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I've finished furniture, cars, boats....lot's of spraying, sanding, and detailing. I'd like to follow a proven plan as I experiment with finishing guitars. I haven't done much pore filling and although my results are good....it is taking forever to accomplish. I'm looking to only do clear or tinted finishes initially. What I would like is to know if there is a standard approach to filling and finishing using nitro among the upper echelon builders. I'm getting a million ideas from the web but if there is a general way of doing this....it isn't yet clear to me.

Is there a website somewhere that lays out the quintessential plan, step by step, to get a mirro nitro finish that anyone can link to?

Questions:

1. I'm using Behlen sanding sealer 200 for pore filling. Am I trying to achieve a pit free surface with successive coats and sandings at this stage or will the vinyl sealer and topcoats of nitro eliminate the pits as the thing progresses?

2. Do I REALLY need vinyl sealer? Behlen doesn't mention it in their instructions but many luthiers do this step.

Any advice? Links?

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

I would like to reply but I am not an upper eschelon builder but there some here who can help you.

1. don't use sanding sealer for pore filling. It will keep shrinking into the pores. It also can impair clarity and adhesion. Insofar as possible, you want a pore free surface right from the start.

2. No.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

It's all realtive. To me, everyone is an upper eschelon builder.....so fire away.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

For the "quintiessential finish", use the "ultimate plan" that most of the great finishes I've ever seen use:

1. Pack up your "in the white" guitar body and neck carefully
2. Ship them to Joe White (with the requisite $$)
3. Joe does his magic on them
4. Joe ships your guitar and neck back to you
5. Smile at your reflection in the back

Cheers,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

I am with Todd except I seal with shellac instead of vinyl sealer. Z-poxy grain filler, shellac sprayed 2 coats then Behlen instrument lacquer, 3 to 4 weeks for lacquer cure then wet sand and buff.

I agree on the Joe White finishes but that route is not for me I enjoy to do it myself and when people complement me on the finish, I can smile and say thanks.

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

I'm with Fred totally.

I also fill with z-poxy, seal with two coats of shellac, then spray nitro. Check out the tutorial section, Todd Stock has an excellent tute on z-poxy pore filling.

Chuck

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The consensus is, to get a "perfect" finish, one should start with a flat surface. Surface preparation is key, especially if you want a thin finish. Sanding sealer is not the same as a pore filler, as Howard pointed out. Behlen has an excellent product, Pore-O-Pac, which is an oil pore filler available in different colours. This is what I personally prefer, 2 applications may be needed.
I have tried medium CA, 5mn epoxy, sanding slurry with shellac or varnish to pore fill: they all work and have advantages and drawbacks. Some woods require more than 1 application with all methods.
In the end the goal is to have the filler only in the pores, and none left on the wood surface before sealing or shooting the first coat. Shoot a coat of clear shellac or lacquer before pore filling with a coloured product to protect maple/white purfling lines if any. Obviously the top needs to be masked as well.
If I could apply medium CA with a surrogate body while being a couple of miles away, I would choose that. As it is, it is way too aggressive for my nose and eyes, and I am wearing respirator and goggles with an exhaust fan on… That being said it cures fast and sands beautifully.
I find epoxy hard to control and not as easy to scrape or sand.
Sanding slurry needs to be left to cure at least a few days to prevent excessive shrinking. Some people also use egg whites.
Some woods do not need pore filling.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I have developed an allergy to CA and use it as sparingly as possible as I get a tightness in my chest from it if I use large amounts or for long periods of time.

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Laurent, this is very interesting. Due you know if is is compatible with water bornes? How is the hardness?
Also, like wood putty, do you have to be carfull to match colors? And do you use it on tops?

Mike

Thank you EVERYONE for your helpful replies.

So......check me on this approach and point out anything really WRONG, please.

Figuring this is mahogany:

1. Surface prep....to 220 grit.
2. Clean out pores
a. Blow out w/air? Alchohol wipe?
3. Spray clear, dewaxed shellac.
4. Sand back down to wood with 220.
5. Pore 'O' Pac to fill.
6. Sand back down to wood with 220.
7. Maybe two applications of Pore 'O' Pack.
8. Seal with two coats of shellac.
a. Do we sand between these coats?
b. Prior to final nitro....sand shellac with 320? 400?
c. How long do we wait for shellac to cure before nitro?
9. Appy mist coat of nitro and let it blow off.
10. Apply wet coats of nitro.

Anyway.......very nice having you guys around at this stage. I know I could experiment and figure this out but having the best advice early on saves LOTS of time with finishing.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Re #5: unless you want the stain in the pore filler (Pore o Pac is good, but there are many good brands and other types of fillers) to stain the wood, you need a sealer coat under it. So if you just sanded back to wood, seal again.

There are many different finishing schedules that can produce an excellent finish. I have mine, but I don't claim to be a master and I don't know what echelon I'm in. Everyone gets different results from their equipment and materials and environment, so rather than mechanically following some step-by-step recipe like you are in chemistry class, what matters more is that you understand the process and get a feel for your materials and equipment. You are going to have to check your results and vary your process in any case, unless you are one of the finishing robots in the Taylor factory.

That being said, StewMac has a finishing book that I have never looked at, and other guitar making books have sections on it. Bob Flexner's finishing book covers nitro and just about everything else and is first rate. I think Bill Moll posted his finishing schedule on MILF a few years ago, and it was close to what I do.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

As Howard points out, there's no magic recipe and it's an ongoing, evolving process. If I've used the exact same method for 3 guitars, I would be surprised. This is what I do now, and by no means is a perfect or set method, but it works for me:

1 - sand the wood to 180 or 220
2 - clean thoroughly with air gun and naphtha wipe
3 - spray a light cut of shellac
4 - pore fill as cleanly as possible without pulling the filler out of the pores (I use shop paper towels 45º to the grain and do one small area at a time)
5 - maybe 1 hour later wipe accross the grain the pore fill on wood surface with paper towel lightly moistened with naphtha
6 - let dry overnight
7 - clean again with naphtha and sand lightly with 320 or 400 to remove any stain from the filler (and sanding with finer grits will expose any scratches hardly visible with 220)
8 - go over purflings, centre strip etc. with small razor blade and/or grinded #11 x-acto blade to remove filler (this is where it is important not to sand the sealer before pore-filling)
9 - very light sanding with 220
10 - go back to 3/4/5/6/7/8 if the pores are not completely filled
11 - mask top and bindings and apply stain if any (and let dry overnight and clean up if it's an oil stain)
12- spray another shellac coat (and scuff if necessary for you finish to adhere to it)
13- start your finishing schedule.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Maybe, this is one of those areas of secrecy... but Laurent, there is a wide range of color possibilities with theat Behelen product. Do you mix & match?

I like the idea of a putty type filler. I have long thought a clear "paste" type epoxy would be ideal, but I have yet to find such a thing.

Mike

THE biggest difference between finishing a car and finishing a guitar is that you want the guitar to look good from 6 inches away - the car can look good from 6 feet away (big difference). I've seen a few "good" custom car finishes, and none of them would hold a candle to a good guitar finish.

The one time I used nitro I followed a schedule something like this (after all the pore filling stuff):

-1 mist coat, gas off 1 day
-3 wet coats straight nitro 1 hour between each
-let hang 1 week
-level with 400 grit dry
-3 wet coats straight nitro 1 hour between each
-let hang 1 week
-level with 600 grit dry
-3 wet coats nitro thinned by 15% 1 hour between each
-let hang 1 week
-level with 1000 grit wet
-1 wet coat nitro thinned by 30%
-let hang until you can't smell the nitro any more (8 weeks in my case)
-buff out starting from 2000 or 4000 grit (pick your favorite buff-out schedule)

The idea is that successively thinned coats will melt into the successively smaller scratches left by the increasingly-finer sandpapers, and this seemed to me to be more efficient than spraying a bunch of coats and then trying to level & buff out the whole thing in one fell swoop.

You can adjust the number of coats to get the desired finish thickness (the schedule above was for a solid-body electric).

So it basically took me ~3 months to finish the guitar with nitro. Which is why I've never gone back to it.

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The member formerly known as erikbojerik....

Mike, the use of "microballoons" (check out West Systems) in epoxy really helps thicken things up....might be what you're after. Test it.

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Dave
Milton, ON

Can someone give me Joe's contact info

Thanks
Neil

There's a step by step plan on the LMI website that's a pretty good start, but as others have stated, it's best to develop your own plan that suits your equipment, shop, and style.

http://www.lmii.com/CartTwo/Nitrocellulose.htm


Chuck

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"To live a creative life, we must lose our fear of being wrong"
- Joseph Chilton Pearce

No mix and match, but when the walnut coloured product is not appropriate I add colours to the natural Pore O Pac.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Most of this conversation has centered on an instrument with no coloring (dye or stain). Stains mask grain, and dyes go directly into the wood. So, my latest (oak) parlor will have a heavy dye to get a dark oak. I've tried to use Mcfadden's pore filler on bare wood, sand and then dye with no wash coats of shellac or vinyl sealer. Looks pretty good, but some of the grain shows ( may have pulled some filler out when dyeing the wood). Alternately, I could dye the oak first, then fill the grain and seal, but cannot sand off the filler residue, and don't know if naptha would start to pull the dye. The dye is waterbase Trans-Tint.
Anyone have any ideas?

Here is my Surrogate Toxic Applications Body:


Actually, my son wearing my 3M forced air helmet. It's a significant investment, and requires a large compressor and special filters, but you can enter a cyanide atmosphere and breathe fresh air. I got it after I started developing solvent/catalyst/whatever sensitivity which happened after spraying a kitchen remodel with automotive 2 part urethane with makeshift ventilation and just a standard respirator. I was layed up in bed the whole next day and start getting headaches if I smell lacquer thinner now. Haven't tried it for CA fumes but don't see how it wouldn't work. And everyone should have the biggest baddest compressor they can anyway

Peace,
Sanaka

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...imagine there were no hypothetical situations...