Rust Removal Part 2, or 3, or 4???
01-11-2004, 08:37 PM
#1
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Thread Starter
Rust Removal Part 2, or 3, or 4???
Earlier this week, I fixed a number of rust spots on the 993, most due to PO neglect. The front windshield pillar looks great, the hood looks great, the underside of the driver door looks great, the door sill looks great. OH - and I replced the leaky oil cooler on Thursday night... Soooo...
I washed the car Friday night. However - when I did - I noticed a bit of "brown water" coming out of the left bottom corner of the rear window - so I removed that window weather strip- and yes - rust in the lower corner, as the rear window hadn't been properly resealed (or rather - NOT resealed in the bottom 1/3 of the window, so water collected in the channel - and sat). Anyway - I figured I'd take some pics as I did some of the work - and hope that it helps some other folks out…
1 - After lifting the window seal - this is what I was greeted with - rust all along the channel. Using compressed air, I blasted out any loose particles and then went after the scales with a bronze wire brush. I also lifted the rear window up about 4" after removing what gasket material was present. I was fortunate, as nothing was perforated, so no welding or leading had to be done, and under the glass/beading - everything was intact. To remove the seal - I use a putty knife, bent at 90 degrees and heated. It melts the old seal and if you are careful, will not scratch the paint under the sealer. Work slowly and carefully - and if you do scratch the metal - YOU MUST TREAT it…!!!
2 - Treating the rust. I like two products - Rust Mort, which is the first treatment. After that sets, I use PermaTex Rust Stop, which seals and closes the porous metal. The picture below is after the above treatments are complete. The "black" is the treated rust, the "blue" is the PermaTex setting up - and you'll notice the paint chipped edge. While the Permatex sets - you can slightly "feather" the edge of the old paint, which will set up the next step.
Here is a picture of the left inside edge where I also removed some rust bubles and spiders - before treatment:
3- After the rust chemicals are set (24 hours), use a filler primer. This is heavier then normal primer, and will fill the imperfections. As well - take a small artists paintbrush - and draw the primer up to the feathered edges of the existing finish paint. In short - you want it prouder (higher) then the existing paint, so it may be leveled with 1500 grit and a sanding block. For the channel, you can simply paint it in. See the photo below, as what it should look like before sanding - notice the filler is slightly higher then the surrounding paint…
4- After the primer fully sets, begin to feather it into the existing paint. WORK GENTLY with 1500 grit - keeping the paper wet as you work. The water draws the paint/primer off the surface, and keeps the grit clear. For a sanding "block" in a small area - I use a plastic body filler tool cut to about ¾" in width. Again - the only pressure should be from a VERY light touch as you feather these together. When you are set - it will look like this:
5 - Color fill base primer. Since my car is white - I use a white primer as the finish primer set. Typically - I shoot 3 coats, lightly sanding between each coat. When you do that - you are set for the final topcoat. The picture below if the final white primer feathered and set (notice - I left the channel with the grey filler primer, and topcoat will be applied over that, and then filled with window sealant.
6 - Below is a picture of blocking off the spray area. In this photo, it's on the left inside edge, which had rust bubbles, which I removed during this process. Here - the "spray area" is smaller then the area blocked off, as you DON'T want to spray edge to edge, as it will create "ridges" Rather - start and finish spraying before the tape edges are reached - and use several light coats - NOT a single heavy coat (or it will run). As well - you'll notice I use USPS Postal tape, and for a reason. If you are interested why - ask me. Anyway - the next two pictures are the "before" and after "spray". The other sections are "sprayed" using a similar block-off, spray technique
Before:
After
7 - Below is what the "working area" looks like after the final top-coat is applied. Notice the "overspray", which will be wet-sanded with 2000 grit and feathered into the existing paint. It's beginning to look like a "finished job.
8 - The fished product. In a week or so, I'll finish it off with rubbing compound, but here is what the final product looks like. The steps to complete to this point included - a primary blending wet sand. Next - filling the window channel with sealer, and then applying a top-coat of 3M Re-sealer, so that the window edge/sealer won't allow water to collect. The sealer is applied in such a way that when water runs down the channel, it exits under the weatherstrip and not collect in the channel. Also - a tip to reinstall the weatherstrip is to use a thin film of white lithium grease along the "V" of the molding - and it will press right in. Some use soapy water - but, I think I have an aversion to water in that area…. Here is what it looks like - the same area - waiting to be rubbed out in the next week…
Best to all…! And if you wondered why I haven't answered your e-mail or PM this weekend - know you know why..
I've been a bit busy.. BUT - I LOVE MY 993!!!!
I washed the car Friday night. However - when I did - I noticed a bit of "brown water" coming out of the left bottom corner of the rear window - so I removed that window weather strip- and yes - rust in the lower corner, as the rear window hadn't been properly resealed (or rather - NOT resealed in the bottom 1/3 of the window, so water collected in the channel - and sat). Anyway - I figured I'd take some pics as I did some of the work - and hope that it helps some other folks out…
1 - After lifting the window seal - this is what I was greeted with - rust all along the channel. Using compressed air, I blasted out any loose particles and then went after the scales with a bronze wire brush. I also lifted the rear window up about 4" after removing what gasket material was present. I was fortunate, as nothing was perforated, so no welding or leading had to be done, and under the glass/beading - everything was intact. To remove the seal - I use a putty knife, bent at 90 degrees and heated. It melts the old seal and if you are careful, will not scratch the paint under the sealer. Work slowly and carefully - and if you do scratch the metal - YOU MUST TREAT it…!!!
2 - Treating the rust. I like two products - Rust Mort, which is the first treatment. After that sets, I use PermaTex Rust Stop, which seals and closes the porous metal. The picture below is after the above treatments are complete. The "black" is the treated rust, the "blue" is the PermaTex setting up - and you'll notice the paint chipped edge. While the Permatex sets - you can slightly "feather" the edge of the old paint, which will set up the next step.
Here is a picture of the left inside edge where I also removed some rust bubles and spiders - before treatment:
3- After the rust chemicals are set (24 hours), use a filler primer. This is heavier then normal primer, and will fill the imperfections. As well - take a small artists paintbrush - and draw the primer up to the feathered edges of the existing finish paint. In short - you want it prouder (higher) then the existing paint, so it may be leveled with 1500 grit and a sanding block. For the channel, you can simply paint it in. See the photo below, as what it should look like before sanding - notice the filler is slightly higher then the surrounding paint…
4- After the primer fully sets, begin to feather it into the existing paint. WORK GENTLY with 1500 grit - keeping the paper wet as you work. The water draws the paint/primer off the surface, and keeps the grit clear. For a sanding "block" in a small area - I use a plastic body filler tool cut to about ¾" in width. Again - the only pressure should be from a VERY light touch as you feather these together. When you are set - it will look like this:
5 - Color fill base primer. Since my car is white - I use a white primer as the finish primer set. Typically - I shoot 3 coats, lightly sanding between each coat. When you do that - you are set for the final topcoat. The picture below if the final white primer feathered and set (notice - I left the channel with the grey filler primer, and topcoat will be applied over that, and then filled with window sealant.
6 - Below is a picture of blocking off the spray area. In this photo, it's on the left inside edge, which had rust bubbles, which I removed during this process. Here - the "spray area" is smaller then the area blocked off, as you DON'T want to spray edge to edge, as it will create "ridges" Rather - start and finish spraying before the tape edges are reached - and use several light coats - NOT a single heavy coat (or it will run). As well - you'll notice I use USPS Postal tape, and for a reason. If you are interested why - ask me. Anyway - the next two pictures are the "before" and after "spray". The other sections are "sprayed" using a similar block-off, spray technique
Before:
After
7 - Below is what the "working area" looks like after the final top-coat is applied. Notice the "overspray", which will be wet-sanded with 2000 grit and feathered into the existing paint. It's beginning to look like a "finished job.
8 - The fished product. In a week or so, I'll finish it off with rubbing compound, but here is what the final product looks like. The steps to complete to this point included - a primary blending wet sand. Next - filling the window channel with sealer, and then applying a top-coat of 3M Re-sealer, so that the window edge/sealer won't allow water to collect. The sealer is applied in such a way that when water runs down the channel, it exits under the weatherstrip and not collect in the channel. Also - a tip to reinstall the weatherstrip is to use a thin film of white lithium grease along the "V" of the molding - and it will press right in. Some use soapy water - but, I think I have an aversion to water in that area…. Here is what it looks like - the same area - waiting to be rubbed out in the next week…
Best to all…! And if you wondered why I haven't answered your e-mail or PM this weekend - know you know why..
I've been a bit busy.. BUT - I LOVE MY 993!!!!
01-12-2004, 12:34 PM
#3
Banned
Thread Starter
Originally posted by DJF1
Isn't it great to have you on our board???
Isn't it great to have you on our board???
... 
01-12-2004, 01:03 PM
#4
Drifting
John D. ............... Sorry to say this, but you have to remove the windows for a 100% good repair. This will only last for a year or so.... 
BUt for the sunny side now, you did a nice job here I have to say!
BUt for the sunny side now, you did a nice job here I have to say!
01-12-2004, 01:12 PM
#5
Banned
Thread Starter
Hi Arjan..!
Yes - you are correct..! When I did lift the rear window up, the rust had not worked under where the window sealant had covered it - it had only rusted where it was exposed to water collecting in the channel that was "exposed".
So - I treated that with Permatex, too, after removing as much as the old sealant as possible - then resealed the window back down, and focused on the rest of the channel. Now - if it lasts only a year or 2 - that's OK - as by then, maybe the rest of my car will be all done - so I'll have something to fix again
I enjoyed your thread in the 964 Forum where you have a similiar problem - and the workmanship on your repair is excellent as well..!!! My thanks for your post!!
Yes - you are correct..! When I did lift the rear window up, the rust had not worked under where the window sealant had covered it - it had only rusted where it was exposed to water collecting in the channel that was "exposed".
So - I treated that with Permatex, too, after removing as much as the old sealant as possible - then resealed the window back down, and focused on the rest of the channel. Now - if it lasts only a year or 2 - that's OK - as by then, maybe the rest of my car will be all done - so I'll have something to fix again
I enjoyed your thread in the 964 Forum where you have a similiar problem - and the workmanship on your repair is excellent as well..!!! My thanks for your post!!
01-12-2004, 03:37 PM
#6
Drifting
No thanks
John,
No thanks, I like looking at topics with pictures myself, so I showed a few on the 964 forum as you noticed.
I hear that the rust under the window seals is a common problem, also for the 993's.... this is bad. ;(
No thanks, I like looking at topics with pictures myself, so I showed a few on the 964 forum as you noticed.
I hear that the rust under the window seals is a common problem, also for the 993's.... this is bad. ;(
01-12-2004, 04:50 PM
#7
Banned
Thread Starter
Re: No thanks
Originally posted by Arjan B.
.... also for the 993's.... this is bad. ;(
.... also for the 993's.... this is bad. ;(
Well - I think between our pictures - we have scared everyone away from posting to this thread!!!
Anyway - your front windshield is worse then mine, when I repaired mine..!!! My rust was more on the outside of the pillar (a 1" x 3" area that was pitted and had no paint - almost like it was "nicked" and left outside for months). However, the windshield channel and under the windshield sealer was fortunately, not as bad as yours. When I first got my car - I did a "quick fix" to arrest further damage, and recently - did the proper repair, using a similiar method as I posted above. For that - there is hope!!! Pictured below is that same pillar rust area today...
I hope this gives you some inspiration as you get your 964 finished up - as these cars are wonderful - and I just sit in my garage gazing at it.....
Best to you!!!!
Completed pillar:
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01-12-2004, 05:07 PM
#8
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John,
Porsche should repair the rear window rust properly under warranty (Technical bulletin). If the other rust is from PO neglect your probably on your own. If you don’t have the tech bulletin let me know I’ll e-mail it to you.
Porsche should repair the rear window rust properly under warranty (Technical bulletin). If the other rust is from PO neglect your probably on your own. If you don’t have the tech bulletin let me know I’ll e-mail it to you.
01-12-2004, 05:20 PM
#9
Banned
Thread Starter
Hi Rich & Kim..!
Honestly - I believe that the rust was the PO not really caring or taking care of the car - rather then a factory problem, in this case.
As well - it also looks like he had parts of the car "touched up". While the overall quality of those was pretty good - I've found some pretty "stupid" things not done correctly by either the paint shop or whoever replaced the windshield (like the missing sealant and not fully installing/sealing the rear window)...
While I wish my car was eligible - I'm sure it's not. But - my thanks for your offer...!!!! Besides - how much fun can you have with a $16,000 993??!! BUT - aside from these minor cosmetic issues - my car RUNS JUST BEAUTIFULLY!!! (well - it does now, since the rotors, calipers, clutch, clutch slave, filters, plugs, oil, alarm, passenger door handle, oil cooler, exhaust, engine tin, water leak, pedal cl..... oh nevermind - it's work in progress.... )
Honestly - I believe that the rust was the PO not really caring or taking care of the car - rather then a factory problem, in this case.
As well - it also looks like he had parts of the car "touched up". While the overall quality of those was pretty good - I've found some pretty "stupid" things not done correctly by either the paint shop or whoever replaced the windshield (like the missing sealant and not fully installing/sealing the rear window)...
While I wish my car was eligible - I'm sure it's not. But - my thanks for your offer...!!!! Besides - how much fun can you have with a $16,000 993??!!
BUT - aside from these minor cosmetic issues - my car RUNS JUST BEAUTIFULLY!!! (well - it does now, since the rotors, calipers, clutch, clutch slave, filters, plugs, oil, alarm, passenger door handle, oil cooler, exhaust, engine tin, water leak, pedal cl..... oh nevermind - it's work in progress.... )
01-12-2004, 06:12 PM
#11
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Thread Starter
Hey 24FPS...
Well - I'm lovin' my 993 as well - can you guess??
Also - I believe, and have been told that yes, there is a factory warranty (it's in my warranty booklet) - but there are a couple of caveats. First - my 993 had portions re-sprayed, and in looking at the receipts, it wasn't done by a Porsche Dealer (there was no receipt for it - but it has been touched up). The areas I can tell is where the PO dorked the RF splitter and induced a small leak in the oil cooler. At the same time, certain areas looks like they were hit with the spray gun as well. My guess is whatever body shop repaired the splitter with BONDO and fiberglass tape is that shop... Second - a 3rd party installed the windshield. That, I do have the receipt for - and while it's factory glass, those are the folks who probably nicked the pillar that rusted - and it was left "open" and rusted. I know the factory won't cover that - as that work was done outside their Dealer Network...
I also am pretty good friends with the folks at IRA - and if there was a way to make it fall under the TSB - I'm more then certain they would have assisted in any way possible, but from my own research, I wouldn't ask them to go out on a limb for me. I guess in my world - it just wouldn't be right, knowing it was either a 3rd party "shop" or the PO - or more likely both - that caused these small rust issues...
And besides - I wouldn't be able to post pics in this thread if the Porsche Dealer took care of it under warranty..
Well - I'm lovin' my 993 as well - can you guess??
Also - I believe, and have been told that yes, there is a factory warranty (it's in my warranty booklet) - but there are a couple of caveats. First - my 993 had portions re-sprayed, and in looking at the receipts, it wasn't done by a Porsche Dealer (there was no receipt for it - but it has been touched up). The areas I can tell is where the PO dorked the RF splitter and induced a small leak in the oil cooler. At the same time, certain areas looks like they were hit with the spray gun as well. My guess is whatever body shop repaired the splitter with BONDO and fiberglass tape is that shop... Second - a 3rd party installed the windshield. That, I do have the receipt for - and while it's factory glass, those are the folks who probably nicked the pillar that rusted - and it was left "open" and rusted. I know the factory won't cover that - as that work was done outside their Dealer Network...
I also am pretty good friends with the folks at IRA - and if there was a way to make it fall under the TSB - I'm more then certain they would have assisted in any way possible, but from my own research, I wouldn't ask them to go out on a limb for me. I guess in my world - it just wouldn't be right, knowing it was either a 3rd party "shop" or the PO - or more likely both - that caused these small rust issues...
And besides - I wouldn't be able to post pics in this thread if the Porsche Dealer took care of it under warranty..
01-12-2004, 06:35 PM
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John:
I followed Arjan over from the 964 forum. I agree you did fine if you want the job to last only a couple of years. If I did that much work, I would want it to last much longer than that, and I would want the paint to be ready for subsequent paint applications. Arjan is correct that removing the windshield is a better repair, but if you got all the rust, a spot repair like you did will work. I do have conserns with your recommended paint system.
NASA has results on the internet on paint systems tested at the Kennedy Launch center on the launch structures. Granted they are not cars, but steel is steel, and the corrosion chemistry is the same. I have their test report. That report, and my personal experience are the basis for concluding that you cannot design a paint system and expect good results. The only chance you have for good results is to obtain the procedures from a reputable supplier, buy their products, and use them strictly according to instructions. Never mix brands in the same paint job, and never use a product that is not part of a documented paint system from a trusted paint supplier.
Paint is a complicated system, where each layer must be compatible with every other layer, both when first strayed, and over the life of the paint job. Each layer must accomodate the steel and all the other layers from hottest summer to coldest winter. Each layer must remain bonded for the life of the paint job. The chemistry for protecting metal from rust is complicated, but a good paint system will retard corrosion even if scratched to the base metal.
One more thing directly from the NASA report: "rust avenger" type products are counterproductive to retarding future rust. They are fine for a quick fix, but the NASA report says new rust formed faster when the latex-based "retarders" were used. I am an amateur painter, but I do research for a living. My experience is the same as the NASA report. I have used DuPont's paint systems (Imron and Chronar), and cars I painted in the late 1970s still look great (no special plug for DuPont - I am sure other suppliers also have systems as good or better).
Protect the value of your investment by spending a little more for a documented paint system. It is shocking to me that even professional paint shops seldom follow a proper system. The best ones do, and their work lasts even longer than a factory paint job.
I followed Arjan over from the 964 forum. I agree you did fine if you want the job to last only a couple of years. If I did that much work, I would want it to last much longer than that, and I would want the paint to be ready for subsequent paint applications. Arjan is correct that removing the windshield is a better repair, but if you got all the rust, a spot repair like you did will work. I do have conserns with your recommended paint system.
NASA has results on the internet on paint systems tested at the Kennedy Launch center on the launch structures. Granted they are not cars, but steel is steel, and the corrosion chemistry is the same. I have their test report. That report, and my personal experience are the basis for concluding that you cannot design a paint system and expect good results. The only chance you have for good results is to obtain the procedures from a reputable supplier, buy their products, and use them strictly according to instructions. Never mix brands in the same paint job, and never use a product that is not part of a documented paint system from a trusted paint supplier.
Paint is a complicated system, where each layer must be compatible with every other layer, both when first strayed, and over the life of the paint job. Each layer must accomodate the steel and all the other layers from hottest summer to coldest winter. Each layer must remain bonded for the life of the paint job. The chemistry for protecting metal from rust is complicated, but a good paint system will retard corrosion even if scratched to the base metal.
One more thing directly from the NASA report: "rust avenger" type products are counterproductive to retarding future rust. They are fine for a quick fix, but the NASA report says new rust formed faster when the latex-based "retarders" were used. I am an amateur painter, but I do research for a living. My experience is the same as the NASA report. I have used DuPont's paint systems (Imron and Chronar), and cars I painted in the late 1970s still look great (no special plug for DuPont - I am sure other suppliers also have systems as good or better).
Protect the value of your investment by spending a little more for a documented paint system. It is shocking to me that even professional paint shops seldom follow a proper system. The best ones do, and their work lasts even longer than a factory paint job.
01-12-2004, 07:26 PM
#13
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hey john... your fortune/misfortune is our fortune! (is that right?) .... ahhh... yeah that's it.
cheers!
imho- the nasa report is not in yet re: driving "repair-painted" p-cars on the surface of mars... but i think your repair seems to be a very competent "diy" john. hee. hee. just my 2¢... & i'm sure you will maintain it w/ much carnuba! may the ugly rust-god's stay away & unwanted water be depleted!
cheers!
imho- the nasa report is not in yet re: driving "repair-painted" p-cars on the surface of mars... but i think your repair seems to be a very competent "diy" john. hee. hee. just my 2¢... & i'm sure you will maintain it w/ much carnuba! may the ugly rust-god's stay away & unwanted water be depleted!
01-12-2004, 07:32 PM
#14
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Actually - from one non-paint expert (me ) to another (excellent post!!!!) - I'm in violent agreement with you..!!!
What I didn't post (for a reason) is I use/shoot exclusively are PPG chemicals (Acrylic Laquer). It's the same mix (from filler primer/base primer/top coat) I used when building my 914-6 track car. Now - THAT car had extensive rust (find one that doesn't!! )and I was required to weld in new metal and lead the fairings between the factory flares and the fenders - which eight years later, still look to be in excellent (read "no rust ) condition. In that case - the chemicals I used were suggested by the Factory Paint Rep as being compatible when I was doing that project, and are the same as in this one.
However, in the above case to this diy, the "unknown" which I don't have long-term experience with is using the Permatex 8A product..? I'm not sure how that may effect the long term results - if at all.?? It will be interesting to see....
As well - you make some terrific points - and again - a great post!!! Thanks!!!
) to another (excellent post!!!!) - I'm in violent agreement with you..!!!What I didn't post (for a reason) is I use/shoot exclusively are PPG chemicals (Acrylic Laquer). It's the same mix (from filler primer/base primer/top coat) I used when building my 914-6 track car. Now - THAT car had extensive rust (find one that doesn't!!
)and I was required to weld in new metal and lead the fairings between the factory flares and the fenders - which eight years later, still look to be in excellent (read "no rust ) condition. In that case - the chemicals I used were suggested by the Factory Paint Rep as being compatible when I was doing that project, and are the same as in this one. However, in the above case to this diy, the "unknown" which I don't have long-term experience with is using the Permatex 8A product..? I'm not sure how that may effect the long term results - if at all.?? It will be interesting to see....
As well - you make some terrific points - and again - a great post!!! Thanks!!!
01-12-2004, 07:34 PM
#15
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Thread Starter
Originally posted by 24FPS
.... i'm sure you will maintain it w/ much carnuba! ...
.... i'm sure you will maintain it w/ much carnuba! ...
Sheeshhh.... Everyone has an opinion...!!!