Finish Question for Light & Muttley

[Zaphod B]

Hey, oh talented, gifted, and knowledgeable luthier types (got your attention yet? )

Let's say I'm starting with an unfinished body and neck, such as I might buy from Warmoth. What is the minimum finish treatment necessary to protect the wood - to seal it and provide some level of environmental protection, but not necessarily to provide a hard shell finish?

 

[muttley600]

You can achieve a very nice oiled finish with Danish Oil or Tung Oil. Both can be applied with a rag and are built up with successive coats. I have finished instrument with Danish oil on request and got a good reasonably durable finish. It is not as durable as a varnish or lacquered finish and some don't like the feel of the neck as it may not be as slick as a hard finish. On the plus side it requires very little equipment or skill to apply and you can wire wool lightly and add to it after a year or so and bring it back to as new. Other finishes worth investigating that need a little more prep and skill would be varnishes and lacquers. StewMac and LMI do guitar specific finishes and good instructions on using them. Not knowing what generic finishes are available in the States I'll leave Light to advise you on that. If it was me I'd have a go with Danish Oil or one of StewMacs Waterborne finishes. Consider what you need to do to grain fill and seal as well depending on the timber.Whatever you do practice on scrap wood first.

 

[Milnoque]

It would be helpful to know what kind of wood you want to finish.

Can you be more specific about your vision?

One coat of acrylic polyurethane would provide an ash body minimum protection from the elements, but it wouldn't look like much. I would use two on the back of the neck. Acrylic Poly is pretty durable, but I have no idea how it would hold up on a maple fretboard. This would not be sufficient on mahogany or other more porous woods.

I don't reccommend you finish your guitar this way. I'm just answering your question.

A Warmoth body and neck are expensive. Why not read up on finishing and plan to do a proper job with proper materials.

 

[Zaphod B]

I have a little experience with hand-applied finishing on various cabinet-making projects that I've done over the years. For the last project I used a waterborne sealant/stain/poly top coat series of products made by Minwax. I've also done oil-based stains and poly top coats on various things, all hand-applied with rags and brushes, as I don't have any spraying equipment.

Anyhow, the vision isn't clearly formed yet, but let's say the body would be mahogany, perhaps with a spalted maple top. Neck of mahogany, ebony fingerboard.

The point would be to get an attractive finish but leave the instrument a bit vulnerable to bonks and dings, so that it can easily acquire character.

That's as far as I've gotten in my thinking so far.

 

[gvarko]

I am not light or muttley, but I would second the Tung oil. I have done a few refins in my day and Tung oil works best IMO. Nothing gives an even top coat with a minimalist finish like Tung oil. There's really no way to do it wrong. Just wipe on, let dry. Hit it with some super fine steel wool and repeat until you are satisfied.

 

[Zaphod B]

Thanks, guys. Any other opinions are appreciated.

I would like to add that I once finished a pair of oak-veneered speakers with some Formby's oil-based "hand-rub" poly, applying three thin coats with a rag with fine steel wool in between coats. The finish came out very nicely - enough coverage to protect the veneer, but thin enough that the structure of the grain is very visible. That's kind of where I'd like to go with the body, and I think the tung oil would serve well for that.

As for the neck, I really don't like sticky finishes on my necks, so I don't know what would be most appropriate.

 

[Light]

Oil finishes will void your warranty from Warmoth. They require a hard finish on most of their necks, except for oily woods like rosewood (necks or fingerboards). Also, as far as I'm concerned, they are right to do so. A guitar needs a good film finish to be stable. My recommendation would be either the Stew-Mac waterborne finish or a LMI's KTM-9 (which is a similar finish). Get Dan Erlewine's book on finishing, and follow the directions. The water borne finishes can be done well really quick (a week or two, compared to a month or two for a nitro finish); they can be brushed, sprayed, or wiped on; and they look pretty good. If you want a satin finish neck, don't polish it like the rest of the body, but just wet sand it to 320.

Or, if you haven't gotten the parts yet, have Warmoth finish them (their rates are stupid cheap, and their quality is quite decent).


Light

"Cowards can never be moral."
M.K. Gandhi

 

[muttley600]

Light, I didn't know Warmoth void the warranty if you use oil finishes. Why is that? By the way I've never had a stability problem with any Oil finish I've used. In fact I've got one I did in my front room now I did about eight years ago and it's as good as the day I finished it except for the usual scratch plate wear, it hasn't got one Its been gigged, taken camping, even been over the Andes!!! Euro Walnut back and sides, Euro Spruce top and Mahogany neck and Ebony for the Bridge and fingerboard. I did brace it quite stiff as I new I was going to be taking it around a bit but it sounds great, typical Walnut and Euro spruce mids and projection.

I have to admit for years I was worried about soft and thin finishes on guitars but I've come to really like em having done a few. As long as the guy or gal its for knows how to care for it. That said I wouldn't use it on a guitar that is gonna be worked very hard on the road and I only use it now when people ask for it. A lot of European makers are using Danish oil as an option these days at least those I have spoken to at recent get togethers.

I'm with you on the choice of StewMac and LMI products I've used both and they are great. Dan's book is also good for anyone who wants a comprehensive reference on finishing guitars. Money well spent.

 

[muttley600]

Thanks, guys. Any other opinions are appreciated.

I would like to add that I once finished a pair of oak-veneered speakers with some Formby's oil-based "hand-rub" poly, applying three thin coats with a rag with fine steel wool in between coats. The finish came out very nicely - enough coverage to protect the veneer, but thin enough that the structure of the grain is very visible. That's kind of where I'd like to go with the body, and I think the tung oil would serve well for that.

As for the neck, I really don't like sticky finishes on my necks, so I don't know what would be most appropriate.

The Tung Oil will do exactly that. As far as using it on the neck you may find that to be a problem at least until the finish has really cured. Tung oil like Danish oil has a habit of feeling tacky when it gets warmed up under the fingers for the first few months. I have used a wash coat of shellac on top of the oil on the neck and that can help. Like I said have a go on some junkers before you commit. The key to finishing is getting the process right from beginning to end whatever you use. The best way to get it right for those who haven't got a lot or experience is to test on scrap first. After 25 years I still do

 

[Zaphod B]

Thanks, Muttley and Light.

I will check out the products from Stew-Mac and LMI.

What's a good source for scrap wood that would approximate the characteristics of woods used on guitar necks and bodies? Does Warmoth sell scrap?

 

[muttley600]

What's a good source for scrap wood that would approximate the characteristics of woods used on guitar necks and bodies? Does Warmoth sell scrap?

I know its no good to you but I keep loads of off cuts just for that purpose. You need to match the colour and grain as close as possible whatever you do. I don't know what you local DIY hardware stores carry in the states but here you can get maple quite easily but the mahogany they sell is rubbish, very poor quality open grain African non descript and often mixed in terms of species. For the Mahogany you'll need to be more careful matching the grain and colour. There are hundreds of timbers sold as Mahogany and the spectrum of grain and colour is huge.

Try and befriend your local cabinet shops or picture framer. Most chuck loads of off cuts every week. They will mostly use good grade timber and will be able to tell you exactly what it is. A weeks worth of their off cuts will keep you in scrap for a good while. They rarely mind if you want to rummage through their trash. I have a few guys visit me to do just that every month or so.

Also a good way to practice your techniques is to get old guitars and strip em down and refinish. After all if it only cost you a tenner you can junk it while you learn. Better that than lose heart as you trash your new Warmoth kit

 

[Zaphod B]

Haha, excellent advice, Muttley - thanks!

 

[Milnoque]

Tung oil can react with some people's sweat. I don't recommend it for a guitar. I have used KTM-9 from Luthier's Merchantile ( lmii.com ) and liked it a lot. I also reccommend the guitar reranch site for info.

 

[Light]

Light, I didn't know Warmoth void the warranty if you use oil finishes. Why is that?

Because it can not provide the protection that they feel a guitar neck (particularly a maple neck) needs. I agree with them on this one, but I've said that enough times, at least for the time being. At a guess, they had a lot of problems with this back in the eighties, and got sick of replacing necks for people.


Light

"Cowards can never be moral."
M.K. Gandhi