Oil Questions

[Bmth Builder]

Hey I have a couple of questions about oil finishes for guitar that are confusing me and making me feel quite dumb for asking lol

I guess I dont really understand what a tru oil or tung oil finish actualy is? Its like varnashing a guitar right? It brings out the colours of the grain for a natural looking finish?

But what does it feel like to actualy play? Is it actualy just like varnishing wood where you can still feel the grain and texture of the wood but its just protected against the elements? Or does it end up smooth like a lacquer finish?

I cant say I would enjoy playing a guitar that actually feels like wood (though I do like natural finishes so you can see the grain), I like resting my arms and hands on the smooth finish of lacquer.

Can moisture get through oil finishes?

Also I have heard shellac is the best way to bring out the grain of wood, is this true? in essence what is shellac, just another type of lacquer finish?

Sorry for the essay, please dont laugh at me haha

[low end fuzz]

this is very searchable,

but tru-oil and wipe on poly, are basically varishes thinned down so much that you can apply them with a rag, they still get a lil absorbed into the wood, but they also build on the surface; which is better for protecting; they still have a hand rubbed feel and look for the most part;

any 'transparent' finish will show the grain

tung oil is a chinese oil from a tree or something, this is the real stuff, you can make this stuff feel like suede, it takes roughly 2-3 months to completly cure on the surface; not that you cant use it, but it will smell and the fact is, its not cured;

this really has no protection from any hits or bumps , but as a feature is the best for keeping moisture out because of how deeply its penetrated the wood, and it makes wood look amazing;

my personal fav. is lacquer the body and oil the neck, if you got time go for the tung if not i use wipe on poly and steel wool the 3rd and final coat;

if its a hand rubbed finish for the whole body its all w.o.p. and sanding is depentant on request

[DC Ross]

this is very searchable

Try searching for tru-oil

[CrazyManAndy]

There have been quite a few topics on this subject of late. You probably won't get any results by searching for "tru-oil" or "tru oil". Try "truoil".

CMA

Edited May 3, 2008 by CrazyManAndy

[fryovanni]

Here is a link to LMI's descriptions of different finishes-link

Most of the oil finishes you will find are polymerized linseed or tung oil. Basically a varnish/oil blend. The varnish is what builds and provides a film finish. To me the oil is not really something I want in a finish on my instruments (my logic is really simple, tap a piece of oil soaked wood, it sounds dead as a doornail. That is my only logic in not wanting much oil penetrating my instruments* only my opinion be it right or wrong). Shellac(wash coat) is a light surface finish that can also be used as a sealer to limit penetration of oils. Oil finishes can have the best look in terms of allowing the natural look of the wood to come through very well. Most shellac has a more color, and is not going to have that clarity. That can be good or bad (I often want a bit of color from shellac). These finishes do not have the durabiity that you get with many other sprayed finishes, but they are easier to repair in most cases. Both Shellac and Polymerized oil finishes are designed to be applied thin and build to a light finish(you do not brush these on heavy as they will not cure properly). You can grain fill if you prefer a smooth finish(Z-poxy fill is a nice and easy), or you can use them without filling also.

Any film finish catalized Polyester to True Oil will not stop the transfer of moisture vapor. They all offer great liquid moisture protection. Depending on the finish and how evenly it is applied you will slow the transfer of vapor at different rates. No matter what your goal should be to apply an even coat, as this optimizes the protection to thickness ratio. Thin very even film finish protects as well as a thick sloppy finish. Good surface preperation is very important with hand rubbed finishes, and because they are so thin great care should be taken to not sand/polish through them.

Rich

[ihocky2]

Edited: incorrect info removed.

For the OP, your best bet is to get Bob Flexners book on Understanding Wood Finishes. He gets very into detail and dispells a lot of common myths. Out of the oil finishes the only true oils are Tung or Linseed (straight or boiled). The rest are either a wiping varnish or polymerized oil, even though the name says something different.

[low end fuzz]

ive got that book, second revision and everything;

"though too thin to resist scraching or water vapour, it has established a firm position in the paint and coatings because it is one of the most water resistant oils"

my point was wanting to use oil on the neck and using the best for keeping beer and sweat from entering the neck;

there isnt any finish you could apply that would guarentee water vapour from passing through thats why you keep your prize instruments in climate control;

tung oil may not 'fully cure' but after a few months its as 'cured' as its gonna be

[ihocky2]

ive got that book, second revision and everything;

"though too thin to resist scraching or water vapour, it has established a firm position in the paint and coatings because it is one of the most water resistant oils"

my point was wanting to use oil on the neck and using the best for keeping beer and sweat from entering the neck;

there isnt any finish you could apply that would guarentee water vapour from passing through thats why you keep your prize instruments in climate control;

tung oil may not 'fully cure' but after a few months its as 'cured' as its gonna be

I do have to appologize, I spoke too soon. After I went back and double checked that book everything you said is completely correct, I had crossed it in my mind with linseed oil which is the one that is not quite as effective. I will still disagree that using it to prevent stains from beer and straight liquid is a bad idea, since it will still absorb them. But as for the water vapor exchange, it is a good choice. But it is one that does need occasional coats placed on in the future. O went back and edited the post so that the incorrect information is not in there to confuse future readers.

[fryovanni]

But what does it feel like to actualy play? Is it actualy just like varnishing wood where you can still feel the grain and texture of the wood but its just protected against the elements? Or does it end up smooth like a lacquer finish?

I cant say I would enjoy playing a guitar that actually feels like wood (though I do like natural finishes so you can see the grain), I like resting my arms and hands on the smooth finish of lacquer.

Also I have heard shellac is the best way to bring out the grain of wood, is this true? in essence what is shellac, just another type of lacquer finish?

Neil,

I dug up a couple pictures of a project I am working on that has a hand rubbed finish (French Polish, Shellac). I sand to 240, then I fill with epoxy, cut that back and level with 800 grit, then go to building sessions with hand rubbed shellac. After the building sessions(which is actually where the guitar pictured is at) I level sand with 1500 and work my way up to 12000 grit and buff. One nice thing about shellac is it is dirt cheap to get set up. Shellac flakes for about 15-20 guitars will run $15, Denatured alcohol or Everclear is used to cut the shellac(again not too expensive), Extra virgin Olive oil(a little goes a long ways), old cut up white T-shirts, and wool(second hand store, old sweater lasts for many guitars), Sand paper, and I like a dense felt block, and finally Epoxy coating(not glue, this is finish, it dries much slower and is also much thinner) which probabaly costs as much as all my other supplies(but a table spoon or two will fill a guitar, so it is still relatively cheap per. guitar). The picture should give you an idea as to how important fill and prep is, as the finish is only built up it has not been leveled or polished(ruff so to speak). Look at the color also, this is one of the lighter shellacs(you can get slightly clearer), but true oil would introduce less color.

Here are a few better shots of the body, look at the Maple to see how the color of the shellac looks(it is pretty white maple binding).

link1

link2

link3

link4

Hope that gives you some answers, and a better idea of what you can expect from hand rubbed a finish. You likely can do a better job than me finishing, as finishing is really not my strongest suit .

Peace,Rich