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Finishing A Guitar.... Lots Of Questions, Much Confusion.


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Hey, I am ready to finish a guitar Ive been working on (other than final sanding) and had alot of confusion about finishing. Ive spent a couple of weeks reading hours and hours every day here, and still am very confused/frightened to start. Ill start with my first question, Is my rig efficient enough to be able to spray a guitar? I have a porter-cable compressor, the specs are "2.6scfm@90 psi", and it is a 6 gallon compressor. For a gun I have the stewmac "production" gun.

Second question - OK, I have the stewmac COLORTONE waterbase grainfiller, sanding sealer and gloss topcoat. Ive read alot of problems with this and that it is very hard to get perfect, its not very durable, and it is not very glossy (a satin finish??). I am looking for a gloss finish for the body and a satin (or oil) for the neck. I also read that the grainfiller is a waste of time; I want to get some "zpoxy" finishing resin to speed up the process, but am not sure if they are compatible if I go with the waterbase finish.

Third question - I'm still debating weather to use some type of satin finish for the neck or tru oil (I have two of the 8oz bottles of it). Ive seen the epic "mahogany and tru oil" thread and learned a lot from jon mattharris and mattia, but are still not sure how to grainfill with it (many coats and wetsanding using truoil as lube, fill with zpoxy, or just lots and lots of coats leveling with steel wool). I am to understand that a satin finish is still more durable than tru oil, and I think that is what I'm after. How do you get a satin finish ? (do I use my waterbase stuff? Can I grainfill using zpoxy?)

Fourth question - For the body I want a glossy, hard, fast curing clear finish and I ve read pros and cons for everything... auto-body sprayable "2 part acrylic urethane" came up, I was wondering opinions, and where I could get some. Does anybody have opinions for what would be good for a beginner with no experience and the spray equipment I am using (if its even feasible at all) and where to get those.

Fifth question - The body is ash topped with maple, and the neck is mahogany sides with a bubinga middle laminate with maple veneers separating them all, and flame maple binding. clicky. The steps for finishing I am assuming would be -

1. sand to 220

2. clean with vacuum/air sprayer

3. apply zpoxy to mahogany and ash (assuming Im doing a satin on the neck and a gloss on the body)

4. sand and re apply with a more viscous application of zpoxy (can someone tell me how to make this happen?)

5. sand and re apply with a less viscous application of zpoxy using denatured alchohol as a thinner (if necessary for sandthroughs etc)

6. cleanup with vacuum/air sprayer

7. mask off FB and neck and spray body with sanding sealer

8. repeat until satisfied with thickness

9. sand and spray choice of laquer

10. repeat until thickness is right

11. do the same steps for the neck only mask off the body and less coats for satin finish using satin finish.

12. wait 3-4 weeks to cure

13. wetsand/buff

- is this the right order of things/right way to do them?

sixth question - OK, the stewmac site tells you how to clean the production gun and it seems excessive tedious and kind of intimidating. I will have to practice before I use real finishes but do you actually have to take the gun apart and put everything in lacquer thinner and clean it all up after every coat? seems like by the time you finish cleaning it your almost ready for another coat! Maybe I just seem lazy but I thought Id ask.

Sorry for the stupid-long post but I hope someone of you will take the time to read it and help me out cus I'm at a loss right now and want to finally get this thing done! But I will however show you some pictures of this guitar and another project I am working on for my rack.

frontal - clicky

sideview - clicky

flame maple rack spacers - clicky

the family - clicky

Thanks a bunch for your patience and any thoughts are welcome, looking foreword to some responses!

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sixth question - OK, the stewmac site tells you how to clean the production gun and it seems excessive tedious and kind of intimidating. I will have to practice before I use real finishes but do you actually have to take the gun apart and put everything in lacquer thinner and clean it all up after every coat? seems like by the time you finish cleaning it your almost ready for another coat! Maybe I just seem lazy but I thought Id ask.

Okay, I'll readily admit to being a moron with respect to finishing. But as far as cleaning the gun, DO IT RIGHT! Good friend of mine works at a company that makes and sells high-end spray equipment and they sell all types of guns. Every week he shares with me another story of how one of their customers has called claiming their new spray rig doesn't work. He takes a trip out and finds that the spray rig with its pumps and compressors work just fine. It's just the gun that's totally clogged. Your choices are simple really, fully clean the gun, or keep buying new ones.

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First, it's refreshing to see some research before asking. +1

You may want to see what the CFM rating at lower PSI is for your compressor (or find the calculations, I can't right now) but for me, a 1.8 mm nozzle is a fire hose. Right now I'm using an HVLP gravity feed gun 2.5 cfm @ 42 psi with a 1.0 mm nozzle. Following manufacturer's directions for thinning, and adjusting the feed and pattern, I can spray just about anything with a lot less waste. It's connected to a 5 gal tank (I know - I need more tank).

2. Grain filler is not a waste of time on a clear-ish finish. Makes smoothing the finish easier in the long run (IMHO)

3. I usually seal my necks with either shellac or tru-oil. I like the way tru-oil stays smooth and doesn't get sticky when things heat up while playing. Nitro and Poly seem to need lubrication while playing :D (again, MHO) Getting the satin finish is done with 000 or 0000 steel wool. This works on just about any finish to tone it down.

4. There is a 2-part poly in rattlecan that you can get at some auto parts stores. In my area, it's $27 a can (can't remember the name right now) and two cans is about right. Only problem is it has high VOC so ventilation/respirator is necessary (Syxxstring can fill in more). I've used acrylic lacquer and my dry cage for the last few projects and been quite pleased. Usually going from paint, to clear, to cut and buff in about 2 weeks.

5. If you're using sanding sealer, sand it to 400 - 220's a little rough.

6. CLEAN THE GUN. It may look/sound intimidating, but it's not. Airguns are VERY simple machines with a few parts and lots of seals. Plus, it's not like you're going to do anything else while the coat flashes/cures :D Isn't that why we all bought our first guitar - to have something to play with while we watch the paint dry?

Please understand that these statements are based on my experience and there are several others out here who can contribute pluses and minuses to this procedure.

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Question 1 -

The gun you were asking about requires:

"This gun requires a 1/4" air hose with fitting and regulator, and a compressor producing at least 3 cfm at 90 psi"

It sounds like your compress or won't keep up especially if its one of the small ones designed for a nail gun. You have to remember that your going to loose CFM in the hose as well. My bet is you will end up with orange peel, spits and all sorts of other problems, based on when I had a compressor that wouldn't keep up with my guns.

Fill your gun with water and see how long you can spray keeping the fan dialed in, I'll bet it won't give you enough to make up a coat on a guitar.

For details on dialing in the gun, and oh yes that does make a difference, the september Rod and Custom magazine has an article on how to spray correctly. It was written by Valspar/HOK's technical instructor and paint superstar, Brian Lynch. Definitley worth owning.

I can't help you with cleaning the gun since I only use gravity feed guns. But make sure you are aware of how much paint is in the gun, when it starts to run low you will have all sorts of spitting and other problems.

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Thanks for the quick replys guys,

You may want to see what the CFM rating at lower PSI is for your compressor (or find the calculations, I can't right now) but for me, a 1.8 mm nozzle is a fire hose. Right now I'm using an HVLP gravity feed gun 2.5 cfm @ 42 psi with a 1.0 mm nozzle. Following manufacturer's directions for thinning, and adjusting the feed and pattern, I can spray just about anything with a lot less waste. It's connected to a 5 gal tank (I know - I need more tank).

2. Grain filler is not a waste of time on a clear-ish finish. Makes smoothing the finish easier in the long run (IMHO)

4. There is a 2-part poly in rattlecan that you can get at some auto parts stores. In my area, it's $27 a can (can't remember the name right now) and two cans is about right. Only problem is it has high VOC so ventilation/respirator is necessary (Syxxstring can fill in more). I've used acrylic lacquer and my dry cage for the last few projects and been quite pleased. Usually going from paint, to clear, to cut and buff in about 2 weeks.

5. If you're using sanding sealer, sand it to 400 - 220's a little rough.

1. So with a smaller (iam assuming diameter, but also in length) hose, you think I should be fine with the setup I have now? Sweet maybe I'll pick one up today. syxxstring, thanks for the info on the gun I did not see it on stewmacs site right away. Thats a bummer, but do you think I could hack it and make it work good for me like kpcrash?

2. Oh, no i did not mean it was a waste of time I just meant the waterbase stewmac stuff was becasue you have to do like 6 coats just to make it feasable, thats why I wanted the zpoxy, which I think I am going to pick up some today if this hobby store is open.

4. as for the 2 part poly wow that is expensive but if it works it works, I have a respirator (the kind lee valley sells) but no real ventilation so that may be a problem... I could use a big fan from my garage's side door to outside, bad idea? I do live in a subdivisions kind of area, neighbors will probably slay me.

5. Thanks for the tip, I just read so many people just go up to 220 (stewmac, people on the forum,) I just thought it was reasonable but maybe Ill try and go higher.

Thanks !

For details on dialing in the gun, and oh yes that does make a difference, the september Rod and Custom magazine has an article on how to spray correctly. It was written by Valspar/HOK's technical instructor and paint superstar, Brian Lynch. Definitley worth owning.

Thanks, I'll look into that. Im pretty sure I will take kpcrash's advice and at least try it out first because I don't want to buy a new compressor and spray cans are shitty/expensive... One more quick question, should I wait for it to reach 45 (if thats what Im spraying at) PSI if it lowers a bunch while I'm spraying? will it start to spurt and give me orange peel etc? I tihnk I might have some trouble because this compressor really $%#*ing sucks. Thanks.

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Your compressor is probably great for a nail gun - just not a paint gun. It may also come in handy if you ever decide to do some small airbrushing. The regulator is supposed to keep the pressure constant so the gauge on the compressor may not be exactly what's going on at the gun (hence hose compensation, etc.).

Even with Acrylic Lacquer I do at least 5 coats - but I'm a "depth of finish" freak. You can make bs rattlecan gloss spray paint shiny... but I like the "oh my gosh! Is that wet?" response.

If you use your fan, check to make sure the motor is sealed. High VOC = High explosion if the fumes get into an unsealed motor. It's kinda cool on a small scale, but if your neighbors bitch about the fumes, imagine their response to your house going up.

As always - try a scrap and see what works for you. Worst case, you stink up the garage and have to clean your gun. And like Syxx, I'm using Gravity Feed now 1) less waste and 2) IMHO, I get a better dial in for pattern/flow.

ONE MORE THING - almost forgot - MAKE SURE your compressor is drained and has a moisture trap before starting. Cracking, orange peel, fish eyes, runs, drags, spatters and pits can be caused by the fine amount of water in the tank due to change of temperature from night to day. :D

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Your compressor is probably great for a nail gun - just not a paint gun. It may also come in handy if you ever decide to do some small airbrushing. The regulator is supposed to keep the pressure constant so the gauge on the compressor may not be exactly what's going on at the gun (hence hose compensation, etc.).

Even with Acrylic Lacquer I do at least 5 coats - but I'm a "depth of finish" freak. You can make bs rattlecan gloss spray paint shiny... but I like the "oh my gosh! Is that wet?" response.

If you use your fan, check to make sure the motor is sealed. High VOC = High explosion if the fumes get into an unsealed motor. It's kinda cool on a small scale, but if your neighbors bitch about the fumes, imagine their response to your house going up.

As always - try a scrap and see what works for you. Worst case, you stink up the garage and have to clean your gun. And like Syxx, I'm using Gravity Feed now 1) less waste and 2) IMHO, I get a better dial in for pattern/flow.

ONE MORE THING - almost forgot - MAKE SURE your compressor is drained and has a moisture trap before starting. Cracking, orange peel, fish eyes, runs, drags, spatters and pits can be caused by the fine amount of water in the tank due to change of temperature from night to day. :D

dude, awesome thanks. Assuming I have to go with spray cans or buy a better compressor, what would you suggest I get for spray cans, or a compressor! lol Thanks

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For rattlecans, I have had really good luck with Rustoleum Painter's Choice Products. Depending on how you want it finished, it's usually 1 can primer, 2 cans color, 3 cans clear gloss. Prime, paint 3 coats wait 24 hours, sand to 400 grit. Paint 3 coats again. Sand again - the exercise here is that you want a smooth finish that completely covers the body. If you go this route - remember PATIENCE IS A VIRTUE (seldom found in humans and never in a duck for those as old as me). Keep the can about 14" back and spray LIGHT! coats. You should be able to see the primer through the first coat or two. After you're done coloring let it sit for 48 hours. Between 24 and 48 hours spraying too heavily can cause "alligator skin". Just know you don't want it. After 48, sand to 400 and start with a mist coat of clear gloss. Add one thin coat every 1/2 an hour for 5 coats. REMEMBER - when I say coat, I mean thin - just over dusting. The reason for the first coat being a dusting is to let the chemicals date for a while before getting serious. Repeat until you have at least 15 coats (sounds like a lot of work - it isn't). Let rest for at least one week. Rustoleum claims the clear cures in 24 hours - in my region it cures in about 1 week. If unsure, wait 2 then cut, buff.

Oh yeah, to know if you're done sanding - you shouldn't see any really shiny spots and for goodness sake, USE A BLOCK.

If you want a better compressor - pick a Lowes/Home Depot/Sears close by - find one that is at least 10 Gal (I like oil-less because I always forget, this is why I'm back to my 5 gal right now) and disregard everything I said earlier in this post. :D

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For rattlecans, I have had really good luck with Rustoleum Painter's Choice Products. Depending on how you want it finished, it's usually 1 can primer, 2 cans color, 3 cans clear gloss. Prime, paint 3 coats wait 24 hours, sand to 400 grit. Paint 3 coats again. Sand again - the exercise here is that you want a smooth finish that completely covers the body. If you go this route - remember PATIENCE IS A VIRTUE (seldom found in humans and never in a duck for those as old as me). Keep the can about 14" back and spray LIGHT! coats. You should be able to see the primer through the first coat or two. After you're done coloring let it sit for 48 hours. Between 24 and 48 hours spraying too heavily can cause "alligator skin". Just know you don't want it. After 48, sand to 400 and start with a mist coat of clear gloss. Add one thin coat every 1/2 an hour for 5 coats. REMEMBER - when I say coat, I mean thin - just over dusting. The reason for the first coat being a dusting is to let the chemicals date for a while before getting serious. Repeat until you have at least 15 coats (sounds like a lot of work - it isn't). Let rest for at least one week. Rustoleum claims the clear cures in 24 hours - in my region it cures in about 1 week. If unsure, wait 2 then cut, buff.

Oh yeah, to know if you're done sanding - you shouldn't see any really shiny spots and for goodness sake, USE A BLOCK.

If you want a better compressor - pick a Lowes/Home Depot/Sears close by - find one that is at least 10 Gal (I like oil-less because I always forget, this is why I'm back to my 5 gal right now) and disregard everything I said earlier in this post. :D

Awesome, thanks for the detailed reply but I wasnt thinking of painting any colors, just finishing with clearcoat... and in that I do not know what to choose to bring out the grain/be durable and shiny :D Would you still recommend the rustoleum stuff for just the clear gloss? Thanks.

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Check this post. It has pictures of a plywood guitar I built (don't ask - just read the thread if you're curious). The body is dusted with black and flames via airbrush and cleared with the Rustoleum. It provides a crystal clear finish. Depending on the type of wood - there are many ways to accent grain (rubbing stain on grain, roughing the grain with steel wool, etc.). But in short - yup - it works great.

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First, it's refreshing to see some research before asking. +1

You may want to see what the CFM rating at lower PSI is for your compressor (or find the calculations, I can't right now) but for me, a 1.8 mm nozzle is a fire hose. Right now I'm using an HVLP gravity feed gun 2.5 cfm @ 42 psi with a 1.0 mm nozzle. Following manufacturer's directions for thinning, and adjusting the feed and pattern, I can spray just about anything with a lot less waste. It's connected to a 5 gal tank (I know - I need more tank).

2. Grain filler is not a waste of time on a clear-ish finish. Makes smoothing the finish easier in the long run (IMHO)

3. I usually seal my necks with either shellac or tru-oil. I like the way tru-oil stays smooth and doesn't get sticky when things heat up while playing. Nitro and Poly seem to need lubrication while playing :D (again, MHO) Getting the satin finish is done with 000 or 0000 steel wool. This works on just about any finish to tone it down.

4. There is a 2-part poly in rattlecan that you can get at some auto parts stores. In my area, it's $27 a can (can't remember the name right now) and two cans is about right. Only problem is it has high VOC so ventilation/respirator is necessary (Syxxstring can fill in more). I've used acrylic lacquer and my dry cage for the last few projects and been quite pleased. Usually going from paint, to clear, to cut and buff in about 2 weeks.

5. If you're using sanding sealer, sand it to 400 - 220's a little rough.

6. CLEAN THE GUN. It may look/sound intimidating, but it's not. Airguns are VERY simple machines with a few parts and lots of seals. Plus, it's not like you're going to do anything else while the coat flashes/cures :D Isn't that why we all bought our first guitar - to have something to play with while we watch the paint dry?

Please understand that these statements are based on my experience and there are several others out here who can contribute pluses and minuses to this procedure.

Did I read your post right? You are using a HVLP gun at 2.5 CFM. Every one I have seen is usually around 12 CFM or much higher. Even the conventional guns usually want 6 CFM. Please point me to the gun you are using because I would love to get a HVLP without getting a turbine compressor or a monster compressor.

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Check this post. It has pictures of a plywood guitar I built (don't ask - just read the thread if you're curious). The body is dusted with black and flames via airbrush and cleared with the Rustoleum. It provides a crystal clear finish. Depending on the type of wood - there are many ways to accent grain (rubbing stain on grain, roughing the grain with steel wool, etc.). But in short - yup - it works great.

Haha, yes I did see that build. It turned out awesome, the flames are original and look killer. The rustoleum looks great, I'll go and check it out. My first guitar was made of plywood.... diddnt even know it untill i decided to strip it; when i took the pups out i was confused by the layers thinking "this cant actually be plywood". Oh, for accenting the grain I have some stewmac colotone dyes and am doing the classic triple step finish with black, sandback, etc. Btw maybe someone reading this will know... can I get tiger eye brownish color ? I have the red, black, and brown. I picked up some spray cans of this "verathane" high gloss stuff for my flame maple rack spacers.... They have about 8 coats on them right now, im thinking let dry overnight, level sand, apply more coats? Ill post finished pics later.

another side note, hobby store WAS open today and I was able to pickup 2 boxes of Zpoxy, I wasn't sure how long one box would last me so I bought them out of their stock. I did the same with my truoil when I went to wholesale sports, hah. I read alot about truoil being available at wal-mart, but I went to two super-centers today and decided, what the heck Ill take a look anyways and they only had the spray cans, ***'s up with that? Anyways, thanks again Ill try them out and post some progress pics when im nearing completion.

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Did I read your post right? You are using a HVLP gun at 2.5 CFM. Every one I have seen is usually around 12 CFM or much higher. Even the conventional guns usually want 6 CFM. Please point me to the gun you are using because I would love to get a HVLP without getting a turbine compressor or a monster compressor.

Yes, actually it's 2.6 CFM technically. The thing is I use a small detail gun and (usually) a 10 gal tank. I can get more air using a gun that accepts 15-45 psi over a gun that requires 12 CFM and operates at 12 psi. I dial in the pattern and start shooting. To be completely honest as well, my favorite gun is a no-name from Harbor Freight. I have others from working with my FIL on furniture, but love the control I have from this little gun. As already stated, I am a firm believer in using thin coats and so far I have had great results with this shooting acrylic, acrylic lacquer and nitro lacquer. PM me if you want a pic. For airbrushing I still believe in my Iwata - this other gun just completely surprised me.

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Hey...I'm kinda late to the thread...but anyway. This is the gun that I have been using with the exact same compressor you have.

spray gun

It's a small gun but it holds plenty of finish for a coat or two on a guitar body. I have seen this gun on sale for as little a $6.99.

Have you glued the neck into your guitar yet? If not, don't until you are done finishing....especially if you are going to use a different finish on neck vs the body. Just mask the gluing surfaces while you apply your finish.

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... If you use your fan, check to make sure the motor is sealed. High VOC = High explosion if the fumes get into an unsealed motor. ...

Just to add, if you are spraying in your garage, be aware that your water heater and furnace can also be a source of ignition.

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