opinions needed on wet sanding, old versus new methods

[vetteman]

First time poster. Background: I started painting 2 years ago with my first car, my 70 Vette. I bought all my stuff from len, and has several long knowledgeable phone calls with him. First off thanks for all of the advise and the great stuff I bought from you, The 70 turned out great. Ended up using glasurit 22 line single stage. after some sample panels and many mistakes, I got it down!!

When it comes to color sanding (wet sanding) a single stage, would you stick with the old tried and true hand blocking, or go with the newer orbital power systems? The reason I asked is that after doing a 1 ton chevy dually (with rm bc/cc) my arms are killing me!! I have another vette that I am starting, and will again be using the 22 line, will the new air sand system work with this type of paint?

I am concerned with swirls, do you get these when using the air sanders? With the hand fashion these are minimal. Do these add to the buffing phase work?

On the 70 I worked it with hand sanding1200/1500/2000/2500/3000, and three levels of compounding and buffing. I'll gladly buy one of these soft pad orbitals if I can get some feedback on their usability, and the pros/cons.

Thanks again len on all your help in the past, and will be contacting you soon for another order.

Frank

[Porter]

Frank,

It depends on how well your paint laid down, orange peel, trash, etc.

My first full repaint was my brother's 70 Vette Roadster back in 89, full strip, gel coat, epoxy, 2K surfacer, bc/cc. Cut it with 1500 wetsand, 3M microfinishing compound, black beauty swirl mark remover. Came out great, better than factory. Then you get into the issue of over-restoration. A Corvette has a lot of contour, you can only do the somewhat flat surfaces on any car with the 3M trizact ? airvantage sander, drysand stuff.

Used the same method on my 66 Cadillac, PPG Omni bc/cc ,left a little peel in the paint, looks better than a new 2005 Cadillac.

Some of the pros here with a state of the art spray booth never colorsand any cars.

HTH,

Porter's 2 cents for the day

My car can be seen here:

http://www.modifiedcadillac.org/

[Henry]

but I might have to think twice on a vette that era. Like Porter said, all the contours. I still would use the dry method with the PROPER sander. There is a foam intermidiate pad I bought from Len that I use in tricky areas. When I started dry sanding with Finish Film I used the interface pad all the time. Then, as you gain some experience with controling what the sander is doing you become more in control. WithOUT the pad the job goes quicker.
I would FF the vetter because although there are a ton of contours, all the panels that lead to them are basically float. Even the tops of those big front fenders. Just go gingerly from the flats to the peaks. DO NOT bear down on any peek be it dry or wet; you create too much heat.
The swirls you spoke about, as far as I'm concerned, did not come from any sanding but from buffing and the chemicals you used to buff.
You'll find that the buffer you use, the pads on the buffer and the brand you use all play a triple roll in the outcome. The Makita 9227C is the favored choice of buffers and Presta Products are a hands down winner over any 3M stuff. I used Mirror Glaze then switched to PRESTA line and was very happy. Then Robert created this True Finish now SURE FINISH stuff. It does work great. Also, to show how important a buffing pad is consider this. When you use Sure Finish you use it SOLELY for the compound and the polish/glaze. BUT you change the pad for the particular operation you are performing.
Robert has brought us a wide variety of buffing pads. I like compounding with wool but switch quickly to Roberts ORANGE pad. I think it's almost impossible to burn with this orange pad. One time I tried just the orange pad for compound all the way thru to finish just using more product and wiping residue off the surface. THEN, at the end use micro fiber cloth to remove residue, film, etc.
I would do the entire vette dry; with the machine other than the creases within the hood but even there I would use dry finish film on a proper rubber block. Sorry to get so long but I was so amazed and fearful of sanding dry that I've done many tests. Now, I cannot believe all those hours over all those years wet sanding. Henry

[Len]

If Finishing Film and machine sanding were not invented I'd be retired by now. In my opinion this is the single longest/hardest step in the entire restoration process, it makes stripping the paint off look like childs play. Once you use a "good" random orbital sander with an interface pad and Finishing Film you'll never go back to wet sanding unless it's just in a tight spot. We power sand just about every job that needs color/clear sanding because it takes a two/three day job of hard work and turns it into an hour or two of easy sanding. We don't sand on peaks or edges but instead stop about a half inch short and let the buffer do the work close to the edges.



http://www.autobodystore.com/Filter/3M_FinFilm_in_use.jpg
http://www.autobodystore.com/avcomposite.jpghttp://www.autobodystore.com/Makita-9227C_2a.jpg
http://www.autobodystore.com/SF1.jpg
Color Sanding and Polishing Products Link (http://autobodystore.net/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=M3)

[Henry]

If you don't understand the center picture of the car Len posted then you're like I was the first few times I looked at it. That is a picture of the AIR SANDER in someones left hand actually sanding. I couldn't figure it out. I thought, so big deal, here is a car being sanded thinking it was being done by hand sanding. It is the most revolutionary thing to come along that does the job better in a fraction of the time.
By the way, I think one of the best benefits is that sanding dry instead of wet allows you to SEE what you sanded all the way down to the pores of any orange peel. In wet sanding you had to sand then squeegee the area to see what you did. To me, it allows consistency especially in an area that is more dry or has heavier peel. Henry

[vetteman]

Thanks Guys, Like I said after wet sanding and buffing my large dually, My arms are about dead!! :-) I think you have me just about convinced to go with the air advantage, and the sanding pads over going the hole body with wet sandings!! I'll be in contact with you len.

[Porter]

Vetteman,

By all means follow Lens lead with the FF and the proper equipment. Just figured I'd kick off your thread.

I hope that one ton dually was a show truck.

All depends on how much equipment you want to buy and how many full repaints you do every year. I'm just a weekend summer warrior with a home garage and a full personal car repaint every few years. The finished job depends on the customer's wallet too. Maaco isn't colorsanding any of their paint jobs.

Always easier to have the proper tools and equipment, the must have stuff for a business, time is money. Autobody collision work requires a factory new finish with the right stuff to get the job done in a competitive fashion, you can't afford to not have the proper time saving equipment to be competitive.

Still helps to lay your paint down nice and smooth, the colorsanding will compensate for marginal painting conditions and equipment.

Take a good look at some of the new cars and their paint finish for comparision.

Porter ( the wetsanding dinosaur )

[Tom S]

What is the actual time that it would take to hand sand a mid size car and what is the time using the machine?

Tom

[Len]

If the surface has very little peel it will be much faster using either method. If the surface is sprayed dry (rough) or has a lot of orange peel it can take much longer especially by hand.

It will also make a difference in how smooth you want the surface to be. Usually we don't make the surface perfectly flat, we usually just level the peel so that it's barely visible then we polish. If we were to sand it totally flat it would take longer and if we were to sand it flat by hand it would take much longer.

The typical hood could take us from one half hour to two hours to sand by hand and that same hood may take ten to fifteen minutes to sand with the Airvantage and 1500 Finishing Film.

Time is not the only consideration, the amount of effort needed to color sand paint is MUCH greater by hand than with a machine.

[vetteman]

Vetteman,


I hope that one ton dually was a show truck.

Porter ( the wetsanding dinosaur )

Well kinda, I use it to pull the vettes around so I wanted it to look nice. I also HATE the way the big three are turning out cars with nasty paint jobs on them. I bought a 2004 vette, and made them take it to a very good detailer that they (and I) use, and they paid to sand out the orange peal!! Nothing looks worse than peel in the sun!!

I guess I got a little anal on the 70 when I did it, I went to 3000 on the paper. It's not a restoration, so no need to worry about "it had peel in it when it was new" crap.

I am starting to do a couple of the club guys cars, and to be honest, I want the same results I got with all of the wet sanding on my 70, but I am not sure that my arms are up to it any more!! :) :)

Another question I had is can you use these air advantage wet? Or would you need to use a water bug?

[Len]

You can use the Finishing Film and the Airvantage wet but you can't see what you're doing. I would sand with the Finishing Film dry then switch to 4000 grit Abralon wet. Since the Abralon is so fine you don't need to worry as much about sanding off too much material.

To make the surface very flat you can also block sand wet starting with a coarse grit like 800 wet then switching to 1500 Finishing Film dry on the machine then to 4000 grit wet on the machine.

Like I said... it all depends on the final result you're looking for.

[Chris L]

I am doing a 71 vette myself for a customer using Matrix single stage urethane.I used a few different methods on sanding and buffing.The one i like best on this paint is 1500 dry finishing film followed by trizact 3000 wet.Then sure finish.

[Len]

Trizak is a good product but you need to change the pad on your sander because it has a "Hook-It II" surface. 3M (in it's marketing wisdom) switched the hood and loops so that you can only use 3M products with a Hook-It II pad. Trizak may work ok but I don't like their marketing ploy so I use 4000 grit Abralon instead.


http://autobodystore.net/Merchant2/graphics/00000001/MirkaAbralon2.jpg

4000 Grit Abralon Link (http://autobodystore.net/Merchant2/merchant.mvc?Screen=PROD&Product_Code=M8A2414000-5&Category_Code=M3)