Wetsanding and buffing fresh paint

T

transamfan

New member
I do restoration paint jobs in my spare time as a hobby and a way to make extra money. I get good results when I cut and buff but I'm looking to perfect my buffing skills because I believe it will help me take my work to the next level. Most of the discussion on this forum is aimed at paint correction of factory paint that has been neglected over time which is very different from the paint that I work on. When it's all said and done I will have 5-6 coats of clear on the car and usually wetsand with 1500 then 3000 before buffing, and I have been using Menzerna compounds/polishes with Lake Country CCS pads. The clear I use is very soft and buffs easily.



Questions:



I usually start my sanding with 1500 on a DA. Sometimes I have a little more orange peel in some areas vs others so I have to spend more time sanding there to get it out. It seems like in these spots I end up with a bit of a ripple effect when looking at reflections once I get it all polished up. I assume this is because although the panel and paint are flat, the clear is not due to the sanding with the DA. I am thinking about starting my sanding on this next car with 1000 on a block to get all the orange peel out and then moving to the DA. Will I be ok to go with 1500 to get the 1000 scratches out you think, or maybe 1200? Maybe 1000 to start with is too much? By the way, I plan to use Megs Unigrit 1000 and then I'm gonna try the Norton Dry Ice system on the DA since I read a good post about it here recently.



Once I get the clear flat with the sanding, I'm ready to bring the shine back. The car I have in the shop right now is black and I'm looking to get the best gloss/depth possible. How much of this is going to be the products I use vs just having good technique? If I get the clear perfectly flat with the sanding, then remove all the sanding by compounding and then remove any defects of compounding with polish, the surface of the clear should be perfect and defect free, but can getting it defect free with one group of products vs another make a difference in the final appearance? This is the real questions I'm hoping to get answered because I've only used Menzerna's stuff and I've always wondered if I'm missing out on something.
 
With 5-6 coats of total clear to work with you should be perfectly fine starting at 1000 grit and moving to 1500 and then 3000 from there. I too have heard some good things about Norton's Liquid Ice system and know a few painters who recommend it, but depending on how fresh the paint is when you're buffing it I wouldn't recommend using a DA. And, to be honest, I question if the Norton system (I've never used it personally, but based on what I've seen) will really give you better results than the Menzerna you're already using.



Unlike with a sanding disc, a polishing pad has the tendency to grab at the surface and could cause "paint wrinkle" as a result of the DA's motion pattern. On fresh paint it's better to stick with a rotary as a rule.



What specific Menzerna polishes are you using? And what are you finishing with? 85RD, 106FA, or something else?
 
You should definitely be able to start with 1000 grit, then 1500 then 2000 and if you want finish with 3000. I would stick with Menzerna polishes, but you may want to try blocking the pain instead of a d.a. It should finish out even flatter.





John
 
JohnKleven said:
You should definitely be able to start with 1000 grit, then 1500 then 2000 and if you want finish with 3000. I would stick with Menzerna polishes, but you may want to try blocking the pain instead of a d.a. It should finish out even flatter.





John
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John, sorry but I don't agree. First there's really no need for the added step of 2000 grit if he's working via DA, going straight from 1500 to 3000 is fine. Second, I don't know where you're getting that blocking by hand will finish out flatter than using a DA -- if anything the DA gives you a more consistent bed of sanding marks with less chance of instilling deeper tracers.
 
Shiny Lil Detlr said:
John, sorry but I don't agree. First there's really no need for the added step of 2000 grit if he's working via DA, going straight from 1500 to 3000 is fine. Second, I don't know where you're getting that blocking by hand will finish out flatter than using a DA -- if anything the DA gives you a more consistent bed of sanding marks with less chance of instilling deeper tracers.
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:xyxthumbs
 
Shiny Lil Detlr said:
John, sorry but I don't agree. First there's really no need for the added step of 2000 grit if he's working via DA, going straight from 1500 to 3000 is fine. Second, I don't know where you're getting that blocking by hand will finish out flatter than using a DA -- if anything the DA gives you a more consistent bed of sanding marks with less chance of instilling deeper tracers.
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:xyxthumbs:xyxthumbs
 
What specific Menzerna polishes are you using? And what are you finishing with? 85RD, 106FA, or something else?
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I have Power Gloss, SIP, and 106FA. I think I may get some PO85RD to try out as well. I read a lot of good things about it and I believe it should get me a little more gloss than the 106FA.



I too have heard some good things about Norton's Liquid Ice system and know a few painters who recommend it, but depending on how fresh the paint is when you're buffing it I wouldn't recommend using a DA. And, to be honest, I question if the Norton system (I've never used it personally, but based on what I've seen) will really give you better results than the Menzerna you're already using.
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I was going to DA with the sanding discs, and buff with rotary, only gonna use DA to finish buffing if I need to. Also, I was talking about the Dry Ice sanding discs, not the liquid ice compound.





I see what John is saying and I have to say it makes a lot of sense to me. When I spray a car some spots have more orange peel than others. If I use a block and wetsand by hand until all the orange peel is out I should have a level coat of clear over the whole car. Then I could get after it with the 1500 on the DA and remove the sanding marks and any tracers created while blocking. When starting with the DA to remove orange peel I think I often create an uneven surface. Although all the orange peel is out there are very subtle waves in the clear, and that's what I want to avoid.
 
Nope. A d.a. Is NOT as flat as blocking, especially if you're using an intermediate pad onyour d.a. I do probably 10+ full car sands per year, some I do dry with d.a. Som

wet with a block. The D.A. Cuts the time dramatically, but will never finish as flat. You won't find a d.a. Being used on big money hot rods.



I like to go from 1500-2000 as it makes for an easier polish in my opinion.





John
 
transamfan said:
So you're saying no DA at all huh? That would take some time for sure.
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John is welcome to his opinion of course, but to be honest I've talked to a few darn good painters and while they do use hand sanding techniques for certain jobs, they do the majority of their work via DA.



I guess if you can find the combination of techniques that works best for you (maybe 1000 grit by hand, then 1500 and 3000 via DA) that's what is most important.



All that said, while I do not have any experience with the Norton Dry Ice abrasives you mentioned, I will say that I use Meguiar's Unigrit abrasives pretty much exclusively (3M Imperial Wetordry if I run out in the middle of a job in a pinch, but that's rare) and I've always been happy with the results.
 
I'm not saying no DA. I'm saying a DA is not as flat as a block. I use a DA regularly, actually I used one today. There is a reason why people long block bodywork before paint, which takes much more time, but looks way better than a DA. The same applies before the paint is applied, and after.
 
JohnKleven said:
I'm not saying no DA. I'm saying a DA is not as flat as a block. I use a DA regularly, actually I used one today. There is a reason why people long block bodywork before paint, which takes much more time, but looks way better than a DA. The same applies before the paint is applied, and after.
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That's 2 totally different applications all together. Bodywork, because you're using MUCH coarser abrasives, requires blocking to ensure the appearance of perfect flatness. Sanding the clear that goes on top with a MUCH finer abrasive does not. The key to doing full wet sands above and beyond applying additional coats of clear(on bccc) is the initial removal of heavy media which can quickly and effectively be done with a DA. After that you're basically refining your scratches. The more refinement your choose to do, the less need is required for heavy compounding.
 
David Fermani said:
That's 2 totally different applications all together. Bodywork, because you're using MUCH coarser abrasives, requires blocking to ensure the appearance of perfect flatness. Sanding the clear that goes on top with a MUCH finer abrasive does not.
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I agree with you David to a point, as your statement is true. However, why not finish the CC to the same level as the bodywork, meaning to shear the orange peel off. This will eliminate any waviness in the paint, that can come from DA sanding. I may be overanalyzing this, but for someone like myself, who is very passionate about creating a perfect finish, I'm talking about 5%. Blocking takes more time, and both methods can and will provide incredible results, but I think blocking gives you that extra 5%.
 
Again, flat body work is on a totally different level than the flat outer surface. Mainly because your base(primer) is finished in much coarser abrasives. Especially seeing that clear coat is typically the thickness of a single sheet of paper. External waviness comes from incorrect removal of the surface (i.e. orange peel). As long as that has been done, I really don't believe anyone's eye can pick up a variance measured in single digit microns. It goes beyond passion at that point. In most extreme cases, to create a "perfect" finish, besides removal of orange peel, the base requires extensive blocking in between coats too. Now that's a noticeable difference.
 
I think I've decided to go ahead and start with 1000 on a block to get all the orange peel out and use the DA from there to refine the scratches. I know that in the past I have had ripples in panels that looked flat before the cutting and buffing were done, and I've always felt that they were do to an uneven clear coat surface created from the DA. I'm gonna give the block a try and see how it works out. I think we can all agree that after using 1000 grit on a block to remove the orange peel I will have a uniformly flat surface of clear coat to polish up.



Another thing that has not been mentioned yet in the discussion is urethane wave. This is something that us painters have to be aware of in addition to orange peel when layering clear on heavy for custom jobs and show cars. This is why a lot of times painters will spray 3-4 coats of clear, block it down with 400-600 grit, and then spray a final flow coat. I suppose that if you were to put the clear on too heavy in the flow coat you could end up with some wave as well which would require sanding with a block to get it out. I really doubt a DA would flatten urethane wave.





One of my questions that still hasn't been addressed really is this...When compounding and polishing until all defects are removed from the paint, is it possible for the final appearance to be different if a different set of products were used? Is the final appearance dependent only on a perfectly flat, smooth, and defect free clear coat, no matter if I got there using Menzerna, Meguiars, or any other compounds/polishes? Since I use the same clear on every job I do I am looking to find the magic formula for cutting and buffing that I know will produce the best results every time. Unlike in the detailing world, once I figure out what works best on my clear I will be able to use the same process every time.
 
David Fermani said:
Again, flat body work is on a totally different level than the flat outer surface. Mainly because your base(primer) is finished in much coarser abrasives. Especially seeing that clear coat is typically the thickness of a single sheet of paper. External waviness comes from incorrect removal of the surface (i.e. orange peel). As long as that has been done, I really don't believe anyone's eye can pick up a variance measured in single digit microns. It goes beyond passion at that point. In most extreme cases, to create a "perfect" finish, besides removal of orange peel, the base requires extensive blocking in between coats too. Now that's a noticeable difference.
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:werd: to the :nerd:



:D
 
transamfan said:
One of my questions that still hasn't been addressed really is this...When compounding and polishing until all defects are removed from the paint, is it possible for the final appearance to be different if a different set of products were used? Is the final appearance dependent only on a perfectly flat, smooth, and defect free clear coat, no matter if I got there using Menzerna, Meguiars, or any other compounds/polishes?
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In a word, yes. It really depends on how your particular paint reacts when worked with the abrasive set in a given polish or line of polishes. The best thing you can do is give some other finishing methods a try (as mentioned before 85RD should finish down better than 106FA because it's a finer grade polish, or you could give M105/M205 a shot, or 3M PI3000 to finish with Ultrafina SE, etc.).



The "jeweling" effect from different techniques and different pads/polishes can most certainly make a difference in the final appearance and in large part it's the pad/polish/speed/pressure coupled with whatever meshes with your particular environmental conditions and buffing style.



Since I use the same clear on every job I do I am looking to find the magic formula for cutting and buffing that I know will produce the best results every time. Unlike in the detailing world, once I figure out what works best on my clear I will be able to use the same process every time.
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The only thing I would say to that is to keep in mind you'll want to account for any variances in the application and curing environment.



If you have a booth that is perfectly controlled for temperature, humidity, airflow, etc. and always shoot under the exact same conditions, you're right that the paint should react the same every time. However if you're shooting in conditions where one of those variables changes, the paint could cure differently and thus react uniquely as compared to a previous spray-out.
 
That's what I thought. The last car I did was black and it came out nice after polishing but I felt it could look better. I'm gonna get some 85RD and give that a try and I suppose I'll just spend a lot of time doing some comparisons on this next one.



When it comes to variations in painting conditions, they're all over the place. It's nearly impossible to spray in the same conditions no matter what you do. While I'm sure it will make a difference, I think the differences in how the clear finishes out would be minimal compared to the differences you guys deal with when working on all the different cured factory paints.
 
David, in my opinion you covered one of the "keys" to obtaining the correct finish.

One thing in these discussions that should be mentioned is "what manufacturers clear is used and which one of them".

Many clears out there and each has it's own quirks.

Another thing is "how long was the clear allowed to air cure", since the ones referred to and used by folks here require air and time for crosslinking.

One other variable is if the clear requires a catalist and was the correct percentage added.

When I hear the term "soft clear" regarding refinish material clearcoats, and do some investigation, find one or both of these items to be the reason for the softness.

In most cases when one attempt to wetsand and buff "soft clears" there may be some "movement" of the substrate resulting in "waviness".

Just a thought or two.
 
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