2 weeks ago I started in on the rust repair on the car. The first bit was actually fixing up some small problems on the replacement door that I put on. Those came out great, but I didn't get a chance to photograph them, unfortunately. Anyways, here is what was the biggest rust problem. This is the front valance, below the bumper. I didn't take a before picture, but here is what it looked like immediately after cutting out the corroded area.





I cleaned up the metal behind as best as I could with a little bit of sand blasting and a wire wheel attached to my mini-air grinder. I welded up the holes on the inside just for piece of mind, primed it, and then cut the patch piece for the front.

I cut the patch to the exact size of the opening, welded a nail to it so I could hold it while I tack welded it in place all with the hope that I could get the piece in flush so the repair would be invisible.

This started well, but it turns out that some of the surrounding metal was still not so great and the welder just burned it away, leaving more holes. Rather than start from scratch, I just made more small patches to cover them. I really should have cut out a bigger hole, but as I was contemplating redoing it, I realized that this whole panel will eventually be covered by the front spolier and is also going to be covered in a rubberized undercoating, so the patches won't even be seen.

I had to stop working because it was getting dark and I needed a new wheel for my grinder, but this is where I left off.



After I go over it with the grinder and clean it up, it should look pretty good. The panel feels very strong and shouldn't let in any more water or road grime.
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After reading up on painting, it became obvious that I was going to need a more serious compressor to power the spray gun. I've also been using my cut-off tool and die grinder fairly frequently, and the little 12gal compressor just hasn't been able to keep up. After almost 1 and a 1/2 months of looking around, I found this 5hp, 26gal Campbell Hausfeld. I've order an low volume low pressure spray gun to go with it and will take a stab at spraying on the epoxy primer very soon. I already had a moisture trap set up in the garage that I have been using to airbrush my models and it should work fine with the automotive spray gun.

Apparently, this compressor is an oil-less model, which is nice, but its extremely loud. It keeps up much better with my air tools, although, I do wish the tank was larger.


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After months of looking at the horrible paint and watching the rust spots grow. I finally started to spray on some new paint. Friday night, I started work on the trunk by filling the holes that hold the "belt line" chrome trim in place. The trim seems to trap moisture and is responsible for pretty much every single bit of rust on the car, so I decided to do away with it all together. I'm not terribly fond of how it looks, either and its very expensive to replace so shaving it off was an easy decision.

I used some non-galvenized nails to plug the holes. I tried to find nails that had heads that were just slighter larger than the holes so that they would be easy to grind off.



Next, I went about touching up some of my welds that ran around the inside seam of the trunk. It seems like water seeped in through the trim holes and then was trapped against the trunk seal. This was very time consuming as the patches were tricky to make because of the complex curves. The total amount of time for these repairs was probably about 5 hours. I still need to grind down the welds some more but I am still waiting for a carbide burr in the mail.

Once the rust had been dealt with, I stripped the entire trunk panel with 60 grit sand paper on my gigantic Craftsman sander. There were 2 thick layers of paint on the trunk so this took almost 2 hours. The amount of dust it generated was unbelievable. Doing this in the 90 degree heat is really a miserable experience so I just blitzed it without taking a break.







This being my first time using my spray gun set up, I was pretty nervous. I set up my moisture trap, used a nice, high quality hose that was just long enough, and set the pressure to the exact recommendation for my gun. The gun itself is a Chinese made clone of a much more expensive gun and it was recommended for the type of work I'm doing. It was only $80 which made me sort of nervous (when you consider that name brands are 4 times as much) but I figured it was probably worth a shot. I bought two guns because it supposedly a bad idea to mix your primer gun with your color and clear coat guns and also because I needed two different tip sizes.

The first coat of primer I used is Dupont's direct to metal epoxy primer. This is the stuff that they use on modern paint jobs and you use it without any sort of etching primer underneath it. Because of this, you're supposed to scuff the steel with a pretty rough grit paper (like the 60 grit that I used) so that it has something to bond to. Its pretty expensive stuff, but it takes VERY little to cover a panel. Its a two part system with the epoxy and then a temperature specific activator. It supposedly seals the metal just about as well as anything can and also provides a great base to start applying bondo to.

The spraying went incredibly well. The gun is stupidly easy to use and produces almost no overspray. It is a low volume low pressure design with a gravity feed cup so its very efficient with its paint use and consumes very little air. My compressor kept up without a problem which was a huge relief to me (I figured that was going to be the biggest hurdle to overcome) and the air coming out was clean and moisture free.







The epoxy cures into something that almost feels like plastic. It seems extremely durable and I'm very happy with the result. I did get a 1 small run but it will sand out very easily. I quickly dialed back on the amount of paint that the gun puts out and that seemed to solve the problem.

I also managed to pick up a new fender for $20 (as well as a better driver's side door and a rear panel) from a guy in San Jose who had some spares. It was in good shape with no serious dings and just a minor bit of rust on the very bottom.

I stripped it with my sander and an abrasive disc and sprayed it on Saturday. It looks as good as new now. I also welded up the holes for the side reflectors (they had them on the US cars but not in Europe so I decided I prefer how the fender looks without them), the trim holes, as well as the holes for the bumper's side pieces (I am switching to a much smaller bumper eventually).





This is some of the dust left after stripping the fender.



The fender came out very nicely with just one spec of dust landing on it that was easily sanded out. It still needs a little bit of bondo in its one dent and to clean up the welds, but overall, it looks just about new.

I did manage to catch my leg with an abrasive disc while cleaning around the lip of the fender. It still hurts and it put a pretty good sized hole in my jeans.



Tonight I'll start stripping the new door. My plan is to get epoxy primer on all the removable panels, then switch over to painting them fully. Once those are done, I'll tackle the roof, door jambs, and rear quarter panels but I need to pull the glass out for that.
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So the big reason I was able to get the car for such a low price was that the previous owner drove it into his (park) '66 Nova. The damage was completely limited to the BMW's front fender and driver's side door, thankfully, and it looked much worse than it really was. To get me by, I bought a door from a salvage yard. I went to work on it about a month ago, fixing the smaller bits of rust, but I discovered some more nasty bits that were in harder to repair places. So, when I saw a door for $50 I figured it was a good deal and worth the effort.

So this is the 3rd driver's side door that I've had since having the car. My hope was that it would be the last, but I've learned to never be to sure until the 30 plus years of paint have been stripped away...



Thankfully, stripping the door was not too bad. I finished the whole outside surface in about an hour working at a pretty casual pace. I was able to do most of it with the big sander and went over the hard to reach parts with the abrasive disc on the sander.







The good news is that the panel is in pretty good shape. There are two small holes in each of the corners, but both are easy fixes. Someone stripped the panel at some point and loaded it up with bondo. The rust holes had been covered with bondo, too, which is a complete joke and of course was not holding up at all. The doors on the 2002s all seem to get the same dents in them too from failed door stops, and this one has a small one. It looks like someone tried to pulled it out, but didn't weld up the holes from the puller. I'll close them up with the welder and then properly pull the dent out.

Ann tried to take some photos to show the mess that all this work creates.







It was only about 1.5 hours to get all this work done which really wasn't too painful.
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Last edited by Colin on 9-9-08 10:50; edited 1 time in total

Colin,

Real nice work. I really appreciate any blog where the work is all "home grown". Keep up the great work and keep us posted.

looks great man keep it up!

With most of the door stripped away, 2 small rust holes were revealed as well as the usual dent that the doors get when the door brakes fail. The front corner of the door had rust through with a similar, but much smaller, hole on the back side. Here is the worst hole being repaired.



This is the back side. I actually started by cutting out a small rectangle on the outer part of the door skin which revealed some rust on the section shown in the picture above. I just cut a little triangular section out as the effected area was very small.



Here is the patch piece being test fitted. I tack welded in the two bottom corner in first so then I could bend the piece up to match the contour of the door.



Here are the completed welds. I'll grind them down tomorrow and they should be nearly invisible.



This is the opposite side of the door. You can see the fresh metal below it.



Again, here is the tiny patch being test fitted. I tacked welded the corners and then tapped down the warped parts with a hammer to make sure it was nice and flush.





And this is the final product. It'll need a little bit of bondo but it is much better than the rust hole that was there.

I was also able to fill all the trim holes in the door, the holes left from a body puller and I pulled out the major dents. I don't have pictures of that as I haven't quite finished them up, but hopefully I can take some tomorrow.
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Wednesday night I finished patching the other rust hole in the door and pulled the dent out a bit. Last night, I sprayed on the epoxy primer, too. I didn't get to take pictures because both times I had to work very quickly. It looks quite a bit better and is now awaiting body filler.

For now, I am turning my attention to the roof, door jams, and the rear section of the car. I am ordering new door and window seals, which, amazingly, will exceed the cost of the paint!

The last major bit of welding is to install the new rear panel. I have the replacement one nearly prepped but I still need to cut out the old one. I'll also be removing the fuel tank and fixing a small rust hole in the spare tire well.

I'm hoping to get all this completed this weekend, but Sunday is Monza so that may cut into things a bit.
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Hey colin glad to see the door and fender going to some good use. It is looking good. Jason

Last week I got some epoxy primer onto the new driver's side door. I was able to pull the big dents most of the way out by welding some nails to it and pulling with vice grips and all the rust holes are now nicely patched.





I started up on what I knew was going to be the biggest part of this whole project and that was replacing the rear panel. The pictures don't show it, but my rear panel was rusted through in many places and was pretty bent out of shape.









I just cut carefully along the seams of the panel with a big cut off wheel. The spot welds on the vertical support had to be drilled out. You can also see the battery in its new spot in the trunk.



Here is the area where the fuel tank sits. It was pretty awful looking, but, fortunately, there was no serious rust. The tank sits on some closed cell foam rubber so I went to Home Depot to find some stuff to replace it with. The rust I cleaned up with a wire wheel.



Here is the new panel partially welded in. I opted to fill the seams for a cleaner look.







It looks terrible because of the paint, but the new panel is very solid and straight and makes me feel much better about the back end of the car. Everything lined up perfectly and the trunk closes better than ever.

I am also converting the car to the earlier style small bumpers, so I am filling all the holes left from the "big bumpers." I'll be using a fiberglass reproduction of the original bumper more for practical purposes than anything. I like the look of the small bumpers much better but I don't want to pay the absurd prices that the chrome ones command.



Finally, I painted the inside of the trunk with some flat black Rustoleum enamel. It looks so much better in there now that I can hardly recognize it.

I spent a little bit of time yesterday welding over the big bumper holes, but ran out of welding gas so I had to call it a day, sadly. This weekend I'll strip the roof and the entire rear end of the car and spray it with epoxy primer. After that, I plan to start in on the bondo and shooting some color.

Thanks to my girlfriend, Ann, for taking all the detailed photos.
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Colin,

Fantastic work as always. This blog is a great read.

Can you tell me more about "I'll be using a fiberglass reproduction of the original bumper".

Thanks

Lance

indisguise wrote:

Colin, Fantastic work as always. This blog is a great read. Can you tell me more about "I'll be using a fiberglass reproduction of the original bumper". Thanks Lance

Lance,
I'm glad that you've enjoyed the blog. The fiberglass bumper that I've referred to is the one available from the FAQ Store on this forum. I've seen several pictures of it by searching the archives here and it looks quite good. I simply can't justify (read "afford") the price of a nice looking chrome bumper.
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When I do restoration I usually have the whole chassie diped in acid it sounds really hardcore but it really expose all rust and potential weak spots. I appriciate the work you did but you have really only gone halfway.

rover1 wrote:

When I do restoration I usually have the whole chassie diped in acid it sounds really hardcore but it really expose all rust and potential weak spots. I appriciate the work you did but you have really only gone halfway.

As the thread title here is "1974 Rolling Resto" you will appreciate the fact that, rather than only going "half way," I've gone as far as I can go. Most of the time, after a days work, I drive the car home or to work the next day. Furthermore, my entire paint and bodywork budget is less than the cost of an acid dip. Maybe next time I do a restoration, I'll dip the car and then send you the bill so then you don't need to worry about how someone else restores their car.
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Thanks for your blog. It's definately given me some ideas. I'm just starting and will not have a rolling restoration.

PS Love to see the bumpers when you get them.

great work. If you like, I think you can use a special chrome paint on the fiberglass bumper available from Alsa corporation if I remember the name correctly. It is sprayed on a gloss black base coat and can be clear coded.

bluedevils wrote:

great work. If you like, I think you can use a special chrome paint on the fiberglass bumper available from Alsa corporation if I remember the name correctly. It is sprayed on a gloss black base coat and can be clear coded.

Thanks for that. I've actually considered doing that, but I'm not sure which way to go yet. I need to see the rest of the car first before I can make a decision. My girlfriend thinks I should color match the bumper to the car like on "new cars."
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nice work. this is going to be one good car when you are done .

Colin's currently sanding so I figured I'd post a few photos on our (almost real-time) progress. Having procured a new tank of CO2 and a full set of new seals, we're really planning on getting a lot done today!

Colin started by sanding the roof which thankfully just had surface rust and came out pretty nice and clean! Then it was time to remove the front and back windshields. Just a few cuts to the seals, a little push from the inside, and the back came right out. The rust looks pretty minimal so we're hopeful that it will clean up okay.





The front windshield also came out pretty easily... to reveal some serious rust! The seals were so shot we could feel the moisture still in them, and there was even a pool of water that had accumulated on the bottom!









More pics after the sanding...

After an entire weekend of work, I've stripped the entire back portion of the car, the roof, and the A-Pillars. This was a tremendous amount of work. I had to fix several rust holes around the windows, which, of course, added a fair amount of time to the whole process. There is also a big rust hole under one of the seals for the quarter windows and although it isn't structural, it still annoys me. I'll be patching it soon. My seals were also pretty shot back there, so I need to replace them.

I got the epoxy primer on, albeit with a few runs as I was spraying in lower temperature. It looks pretty decent for the most part and the runs should sand right out. Today, I'll start in on the body filler, but for the most part, things are pretty straight.

After that, I just need to do the passenger side fender and door and then the front section of the car. I'm leaving the hood for last.

I still need to figure out how to paint inside the engine bay...
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I am doing that myself right now, check with Esty, she did a damn good job on her's and was very helpful with some tips.

Justin

I've been quietly working away on the car. Sorry for the lack of updates. I've got most of the bondo on and am nearly ready to start putting color on this weekend.
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great work on your car. it's nice to see a restoration that is about fixing the car and not about 'breaking the bank'. i will definitely direct my friend's son to your post as an example of what can be done while still driving the car.
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Color and clear are on the body. Pics to follow shortly.

The amount of prep was tremendous. Off the top of my head, I had to do the following:

-Weld in new rear panel
-Straighten passenger side rear tail light area
-fill all trim holes
-fill all "big bumper" openings
-weld rust holes around windows
-weld rust holes in low part of fender
-weld rust holes in the front skirt
-pull a dent out of the nose + bondo
-straighten replacement fender and weld the seam
-bondo several dents

All this work, before spraying, is probably over 100 hours of work with just me doing it. Painful!

I still have to strip and paint the hood, strip and paint the passenger door, and then paint the trunk and driver's door. Those are already epoxied so they aren't too much work.

The car looks good. Spraying in the driveway wasn't too hard. The worst part is that it probably stunk up the whole block.

The basecoat went on very smooth with only 3 small runs that I quickly sanded out and then touched up with my Iwata airbrush (that I use to paint model cars). I laid the clear on super thick, just as I do when painting models so that I have plenty of material to sand without going through it.

The amount of physical effort it took to do this alone is absolutely punishing. The car looks SO MUCH BETTER though.
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Amazing amount of work. Wow!

Colin, how did you prep your windshield area? I'm doing this on my '76 right now. I've pulled the windshield out, and have masked off the area today.

I'm ready to sand in the next couple of days, but was wondering how to prep for paint.

I was thinking sanding it down, applying por-15 to the bad areas. Then scuffing the por-15 a bit. Then give it a shot with some primer, and then hit it with two coats of rattle can paint I had matched to my car.

Does that sound about right?What did you do?

-Andrew Poon
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1972 2002 - Chamonix rusty car
1976 2002 - Mintgrun, daily driver in the summer
1980 320is - Winter daily driver

Artistic wrote:

Amazing amount of work. Wow! Colin, how did you prep your windshield area? I'm doing this on my '76 right now. I've pulled the windshield out, and have masked off the area today. I'm ready to sand in the next couple of days, but was wondering how to prep for paint. I was thinking sanding it down, applying por-15 to the bad areas. Then scuffing the por-15 a bit. Then give it a shot with some primer, and then hit it with two coats of rattle can paint I had matched to my car. Does that sound about right?What did you do? -Andrew Poon

Hi Andrew,
I'm by no means an expert, but I did read a book...

:p

I think I saw the shots of your car and the rust. It doesn't look too bad. I would get a wire brush wheel for a grinder and hit the rust with that. It should remove it pretty well. Once you have it clean deep down into all the pits, you can either cut it out and weld in patches (I had to do this in one of the holes around my windshield) or you can just bondo over the pits. If you're bondoing, I would spray DTM epoxy primer first. This stuff is awesome and will seal the metal extremely well. POR-15 is an epoxy based paint but the epoxy primer will be easier to paint over (and its easy to spray). After the epoxy and the bondo, you can seal the bondo with some 2k urethane primer surfacer. Remember that the 2k primer will absorb moisture, though, so if you're planing on leaving it, its probably not a good idea.

I'm not sure how well the rattle can paint will work out, but maybe you can get the color close enough that it won't be noticeable. The thing is that you could get a cheap spray gun and pretty easily get your paint color matched at an automotive paint shop and then sleep easier. Its a bit more money and effort, but it'd be well worth it. If your paint is already a urethane, you can feather in the new paint and then clear over it pretty effectively. Body shops do this and it looks quite good.
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Colin,

Thank you so much for posting your pictures!Becuase of your pictures, I now will be looking for rust around my windshield and rear window. I think my car is pretty much dry, but you never know. So far I have only run into surface rust. Post your finished paint when you can. Did you keep the color the same?
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1973 Chamonix

Jimbosocal wrote:

Colin, Thank you so much for posting your pictures!Becuase of your pictures, I now will be looking for rust around my windshield and rear window. I think my car is pretty much dry, but you never know. So far I have only run into surface rust. Post your finished paint when you can. Did you keep the color the same?

Yeah the windshield rust was a bit scary. There was literally a pool of water trapped behind my window seals! It looked worse than it was and I really only need to weld up a few holes in the front.

The color I went with on the car is a very dark grey. The main section is painted and has clear on it, but I screwed up the clear the first time, so I brought it down with some 400 grit and resprayed it yesterday. Its been curing, so after work today, I'll hopefully have some pics.
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