My first wet sanding Experience

**angryfx45** · 10-02-2016, 05:56 PM

Slight update, had about 2 hrs to work in the car again. I just did the lower part of the hood kind of a 50/50 shot after a long careful pass with m100 W/micro fiber cutting pad.

I kinda like this better than the m105 W mf cutting pad.

I think it will take a good 3 passes with either 105 or 100.

Hopefully ill have some more time sooooon

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**angryfx45** · 10-02-2016, 05:57 PM

Originally Posted by Accumulator

The OP on my S8 is simply *TERRIBLE* on a few panels despite their then-new robotic paint system. Oddly enough the A8 (same plant, same paint, built a few months earlier) isn`t as bad. I just live with it as I`m all about thick clear.

Heh heh, the reshot front bumpercover and hood of the Crown Vic are so bad that the texture makes the paint appear semi-matte despite proper polishing! No, I`m not leveling that either. OP is something that just doesn`t bother me for some reason...same with most paintchips and also dents even when they`re prett bad. Now wash-induced cobweb-marring or a hologram? Wouldn`t take it down the driveway with flaws like those, but chips, dents, and OP are OK. Everybody`s different...

Yup factory orange peels dont bother me but this repaint was a horrid.

Just pure UGLY.

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**JustJesus** · 10-02-2016, 07:13 PM

Originally Posted by angryfx45

...

I coulda taken it back to the shop to have it fixed but from the way they buffed the car, with holograms and etc etc i decided to tackle on the job myself.

i chatted online with some guy who had similar experience. He *did* take it back, and unfortunately, they made it worse! Ruined other panels that they shouldn`t even have touched. nasty. So you may have saved yourself some headaches.

I bought 6 pcs of 3000 grit, 2 2500 grit, 2 2000 grit.

I did not buy 1500 bcuz i was so scared i would go through the clear.

I know the feeling. There`s so much fear put into us "new" guys that we might get overly cautious. But, to me, that`s a good thing!

----

Okay, hopefully I can give you some pointers and you won`t take it negatively. Some constructive criticism. Just so we`re clear, I AM NOT A PROFESSIONAL. Nor am I a seasoned veteran in the field. But I like to tinker and DIY when I can.

First... You want to use a thin tape, I like 3M`s thin 1/4" blue vinyl. Or maybe it`s 1/8" (?) - tape off the high points and edges. In your case, the edges of the hood, and you have at least two body lines that run front to back. You want to tape those off for sanding. Why? Paint tends to be thinner in those areas, as gravity does it`s thing and paint gets drawn down. It would be easier to burn through those edges and lines.

So i had sprayed a 2 by 2 area of the hood first and soaked the 2000 sand paper wet previously.

And did my first initial pass real carefully.

As you can see i was so scared i did maybe 2 3 passes and stop to wipe and check my result.

For being your first time, I`d say this isn`t bad. I`ve seen worse. Way worse. When it comes to sanding, especially by hand (BTW, you did this by hand, right?) you want to do many strokes, close together. You want to move little by little. So if you`re going from left to right, move a little bit at a time. A 1/4 of an inch? I`m sure people have different opinions on this. But if you look at your pic above, you can see those "high" spots, the glossy parts. You want to avoid that, and get a more uniform finish.

In my thread here, http://www.autopia.org/forums/click-...tml?highlight= ,you can see in my first pass I had some "gaps." That`s what we want to avoid. But looking at the other pics, you can see how it is more uniform as I did more. That was done by hand. I`ve found that doing it by machine, you get a much more uniform finish. You can see some of that on this thread here... http://www.autopia.org/forums/machin...tml?highlight=

First impression of the wet sanding was unlike when it was dry. Once wet and rubbed against the hood of the car. It grabbed and kind of clung on to the paint.

It wasnt gliding rather biting the paint and i was using some force to push and pull.

Im not sure it this is the right way to wet sand but this is what i felt.

From what I gather, you do not want it to be grabby. On the other hand, you also don`t want it to just *glide* over the surface either, sort of like hydroplaning. Using "some force" to push and pull sounds kind of bad. Not sure how much force you used, but IME, you don`t need a whole lot.

Paying attention to the edges and curves.

Good man!

I was done with my initial passes and dried the hood and checked.

There still was high spots and i knew it wasnt good enough so i banged the parts out that valleys and peels were showing.

Again, you want to shoot for some consistency in the finish. You want it to be uniform. As much as possible. Doing this work here, will get you better results later, when you`re done with the polishing.

I knew i couldave done alil bit more but i was scared and wanted to buff it out and maybe resand againg if needed

I`m curious to know how much paint (clear) you have on there.

I gotta go, but I`ll see if I can add more to this later....

**angryfx45** · 10-02-2016, 07:48 PM

Originally Posted by JustJesus

i chatted online with some guy who had similar experience. He *did* take it back, and unfortunately, they made it worse! Ruined other panels that they shouldn`t even have touched. nasty. So you may have saved yourself some headaches.

I know the feeling. There`s so much fear put into us "new" guys that we might get overly cautious. But, to me, that`s a good thing!

----

Okay, hopefully I can give you some pointers and you won`t take it negatively. Some constructive criticism. Just so we`re clear, I AM NOT A PROFESSIONAL. Nor am I a seasoned veteran in the field. But I like to tinker and DIY when I can.

First... You want to use a thin tape, I like 3M`s thin 1/4" blue vinyl. Or maybe it`s 1/8" (?) - tape off the high points and edges. In your case, the edges of the hood, and you have at least two body lines that run front to back. You want to tape those off for sanding. Why? Paint tends to be thinner in those areas, as gravity does it`s thing and paint gets drawn down. It would be easier to burn through those edges and lines.

For being your first time, I`d say this isn`t bad. I`ve seen worse. Way worse. When it comes to sanding, especially by hand (BTW, you did this by hand, right?) you want to do many strokes, close together. You want to move little by little. So if you`re going from left to right, move a little bit at a time. A 1/4 of an inch? I`m sure people have different opinions on this. But if you look at your pic above, you can see those "high" spots, the glossy parts. You want to avoid that, and get a more uniform finish.

In my thread here, http://www.autopia.org/forums/click-...tml?highlight= ,you can see in my first pass I had some "gaps." That`s what we want to avoid. But looking at the other pics, you can see how it is more uniform as I did more. That was done by hand. I`ve found that doing it by machine, you get a much more uniform finish. You can see some of that on this thread here... http://www.autopia.org/forums/machin...tml?highlight=

From what I gather, you do not want it to be grabby. On the other hand, you also don`t want it to just *glide* over the surface either, sort of like hydroplaning. Using "some force" to push and pull sounds kind of bad. Not sure how much force you used, but IME, you don`t need a whole lot.

Good man!

Again, you want to shoot for some consistency in the finish. You want it to be uniform. As much as possible. Doing this work here, will get you better results later, when you`re done with the polishing.

I`m curious to know how much paint (clear) you have on there.

I gotta go, but I`ll see if I can add more to this later....

The whole point of me putting my first exp was to get pointer criticism etc etc. So i really appreciate it and thank you!!!

I did tape off the side edges of the hood. Also the front hood line curves i actually did not even sand bcuz i was scared of burning through.

But like u said if i had those thinner tapes yes it would be much better.

My stroking was actually somewhat very long maybe half an arm length at first and it gradually got smaller as i passively learned the techniques.

But it still wasnt very short. So ill need to fix that in the future.

The amount of clear put on? Honestly i have no idea aside from it being a genral body shop job.
Im assuming it was a typical amount 2 coats maybe so i am never going to be redoing the full panel just where there may be too much orange peel? .. but after i buff & polish i might not even touch it, being that i will be coating it with CQuartz uk once im done in a matter of days to weeks.

Again thank you for the comment. And i have learned a great deal from your experience. And im able to understand better, now that i have my own experience also.

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**Stokdgs** · 10-02-2016, 08:11 PM

Congrats on taking this project on without any experience !

What would have made the sanding easier,uniform, and flatter, would have been to use a 3M black rubber sanding block and water constantly running on the panel being sanded, or a bucket of clean water with a few drops of soap and a big sponge, to make the water more slippery..

Assume the paint shop sanded the areas flat to begin with and that will help you get a better result after all the compounding you have to do..

Is that black paint a jet black or a metallic black ? It looks like a jet black from here so far...

Audi factory paint is pretty hard as are most German car paint so if they used the Factory Pack paint, then it will still act almost the same..

Assume you waited long enough for the paint to dry and cure before you started this, right ?

When I painted in shops, the only way you would get orange peel would be if you applied the paint too dry...

You have to paint it so it is wet enough that it will self level and come out pretty darn smooth and glossy..
Then, there is less work to do at the compounding stage in the process..

You are doing a great job !
Good luck !
Dan F

**angryfx45** · 10-02-2016, 08:59 PM

Originally Posted by Stokdgs

Congrats on taking this project on without any experience !

What would have made the sanding easier,uniform, and flatter, would have been to use a 3M black rubber sanding block and water constantly running on the panel being sanded, or a bucket of clean water with a few drops of soap and a big sponge, to make the water more slippery..

Assume the paint shop sanded the areas flat to begin with and that will help you get a better result after all the compounding you have to do..

Is that black paint a jet black or a metallic black ? It looks like a jet black from here so far...

Audi factory paint is pretty hard as are most German car paint so if they used the Factory Pack paint, then it will still act almost the same..

Assume you waited long enough for the paint to dry and cure before you started this, right ?

When I painted in shops, the only way you would get orange peel would be if you applied the paint too dry...

You have to paint it so it is wet enough that it will self level and come out pretty darn smooth and glossy..
Then, there is less work to do at the compounding stage in the process..

You are doing a great job !
Good luck !
Dan F

Thank you for the spirit!!!! And the wisdom.

Yup it was sanded at the shop previously once, i know this bcuz when i went to check out how they were doing, they had just sanded it.

This paint is Jet Black, non metallic.
Pain in the ass cuz it shows everything..... i mean everything!!

I had waited about 3 4 wks prior to tackling the job.

I am actually friends with the owner of the body shop however the worst part is hes in charge of the mechanical repairs and does not know any bodywork nor detailing or finishing. He just hires ppl to do all the bodywork for him. So even if i took em back im sure he/ his workers arent able to do a nice job.

I think i learned alot about wet sanding from this exp. Will not say that im confident but i understand more now. Just watching videos or reading about it isnt enough until you lay your hands on it i think.

Thank you all

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**Accumulator** · 10-03-2016, 12:33 PM

Just FWIW, the current (water-based) paints that Audi shops in my area use tend to "die back"/shrink over time, often exposing prep marks/sanding scratches that absolutely were *NOT* visible for the first weeks/etc. after painting. Could certainly just be a user-error situation unique to my guy`s shop, but I thought I`d mention it.

**JustJesus** · 10-03-2016, 12:40 PM

Accumulator - Die-back, that`s something I began to research last week. Still don`t know much. By chance, do you know if that`s more inherent in waterborne paint systems?

**Stokdgs** · 10-03-2016, 12:47 PM

Originally Posted by Accumulator

Just FWIW, the current (water-based) paints that Audi shops in my area use tend to "die back"/shrink over time, often exposing prep marks/sanding scratches that absolutely were *NOT* visible for the first weeks/etc. after painting. Could certainly just be a user-error situation unique to my guy`s shop, but I thought I`d mention it.

This is really too bad...

The body guys that fix the metal always scratch it up with grinders, files, 40-grit sandpaper.. They even finish sand (for them) the bondo with 40-grit paper...

What I always did was take the time to remove all sanding/grinding, etc., defects in the bare bodywork, bondo, before any primer was painted on the surface.. I always thought everybody did it this way...

An air powered D/A sander is the most perfect tool to use for this clean up part..

Then, when it`s all smooth, you apply several coats of good primer followed with a guide-coat and wet block sanding to insure its really straight, flat, and perfect to begin the paint process....

Guess the people out there today just don`t get it or something?
Dan F

**angryfx45** · 10-03-2016, 04:46 PM

Not to mention general bodyshops cutting corners and just drilling holes everywhere to push n pull.

On the othere hand i do understand the overhead costs and jobs constantly waiting to be handled.

I am almost done with m105/ 100 step and thought to give you guys a quik shot.

Night n day difference so far evnthough im not done buffin n polishing yet

Some cloud shots

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**JustJesus** · 10-03-2016, 05:25 PM

That looks good! ! !

**Accumulator** · 10-04-2016, 12:53 PM

Stokdgs- Yeah, I`ve had that "use finer paper and just charge me for the additional time/materials" talk with them, one of these times perhaps it`ll stick. Sigh...another case of my having to tell Professionals how to do their jobs.

Originally Posted by JustJesus

Accumulator - Die-back, that`s something I began to research last week. Still don`t know much. By chance, do you know if that`s more inherent in waterborne paint systems?

Actually, I expect it more with single stage lacquer (it`s happened on the Jag in a few redone spots). But yeah, it seems to be more of an issue *at the shop that does most of my work* since they switched to the water-based stuff. Frustrates me, but at least those guys *never* mess up the rest of the vehicle.