Official Luthiers Forum!

I apologize in advance for what is a very basic question but I am building what is just my second guitar so my experience is VERY limited. My first guitar I had finished by a professional wood finisher and I was very dissapointed in the results. So I figure I will do this one myself.
I have sparyed 6 thin coats of Lacquer and am ready to sand the surface level before spraying another 6 coats.
What grit of paper should I use?
What I have been using on custom inlay pickguards is 400 grit and that has worked quite well. Is that grit OK for the guitar?
thanks for your patience...

Hello Bill -
What type of lacqure are you using?
My experience is limited to the KTM4a and KTM9.
For both I used Mike Doolins Finishing Schedule found here

Hope this helps -
For more finishing tips and information, dont forget to check out the OLF Online Resources Page

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Lance@LuthiersForum.com

I am using Nitro Lacquer..
Thanks for pointing me in the right direction.

HI Bill,
This is a not so basic question and is a good one. One thing that will help is to always get a data sheet on the product you are using. It will contain important information such as dry time and recoat time and if sanding is required between coats etc. Many times this is even written on the side of the can. For the product I use, a catalyzed urethane, I can get away with sanding with 180 grit between coats. Since it is a high solids product the next coat hides any scratch marks. Since lacquer has a longer cure time you need to use the grit that allows you to sand without gumming up the paper. This means sometimes going down to 220 or even lower. The amount of sanding you want to do will also determine what grit you should use. For example, if you just want to lightly scuff sand you can get away with using a higher but if you want to completely level the surface you may have to use a lower grit.
Hope this is helpful.

Bill, I use a 400p 3M gold paper between coats with nitro lacquer and the next coat melts out the sanding marks quite well. I think the 400p is about the equivalent to a 220 or so in CAMI grade.

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Dave Rector
Rector Guitars

Thanks for the help...I am using the 400 paper.
It already looks better than the first guitar...let's hope I don't mess it up:)

    Nitro finishing is more a process than a procedure. Here is my finishing sequence
Seal coat ( schellac or vinyl sealer )
fill ( I use a mineral base pore o paq )
           to this I will ad stain dark walnut
   On Mahogany I will stain before sealing but still use a colored filler

seal again

1st day
   1 coat of lacquer every hour for 6-8 hours. I want about .012 build. I use a business card wedged in the soundhole. This can me referenced before starting and check as you go

   Let set 2 weeks and drop fill then level sand.

Level sanding I will start at 420 never without a block.
    I will work up to 1500   I am looking for sand through and any imperfections. Once I am happy I will spray 2-3 finish coats
    again let set 2-3 weeks, then wet sand starting 600 working to 2000 then the buffing and polishing strart.
i use 3M products perfect it finesse it and hand glaze
   I will spend alot of time as this is what make the guitar look good.

    Once you find your technique that work for you be careful of any changes. This is one of the hardest things to learn

john

thanks for the info!!! I really appreciate the help.
What type of sanding blocks are you using?
I looked at my blocks, which are a heavy rubber material, and can see that they are no longer flat.

[QUOTE=Bill N] thanks for the info!!! I really appreciate the help.
What type of sanding blocks are you using?
I looked at my blocks, which are a heavy rubber material, and can see that they are no longer flat.[/QUOTE]

For between coat and final leveling I use 2" x 4" 3M hard rubber sanding blocks. You can find them at most auto parts stores. I take 3 of them and laminate togather becasue they are pretty thin. you can use almost any flat bottom block.

I went to my local hardware store and found the 3M Sandblaster Gold sanding sponge block. I could not find any in 400 grit but they did have 320. They worked amazingly well.