--Polishing paint by hand, some info?--

7

79 Bird of Prey

New member
Hey, this is my first thread on the board, seems like a nice place. I have read most of the articles (although since the server is down i can't go back to them for reference). I work on and build classic cars. im still new, but have a good teacher. i currently own a 79 Trans Am Gold SE which is in the process of being built into a race car. In any case, i have a question about polishing a cars paint.



When painting, wet sanding is usually done to achiece a nice even paint, however one can see the marks (scratches) in the paint from the sand paper.



My question is, can you polish a car by hand to remove these scratches from wet sanding? i ask by hand because i am afraid of using a machine on delicate paint, for fear of swirl marks and other imperfections. if one can do it by hand, what is to be expected? how long would it take? how much work and how severe of a scratch can be removed by hand?



thanks!
 
:welcome to Autopia 79 Bird of Prey!



A ’79 TA :woot: , man I had some good times in one of those. A college buddy had one and we covered a lot of countryside, scrubbed off a lot of tire tread (somehow managed to stay alive) and just plain had gobs of fun.



Power buffing is standard procedure on high quality finishes.



Polishing paint is no different from carving wood, chiseling stone or grading a building site. You start with the heaviest cutting tools to get the surface close then use progressively finer tools to get it precise and smooth out the imperfections left by the previous tool. If you skip a step the imperfections left by the previous tool won’t be removed and the result will be unsatisfactory.



I guess you can cut a football field out of a hillside with a rake but I wouldn’t recommend it.



Similarly, it is theoretically possible to sand, cut and buff by hand but nobody does it because:



a) it’s a ridiculous amount of work.



and,



b) you’ll never be able to do it as consistently or as well as with a machine.



There's no more reason to be “afraid� of a power buffer than of a table saw. Both can do a lot of damage when used wrong. Both will give excellent results when used with skill.



There's a lot of information here about power buffing. I’m sure if you spend some time reading you’ll get comfortable with the concept.

:buffing:





PC.
 
LMAO at the smiley. thanks a lot for the info. would you be able to give a reference as to how abrasive of a polish would be needed after wet sanding for different grit sand papers?



as in, how bad of a scratch does the fine sand paper used in wet sanding produce? obviously, its nothing you can feel by hand so its not deep, but you certainly see it!
 
After wetsanding you will need the most aggresive, then graduate down to a medium, then a finishing compound. Not much you can do about it. Paint is a very sensitive thing, even washing with a sponge can cause swirls that finishing compounds can barely get out, so imagine the marring sanding causes. Forget about doing it by hand, I would pay a pro a couple hundred before I did that if I was you. As for scratch removal, unfortuneatly I don't know too many people that can fix a scratch that goes to primer w/o noticing the repair. My question is if it's a true race car why worry about it, you will end up with damage at least every other race yeah?

http://autopia.org/forums/showthread.php?s=&threadid=36208&highlight=abrasive+list
 
Each compound manufacturer will have specific recommendations for what product sequence to use but by and large most expect you to compound after wetsanding with 1200 or 1500 grit paper. Going finer with the paper will make buffing easier. You trade off more hand sanding time for less buffing.



I you’re planning on hand sanding I would highly recommend using Meguiar’s papers. They cost a little more but they’ll pay you back big-time by making the compounding stage easier and faster.





PC.
 
Basically you're looking at the full line of polishes, after sanding. For most brands, you will need to step down 3 times (rough compound, mild compound, finishing polish). For my favorite brand, Mezerna, you might be able to get away with Powergloss -> PO85RD if going via rotary. This'll leave a great looking shine, and the chance of doing paint damage, in the hands of an experienced pro, are close to zero.



In the wrong hands, however, serious damage can result. If you post your location, there might be a board member near you who can help you out.
 
im in Freehold, New Jersey. i haven't gone through my profile too much. i would not like to learn how to polish using a machine on my first paint job, yea i would rather have a pro do it.



its a drag car, btw, so i wont be rubbing up against other people. the main damage will be on the lower rear quarters from dirt, rocks, and burnt rubber scratching the paint. but the rest of the car should be fine.
 
79 Bird of Prey- Welcome to Autopia. Cool car, my first new car was a '77 T/A.



The wetsanding is a *LOT* riskier than doing your polishing with a PC or a Cyclo. Wetsanding is like performing surgery, machine polishing is like using an electric toothbrush instead of a regular one. But if you want to do it by hand it can be done if you have the time and patience (though it will depend on your paint too, hard paint is gonna be, well, hard).



If you do your final sanding with 2,500 or 3,000 grit you can *usually* polish out the sanding scratches with 3M PI-III RC (pn 05933), but you'll have to follow the 05933 with their PI-III MG (pn 05937). Been there and done it (by hand), so it oughta work for you too. But I'd spend the money for a PC/Cyclo to make it *THAT* much easier.



And as the Other PC said, use the Meg's Uni-Grit paper. It really does make a difference ;)
 
wow, thanks for all the information. i didn't realize wet sanding would leave such deep cuts that a rough compound would be needed.



on a side note, the car will be painted Solar Gold. i love the original paint on this car, but how much better will it look with a carnauba (sp) and synthetic wax job (like in the Perfect Shine)? will it shine up like a similar yellow?
 
Hard to say how it'll look, there are just *so* many variables...the paintjob itself, the prep like wetsanding/polishing (99.9% of it is prep), and then the Last Step Product will contribute that last 0.1%.



Most of the differences between LSPs are pretty subtle, but everyone has their favorites. I'd use an old-school approach on that car just because I had one back in the day...but you might like something completely different.
 
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