Tung Oil - Who Uses It And What Kind Do You Like

[erikbojerik]

Doug, when you say "that gun oil" are you really referring to Tru Oil? Might you be referring to the oil that the gun guys use on the metal parts of the artillery (which is a real mineral oil)? That stuff does stink.

I used Tru Oil (Birchwood Casey...I don't think there are any others) on my bass proj, and I found that while there was a definite odor, it was fairly pleasant (like raw nuts) and didn't exactly fill the room. In fact, the reason I liked it is because I could apply the finish in my basement in the winter without stinking up the rest of the house (finishing in the same room as the furnace...).

It does build, but slowly as you are supposed to apply it thin. I put on the first 3 coats thick, full strength, and wiped off, let dry for a day, then applied full strength as thin as I possibly could 3 coats a day (20 min between) for 8-9 days, letting it sit 3 hours and scuffing with 1000 grit Abralon pad at the end of each day. The last 10 coats or so were cut 50/50 with naptha, which gave it a real nice shine. Gentle Tshirt buff after that, almost poly-like gloss. Almost, but not quite.

I applied about 40 coats in all. It filled the grain of flame maple nicely, bocote and walnut somewhat (it was perfectly level at the beginning but shrank in slightly over the next couple of months), and padauk not at all. I really like the feel of it and it was dead easy. The padauk has also surprisingly retained a nice blood red color for over a year (indoors away from the windows).

I would not use it on the soundboard of an acoustic, because it is a penetrating finish that would dampen the response. It would be great on the neck.

I have no experience with tung oil, which I understand is a different beast. Tru Oil is closer to a varnish I think.

[ooten2]

When using Danish oil or Tung oil, this is the procedure that I have used. I try to stick to it as much as my patience and finger cramps will allow.

http://home.insightbb.com/~jpaquay/oil_fin.txt

I am very happy with Formby's tung oil on necks, because it leaves a very slick and very natural woody feel. It does seem a little watery when applying, and takes a full day before the sticky is gone and ready for the next application.

I'm not so up on Danish oil because it seems to darken the wood too much and to my nose it stinks worse than some chemical plants I've worked at. (ok, not quite that bad!) That was Watco Danish oil, anyway, and the smell seems to linger for months and months on the guitar.

On my last 3 projects, I've switched to Tru Oil. It seems to build faster then tung, dries quicker, and is easier to get a good shine, if that's what you're after. It certainly has a smell, too, but to my nose it's not so bad, actually smells kinda good. And the smell goes away ALOT sooner than the Watco Danish oil.

As of right now, my preference is to put Tru Oil on the body, and Formby's Tung oil on the neck.

Edited November 9, 2006 by ooten2

[Mickguard]

Doug: the stuff I've been working with is a varnish, actually it's marketed as a marine varnish, not quite the same thing as Tru-oil, I guess. What I like about it is that it gives a nice hard and glossy surface. It's really hard to tell from an ordinary finish at a distance, but it's much smoother and warmer to the touch. It's quite resistant too, and waterproof as well. But since it's only plant oils (those other oils have petrochemical additives in them) it starts to cure as soon as the air touches it. Mostly that means it skins over, and the 'crystals' happen when tiny bits of skin get mixed back into the soup.

[doug]

Sorry, it's the Birchwood-Casey that I referred to. To me it was nasty smelling. Used it a couple more times just to make sure about it, then put it on the shelf and never opened it again. Yeah, I know it's polular so don't be offended. This thread is for voicing experienced opinions afterall.

ooten2 mentions build. Well that's another subject. Tung oils (and Danish) are typically made to go into the wood, not on it. Honestly I'm not sure what Tru-Oil is, but it may be a finish that goes on top.

As I mentioned earlier, each finish has unique characteristics and purpose. I use tung oil for sealing a wood surface that I want to leave feeling and looking like wood. That means I make no attempt to build anything on the surface any more then it takes to close the pores.

Varnish is for surface building. It soaks in some, but mainly it goes on top. It's forgiving and can be applied almost any way you can think of from spray to paint brush.

Great dialog!!!

-Doug

[erikbojerik]

The MSDS for Tru Oil gives 56% "mineral spirits", 33% "modified oils" and 11% "linseed oil". Pretty helpful, eh?

I think if I stopped after 2-3 coats of Tru Oil, I'd get the same woody effect that Doug gets with tung. But Tru Oil has no poly, so the finish may not be as hard. I will try this with the neck on my current acoustic proj (flamed walnut).

Some people do shoot Tru Oil, and there's a thinned-out rattle can version available. It definitely builds, to me it acts more like a varnish than a pure oil.

[ooten2]

I totally agree about Tru Oil, it behaves differently than other "oils". But I still think it smells ok.

If tung oil is made to go into the wood, and tru oil does go on top, that's probably why I prefer tung oil on the neck. It feels more "woody" to me and less "finished". However, I'm not knocking tru oil for necks, because it feels nice, too. I prefer both of them over a lacquered neck.

I would also be interested if anyone has good results with coloring while using an oil finish.

[fryovanni]

I have never done a full guitar in an oil finish, but I am kinda curious. When you guys are applying the finish. Do you burn in each subsequent layer, rubbing the new finish into the previous coat? Or is it a series of layers that cure. I read through the grain fill method in the link above. A little different than what I do with the Pumice during the grain fill stage(Shellac/FP), but the idea is similar. Is there a special method you use to apply the finish(in terms of rubbing), or is it more of a wipe it on thick let it set/ wipe it off. Sorry if the questions are a little basic. I am just trying to better understand the process.

Peace,Rich

Nevermind; I did some research. Each layer cures seperately(no melt in). Wipe on Wipe off. I did notice that using shellac as a sealer or wash coat is recommended, and also commonly used as grain filler method(same technique as French Polish). Nifty finish. I will have to give it a go one of these days.

Edited November 9, 2006 by fryovanni

[Mickguard]

The MSDS for Tru Oil gives 56% "mineral spirits", 33% "modified oils" and 11% "linseed oil". Pretty helpful, eh?

Yes, it is. Takes all the mystique away. Reads more like snake oil.

[doug]

I could never really figure out what the shellac coat is for. It almost makes no sense. Both make wonderful sealers and fiber stiffeners, but it just seems like a nice polymerzed blended tung oil should be just fine alone. However, I can see shellac being used to fill grain like French polish. Then again, that defeats the purpose of using oil. Oil doesn't really fill larger grain as others have already identified.

There are several varieties of oil based dyes that can be mixed right in the tung oil. They produce translucent color. Yes, they take on that amber too. So blue dye looks greenish (blue+yellow=green). I've used it on toys, clocks, curios, and jewlery boxes for effect. Just remember that it should have many overcoats after the dye stage.

-Doug

[erikbojerik]

I could never really figure out what the shellac coat is for.

I agree. I never bothered with it, just went straight Tru Oil. It definitely penetrates, but also builds.

Rich, the way I did it was to take a white cotton T-shirt and cut it up into 2"x2" squares. Put a cotton ball in the middle, fold the corners up and tie it closed (twist-tie) and you have a disposable wiper. You saturate the cotton ball and have at it. Use it as long as it stays wet, then chuck it.

Tru Oil cures like poly; if you apply tack coats on top of one another, a few at a time, they will bite back. If you let it dry completely between coats, you need to scuff sand before the next coat. If you sand through the coats, you get witness lines etc but they're easily covered by the next coat.

[ooten2]

For my applications I've used old socks or an old T shirts. I've never tryed shellac either.

When using tung or danish oil, I go heavy on the first coat. On the second coat I use steel wool or very fine wet/dry sandpaper with oil to fill the pores. After that, daily steel wool scuff and light coats of oil, just wipe on, wait a few minutes, wipe off. I do most of my guitar-related work on weekends, so usually I start the finishing on a Saturday, and end up the following weekend, so I would guess I put on around 7 coats total.

For tru oil, I just do the wipe on and off thing without the pore filling. I do hit it with steel wool in between coats. The manufacturer says you can re-coat in like a couple of hours or something, but I like to wait a full day.

Hey Rich, the guitar I made with the myrtle and limba I bought from you was finished with tru oil. To me, the myrtle looks great, and the limba is simply fantastic. But the myrtle gets the attention of everyone that I show the guitar to. That myrtle is just wonderful stuff! Anyway, I would suggest buying a bottle of tru oil (here it's available at Wal Mart in the gun section for less than $5), and trying it out on something. Don't need any fancy expensive application equipment, just an old sock.

Erikbojerik, I'm currently working on a peruvian walnut project. Can't wait to see the results, as I've heard from several that walnut looks great with oil finishes. Would you recommend pore filling walnut when using tru oil? Thanks.

Great thread!!

[fryovanni]

Doug, Erik- Like I said I am not familiar enough with oil finishes to say why a shellac coat would be used. If it is on acoustics it may be used to limit the penetration???(total guess....) I can understand why you would opt for a french polish style of filler. It burns 100%, is super thin, allows you to flash off the surface cleanly(and reapeatedly in a short period of time). Grain fill is extreamly fast with french polish.

I guess I am a bit torn. I hate sanding, and french polish requires next to no finish sanding. Applying French Polish finish does take a bit of time. I like the speed of shooting a finish, but it seems like oil finishes are tuff because you have to apply by hand, and sand more frequently. I suppose I just need to give it a go, and see how it goes.

Erik- If you are grain filling. Have you ever tried french polish style grain fill with pummice?

P.S. I have already picked some up to do a little test work.

Peace,Rich

Edited November 10, 2006 by fryovanni

[Mattia]

Shellac coats are semi-regularly used on acoustic instruments for the simple reason that oils dampen vibration. This includes most oil vanishes. Shellac, on the other hand, dries so hard it can actually decrease the damping of a piece of finished wood, make it transmit sound better. So: seal with shellac, prevent the oil from soaking into the wood, voila.

Personally, I'd do the shellac seal if I was thinking of oiling an acoustic guitar top, but back and sides are likely moot...

[doug]

Interesting point about the shellac and dampening. I might have to give it a try too one of these days. Not to keen on grain filling though, but a wash coat sounds good. Something about having the grain feel, I just like it.

What type/brand of shellac do you like Mattia? Do you use the flakes, or pre-mixed stuff? Blonde or amber?

-Doug

[Mattia]

Flakes, get them locally, dissolved in denatured alky. Dewaxed, generally, and usually blonde although I'm not averse to a bit of colour.

[erikbojerik]

I did not grain fill on my bass, as I didn't really care if the pores showed or not. I tried to just get the Tru Oil to fill the grain, but was only semi-successful (with 40 thin coats).

Yeah, if you don't want the pores showing, you should grain fill the walnut. Either way it will look spectacular under the TO.

I might try French Polishing on the rosewood back & sides and neck of my acoustic proj. And now I'm thinking I may try the shellac + oil on the spruce top, provided it looks good on scrap.

Because the TO goes on so thin, you don't have to "sand" as much as you think, no more than a scuff really. The last 5 coats I did (cut 50/50 with naptha) I didn't even bother to level, it flowed out so nicely and cured very shiny.

[fryovanni]

I did not grain fill on my bass, as I didn't really care if the pores showed or not. I tried to just get the Tru Oil to fill the grain, but was only semi-successful (with 40 thin coats).

Yeah, if you don't want the pores showing, you should grain fill the walnut. Either way it will look spectacular under the TO.

I might try French Polishing on the rosewood back & sides and neck of my acoustic proj. And now I'm thinking I may try the shellac + oil on the spruce top, provided it looks good on scrap.

Because the TO goes on so thin, you don't have to "sand" as much as you think, no more than a scuff really. The last 5 coats I did (cut 50/50 with naptha) I didn't even bother to level, it flowed out so nicely and cured very shiny.

I will give the TO a shot. I am curious to see if it will take a high polish.

If you try FP it does take a little getting used to. The real trick is getting the right amount of alc./shellac/ and oil loaded, and of course keeping the speed you rub at correct. Since you are working with a hot surface. You basicaly have a trail behind the cloth that is new plus melted shellac. You have to get enough solvent to burn, but not so much that it doesn't flash back before you go over your trail on the next pass. After you get it down it is like butter. Really after grain fill it will be smooth and shiny(first day). If you work it for about a week 1 session a night it will have plenty of build to polish and buff. The key to FP is less is more. Don't try to put too much on because it will get too thick and you will have a mess(takes a fraction of the effort if you just press thin coats, as you really don't need thick coats to get a killer finish.

Peace,Rich

[doug]

So what happens after let's say 6 months? Does the French polish shrink into the grain? FP is an age old highly regarded method of instument finishing so it must be good. Some day I'm going to have to give it a shot.

-Doug

[fryovanni]

So what happens after let's say 6 months? Does the French polish shrink into the grain? FP is an age old highly regarded method of instument finishing so it must be good. Some day I'm going to have to give it a shot.

-Doug

Not really. It could if you went too thick I suppose. The idea is to flash fast thin coats. If you need to touch it up in three years you use the same process as building coats. Just melt more coats in(again not too hot, just enough to melt a bit and add a bit). Very forgiving down the road. Unlike a poly it does not have individual layers. It is pretty hard to screw up as long as you get the process, and you can totally repair any glitches along the way(or down the road as I mentioned above). Good finish for a low tech moran like myself.

Peace,Rich

Edit; Doug. I hope I read your question correctly. If you were taking more about the grain fill itself. The grains are not filled with a thick glob of Shellac. It is mainly Pumice and surface wood that gets picked up as you polish it down into the pours(looks very nice IMO). Some people that FP also use other fill methods(zpoxy, CA or what have you). You can also use CA as spot filler during the FP grain fill process for spot repair(if it is needed).

Edited November 10, 2006 by fryovanni

[brian d]

It is mainly Pumice and surface wood that gets picked up as you polish it down into the pours(looks very nice IMO).

Rich, does the pumice actually get left mixed with the shellac for the grain fill? Pumice is grey coloured isn't it? Do you have any good links for basic FP process?

Thanks,

Brian.

[fryovanni]

It is mainly Pumice and surface wood that gets picked up as you polish it down into the pours(looks very nice IMO).

Rich, does the pumice actually get left mixed with the shellac for the grain fill? Pumice is grey coloured isn't it? Do you have any good links for basic FP process?

Thanks,

Brian.

Some of it does collect, but mind you I am talking about using very small amounts. I sprinkle a bit on a paper and just pick up tiny amounts on the pad I am using(I think it is called a munica? a bit of wool rapped in old T shirt material). A small dusting on a piece of paper does a very large area. You rub the surface(which is like sanding with the pumice) both picking up some wood dust and shellac and pumice. All of which winds up being slowely pushed into the grain. After it is pretty level. You wipe the surface with a clean cloth loaded with a bit of alcohol(that removes any pumice that is just setting on the top, kinda cleans). The pours wind up looking several shades darker than the rest of the surface. This sapele was filled using this method-click. That and this pic are both taken just after grain fill (no building coats yet)-click. I am kinda glad I took those as I think I have used them like three times in the last week or so as examples.

I will look around for a link to a web site with directions. I know I learned how to do this from a very good site I found some time ago.

This is a good one-link1

Here is a fair link. This has an animated gif that shows you what it looks like when the the tail from the rag is flashing correctly. This is a very accurate picture of what you want to have happening(your load and speed are working right)-link2

Peace,Rich

P.S. I would say I can get a nice looking finish French Polishing, but I am anything but a master hand rubbed finisher. I prefer to shoot, but my schedule is just not making it possible right now(French polishing can be done later at night which works for me right now). So if you have any advanced questions I am going to not be much help.

Edited November 11, 2006 by fryovanni

[ooten2]

Wow, Rich. That sapele looks really great.

Edit: Cool links, too. I'm getting into this FP thing, might have to give it a go sometime soon.

But I'm still going to do the tru oil thing on the walnut. I think I'll skip the pore fill. I didn't fill the limba project and was really happy with the results. Thanks for all the great info guys, this thread is giving me a ton of good info.

Edited November 11, 2006 by ooten2

[fryovanni]

Wow, Rich. That sapele looks really great.

Thank dude. I think the tree is doing most of the work . I am a fan of Sapele's natural color.

Peace,Rich

[brian d]

Thanks Rich,

That Sapele is gorgeous. I have a lot of reading and experimenting to do with FP now. Thanks for the links and your input, that gives me a starting point at least.

Regards,

Brian.

[fryovanni]

Thanks Rich,

That Sapele is gorgeous. I have a lot of reading and experimenting to do with FP now. Thanks for the links and your input, that gives me a starting point at least.

Regards,

Brian.

Brian,

If you want to give it a go. Find some old real wool socks or a sweater(I picked up a $2 second hand wool sweater), and some worn out T-shirts. Cut them up just like they describe on those pages(small bundle of wool-not too big and wrap it up and twist tight). Beyond that you can pick up a pound of ultra amber flakes(maybe $20), a jug of denatured Alcohol($6), a can of pumice(like $5), a jar of extra virgin olive oil($3), and three nice jars with tips that can drip. The flakes will do several guitars. A small amount of pumice will last forever. Very inexpensive to get set up. Maybe $35 will set you up for 3 or 4 guitars. It is a real hands on kinda thing. Read up, but the whole trick is in loading and rubbing.

Peace,Rich