Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Wet sand after paint job with pics

Thread Tools
 
Search this Thread
 
Old 05-07-2007, 02:57 PM
  #31  
H2
Addict
Rennlist Member

 
H2's Avatar
 
Join Date: Feb 2003
Location: Northwest
Posts: 5,988
Received 34 Likes on 29 Posts
Default

Originally Posted by Mrmerlin
Hey I just realised that you have a cover on your new paint I would suggest that you remove it so it doesnt mess up something on the roof or hood let the sun cure the paint for a month atleast.
Yes....but....wouldn't acid rain drops on new paint be worse....if not garaged?

H2
Old 05-07-2007, 03:14 PM
  #32  
BC
Rennlist Member
 
BC's Avatar
 
Join Date: Dec 2001
Posts: 25,152
Received 87 Likes on 56 Posts
Default

Originally Posted by Podguy
Then again if it was my car I would not go anywhere near the new two pack stuff.
I just don't understand why this phrase keeps on coming up. Its seems like you are saying "If it was me, I would never use those new computers without the punch cards and vacuum tubs,"

What the hell is wrong with two part paint? Are you just saying you always want to use single stage solid colors?
Old 05-07-2007, 03:16 PM
  #33  
BC
Rennlist Member
 
BC's Avatar
 
Join Date: Dec 2001
Posts: 25,152
Received 87 Likes on 56 Posts
Default

Originally Posted by Podguy
I do not mean to be critical here. Matching the quality of the original paint is very costly and time consuming.
The original paint is not god's own ****. It fails in the clear coat on a regular basis, and is dull as **** in most cases if you haven't rubbed it out to within a nano meter of going though the clear. The only thing that the original paint is good for is being HARD.
Old 05-07-2007, 08:31 PM
  #34  
Ron_H
928 Barrister
Rennlist Member

 
Ron_H's Avatar
 
Join Date: Sep 2002
Location: Sunnyvale, CA
Posts: 4,772
Likes: 0
Received 5 Likes on 4 Posts
Default

Kevin said: " ..... My car goes in about two weeks for total paint. cost = 800.00"

If I could get a total paint job in California for $800, I would probably have to know the painter well, be dating his dog and walking his daughter......er....well something like that anyway. And then have to buy him a keg a month for a year...And then maybe he would do it.
Old 05-07-2007, 08:58 PM
  #35  
Marine Blue
Addict
Rennlist Member
 
Marine Blue's Avatar
 
Join Date: Jul 2004
Location: Temecula, CA
Posts: 16,020
Received 807 Likes on 469 Posts
Default

Car looks awesome.........Great color too!
Old 05-07-2007, 09:16 PM
  #36  
djurek
Drifting
 
djurek's Avatar
 
Join Date: Mar 2007
Location: royal oak, mi
Posts: 2,131
Likes: 0
Received 0 Likes on 0 Posts
Default

i like the paint, color and especially the clear sidemarkers.
Old 05-08-2007, 01:34 AM
  #37  
Podguy
Three Wheelin'
 
Podguy's Avatar
 
Join Date: Sep 2003
Location: SF Bay Area
Posts: 1,526
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by 0utlier
Everyone is welcome to express their opinions in this thread. Podguy, your input is always welcome. You are very knowledgeable. This whole paint and detail topic is quite peculiar though. Everyone seems to think they know the "right" way, yet opinions on the "right" way vary tremendously. There is definitely no documented, textbook method that is accepted as the "right" way.

Most of what I've read says it is extremely difficult to lay a flat coat of paint using today's enviro-friendly concoctions. Only the most talented painters have the skill. So yes, it seems it is possible to lay perfect paint, but not the norm.

I didn't read anywhere that even mentioned waiting more than a week or so for color sanding to take place after a re-paint. Maybe it is due to the need for the car to be out of the shop, but I thought I would at least find something about the merits of extended curing time prior to wet sanding.

I will say I have no real world experience with paint. I only know what I've read, and I read everything I could get my hands on. My take was there seems to be many paths to the finish line, and most are adamant that their path is the right one. Almost like a religion.

Is my paint job perfect? Absolutely not. Was my paint guy the Yoda of painting? Hardly. My intent was not a show winning paint job. I was not looking to impress other paint guys. I could never justify spending that kind of money on a driver. I wanted a paint job that looks great to 95% of population as they look in awe of the car. I think I achieved that goal.
Scott,

I am not attempting rain on anyones parade. The after pictures show a nice shiny car and if the owner is happy that is the most important thing. There are some points I was attempting to make that might help others.

1. The comment on the car cover and leaving the car in the rain are on the money. If a car cover can leave behind marks and if rain can spot the paint then the paint is not yet cured.

2. The paint as applied was crap. The painter was either drunk or a beginner. There is no reason the new paints will not lay down flat. In fact with the new HPLV guns like Sata and Iwata you have to be a nitwit not to get a pretty smooth finish. The guns almost apply the paint themselves. Now if you are using a cheap Harbor Frieght gun then it is a different story.

3. Beyond color sanding the quality of a paint job is directly related to how smooth the paint was appied. Otherwise just get out a roller and go for it. Color sanding to cover up a bad application will end up looking good, but it will also take away from the longivity of the paint. When you color sand you change both the thickness of the paint often creating the thinnest paint where it was applied the thinnest and the UV protection.

4. Longivity of the paint is greatly affected by its treatment. When the clear coat is applied the UV protectants float to the surface. When you color sand you are removing some of these protectant chemicals and weaking the paint. If you wait a while for the paint to fully cure and then sand what has moved to the surface you are removing some oxidation. Since paint will continue to cure for many months and even a year the longer one waits the less paint that needs to be removed by color sanding and the smoother the finish will become. Oxidation is easier to sand giving a natural barrier from going too deep allowing for a perfect surface for buffing.

5. All of the professional paint systems in use today are designed for two things - making the paint company rich and getting the car out of the shop as fast as possible. A truely good paint job requires many coats and sandings between. It also requires aging the paint between sandings and layers so that you have a sold base to work from. As the paint cures the under surface will change. Remember youa re working with complex chemistry here.

6. Blocking at each stage guarantees a smooth finish. The high gloss and depth of a good paint job is a result of translucense. That is you should be looking down into the paint through several layers. Few of the base clear coat systems can give you this depth. House of Color is probably one exception to this rule. The base coat is deigned to be opaque and the clear to add depth. As a result you are looking through a finish to see the actual paint.

7. The paint application on the 928 is pretty good from the factory. The early 1980s cars had some chemical problems with the paints and Porsche ended up getting sued by Porsche owners as did BMW and a couple of others. Staring with the 85 or so models the paint formulas were changed and the paints had better longivity. it is difficult to get factory conditions. Further factory paints were applied over bare metal. it is impossible to get a quality job painting over an existing paint job. Eventually the paint will begin to fail under the new paint and what looked nice can even bubble and peel. Remember Chemisty is at work here.

8. I am not criticizing the paint on this particular car other than to suggest the correct solution was to sand the clear coat as applied and put on a second coat on as smooth as possible. This would have been a better long term solution than color sanding somthing that needed some severe sanding and upsetting the UV layer. Since this is a friend of a friend I can unserstand the reluctance to do more on the car. Besides the cost of another coat of clear is not cheap either.

Look what I am doing here is sharing my experience to hopefully help others not make similar mistakes. A paint job is the single most expensive componet on the 928. It is more expensive than the motor or the interior. To preserve the value of the car the paint should be done right. Of course the owner will never get the price back when selling, but it is unlikely the owner will ever get back any repairs or improvements done to the car.

Dan the Pod Guy
Old 05-08-2007, 09:01 AM
  #38  
Kevin Michael
Rocket Pilot
Rennlist Member
 
Kevin Michael's Avatar
 
Join Date: Apr 2004
Location: gettysburg pa.
Posts: 3,298
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Ron_H
Kevin said: " ..... My car goes in about two weeks for total paint. cost = 800.00"

If I could get a total paint job in California for $800, I would probably have to know the painter well, be dating his dog and walking his daughter......er....well something like that anyway. And then have to buy him a keg a month for a year...And then maybe he would do it.
So there's no confusion here, the 800.00 is the cost of the paint! It will take myself and my talented nephew 3-4 days in the shop to complete. This will be a single stage paint with the final two coats a single stage/clear combo(very cool show car trick) to make the car look intensely wet when cured. Prior to paint, we will be sanding the entire car and doing 416 to balance the surface, then lots of long-blocking, 3 coats primer, lots more blocking, then we will start shooting. I can't wait!
Old 05-08-2007, 12:10 PM
  #39  
BC
Rennlist Member
 
BC's Avatar
 
Join Date: Dec 2001
Posts: 25,152
Received 87 Likes on 56 Posts
Default

Can you elaborate on the single + clear trick?
Old 05-08-2007, 12:18 PM
  #40  
Fabio421
Man of many SIGs
Rennlist Member
 
Fabio421's Avatar
 
Join Date: May 2005
Location: Florida, USA
Posts: 8,722
Received 11 Likes on 5 Posts
Default

Whats a 416 trick?
Old 05-09-2007, 03:48 AM
  #41  
Podguy
Three Wheelin'
 
Podguy's Avatar
 
Join Date: Sep 2003
Location: SF Bay Area
Posts: 1,526
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by BrendanC
Can you elaborate on the single + clear trick?
Brendan,

He is just using a single stage paint as the base coat. It you look at the House of Color paints they generally sell a base, a color and a clear. If you are doing a Pearl job then there are four coats. The pearl is put on over the color coat using a special translucent material. If you want fancy take a look at the Alsa site.

You can get a good job this way, but don't ever screw up on one of the stages. You better have a super clean booth for the application of each coat.

Personally I am against full priming and blocking. Some people will strip to the metal, coat with a thin layer of Bondo (Plastic Filler) and then block the filler so only a very thin coat is left on the entire panel. From there you build the primer. Believe it or not but many older Ferraris were done this way. I do not know if this is still true.

Top much primer and when the paint chip you see the primer. To avoid this use a primer the same color as the car. Yes you can have primers tinted to the car color. But then if you spray only black it does not matter.

Dan the Pod Guy
Old 05-09-2007, 08:20 AM
  #42  
M. Requin
Rennlist Member
 
M. Requin's Avatar
 
Join Date: Mar 2007
Location: Central Virginia
Posts: 3,625
Received 60 Likes on 39 Posts
Default

Originally Posted by Podguy
Brendan,

He is just using a single stage paint as the base coat.
I think he's referring to the practice of mixing base and clear for the final coat. Some shops do it.
Old 05-09-2007, 10:32 AM
  #43  
Kevin Michael
Rocket Pilot
Rennlist Member
 
Kevin Michael's Avatar
 
Join Date: Apr 2004
Location: gettysburg pa.
Posts: 3,298
Likes: 0
Received 0 Likes on 0 Posts
Default

The 416 is a product that basically is a skim coat(not a multi purpose filler). It balances the surface and is easy to work and sand. Dan makes a great point on the primer. This is the most important step in my opinion. Screw this up and everything after is crap! I like K-36. I recently widened my rear quarters as some of you know. I had a salesman give me some body-filler to try as he said it was the end-all be-all of fillers. So I said what the hell, What would I lose. I finished the work , baked it in the sun for two days, then sealed it ,primed it, let it set for two more days, then shot the base and clear. Next day I cut it and buffed it out. It was absolutely beautiful! No mistakes. Then a month later it starts shrinking and at the right light you can lightly see part of the seams! No worries though we are redoing the whole car soon. BTW, that product was Chromalite, and I would stay clear of it as it is trash.
Kevin
Old 05-09-2007, 03:35 PM
  #44  
JHowell37
Drifting
 
JHowell37's Avatar
 
Join Date: Jul 2004
Location: Davidsonville, MD
Posts: 2,725
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by Kevin Michael
The 416 is a product that basically is a skim coat(not a multi purpose filler). It balances the surface and is easy to work and sand. Dan makes a great point on the primer. This is the most important step in my opinion. Screw this up and everything after is crap! I like K-36. I recently widened my rear quarters as some of you know. I had a salesman give me some body-filler to try as he said it was the end-all be-all of fillers. So I said what the hell, What would I lose. I finished the work , baked it in the sun for two days, then sealed it ,primed it, let it set for two more days, then shot the base and clear. Next day I cut it and buffed it out. It was absolutely beautiful! No mistakes. Then a month later it starts shrinking and at the right light you can lightly see part of the seams! No worries though we are redoing the whole car soon. BTW, that product was Chromalite, and I would stay clear of it as it is trash.
Kevin
Was that something you had to mix and apply by hand or was it a knock-off of Slick-sand that you spray through a gun? I'm also wondering if it was one of those squeeze tube fillers that dries and doesn't use hardener.
Old 05-09-2007, 03:44 PM
  #45  
JHowell37
Drifting
 
JHowell37's Avatar
 
Join Date: Jul 2004
Location: Davidsonville, MD
Posts: 2,725
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by Podguy
Personally I am against full priming and blocking. Some people will strip to the metal, coat with a thin layer of Bondo (Plastic Filler) and then block the filler so only a very thin coat is left on the entire panel. From there you build the primer. Believe it or not but many older Ferraris were done this way. I do not know if this is still true.
Can you elaborate more on this? Are you against skim coating entire cars? When you say "full priming and blocking" what do you mean? I can believe older Ferraris were painted how you've described. During the 50s, 60s, and early 70s, Ferrari was a very low volume producer and the cost for the machinery to produce exact body parts would have been prohibitive. It's widely known that older Ferrari bodies were essentially custom made and thus, would incorporate large quantities of filler. That was discussed by Junior Conway 15 years ago in the article about $60K paint jobs he did on older Ferraris.


Quick Reply: Wet sand after paint job with pics



All times are GMT -3. The time now is 06:15 AM.