Painting headstock and finishing Korina neck

[nickyp]

Hey all. I searched but wasn't able to find any discussion on this topic.  I'm putting together my first parts-caster, and am planning on finishing the Korina neck myself.  I'm hoping someone with experience can help me understand how to approach this.

First, I was thinking of creating stencils and spraying some paint on the headstock for a little bit of custom art to make it interesting.  Has anyone attempted this?  Is it necessary to use a grain filler, primer, or anything else for the paint to stick and look good? 

Same for finishing the rest of the neck, would a grain filler be needed?  I was thinking about doing either a nitro satin or a nitro gloss and sand the back of the neck to a satin finish.  Does anyone have any recommendations for a product to use, number of coats, or a defined process for finishing this type of neck?

Many thanks!!!

 

[nickyp]

Alright so I did some more research and spoke to a tech at Warmoth.  He mentioned the stewmac clear grain filler as a good option.  From what I've read this will require several coats for a wood like Korina.  I've also seen that you can use many coats of nitro as a grain filler, but supposedly this will shrink over time?  In any case...I'll try the clear grain filler and clear gloss nitro finish and let you guys know how it turns out.

As far as the design on the headstock, I guess I'll just use some spray paint in between coats of Nitro  :dontknow:

I found this helpful guide on Stewmac.  https://www.stewmac.com/How-To/Online_Resources/Learn_About_Instrument_Finishing_and_Finish_Repair/Nitrocellulose_Finishing_Schedule.html

 

[Cagey]

Alright sI've also seen that you can use many coats of nitro as a grain filler, but supposedly this will shrink over time?  In any case...I'll try the clear grain filler and clear gloss nitro finish and let you guys know how it turns out.

Any finish material, nitro included, will eventually fill the grain if you keep sanding it back and reapplying fresh coats. But, the number of coats needed is usually high, and the cost gets out of hand as you're essentially shooting a complete coat, sanding it off, then shooting it again over and over until the voids are filled. You can turn a helluva lotta lacquer into dust doing that, which isn't helpful.

For woods that have fairly fine grains that don't need a lot of filling, there's such a thing as "sanding sealer", which is essentially a compatible version of your end finish but of a higher viscosity. Doesn't work for more open grained woods like Swamp Ash, Mahogany, Korina, etc. for the reason cited above.

Grain filler is the thing to use. It's fast and easy and relatively inexpensive. Even on deeply grained woods like Mahogany you rarely need more than three coats.

Lacquer will shrink, and it often won't be obvious at first. But, 6 months down the road you'll start seeing imperfections show up and wonder what you did to deserve such a thing. So, patience is key. Your finish will only be as good as your substrate, so spend the time to get that right.

 

[nickyp]

Alright sI've also seen that you can use many coats of nitro as a grain filler, but supposedly this will shrink over time?  In any case...I'll try the clear grain filler and clear gloss nitro finish and let you guys know how it turns out.

Any finish material, nitro included, will eventually fill the grain if you keep sanding it back and reapplying fresh coats. But, the number of coats needed is usually high, and the cost gets out of hand as you're essentially shooting a complete coat, sanding it off, then shooting it again over and over until the voids are filled. You can turn a helluva lotta lacquer into dust doing that, which isn't helpful.

For woods that have fairly fine grains that don't need a lot of filling, there's such a thing as "sanding sealer", which is essentially a compatible version of your end finish but of a higher viscosity. Doesn't work for more open grained woods like Swamp Ash, Mahogany, Korina, etc. for the reason cited above.

Grain filler is the thing to use. It's fast and easy and relatively inexpensive. Even on deeply grained woods like Mahogany you rarely need more than three coats.

Lacquer will shrink, and it often won't be obvious at first. But, 6 months down the road you'll start seeing imperfections show up and wonder what you did to deserve such a thing. So, patience is key. Your finish will only be as good as your substrate, so spend the time to get that right.

Thanks for the feedback Cagey. Sorry I didn't reply earlier, I was busy obsessing over building this guitar  :blob7:  I did follow your advice and use the clear grain filler from stew mac.  I found this to be pretty difficult to work with and didn't come out great, and ended up not filling the grain completely which I wasn't too upset about because it's just the neck and i'm going for a satin finish anyway. 

However, after 7 coats of lacquer and letting it cure for a few weeks, trying to level the finish and give it a satin feel...i think i sanded through to bare wood.  I was surprised because this was some pretty light sanding with 1200 grain sand paper, not for long at all.  I guess the shape of the neck put too much pressure in some spots and it sanded through.

I think I'm going to try starting over with a wipe on satin poly.  I suppose I'll need to sand the whole thing back to bare wood and start from scratch.  If anyone has any tips for this I'm all ears!


The headstock came out pretty good, i ended up using a few coats of spray shellac to fill the gran and make a barrier coat, then sprayed a couple coats of black lacquer over a stencil i make to add a little something extra.  A couple more coats of shellac on top and polished it to a pretty decent gloss. 

 

[nickyp]

Here's a pic of the "finished" guitar.  In fact the finish itself on the neck did not work out so well, so i will be taking it off and trying again.  Love the guitar as a whole though, and Warmoth did an awesome job finishing the body.

 

[Cagey]

I can imagine grain filling on a neck being a pain in the shorts. No flat spots to speak of. I don't know what Warmoth uses, but I don't think it's the traditional stuff us regular folks use - it's some sort of polyester base material that they probably spray on. Otherwise, the neck woods that need filling would probably cost a lot more than they do.

Lacquer is super-easy easy to strip. All you need is a cheap can of acetone (lacquer thinner) rather than the hyper-toxic stuff you need for polyurethane. Wipe it on (generously), or better yet, soak a rag with it and lay it on the finish. It dissolves the lacquer, and you wipe it off. Might take a couple passes to get it clean. Do that, and you won't have to worry about finish incompatibilities.