Problem After Sanding Down Touch-up Paint

Almost forgot, would it be a safer route for a newbie to use 3000 grit wet sandpaper ? It'd take longer but might be safer, but again im far from being the expert here.......i'll let you be the judge of that Guitarman.



Thx:bow
 
When wet sanding a chip(previously filled with match paint), should i tape around it, to only let the built-up chip exposed ? Cause if i use a regular sanding bock, i will freak out seeing how large an area i sanded :scared
 
We owe you our gratitude, Guitarman! :bow :bow



I would like to thank you for your insight into my dilemna :xyxthumbs .



If I may, I'd like to ask a couple more questions. Have you ever tried any of the Langka type products and, if so, what was your opinion? Not trying to start a big discussion or a debate, just curious because I have not tried them and consider your opinion valuable.



Thank You VERY Much! :up
 
Again guys, happy to assist...



slvrshadow. I personally haven't tried the Langka myself, I do it the "old school" way of building up and sanding. But I know that topic has been largely posted here, so i'm sure you can dig up some valid opinions.



Chip, yes, that's a good photo of just how to wrap the sandpaper, because indeed he has it folded over the edges (hard to see but I can tell) and wrapped over top too. That's a bit different type pad/block than the one I use but it's the same approach no matter.



Chip, I wouldn't tape around the spot you're touching up. The whole object is to blend the spot into the surrounding area, and taping will not lead to that end.





Also, what can happen if you take a lot of paint off the spot you're sanding is- the taped off area will be built up and untouched, and you'll again see a 'waver' or indentation in the paint from the depth difference, or dichotomy between the spot and surrounding/taped area. Strongly advise against it. You can tape off ridges and door creases/edges when doing whole panels(to avoid cutting through since those areas are thinner), but I always recommend you remove the tape when near done and make a light pass or 2 over it to blend the sanded area in with it. You just don't want a huge level difference defined by a line. Make sense?





Yes, you WILL probably freak after you've sanded the area down and dried it, that's a given for a neophyte, but trust me- after you've hit the area with your first pass of rubbing compound, you'll be breathing easier, and be stoked at the results. It works every time.



As mentioned in my article, you might have to compound 2x, polish 2x in succession to get good shine/clarity, especially by hand. I always use a rotary now for the compounding and polishing phases, but in the past a friend and I did EVERYTHING by hand on a couple show trucks I painted, from wetsanding to final polishing, and the trucks looked amazing. It CAN be done by hand alone, so don't let that scare you.



When I spoke about 5-6 passes, that's a general rule, and there are variables of course-the make of car (Chryslers I have noted are seemingly thinner than Fords as far as clearcoat) and the type of block and the pressure you apply also come into play, but I will stand pat on what I said as a guide. Once you make 2-3 passes, dry the area. You will see what you have done and how much orange peel you've taken off. Remember, orange peel looks like small dark dots against a sanded panel, because you are seeing the depressions via that shadeing difference.



SURE, you can use 3000 grit, it will give you better control over what you're cutting at first. I think that's a good idea if you're apprehensive.



Use X strokes over the touch up, yes. You'll get a flatter , more even result.



You just have to trust the science.
 
Holy jesus in heaven !! you got all my gratitude for such a thoroughly explained procedure......i cant shake your hand,but i would if down there with you...........thanks VERY much guitarman, your help is MUCH appreciated for sure ! :bow



:wavey
 
This has been a great thread. I was really hoping something like this would be written because I am getting ready to work on some rock chips as well. Thanks to everyone involved. Truly what Autopia is all about!
 
One thing for all you guys to bear in mind when starting out;



Err on the side of caution if you wish, you can always stop after a few passes, compound the area, polish the area etc. and see what you've got. If you feel you need to take off some more, go ahead and wetsand again and repeat the process. Better to go through the process multiple times than to take more paint off than you want initially. It takes some experience to know what the right amount is, and that of course will vary per circumstance, be it a scratch you're sanding, a touch up, orange peel etc. They will all require a different amount of sanding.





Cheers.
 
I agree with Aurora! Touching up paint and wet-sanding is a DELICATE task. It's far too easy to screw things up if you're not experienced at it. This thread should serve as a reminder and a guideline for anyone who wishes to attempt this type of work for the first time.



"HALL OF FAME" :xyxthumbs
 
When I encounter a depression/indent, how do I know whether my clearcoat is not levelled properly or the metal is dented?
 
Just wanted to chime in with my appreciation for everyone, specially you guitarman, who can take the time to help out all of us 'newbies'.
 
Guitarman is a Saint over on our Thunderbird board.

He is always most helpful and professional and I've met him a few times and he's just as nice in person as he is in these forums.



Great guy and he knows what he's doing.

We need him here.
 
Good information here. I hope it works on a major project that I have to do.

My wife's new Rav4 was keyed three times in the last month. It's dark metallic blue :shocked



Three deep scratches down the driver's side, spanning both doors and both fenders.



She's not parking by the mailboxes anymore.
 
I have tried this in the past (years ago) and have found that if you try to sand the area you get a thin ring around the chip. I am wondering why you would not just use langka to knock the blob down then lightly hit the area with 2000 or 3000 grit if needed , polish and be done?
 
agentf said:
I have tried this in the past (years ago) and have found that if you try to sand the area you get a thin ring around the chip. I am wondering why you would not just use langka to knock the blob down then lightly hit the area with 2000 or 3000 grit if needed , polish and be done?



I know now from experience that it's near impossible to make a perfect chip repair on light colored (especially metallic) paint. That "thin ring" is the reason this thread was started in the first place. It occurs when you've accidently lowered the clear around your chip too far. It's actually very easy to do when you're inexperienced with wet-sanding. It can also occur from using Langka if you apply too much pressure for too long a time. Langka does have abrasives!!!! Yes, it can scratch/mar the clearcoat!!! Langka requires alot of finesse to achieve that "perfect leveling" of the blob left behind. If you use Langka too soon, you will almost inevitably remove too much touch-up paint from your chip. If you wait too long to use Langka, it will require much more effort to level that blob and possibly lead to marring the surrounding area and again removing too much paint from the chip. If you're able to time the curing of your particular touch-up paint just right, level the blob with Langka to "barely" above the original CLEARCOAT SURFACE, and......wet-sand delicately + briefly enough to level any remaining blob to the original paints level, then you MIGHT have accomplished a paint chip repair to NEAR perfection.

This, of course, is assuming you've practiced until your technique is near-perfect AND after all that work your touch-up paint is an EXACT match to the factory paint!



If you're willing to put the time and effort into it, and if you keep your expectations realistic, you will be "successful". If you're happy with the result, that is all that matters!:xyxthumbs
 
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