What grits to use for final finishing?


Junior Member
I have finished spraying a headstock with nitro. The surface isn't perfect because I didn't sand inbetween coats. There isn't a lot of orange peel but there is build up at the machine hole area and along the edge. What grit should I start with? Is 400 right or would 600 be best?

If you've got orange peel/build up try using a #320 3M sanding sponge first, you'd be sanding forever with anything finer. If you have both some orange peel AND build up, don't be surprised if you need to shoot some more lacquer after getting that all sanded back down even. How many weeks has it cured?
If you want a glass like surface you'll need sand enough to cut down through all that orange peel to form a level surface from the lowest point.  Starting with 400 (or as mentioned 320) is probably where you need to be - you absolutely should use some sort of backing or sanding block.

A note of warning though, depending on how bad that orange peel is you may be at risk of cutting through to the wood, and again as mentioned, you may need to shoot additional coats in order to have a decent final finish thickness.

Once you have wet sanded the surface level and to an even matte appearance only then do you begin moving up in grit.  The idea is to use the next higher grit only as long as necessary to eliminate the deep scratches of the prior grit, then you move on up the schedule.  I start at 600 then 800, 1000, and 1500.  Beyond that I use polishing compound on a buffing wheel.

Sanding between coats is not always required, but as soon as you start seeing orange peel it is best to start sanding in order to reduce or eliminate the problem.  Wait too long and your workload just grows.
Depending on the weather it needs at least 3 weeks of cure time.  I waited that long in November for my guitar body and it turned out to be soft.  Should have waited longer.  Now I have to wait for the weather to get better before I try again.  I bring this up because of the time of year and I know the feeling of being almost there.  I have to do something, Right?  Nope, wrong answer.  Another nice thing is Nitro lacquer will shrink and pull a lot of the imperfections out with time.  If you do get antsy to move forward on the guitar, wait for it to harden properly, then build it and come back and finalize the finish in 2-3 months.  That is what I would recommend.

Thank you guys. After curing for 2 weeks I went from 400, 600, 800, 1000 with block. This was done on the flat front headstock only. Unfortunately I have some small chips around the edge in about 3 places. Bums me out. I shouldv'e done the whole headstock or maybe used oil.

But all in all it looks OK. Thanks for your help.