Repaint of Nose section / questions
06-20-2002, 11:57 AM
#1
Racer
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Repaint of Nose section / questions
Greetings fellow money pit drivers ! <img src="graemlins/wave.gif" border="0" alt="[byebye]" />
Car: 1989 S4
Paint: Silver Metallic
Problem: Clearcoat flaking off in spots (looks like a sunburn...) and a 1 inch piece where the finish has chipped all the way through to the nose itself. The clearcoat flakes are only in a few areas and are confined to the very tip and top of the nose. The rear bumper also has a spot where he paint has cracked, but that is very small and hardly noticeable compared to the nose.
Looking over the various websites on car care, detailing and misc. tips, I have read that there are people who use an airbrush for touchup type work. My other hobby is scale modeling and I feel very confident using an airbrush. I would either like to do as much of the prep work involved before handing the car over to a pro to shoot the nose or to try and do it myself and learn a lot in the process.
I am more than willing to invest time and money into getting the correct equipment and supplies. If the job ends up being too big for using airbrush and the cost may be more for me to do it myself, then I probably will take it to someone. But I really would rather do it myself.
Are there any websites out there (are there any sites other than Rennlist ? <img src="graemlins/icon501.gif" border="0" alt="[icon501]" /> ) that pertain to do-it-yourselfers regarding this ?
Thanks in advance (especially to Greg...)
Rob
Car: 1989 S4
Paint: Silver Metallic
Problem: Clearcoat flaking off in spots (looks like a sunburn...) and a 1 inch piece where the finish has chipped all the way through to the nose itself. The clearcoat flakes are only in a few areas and are confined to the very tip and top of the nose. The rear bumper also has a spot where he paint has cracked, but that is very small and hardly noticeable compared to the nose.
Looking over the various websites on car care, detailing and misc. tips, I have read that there are people who use an airbrush for touchup type work. My other hobby is scale modeling and I feel very confident using an airbrush. I would either like to do as much of the prep work involved before handing the car over to a pro to shoot the nose or to try and do it myself and learn a lot in the process.
I am more than willing to invest time and money into getting the correct equipment and supplies. If the job ends up being too big for using airbrush and the cost may be more for me to do it myself, then I probably will take it to someone. But I really would rather do it myself.
Are there any websites out there (are there any sites other than Rennlist ? <img src="graemlins/icon501.gif" border="0" alt="[icon501]" /> ) that pertain to do-it-yourselfers regarding this ?
Thanks in advance (especially to Greg...)
Rob
06-20-2002, 04:28 PM
#2
Racer
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Robert,
I've repainted my 928 myself and I wouldn't recommend the airbrush unless you want slightly better short term looks. The existing finish is failing and touching it up won't correct the core problem.
Painting the bumper covers correctly is failry involved. They should be removed from the car, the old finish should be removed (non chemically) and a new finish applied.
The prep and refinishing can be tricky as these parts are flexible, require care in handleing and special paint additives including adhesion promoters and flex agents.
If I had do it over agian, I would remove the covers, and strip and prep them for paint myslef. I would then bring them to a good paint shop for spraying.
I've repainted my 928 myself and I wouldn't recommend the airbrush unless you want slightly better short term looks. The existing finish is failing and touching it up won't correct the core problem.
Painting the bumper covers correctly is failry involved. They should be removed from the car, the old finish should be removed (non chemically) and a new finish applied.
The prep and refinishing can be tricky as these parts are flexible, require care in handleing and special paint additives including adhesion promoters and flex agents.
If I had do it over agian, I would remove the covers, and strip and prep them for paint myslef. I would then bring them to a good paint shop for spraying.
06-20-2002, 06:31 PM
#3
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yeah, you'll just be wasting your time with an airbrush. you'll cover up the bad spots but it'll keep going. pull it off yourself and take ti to a paint shop...
06-20-2002, 07:16 PM
#4
Hi Rob, now that I know what the problem is the choice of what to to do is clearcut. To get a proper finish that will still be o.k in a few years time you must repaint the whole bar/s.
This is a big job by the way and the only way your likely to get it done properly is to take the car off the road for a while.
This is what I recommend. Just as John V says you must get rid of the old finish, you can't construct a building on a bad foundation same goes for your paint. The clearcoat flaking like that makes me wonder is that the factory finish or a earlier repair? Sand it back in a spot and like a tree see how many rings it has. My car's nose was repainted 5 times, it was so loaded with paint the springs at the front were sagging.lol.
Bringing this bar back to bare plastic is a big job, if it is a repair here is another option I would be happy with and believe me, I'm fussy. I would buy some bumper bar stripper, SEM make some, and use that to take of the top coats. This is special stripper for plastic parts. I think it has something in it that reacts with the flex additive. Don't go overboard with it as it will still damage the plastic and potentially warp the plastic. N.B some warping may occur but this goes away when the stripper drys out of the plastic.
So if you get most old paint of with stripper then sand the bar back with 360 - 400 grit wet and dry paper, then you'll have a good starting point.
As John V said the bars really should be off the car. To work on them you'll need a painter's stand there are about $25 U.S. Don't do what I did and put it on the back of a chair in the sun and came back to find it permantly out of shape. I later fixed it with a heatgun and special b/bar filler.
If I haven't scared you yet, I will now tell you what equipment you'll need. Heat lamps are useful but don't get them to close to these parts. I would paint these parts outside on a sunny still day. The compressor that you are using must have a oil/water trap and regulator. My compressor has a dryer and gas trap, remember moisture is your enemy, it will give you blisters in a few months time. Also a gas mask is required so that you don't die doing this job. If you don't have these you will not get a satisfactory result, let me know if you have them before I continue anymore. All the best. <img src="graemlins/c.gif" border="0" alt="[ouch]" />
This is a big job by the way and the only way your likely to get it done properly is to take the car off the road for a while.
This is what I recommend. Just as John V says you must get rid of the old finish, you can't construct a building on a bad foundation same goes for your paint. The clearcoat flaking like that makes me wonder is that the factory finish or a earlier repair? Sand it back in a spot and like a tree see how many rings it has. My car's nose was repainted 5 times, it was so loaded with paint the springs at the front were sagging.lol.
Bringing this bar back to bare plastic is a big job, if it is a repair here is another option I would be happy with and believe me, I'm fussy. I would buy some bumper bar stripper, SEM make some, and use that to take of the top coats. This is special stripper for plastic parts. I think it has something in it that reacts with the flex additive. Don't go overboard with it as it will still damage the plastic and potentially warp the plastic. N.B some warping may occur but this goes away when the stripper drys out of the plastic.
So if you get most old paint of with stripper then sand the bar back with 360 - 400 grit wet and dry paper, then you'll have a good starting point.
As John V said the bars really should be off the car. To work on them you'll need a painter's stand there are about $25 U.S. Don't do what I did and put it on the back of a chair in the sun and came back to find it permantly out of shape. I later fixed it with a heatgun and special b/bar filler.
If I haven't scared you yet, I will now tell you what equipment you'll need. Heat lamps are useful but don't get them to close to these parts. I would paint these parts outside on a sunny still day. The compressor that you are using must have a oil/water trap and regulator. My compressor has a dryer and gas trap, remember moisture is your enemy, it will give you blisters in a few months time. Also a gas mask is required so that you don't die doing this job. If you don't have these you will not get a satisfactory result, let me know if you have them before I continue anymore. All the best. <img src="graemlins/c.gif" border="0" alt="[ouch]" />
06-21-2002, 05:15 PM
#5
Racer
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Well, it didn't exactly scare me... just brought me to my senses. I think I will take it to a pro to have him shoot the paint. What probably gave me the most reason to do it was the fact that even though it was only doing this in a few places, I could expect it to migrate over to other areas eventually. I will ask them first just what I can do to prep as much as possible (or as much as they want me to...).
I checked the growth rings ( <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" /> ) of my paint by sanding carefully through 1 of the clearcoat blisters and it seems there is only 1 layer of paint. I checked using a very good magnifier and only found the clear, paint and then primer coat over the bumper material.
Hopefully it won't be too much money.
<img src="graemlins/oops.gif" border="0" alt="[oops]" />
Rob
I checked the growth rings ( <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" /> ) of my paint by sanding carefully through 1 of the clearcoat blisters and it seems there is only 1 layer of paint. I checked using a very good magnifier and only found the clear, paint and then primer coat over the bumper material.
Hopefully it won't be too much money.
<img src="graemlins/oops.gif" border="0" alt="[oops]" /> Rob
06-21-2002, 08:39 PM
#6
Hi Rob make sure you go to a Porsche recommended repairer because they should have the inserts that you put into the bar to stop it warping when they bake it. They should only bake at a low temp, these bars go out of shape very easily. Also you would normally put the bar on when it is warm as it won't crack the paint if it did go a bit out of shape. So choose your repairer carefully. All the best <img src="graemlins/wave.gif" border="0" alt="[byebye]" />
