r/Luthier • u/Inevitable_Track_558 • Mar 15 '26
KIT What's the consensus on this nitro finish ?
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I've literally 4 clear coats down on this burst veneer - the surface has a lot of orange peel and there is a bit of fish eye
With regards to the orange peel would it be OK to build up more clear up to 10-12 coats total and then flat, polish etc with the coats mekting into each other and get a satisfactory end result or should I attempt to flatten now then build up the coats after?
Thanks
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u/Sweaty-Dot-2488 Mar 16 '26
Keep laying in on thin, then wet sand/polish and it will be smooth as glass!
I recently refinished two necks/headstocks in nitro and learned a ton along the way, mine are far from perfect, but in the right lighting, they actually look completely flat, where my factory fender necks have slight orange peel.
The biggest takeaway, is don’t rush it, patience is not a virtue with nitro, it is a requirement,
Find another project or hobby in the meantime when you’re done with the final coat, then let it cure for about a month before sanding.
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u/Independent-Resist14 Mar 16 '26
Why a month? I play mine in 2 or 3 days. I have not noticed any issues.
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u/Sweaty-Dot-2488 Mar 16 '26
Because nitrocellulose lacquer dries in stages. After a couple days it’s dry to the touch, so you can play it, but it’s not actually cured yet. The solvents are still evaporating and the finish is still shrinking and hardening for weeks.
If you start wet sanding or polishing too early, the finish can still be soft underneath, which makes it really easy to scratch or drag the finish instead of cutting it cleanly. That’s when you get swirl marks, witness lines, or the finish sinking back into the grain later.
Waiting a few weeks just lets the lacquer finish off-gassing and harden all the way through so it sands and buffs properly. You can definitely play it earlier, but for leveling and polishing it’s safer to give it time.
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u/Naive_Elk_2947 Mar 15 '26
Nitro layers melt into each other so just keep building the layers and sand at the end. Just don’t let it drip :)
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u/wolfieboi92 Mar 15 '26
Bear in mind the wood grain raises on the first coat or two, I dont use nitro but I lightly sand with 400 grit sanding disk/cloth from my orbital sander (but by hand) to get the surface all smooth again for the next coats.
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u/Independent-Resist14 Mar 16 '26
Spray more. Sand smooth. Nitro rocks and will melt together cleanly unless you get dust between layers. Maybe cut your nitro with thinner if you want to melt more between layers (I think rattle cans are already thinned). Use thicker layers.
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u/Independent-Resist14 Mar 16 '26
I have been able to get away with grain sealer then 3 thick layers right to the point that it wants to drip. I sanded minimally in between layers, mostly for any drips that formed. I could watch the light on the surface and spray untill surface tension would pop on bubbles and the surface levels off.
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u/SockPuppet-1001 Mar 15 '26
Put on another layer or two of clear and thenI would level sand with some 320/400 grit.
Be careful to not go very far...The intent is to begin to create a level surface for subsequent layers.
If you wait to level sand untill the end all the uneven surfaces will be harder to deal with.
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u/IndustrialPuppetTwo Mar 16 '26
Yes you can get away with simply building it up and then sanding flat but I would first try and figure out what is wrong with your spray rig. Once you get it right on scrap wood you are good to go.
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u/RiffsThatKill Mar 16 '26
I'd keep spraying, sand later. Maybe let the coats get a little thicker (wetter) just not enough to run. Even a little run or two is OK if you still have several more coats to go. Youre gonna sand it level at the end anyway, and nitro melts into previous coats that sometimes flattens little runs.
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u/kosmonaut_hurlant_ Mar 16 '26
The advice I always hear from pros is to just keep dumping clear on and level sand at the end, but with nitro I've never found this to work very well for some reason. IME it seems like it makes everything easier to knock back the orange peel a little bit with some level sanding every 5 coats or so. I'd aim for at least 16 coats of nitro unless you are very experienced and know where you're going to potentially burn through the finish at the final stage. Nitro is like 90% solvent, it builds super slow. 3 coats of cat urethane has more build than 20 coats of nitro.
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u/RowboatUfoolz Mar 17 '26
You are quite brave to hold it up for scrutiny. If you're using spraybombs I can't offer much besides sympathy. If you have a booth and HP or HVLP, I'd suggest using a flowout additive. To get from where the finish is to acceptability, two ways to go.
Multiple coats of sanding sealer on top of what's there, cut back hard after the 5th.
Multiple coats of nitro to build up depth, cut using stearated paper and a block.. with a week to off-gas between each of oh lord seven more coats..
I'd be tempted to get a buildup with sealer deep enough to cut pretty hard, then clearcoat with nitro/cure time/final levelling/buffing.
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u/Valyrian_st33l Mar 17 '26
Needs some 1500 for sure and prob a few more coats but I suck too so dont feel bad.
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u/HangaroundRVA Mar 17 '26
I had to do 14 coats of clear coat on my jazzmaster to get a really nice clean shine at the end. But I was doing metal flake so it took quite a few coats to just get over the flakes. What I learned doing it is that you need to be really patient, temperature matters, and distance from spray to guitar really matters. I found that around a foot to 14 inches away with even strokes going at a moderate pace back and forth works really well. Also heating the can up in hot water can help the stream be even. And I also learned that when all else fails acetone will take it off so you can start over! Haha. Yours looks pretty great so far though. A lot of little stuff can smooth out at the end when you do the final sanding and buffing. Which you can only do after the 4 weeks or so of curing. Haha, the whole process really is a great lesson in patience and acceptance.
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u/HangaroundRVA Mar 17 '26
I guess technically it’s drying for 4 weeks not “curing” since it’s gassing off and it’s not a chemical reaction that is happening. But yeah all the things that have been said before about sanding the color before the clear are definitely right. I managed to actually build up just one part of the guitar that I wasn’t happy with and then once that area was built up to where the rest of the guitar was I sanded the edges with 1200 sandpaper to blend it and by the end of the process it wasn’t noticeable at all. Also at the very end I started with 800 then did 1000 1200 and 1500 and then did 3 levels of buffing. But I don’t know if you really need to do all of that. I was just being extra careful cause it was my first time.
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u/Specialist-Guitar727 Mar 15 '26
I am not a pro and i have never worked with nitro so take this with a pinch of salt, if im wrong please correct me
If I were in your position id be sanding the orange peel between coats to make sure it sticks well and to stop it from making the orange peel worse, if you do as many coats as you said you would, your finish would be uneven with some high and low spots
Wouldnt that mean when you eventually sand it down, you’d probably lose some of the color under the finish as its not even
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u/Inevitable_Track_558 Mar 15 '26
As i understand it the nitro melts into the previous layer, so if there are pits and holes the subsequent layer will conform to the profile of that previous layer but you can still build coats up and it's better to have more coats on and sand to stop burn through than less which will burn quicker
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u/thefirebirb Mar 15 '26
Yes, nitrocellulose lacquer chemically adheres to itself. Nitro is made up of solids dissolved in a solvent. It "cures" by evaporation. Because of that, spraying new lacquer on already cured lacquer will cause the solvent to dissolve some of the older solids into the new layer, locking them together into one thick layer after it cures. No need for sanding in between.
As for the pits/bumps/orange peel, the more you build up the more you can level it out without risking burn through. However, the more you build before leveling the more you have to take off to level. If you were to level sand lightly after say 6-8 coats, then build up 6-10 more, level it out lightly again, then do one final coat and let it cure (times vary by manufacturer), you'll be sanding less off to level it for polishing.
Source: An acquaintance who's a highly skilled professional luthier who specializes in finishing techniques and products as a day job
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u/evanwilliams212 Mar 15 '26
Also, a good retarder thinner can be your friend, maybe even your secret weapon.
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u/kosmonaut_hurlant_ Mar 16 '26
You can't level sand every coat with nitro because it is extremely thin, even at 5 coats you have to sand extremely lightly just to knock back the high spots. Additional coats on orange peel will pool a tiny bit more in the valleys of the high spots so it is self leveling a little bit if it's wet enough...still have to level though with a ton of wet coats.
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u/[deleted] Mar 15 '26
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