How much is too much with wetsanding paint?

[waltklatt]

All paint experts,

I am now at the point where I'm wetsanding the new (August 2005) silver paint.  My dilemma is this:  I wet sanded down an area to the point where the orange peel is gone, leaving a super smooth surface.  The wetsanding is done with a #2000 wet/dry paper, using water and a bit of liquid soap with a hard rubber block.  I am doing a criss cross pattern with the wet sanding motion (thanks Mike Hund) and then polishing out with a Meguairs compound.  All looks great, but the shade of color is slightly different than the surrounding areas.  This was a test area and now can see a slight difference in the coloring of the silver.  
Does this mean I cut too deep into the paint with the wetsanding?

Would like to hear from others who have done this to their cars and how they reduced the orange peel and retained the evenness of the color.  Expecially for the metallics.  
I have done this same method for a solid colored car and it came up perfectly.  Is this a metallic paint problem?

Thanks in advance.
Walter Klatt
1967 220SL-diesel being wetsanded and polished
1963 230SL-gas-stripped and primered.

[ja17]

Hello Walter,
It depends on the paint system being used. Is it a dry coat/ wet coat system, or a straight silver with clear, or a straight silver without clear?

Also what type of paint; polyurethane, urethane, standard enamel, or lacquer?

If you are noticing changes in color on a metallic, you have probably sanded through the clearcoat.



Joe Alexander
Blacklick, Ohio

[mulrik]

My car has a yellow-white paint layer over the original papyruswhite paint layer below. Do you think it would be possible to wetsand it with a 1500-2000 grit paper. THen buffing it up afterwards with some light sanding paste (polish). This way I hope to remove the covering paint layer and work myself into exposing the orignal paint. I have previously been to aggresive with some sanding polish and have exposed an area of the original paint of a small area. Now I wonder if it is possible to do this with the entire car and get a nice result?

'67 250 SL Papyrus White 113043-10-000023

[Bob G ✝︎]

Color sanding paint:
This is an area you have to be carefull. I will asume you had the car painted?
If so ask the paint shop to let you know how mnay coates of clear are on the car 2 mills is standard factory 3 affords a mill of clear to color -sand and polish, do not go passed this point.total surface coating not including body work and filer is 4 mills single stage paint clear coat base-coat 5/1/2 to six in some areas if there is gravle gard in the coating to protect against chips .
The clear coat has a UV sun inhibitor built in that surfaces to the top layer of the clear. This protects the base coat from fading. YOu may notice on older Mercedes-Benz cars the clear coat takes on  a yellow cast . this is  the UV part of the clear coat that has obsorbed the suns rays and is acting likea filter.
 Mercedes-Benz cars came with a orange peel effect from the factory, it is due to the way the paint flows out as they pass through the convection ovens on the assembly line.
It is possible to color sand some of the orange peel out ,but I would hasen to go passed a certain point.
doing so as you have noticed changes the color tone because you have flatten out
the top coat of clear. It is not possible to color-sand out the yellow tint that the paint obsorbes from the UV filters, only flatten the paint out.
I recommend you fine a paint & coating gauge that will messure farrious and none farrious sufaces. Although the reading are not going to tell you how much clear is on the car because it measures from the primer to the top coat of paint . It is a good gauge to use to compare before and after work.
Be carefull and be conservative.

Bob Geco

[Ed Fisher]

Walter:

I have color sanded (wet sanded) many cars following painting and I may have more questions than answers to your post.  If you can get through this, perhaps we can figure it out with the help of the group.

Question #1:  Is there a clear-coat applied over the silver?

Silver is probably the hardest color to paint, detail, and touchup because it has no pigment to speak of, the “color” is made up of the metallic flakes.  Usually, the silver is applied dry, to mitigate metallic sag, and the clear-coat is applied over that.  If you have a clear coat, as has already been said, don’t go to deeply with the sanding.  I usually use 1500 VERY lightly, followed by 5000, and then polishing compound on a low speed buffer.  My current polish of choice is “Perfect It” by 3M.

If you do not have a clear coat, my sincere recommendation would be to color sand the car gently, discontinuing the use of soap as a lubricant, and have one applied.  Actually no soap is ever really needed, the constant flushing action of a dribbling hose at your work area and cleanliness of water in the bucket are the key here.  Also, don’t polish the car if you are going to have a clear-coat applied later.  The paint surface must be pristine.

Question #2:  Are you seeing a color shift, or, could it be that the difference in paint depth and light refraction make the surface look different?  

If it is the latter, this is normal enough and when the entire panel(s) is done it will match the spot that you have already polished.  If it is the former I suspect, as did another poster, that you have sanded through the clear and are now heading into the paint.  If this is the case, and your test spot is inconspicuous, be less aggressive with the rest of the car and perhaps go to only 5000 grit, unless your orange-peel is severe.  Truly, some orange peel is not only acceptable but also original.  Most show cars have eliminated it entirely, since that is how to get the most brilliant shine, but if you are merely trying to clean up a few dirt specs in your paint and fix a run or two, then completely removing the orange peel texture is not really called for here.  The deeper you sand the more material you are removing.

It sounds as though you are being extremely careful, and for that, I applaud you.  Let us know how it is coming.  My guess is that you are only seeing a shift in the light and that it will all match well when you are done.  

Don’t forget to tape those edges!

All the best,

Ed Fisher

[Bob G ✝︎]

Color sanding paint:
Walt:
I like what Ed fisher had to say. I agree that too much sanding is not nessary. 3M products and Meguires both carry special paper that goes from 1000 to 3000 very fine. when you color sand you start with a more agressive paper like 2000 and come back criss crossing you orginal sanding marks with a finder paper say 2500 or 3000. Use the small 3M squeeze to wisk the moister off the surface to check your progress. I count ten strokes and then Squeeze the surface to check my progress. You should be able to see some faint signs of orange peel still in the top coat.
Be aware of high line areas that may have very little paint always use hand sanding with a fine sand paper and hand polish. I liketo use lots of water and some lubrication soap for the sand paper to keep it sliding easy on the surface.
USe a bucket of warm water & a little soap to keep your paper  also youwill need a rubber or flexable backing pad for the sand paper. If you use your hand you leave the chanch of gouging out areas that will not be completely right. Work slow .
When polishing USe slow speed around 1500 to 2000. to work the compound over the paint to get  a gloss I recommend the new 3M soft dul sided wool pads and finish with a Foam polishing pad and a good machine polish or glaze to bring back the clarity the paint should snap back and look like a clear pond of undistrubed water. Distintness of Image or DOI.
If you like go to www.eastwoodtools.com They have a video on color sanding in the video section that may help you make sence of Ed fisher message and mine. This is a hard job but one many home restores have done them selfs with success.
good Luck
Bob Geco

[norton]

Walt try sanding with dry paper, in an out of the way place on the car, just a couple of strokes and then look at the paper if it has a white ish look to it you have clear coat, if it looks silver then you do not.

Mike Halleck
Chesterfield Mi
71 280SL
68 250SL (parts car)
94 E320 Coupe

[Bob G ✝︎]

Walt.
To check if you have goen passed the clear coat. Easyest way is to take some mild polish and rub a small area you worked on. If color comes off you will need to re clar that area. If no color comes off on the rag the clear coat is still OK.
One word of caution be conservative paint unlike our skin does not grow back!
Bob Geco

[George Des]

Walt,

Check into Len Stuart's autobody site and pose this question there. I checked into this site regularly for about three years before I did my own paint job including the color sanding and buffing. There is  enough expertise checking into this site on a routine basis to help you with any problem you may encounter. This is the URL:
<http://www.autobodystore.com/>. Let me know how you make out

George Des

[Chad]

George, clicking on this gets you to that forum. I know it well, prior to prepping and painting a car myself before. Your previous link doesn't work.

http://autobodystore.com/forum/index.php

1967 230SL (Manual)

[George Des]

Chad--thx--the link I cited adds an extra< and throws the correct link off. The site is well worth looking at if doing paint or bodywork and most of the regulars have experience with a wide spectrum of products and techniques.

George Des

[waltklatt]

Paint polish experts,
Thanks George, Chad, Bob, Mike, Ed, Mulrik and Joe.  Have a few responses and questions:
I have done a bit more wetsanding and then polishing.  So far looks great except one small area near the 'infamous' crease next to the headlights where the paint was too thin to begin with.

George, I have followed and read on several articles from magazines on the polishing perspectives and tips + trickes for a good finish.
 
Bob, I used the polisher setting of 1500 rpm and it goves a nice fast spin to polish up the swirls and fine scratches without problem.
The paint has no clear coat on it, should I take it back for one?  

Ed, I'm doing the color sanding very lightly to remove most of the orange peel, but leaving some behind-would say about 75% less orange peel after wet-sanding.

Mulrik, what grade polish paste are you using?  I am using the Meguiars system-level 9 aggressive cutting paste and graduating up through level 5 to 4 and then 2(swirl remover) and then a final coat of just straight Carnauba wax(mothers).

Joe, The paint has no clear coat, only straight silver coat in two layers with 2-3 layers primer underneath.

Should the panel be a little warm to touch right after the polishing?  Is this wrong or am I too hard on the paint?
Might be a good exercise to take the car back for a clear coat after I am done with the polishing-they will have to strip the wax off to get a good adhesion for the clear coat.

Walter Klatt
1967 220SL-diesel
1963 230SL-gas

[George Des]

Walter,

Take a look at the website I cited. It is really not a simple matter to clear coat what you've got right now. I can't remember what you had your car painted with exactly, but it may have been a single stage acrylic enamel. As an example of how this works, most of the paint designed for a clear coat consists of a base coat that is applied only enough to provide "hiding". It is then clear coated with a compatible clear to provide the gloss. There is a time "window" in which the clear coat must be applied over the base coat to ensure a chemical vice mechanical bond takes place between the clear and the color coats. With PPG depending upon whcih PPG system is used(there are several available), I believe this "window" runs anywhere from 15 minutes to a few hours or so. Again, though, the two coats are designed specifically to be used together. There is no sanding or polishing between the base and clear coats. If the time "window" is violated, it calls for the base to be "scuffed" and an additional layer of base to be applied before it can be clear coated. Several of the single stage paints are designed so that clear can be added to the last color coats to give additional gloss but this is a diiferent approach from simply spaying clear over a paint that is designed to provide its own hiding and glos as I belive yours is. Again, read through the many informative posts on Len Stuart's website and I believe you will conclude there is little to be gained by spraying clear over your existing paint work. Let me know if this helps.

George Des