Wet sanding front bumper after new paint.

[jsharp]

My painter put an extra layer of clear on the bumper in order to be able to wet sand and buff. I am wondering if I can wet sand it myself and use my pc to clean it up. If so what sand paper grit is needed and is there any vids that can show me the process. I have some raised bumps in it that need to be worked down. Anybody that can help?

[OBSSEST]

There's a Junkman video that shows him wetsanding some scratches off of a car and then finishing it with a Flex polisher.

http://www.adamsforums.com/forums/ju...rner/14893.htm

If you google "wet sanding junkman" there's a whole series of videos on wet sanding as well.

I'd think you could use the same technique on your bumper and then finish with your PC. I haven't done it personally but after seeing these I'd be confident enough to try it out.

[bowtie628]

i paint for a living.. let the paint cure for about 2 weeks then you can wet sand it with 1500 then 2000 grit.. BE CAREFUL! dont sand to hard or sand in one spot for to long! use a spray bottle with warm water and soap! always sand one spot then dry it to check if you worked down the spots you need to work down.. once your happy with your work then you can use a machine polisher and polish, be careful with the machine polisher, if you dont know how to use one you can burn the clear.. again.. BE CAREFUL! you dont wanna sand through the clear to the base coat, if you do that then you have a problem.

[jsharp]

I have a pc so I am thinking since I have done the rest of the car here and there I can handle not burning through with it but worse case scenario I have to repaint it right? I normally paint myself but this time I just didnt want to do it. I paid 150 for the bumper but he got some bumps in it that he says will sand and buff out. If I had painted it I probably would have corrected it befor I finished painting/clearing but that is just me. Thanks everyone!

[bowtie628]

Originally Posted by jsharp

I have a pc so I am thinking since I have done the rest of the car here and there I can handle not burning through with it but worse case scenario I have to repaint it right? I normally paint myself but this time I just didnt want to do it. I paid 150 for the bumper but he got some bumps in it that he says will sand and buff out. If I had painted it I probably would have corrected it befor I finished painting/clearing but that is just me. Thanks everyone!

yea worse case if you mess up your gonna need a re paint.. the bumps are prob dirt in the clear..

[jsharp]

So if there is dirt in the clear will it do any good to sand it down to get rid of them or will it just make the bump less noticable?

[kiteman]

why are you wetsanding? people usually only do that to remove heavy abrasions or orange peel. if you are doing it to remove orange peel, keep in mind your whole car has orange peel. removing it from the bumper is going to look funny if you don't remove it from the whole car. IMO it's definitely not worth wet-sanding for this reason. for the average daily driver, wet-sanding is definitely not worth any reason either unless you need to fix some heavy abrasions.

[Adam's Polishes]

Originally Posted by bowtie628

i paint for a living.. let the paint cure for about 2 weeks then you can wet sand it with 1500 then 2000 grit.. BE CAREFUL! dont sand to hard or sand in one spot for to long! use a spray bottle with warm water and soap! always sand one spot then dry it to check if you worked down the spots you need to work down.. once your happy with your work then you can use a machine polisher and polish, be careful with the machine polisher, if you dont know how to use one you can burn the clear.. again.. BE CAREFUL! you dont wanna sand through the clear to the base coat, if you do that then you have a problem.

Good advice

I'd say sand down as fine as you can go... if you can finish at 2500 or 3000 then it makes polishing out the residual all the easier.

The front bumper is gonna be a real pain to buff out with all the tight spots so the finer you can do it with sanding the easier you're life will be IMO.

Also are you planning on sanding the WHOLE thing or just the problem areas?

[jsharp]

Just the problem areas. Luckily is all on the top flat part of the bumper. I have a couple on the lower but they would not hurt me in a car show or anything. These on top stick out pretty good on black. This is not a factory painted bumper this is my oem zl1 bumper which I had painted and the orange peel does not match the factory orange peel along the fender well. The rest of the paint is smooth on the bumper except for these few bumps which I think if I hit with 3k and polish it will be more to my liking. If not Ill sand and repait as I am a perfectionist like that! lol

[jsharp]

I tried 3k and it helped but didnt correct it perfectly should i try 2500? I did end up wet sand trouble spots then the whole surface to even up but its still not perfect!

[THUMPER20X]

Use a block and 1500, I just did a complete Mercedes SL55 wetsand. I do it for a living but as long as your careful and go up the grit ladder without skipping you shouldnt have a problem. Lighting is everything.

[Junkman2008]

You know, I see this question often on detailing forums and it is very hard to answer this question without sounding like an azz so please don't take it that way.

In my professional opinion, you are the absolute last person who should be wet sanding on your car because of the specific questions you are asking. You have little knowledge on how wet sanding works and the PC is only good for papers down to 2500 grit. Anything below that and you'll be buffing with that machine until your fingers turn blue. Wet sanding as a finishing act is a finesse art and I would NEVER suggest that a novice even remotely think about doing it. Any professional automotive painters that are reading this are probably shaking their heads. The person who sprayed the bumper should have done this. Now that's my professional opinion, and I would shake you vigorously if you were standing next to me. It's not meant to be mean, it's just that I care about your paint although it's not my car. I just don't want to see you mess it up.

Now here's my second answer. There's a technique to sanding clear in order to make it smooth. You will normally start around 1500-2000 grit, checking it OFTEN, until you get it smooth. A PC is NOT going to fix that damage. Once you get the paint smooth, you start undoing that damage with a lesser grit. If you start with 1500, you follow that with 2000, 2500 then 3000 (most body shops stop at 1500 and start buffing on the car, but they are using rotary buffers and some wicked compounds or polishes). After that, you can use a polisher like the Flex to fix all the wet sanding damage. Here's a panel of my car after I have painted it, wet sanded it and am beginning the buffing part.



Here's the bumper completely sanded:



And completely buffed out:



Wet sanding can be used to remove trash and orange peel out of the paint but there is absolutely no way that I can explain how to do that in words. You have to be shown how to do this. If this was your Yugo, I would say go for it. But on your Camaro? I would never suggest you try doing this without proper instruction. You have started with 3000 grit which is like staring at the paint mean so you are probably okay so far. But if you start stepping up the paper, you are going to find yourself going through the clear a lot quicker. Get to 2000 grit and now you need a different polisher so I advise you to be very careful.

Again, I don't want to sound mean but I want to discourage as many novices as possible from thinking that it is as easy as some are making it sound. I've seen people who do this for a living screw up so a novice is really playing with fire. This is just a heads up to anyone giving this a thought.

[jsharp]

Its not mean at all. I dont plan to step down im gonna just hit the areas with 3k to better them. I accomplised alot with it and did my best to keep steady strokes and consistant pressure. Its no big deal to me to repaint it if i have to. He put 3 coats o clear to allow for sanding. But he is one of those guys that lets his cord bounce on the car and buffer gets away from him time to time. I would rather know my car as a whole is protected vs turning him loose on it and causing me more work he is also the type that rubs his fingers on the surface over and over to test smoothness which causes me work with pc. He taught me how to paint and he has gotten lazy over time o i feel like i could repaint if needed and it would most likely turn out better. So i figured why not sand it and if it messes it up just repaint clear since i wouldnt be happy with it like it was.

[jsharp]

And yes i may not be the one that should do it but u have to practice to get good. Everyone starts somewhere and learns from mistakes. Its not like im doing whole car as the clear is thin. Its just a bumper. For wat i paid 100 bucks i could have it done by a big shot shop for 300. Most charge 3-400 anyway so i would still be in the same price out of pocket