prep sanding for Metllaics

[86chevyk20]

Im painting my k20 sunday and saturday im spending the day preping. Is 400 gritt ok to do final sanding with before base for metellics or should i use 600. I dont plan on wet sanding the primer because im not building a show truck

thanks Liam

 

[HotRodPC]

I wouldn't know Liam. Not a body and paint guy myself, but if you could, take some before, during and after prep pics for us too. Kinda be nice to see your progress. Keep us updated on the process.

 

[Swims350]

how are you going to paint if you don't wetsand the primer?

I'm lost.

If you wetsand the truck before you prime, use 400 nothing finer.

once you prime, you should use 600 before any metallic, solid color 400 is fine.

Now if you mean sealer, then yes most of the time you shoot base right over that while it's wet or what not. In this case I would think 400 is fine. The sealer would be going down first.

The thing is the metallics can sink down or show the 400 scratches and such, where as if something else is laid down first like sealer it would fill those first and then the metallics won't show up anything. IF you use 600 on the final sand before you apply base then it won't have the chance of showing the scratches or blotches etc.

 

[86chevyk20]

you dont have to wetsand the primer right?? and ok im gona use my blocks and 600 gritt.

 

[bucket]

Here's how we do it, and have done it for years. Dry sand the primer with 400, then simply paint it. It's quick, easy, provides a show-quality finish, and it's durable. If you final sand with a finer grit, it's too easy for paint chips to occur later on. The key is to use a QUALITY primer and a QUALITY sand paper (notice I didn't say "name brand"). Inferior primers will shrink and show sanding scratches, inferior sand paper can cause an inconsistent finish, also causing sanding scratches.

Also, not all metallic finishes show sanding scratches. It's the lighter ones like gold and silver that you need to be careful with.

 

[Swims350]

I wetsand anything before paint, it just helps to keep the paper from clogging up and when you do so you add in some dish soap that helps clean the surfaces too, as well as lube the paper.

600 grit is fine to sand with before PAINT, primer doesn't like to stick to much finer then 400.

 

[bucket]

Yeah, we tried 600 grit for a little while and the paint chips too easy for something that sees a lot of time on the road, especially the roads around here. Cheap primer clogs up cheap sandpaper, we have no trouble with dry sanding the primer

 

[Swims350]

do what you want.

I've never seen 400 be less prone to flakes or chips. I've sanded with both, had the same results, good paint adhesion and no sand scratches showing.

I ONLY use 3m or norton paper.

I've not had primer or what not clog paper but for me it's good practice to wet sand.

I know for sure the paper lasts longer that way, you can tell that by feel.

It's just wet and messy.


You can do what ya like tho, sand it with 80 then paint it I don't care, but if you bring it to me and have me paint it, that's how I do it.

 

[bucket]

I'm not trying to knock what you do, just trying to give a couple pointers. As I said before, quality materials is the key. And 3M sandpaper isn't what it used to be either. I don't know how much you have done in the past and I'm also not trying to say you are inexperienced, but I do know that I have done A LOT of bodywork, priming, and paint prep.

Also, this car was actually final sanded with 320 grit. Not a single sanding scratch anywhere to be found.
(click for the biiiiig version)

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[Swims350]

eh just like I said do what you want. Or I should say the Op can do what they want.

I like sticking to what I do. I normally don't use a sealer or final primer, I usually go right into paint after body work. Several I've done in a final prime, all over, but I always go with 400 or 600. I have done more 400's then I have 600's and was planning to do 600 on my truck only because of the metalics.

Like I said most is just general rules of thumb.

I've done my fair share of body work, paint and such, ever since I was 16 or so, it's been about 10-12 years now I guess and my old man has been at it for way more then me.

I just look at it as personal prefference.

you talk to any body man or painter, some are set in their ways and won't change, some will, some do only single stage and swear by it, sme say 2 stage or more. I see it alot and see it on everything, prep, sand, body work, paint etc.

 

[HotRodPC]

Sand it with 80 and paint it??? I just rough up the primer real good with steel wool and the paint sticks real good after that. WTF, dont' be saying **** like that. Someone not knowing any better just might do it.

 

[Swims350]

LOL no doubt.

I bet it won't flake off then. it'll just look rough and scratched.