this thread, I was going to suggest breaking the car up and selling the various good parts to help fund your next car. Obviously not an issue now. I hope the insurance pays out without any problems.

[ketchup]

I hope you're OK after the accident, ketchup.

Seeing the earlier part of this thread, I was going to suggest breaking the car up and selling the various good parts to help fund your next car. Obviously not an issue now. I hope the insurance pays out without any problems.

As the value of this car is so low, I only carried liability, so no "paying out" to be done.  On the upside, that also means no insurance claim means no higher rates in the future because of that.

The engine and transmission are what's worth any money.  I've already listed the parts on an enthusiast site.

And yeah, I'm fine.  Just shaken up, but that's to be expected.  I knew exactly what was going to happen about half a second before impact.  Not a good feeling.  Antilock brakes would have saved it from my mistake.

Now, where'd I put that bike...