Tell Us The Definitive Way to FInish With Tru/Tung Oil


I'm a Newb here and to guitar building. I am planning on constructing my first guitar in the upcoming weeks. I plan on finishing my guitars body with tru-oil, or a similar oil based varnish but have has some real trouble finding a solid method that is clear and easy to read. There are many posts, but the methods are spread out over 10's of posts and hard to follow.

So I want all you Tru/Tung Oil buffs to post your definitive way to finish a guitar body, with pics of the process if you have any, or at least pics of the final product. Don't forget to include what you sealed the grain with, and how durable your finish is!

I think this could be a really good resource for the new kids on the block, so come on, help us out!
1.  always use a sanding block like the 3m one.  home depot
2.  fill with water based filler, black, brown, or clear - repeat as needed to totally fill the pores.
3  when sanding back, use premium grade of sandpaper - it lasts longer, works better on sanding blocks.  home depot
4.  apply oils in the thinnest humanly possible coat - after coat #1 that is.  Coat #1 should be a little heavier to fill any remaining micro-pores, then wiped off so its a thin coat when you leave it to dry
5  dry thoroughly - oils air cure and might feel dry, but they're not.  Give them at least a few days if not longer, like a week, between coats.  Keep coats THIN as humanly possible
6.  no need to sand real oils (ie, pure tung), but you might want to sand or steel wool (synthetic) the 2nd to last tru-oil coat.

Pure tung oil is a preferable finish to tru-oil in my opinion.  It wears well, better than tru-oil, and goes on thin and tough.  It can be buffed to semi-gloss, and touched up with no sanding or muss.  Just reapply and wipe excess off, repeat to build the "depth" you like to blend with the surrounding finish.

however, if tru-oil you must...  then use it THIN or it will go gummy on ya.  THIN.  repeat THIN!~  Thanks~

#320 grit s/paper of coz..  apply the Tung-oil/whatsoevaoil  across the wood grains...

*optional (apply wood stains ~amber~, if you like it to look a bit "vintage" :glasses9:..) 
Just one additional note - using the Birchwood-Casey brand of Tru-oil - it dries a LOT faster than pure tung oil; in sub-optimal drying conditions (my basement in winter with furnaces and dehumidifier going constantly) the extremely thin coats of Tru-oil would dry in 12 hours typically; tung oil applied the same way would take 2-4 times as long.
greenplastic said:
Thnks for your reply CB.

When you sand back, which grade or grades of sandpaper do you use?

First fills - 220 is fine.  Last fills 320 is the way to go - always with the grain.  Last fills can be lighter, easier to sand.
So, would it be true to say that sanding with 0000 steel wool is useless between coats of pure tung oil?

How many coats would you recommend or both pure tung and tru oil? And how should it be buffed?
I've personally had bad experiences with any sandpaper ( up to 2000 and even wet sanding) on tru oil : for me it is very quick sand through and instant witness lines / leopard spots when trying to take down the orange peel of a sprayed coat etc.
I found out micromesh works a lot better for me, I'd use 3200 to remove any runs or big flaw ( mainly get these when spraying, less likely when wiping ), 4000 to level and then 6000 - 8000 to get some shine back.
Then polishing compound after the last coat.
oil finish is not a grain filler.... let me repeat... oil finish is not a grain filler

if you properly care for the grain fisrt - and make things smooth, then the oil will go down on that wood like nobody's business and you'll get a really smooth finish

Tru-0il is not oil.  Let me repeat.  Tru-Oil is not oil.  Its a varnish - treated with some natural oils, but it is not oil.  Treat Tru-Oil as if the bottle said "varnish".  Its a petrochemical product, and it dries harder than oils.  The only thing "oil" about Tru-Oil is that you apply it with your fingers like oil.  It MUST be applied super thin.... Do not try to fill grain with it.  Applied thin, it dries reasonably hard and will not gum.  Because its a varnish, you can knock the shine off it with a synthetic pad or 00 wool.  You dont need 0000 wool.  You just want to tooth it up a little.  The last coat can be buffed a bit if you want shine, or 0000 wool'd if you want matte.
I've found that wiping on tru-oil with paper towels works well... it gives a super thin coat.  It gets tacky in minutes and is dry in about an hour.
There's a line there about paper towels vs getting yer fingers into things... but it was regarding diaper duty, something that I have almost no experience with.
But if I wet sand with the tru oil, it can fill the grain correct?

I have found a product here in Australia which can be found here:

It says it can be used on gunstocks so I assume it is similar to tru oil. The info there says that it can be used for wet sanding to fill the grain and achieve a high lustre finish. Here are the instructions for their wet sanding:

Would finishing a guitar this way work well? Keep in mind I am a beginner and have never finished a guitar before.

I have found a pure tung oil. Would it be better just using a water based grain filler and oil it that way rather than using the bove product?

CB - do you have any picture of the guitars you have finished using your techinique?
Never heard of or used the product you mention. That being said, although you could theoretically grain fill with tung oil or Tru-oil, I'd wager you don't have the patience to apply the 100+ coats necessary to do so; in the case of something really widely/deeply grained like swamp ash, you might not ever get it to fill properly.

Water based or other proper grain fillers will do the trick much more easily and quickly, not a step you want to skip
i beleive the idea is to wet sand the oil with more oil and it forms a paste with the sawdust filling the grains.
the problem with that is going to be the drying times. i'm sure you'll be happier filling the grain and then applying oil thin, at least then you know it will dry.
Gunstock picture do?  I generally dont do oil on guitars for me, preferring lacquer fume madness instead.  Trying to think here... I do have one neck here thats oil finished.  Couple of gunstocks too.  No guitar bodies tho.  Let me know what you want to see.

>added later<
dunno if its what you want, but you can see the filling technique in another thread I just started
Tru Oil is advertised as being a filler as well as a finish.  I haven't applied enough coats to verify this.
I'll be finishing a Walnut body. I don't know how closely grained it is though as I haven't got it yet - should be here by the end of the week.

Any specific comments regarding finishing Walnut?

A Gunstock picture would be great CB  :icon_biggrin:
k, let me see what I can dig out of the safe and snap a shot of

I'm thinknig the Kimber stock came out really nice and I've got a Winchester 94 that did ok too.  I dunno, I'll find some goodies, maybe a baddy too for comparison.
a couple of final questions before I place my order...

- is this product as good as the milkpaint one?
I prefer to order with woodcraft, since I have an account there, and I will be able to order everyting in one go at the same place..;)

- what is a good alternative to Citrus Solvent to cut the first coat of tung oil? Citrus solvent seems quite expensive and comes in large containers only.

- will Mahogany colorered filler add any good effect on Black Korina as opposed to clear (Natural) filler?
is this what I need?

- Will this be a good alternative for 0000 steelwool ?
I haven't been able to find this in any Home Depot type of store so far..

I ordered the oil filler..

Can somebody confirm the Solvent thing? can I use regular paint thinner?
Also, where can I buy micromesh?