clear gloss - number of coats
- Thread starter vtpcnk
- Start date
dmraco
Master Member
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- 4,655
nitro or poly?
Poly I would say 6-8
Nitro...12-16...
that just my prefference.
the Poly you should shoot in one day, not letting the previous coat dry completely...I like about a 30 minute flash time. But it mostly depends on the humidity. have a scrap piece handy to testing. Give at least 3-4 days before buffing.
Nitro must be spread out. Give at least a day or two. You can re-coat even after several days...weeks. The nitro melts together. I have my nitro LP a good month to dry before buffing.
Jackthehack seems to be the local pro when it comes to nitro. I used both the StewMac aerosol and Deft. Both seem to work well. The StewMac will age more than the deft giving your instrument that vintage vibe...
Poly I would say 6-8
Nitro...12-16...
that just my prefference.
the Poly you should shoot in one day, not letting the previous coat dry completely...I like about a 30 minute flash time. But it mostly depends on the humidity. have a scrap piece handy to testing. Give at least 3-4 days before buffing.
Nitro must be spread out. Give at least a day or two. You can re-coat even after several days...weeks. The nitro melts together. I have my nitro LP a good month to dry before buffing.
Jackthehack seems to be the local pro when it comes to nitro. I used both the StewMac aerosol and Deft. Both seem to work well. The StewMac will age more than the deft giving your instrument that vintage vibe...
MattPurland
Junior Member
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- 83
Sorry to hijack your thread, but I'm gonna be doing satin nitro - how many layers should I do? I don't want it to be too thick
Having had to just strip down an all-maple neck and start over, I can't overemphasize THIN coats. I'm shooting Mohawk gloss lacquer from a rattle can over a garnet shellac base coat. Encountered some very minor runs that I tried to wet sand away after a few days using 1200 grit paper. Despite being very careful, I went through the lacquer and removed some of the shellac, leaving slightly lighter spots. While wet sanding, the slurry tends to hide this, so you don't see it until you wipe and dry the affected area. Tried re-shellacing the light spots, but no way could I get them to perfectly match. Of course, the more I stared at the lighter spots, the more pronounced they became in my mind... others might not have noticed.
So if my lesson is any indication, convince yourself before you start that this will take time, keep your arm/hand moving, and force yourself to lift your finger off the spray nozzle in about 1/2 the time you think you should.
ejko
So if my lesson is any indication, convince yourself before you start that this will take time, keep your arm/hand moving, and force yourself to lift your finger off the spray nozzle in about 1/2 the time you think you should.
ejko
Keyser Soze
Senior Member
- Messages
- 206
I'm going to disagree slightly.
Nitro can be re-coated as soon as the first coat is dry. That might be as soon as 15 minutes for early coats. Please note: that means 'dry enough' to recoat, not dry enough to wetsand - that will take ever longer as more coats are applied. Although there is no absolute reason to rush the job. Typically i spray two coats in the morning before going to work, and two coats in the evening. If all goes well I'll have laid down 16-20 coats before calling it quits.
Also, when I spray nitro my goal is to put down as heavy a coat as I can while not being so heavy as to create a sag or run. A slight sag I can live with, as this often 'heals' itself as the finish skins over and then dries. IME nitro seems to pull itself taut - that's why corners sand through so quickly, as that's where it has pulled itself thinnest.
If for some reason I do get a run or a sag that remains after drying I -may- lightly- sand it to soften the general appearance, but will then continue spraying right over it and will not attempt to fully level it until final sanding. As long as you have created a smooth lump (no creases or crevasses) or bulge you can knock it back the the surface level quickly with little risk of sanding through. Sanding is always safer/easier when the finish is at it's most hard/dry.
Thicker coats build (slightly) faster and -more importantly- self level much better. Lighter coats build very slowly and are prone to orange peel and micro craters.
Assuming the surface has been prepped to within microns of smooth then you may be able to get by with as little as six coats of nitro (although this thin a finish will tend to 'relic' rapidly.) Obviously i go a fair bit heavier (but even 20 coats of nitro is pretty darn thin once fully dry.)
One trick to being able to lay down a 'not too heavy' layer is to apply a 'dust coat.' The term is pretty self descriptive - you mist the finish over the surface to create an even layer of individual droplets, wait about 20-30 seconds to allow these droplets to set up, then apply a full thickness film layer. The idea being that all these still tacky little droplets give the film a sort of supporting matrix that impedes the development and movement of sags/runs.
Shorter answer: Figure on 10-12 coats minimum and allow a full month of drying time before wet sanding and polishing.
Nitro can be re-coated as soon as the first coat is dry. That might be as soon as 15 minutes for early coats. Please note: that means 'dry enough' to recoat, not dry enough to wetsand - that will take ever longer as more coats are applied. Although there is no absolute reason to rush the job. Typically i spray two coats in the morning before going to work, and two coats in the evening. If all goes well I'll have laid down 16-20 coats before calling it quits.
Also, when I spray nitro my goal is to put down as heavy a coat as I can while not being so heavy as to create a sag or run. A slight sag I can live with, as this often 'heals' itself as the finish skins over and then dries. IME nitro seems to pull itself taut - that's why corners sand through so quickly, as that's where it has pulled itself thinnest.
If for some reason I do get a run or a sag that remains after drying I -may- lightly- sand it to soften the general appearance, but will then continue spraying right over it and will not attempt to fully level it until final sanding. As long as you have created a smooth lump (no creases or crevasses) or bulge you can knock it back the the surface level quickly with little risk of sanding through. Sanding is always safer/easier when the finish is at it's most hard/dry.
Thicker coats build (slightly) faster and -more importantly- self level much better. Lighter coats build very slowly and are prone to orange peel and micro craters.
Assuming the surface has been prepped to within microns of smooth then you may be able to get by with as little as six coats of nitro (although this thin a finish will tend to 'relic' rapidly.) Obviously i go a fair bit heavier (but even 20 coats of nitro is pretty darn thin once fully dry.)
One trick to being able to lay down a 'not too heavy' layer is to apply a 'dust coat.' The term is pretty self descriptive - you mist the finish over the surface to create an even layer of individual droplets, wait about 20-30 seconds to allow these droplets to set up, then apply a full thickness film layer. The idea being that all these still tacky little droplets give the film a sort of supporting matrix that impedes the development and movement of sags/runs.
Shorter answer: Figure on 10-12 coats minimum and allow a full month of drying time before wet sanding and polishing.
dmraco
Master Member
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- 4,655
good tip for Keyser...I alway tend to air on the conservative side. I tend to have a heavy hand when spraying so I tell everyone to go thin.
concerning drying...I have re-coated as often as every 90 minutes with nitro. It is warm dry day (and I was in a hurry). Best thing to do is have a scrap to spray along withthe guitar. If it has dried and passes a nail test ( slightly press your fingernail against the finish) it is dry enought.
Remember...the term slightly can mean different thing to different people too!! :laughing8:
concerning drying...I have re-coated as often as every 90 minutes with nitro. It is warm dry day (and I was in a hurry). Best thing to do is have a scrap to spray along withthe guitar. If it has dried and passes a nail test ( slightly press your fingernail against the finish) it is dry enought.
Remember...the term slightly can mean different thing to different people too!! :laughing8:
