Finishing a guitar - is NCL the way to go?

[slackboy72]

Okay I've searched and can't seem to find exactly what I'm after.

I have a guitar body of Alder and Maple.
I want to water dye it to bring out the grain of the maple and then do a tinted burst effect.

Now my understanding is I would have to follow this procedure:
1 - prepare the wood for dyeing (sanding, etc.)
2 - dye
3 - sand back again
4 - seal with sanding sealer
5 - start with pigmented or clear topcoats (about 12 coats in total)

Everywhere I read it says that NitroCellulose Lacquer is the best finish for guitar bodies however I have had people laugh at me in paint stores for asking about NCL and telling me to go with acrylic because NCL has carcinogens. One even said I needed a licence to buy it. Another place said they could get some Stylwood by Wattyl and all the thinners and such and never mentioned anything about carcinogens.

So my questions are:
1 - Is the procedure above correct?
2 - Is NCL as highly dangerous/carcinogenic as someone has told me?
3 - If not where do I get the stuff?
4 - Where can I get pigments for solid colors and colour dyes?
5 - Can I spray it over the top of polyurethane?

Sorry if this has all been asked before.

[tim290280]

Might be worth asking in the instrument makers section (or Mods moving it there).

[Neilo]

Hey slackboy, congrats on braving a refinish, not always an easy job!

Nitro is good, but not that easy to get, might wanna try stewart macdonald luthier supplies on the web or gilet guitars in sydney

personally, (and this is from my experience) i've found a german, oil based violin varnish named "ollack" gave a huge improvement on my Fender Jazz bass, although it's pricey.

Applying it by brush with the grain and then sanding with wet and dry 400 grit (dipped in water) between layers to remove high spots and botches is the way to go; this will give you a mirror like finish after about 4 or 5 coats but is a long process like any good varnish job!

2 main issues to look out for are:

1. this lacquer can only dry with UV light, not heat. It also takes a few days to dry properly, don't be tempted to touch it for a few days, it will get dull fingermarks if you do

2. It will need polishing after the final coat, but will turn up beautifully. Though when you are sanding in between each coat, make sure the 400 grit is always wet and that you sand a little of the lacquer off until you have a satin finish; keep lots of paper towel on hand to wipe the water off the guitar to inspect it after sanding.

I hope it all turns out well whichever way you go, sorry i'm not much help with nitro finishing myself, I kinda gave up on it... be sure to post some pics eh?

[durwood]

NCL is an out of date finish, no longer generally available as it has been replaced with materials which are far superior to it. Acrylic lacquer is what is usually used. Thts why you can't find it in a shop now. I doubt if any sales person was even around when NC was in vogue so little if nothiong about it.

Simply NC is the same material as sticky tape, it starts off clear but deteriates and goes brown and cracks especially if exposed to sunlight. Acrylic is basically perspex far better as a clear in sunlight.

On a guitar NC works well as its easy to work with and dries quickly and is not normally exposed to lots of sunlight as its used indoors and lives usually in a case.

Its still available through different suppliers, do a search on the forum here or go back through the NC lacquer threads here in finishing to find suppliers. Mirotone supply it may be worth a phone call to them for local distributor.

Its not poisonous (unless it has lead pigments) probably as safe if not safer than any other as it dries so fast, when used in industry such problems never existed for over the 60 years it was widely used. It was usually sprayed in an open workshop without masks, exhaust fans and spray booths were unheard of. Its only the new better finishes that have caused such problems, the penalty for having a better product.

Your proceedure is sound. water bases stains are available from several sources good paint shops or hardware stores keep such products, Wattyl make the whole range of wood finishing stains, fillers and clears for timber and there are others. You usually buy colours as paints not as pigments alone. and dyes as colours.

Polyurethanes are the better finish so spraying NC over them is a backward step, depending what you are calling Poly the NC may attack it, if not it probaly won't adhere well to it if at all.

Neilo is a bit confused the material he is talking about is as he says varnish, it dries by oxidation ( drys by exposure to the oxygen in the air) it still needs heat to help it if it were cold it would take longer to cure. I sugest you avoid a varnish or enamel for your guitar, lacquer is far easier to work with especially if you are unformilar with this type of work.

[Neilo]

NCL is an out of date finish, no longer generally available as it has been replaced with materials which are far superior to it. Acrylic lacquer is what is usually used. Thts why you can't find it in a shop now. I doubt if any sales person was even around when NC was in vogue so little if nothiong about it.

Simply NC is the same material as sticky tape, it starts off clear but deteriates and goes brown and cracks especially if exposed to sunlight. Acrylic is basically perspex far better as a clear in sunlight.

On a guitar NC works well as its easy to work with and dries quickly and is not normally exposed to lots of sunlight as its used indoors and lives usually in a case.

Its still available through different suppliers, do a search on the forum here or go back through the NC lacquer threads here in finishing to find suppliers. Mirotone supply it may be worth a phone call to them for local distributor.

Its not poisonous (unless it has lead pigments) probably as safe if not safer than any other as it dries so fast, when used in industry such problems never existed for over the 60 years it was widely used. It was usually sprayed in an open workshop without masks, exhaust fans and spray booths were unheard of. Its only the new better finishes that have caused such problems, the penalty for having a better product.

Your proceedure is sound. water bases stains are available from several sources good paint shops or hardware stores keep such products, Wattyl make the whole range of wood finishing stains, fillers and clears for timber and there are others. You usually buy colours as paints not as pigments alone. and dyes as colours.

Polyurethanes are the better finish so spraying NC over them is a backward step, depending what you are calling Poly the NC may attack it, if not it probaly won't adhere well to it if at all.

Neilo is a bit confused the material he is talking about is as he says varnish, it dries by oxidation ( drys by exposure to the oxygen in the air) it still needs heat to help it if it were cold it would take longer to cure. I sugest you avoid a varnish or enamel for your guitar, lacquer is far easier to work with especially if you are unformilar with this type of work.

Maybe i am confused, but that's how my teacher does it, he uses a custom made cabinet full of UV strip lights for this unique lacquer. I made my choice based on the acoustic properties of the finish and this has been the best finish i've ever heard (even with my J bass, which is more or less a collection of planks). Nitrocellulose, Oil, acrylic and (god forbid) polyurethane and all other finishes protect the instrument in varying degrees and in most cases at a cost to the final sound of that instrument, so choose carefully and don''t skimp because you're gonna have to live with it!

[slackboy72]

Thanks guys.

I'm in Canberra Australia so I can't get anything like lacquer from StewMac as they can't ship it out of the USA.

Unfortunately Mirotone only make pigmented NCL it seems.

Think I'll have to go investigate the local paint shop.

[mandoman]

Slackboy72, try contacting Graham McDonald. He lives in Canberra (Cook) and makes guitars, among other instruments. He will put you right. He has tried some of the acrylic finishes. I think some of the information above is somewhat misleading. NCL is still used extensively as a music instrument finish, particularly on guitars. From what I have heard from other instrument makers, the acrylic finishes are getting closer to NCL, but nothing quite matches NCL yet. There are many guitar makers you can talk to in Australia who would be only too happy to help you with tips on finishing.

I use a water based marine varnish, with a french polish on top of the varnish. Is very time consuming and works great and sounds great for mandolins, but I would probably not recommend it for a guitar. With music instruments, sound is critical so please don't use polyurethane.

[dadovfor]

Slackboy

Durobond at Brookvale, Wattyl at Yagoona, and Pylon Coatings at Botany all supply Nitro.

I know that Durobond will do various colours ... not sure about the others though. And sorry ... they're all in Sydney ... but perhaps they may know of ACT suppliers or organise freight??

[slackboy72]

Thanks Mandoman.
Has anyone heard of MiroCat? http://www.mirotone.com/Live-3220/default.aspx
Mirotone have pigments and stains that seem to work with this however it isn't NCL.
It says it's suitable for musical instruments and better than NCL.
I might give it a go.

[jiefu]

NC may not be common (easily ordered in Canberra) , but for acoustic (steel stringed) guitars its head and shoulders above anything else for sound quality! That's whey its still the finish on $3000+ guitars. )

[soundman]

Mirotone do still make Nitro laquer.... but the don't make old style nitro. and they don't generlay call it nitro....they probaly sill make 3 or 4 formulations that are some form of nitro.

You will need to buy 4 liters, and buy the correct thinner too. remember you may be running as low as 30% product and 70% thinner...having the right thinner is very important with nitro....thinner comes in 3 or 4 speeds......medium is a safe choice but fast may be better for small work and sunbursting.

mirocat, I think you will find they refeer to a a precatalised resin laquer....bit the resin is nitro. you realy have to talk to a rep or a techodude, the people in the offices only know the names and the products.

if you want to do a proper sunburst, you realy do need to be working in nitro.

The sunburst effect is a resut of nitro comming onto the market, it works because one coat redisolves the next and they blend to a greater or lesser extent.... you may achieve this with other products but it wont be quite the same.

the mirotone precatalised laquers ( nitro) can be colloured with some of their stain products they no longer sell "mixed stain products" either you work from primary colours or you pay for a colour match to be made. They will sell you a minimuimm of 1 liter of each colour.....if you are only making a few guitars this will last you for ever and the colour is very strong.
The primary colours are quite pure too. combine that with the laquer being near water clear, you can achieve vivid colour and deep translucence.

If you are going to mix stains, buy some laboritory glasswear, for your needs a 30mL pippette will be the go.

Dont even think about using these colours as stains then laying up a heavy coat over the top as the top coats will pull the stain out of the wood.
They do work very well in the finish though.

there is also a sanding sealer product made on the same resin. This can save a lot of work getting a build and sanding. you will need to buy 4 liters if you want this

no you can not put nitro over polly or just about anything else.

Remember on thing, Nitro is a sharp edged tool. You can get very good controll over what you are doing, BUT, you need to HAVE good controll over what you are doing to get good results.

get some practice before you have at your prized work.

There are WHS issues with nitro, It is carcenogenic. But there are equaliy bad issues with so many finish products....two pack resins are much worse you should be working with good ventilation and an organic vapor respirator anyway.

cheers

[jiefu]

Why so much thinner? Really interesting you should say that as I am trying to get a good flat finish with a hvlp setup and Mirotone gloss and always seem to be getting that wavy orange peel finish or lots of small high points that I have to level, despite varying settings and nozzles. I tried thinning at about 20% thinner, but not much different so is the answer to spray it REALLY thin? Thanks

[soundman]

Realy thin... hell yeh...... many finish products will not withstand being thinned too far as the resins get too dispersed and can not bind the solods into a stable finish.

This is not so of nitro and many of the evaporation cured products like shelac.

These products the majority of the cured finish is resin and in a very similar form to the in pot product.

i doubt vey much that ntro would be at all managable thinned under 30 %..

in fact some people runn incredibly thin mixes for the top coats.

this is the beauty of nitro...you can spray it on so very thin and it can dry incredibly fast.

I mean if you are using fast thinner on a warm day.....properly off in 30 seconds.

Amate of mine is a trained piano restorer... he recons with all else going properly you can get 4 coats of nitro on in melbourne in winter.

it is very reasonable to completly finish a whole piece in one day using up to 10 coats... if all is going well.

this is the properties that allow the working up of blended finishes such as sunbursts


this is what you need to do to manufacture sunburst finished guitars in a production line situation.

so imagine you are in the spray room at one of the guitar manufacturers in the 60's
you would throw a solid base coat on, probaly clear... the body would then be left a few hours to harden up and be sanded for a smooth base.

the body would then come back to you
you would spray the sunburst in 2, 3 or 4 passes... maybe working up several bodies at once......some cure up time... then a light de-nibing sand......and a coat of clear over the top.

One of the big factors of nitro is that you can fine sand the finish to remove imperfections then go over with a light fast top coat... the top coat then melts out the sanding scratches of the previous coat leaving a high gloss finish straight off the gun

.

I'm no great shakes with getting the finish to work but I know enough to see than in the hands of one skilled and experienced nitro is an incredible tool.

think about the early days of hot rods and those blended finishes wher the car is one colour at the front and another at the rear and blends in between.
these finishes were not some sofisticated product they were nitro used with art and skill.


Nitro is all about speed.....and the secret to speed is a volotile thinner

A manufacturers dream when the finishes of the past too a day per coat to dry... more in a cold climate

Nitro is an old crude finish product, but in the hands of a skilled operator it is truly magical....

cheers

[soundman]

Oh remember if you stuff up badly... you can just wipe it off with a rag soaked in thinner.....like a bowl of thinner and realy good rubber gloves.

cheers

[jiefu]

Well really grateful your advice - the next 3 or 4 coats will be thinned right down, and I'll do a post let you know how it goes. Thanks !