Problem With Clear Coat Polishing ,, Question

[sbskates]

I have put a clear coat on a dyed body and it is a dark dye cherry color so all the imperfections are showing. i let my lacquer cure for a few weeks after the final coat , usual process of several thincoats over long time etc. i wet sanded from 600 - 3000 grit. but you can still see my snading it didnt buff out. i have a buffer made for this and a felt buffer. any thoughts ? maybe i just need to wet sand more. havent had this happen before.

[Southpa]

all the imperfections are showing

You trying to hide imperfections with clear lacquer ? Lacquer will only amplify scratches and any other "imperfections" in the wood, dye/stain job etc. Ya gotta get it right from the beginning, and keep it right ...or else. It also depends on your own "thats good enuf" level of perfection. So if the imperfections are UNDER the clear lacquer and you can't live with it, then you have to strip it back down and redo. If your problems are within the lacquer then you have to address the gradation of grits you are using. Obviously they won't polish out and you could be there for a long time.

You mention 600 to 3000 grit but we don't know whats in between.

Also your own methods and level of "thoroughness" should be questioned. Wetsanding can be a real chore in itself. What really takes most of the time is assessment between sanding grits. I always have plenty of paper towels handy and am constantly checking the finish. If you don't spend the time its easy to miss something. And you usually don't notice it until its too late. If the scratches are buried then you have to get down to that layer or level of coarseness and sand it out. Yes, you run the risk of tapping into your dye job and really putting it into the crapper.

Edited March 28, 2009 by Southpa

[erikbojerik]

You have to start with excellent finish sanding right at the beginning - any scratches that are visible in the wood won't be fixed by clear coat.

With wet sanding, the purpose of the next-finer grit level is to remove the scratches from the previous grit. The bigger the steps you take (like - say from 600 straight to 3000) the longer you will have to spend on each one. Small steps are preferred. A light touch is preferred (don't dig in).

It is extremely important to thoroughly clean the piece well in between grits, to completely remove any residual grit (screw holes, routs, etc) before moving on to the next grit. If you're dipping sandpaper, change the water between grits too so you don't cross-contaminate different grit sizes. If you have a few chips of 600 rolling around with your 3000, you'll make new 600 scratches that more wet sanding will never get rid of.

Also don't contaminate your buffer with different grades of polishing paste - one buffer for each (I have 2 StewMac foam pads, one for 3M fine cut and one for Meguiars swirl remover).

Wet sanding & buffing quality is directly related to how much time and fussiness you put into it.

[Foggy]

Absolutely sound and excellent advice from both erikbojerik and Southpa. The only way to get a near perfect finish is to keep every stage from the first basic stage through to the last buffing stages as perfect as you can possibly do it.

Any shortcuts taken, no matter how insignificant they may seem at the time during guitar finishing will almost inevitably come back to bite ya later.

Absolute thoroughness is 'THE' name of the game.

Jim

Edited March 29, 2009 by Foggy