Official Luthiers Forum!

Hiya gang -

There had been a few posts a week or so ago about using Tru-Oil as a finish.  I gave it a shot on my most recent build and have to say that it's the easiest appication I've ever done and feel I'll be pretty happy with the end result.  My only problem was with the dang Zpoxy underneath it all...have some high spots to contend with that are telegraphing through.  On the body, that is. 

The neck was sealed with four coats of 50/50 alcohol/Zpoxy wash applied with a rag, which turned out perfect.  On the body, I did the credit-card squeegee method and had the same problem I've always had, leaving an uneven surface (that only shows up after your first coat of anything shiny) after hours of relentless hand sanding.

Anyway, back to the Tru-Oil....my main question is how many coats to use, and do I dare machine buff?  the tute on LMI says to finish it off with some lemon oil and be done with it, wondering if buffing prior to that would be worth it?

I've used Tru Oil over ZPoxy on the neck of all my guitars (7) and have been very pleased with the results. I had been lightly buffing with 0000 steel wool after 5 or 6 coats and then putting on an ultra thin final coat. Currently I'm trying it on a body (Thanks to "Old Man" Ron) and have been very pleased with the results as well. Like you I sometimes get very small ridges on my final coat of ZPoxy. This time I sprayed a couple of coats of shellac and sanded back until the surface was smooth. I went with 6 coats of Tru Oil and lightly buffed with steel wool. For fun I hit it with Manzerna fine on my buffing wheel and it polished up up fairly easily. Not as quick as lacquer, but the shine seems comparable (to my eye anyway). It's also VERY easy to repair. I had a blemish on my headplate that I didn't like after buffing on the wheel. I went back to the steel wool and then another couple of coats of Tru Oil. A couple days to cure and it will be ready to buff. I'll post some pics tonight.

If you have high spots from the zpoxy pore fill then you did not level sand the zpoxy after cure and most certainly did not sand back to wood prior to the 60/40 alcohol/zpoxy wipe down or sand off any high spots after the wipe down cured.

It is not the fault of the zpoxy you just missed a step

Any finish to applied to any pore fill and or seal coat requires the those previous surface treatments be leveled prior to the application of any coatintg being applied over them.

I think there is still a difference in opinion in using z-poxy (or any epoxy grain filler) whether one should sand off all the way back to wood (risking sanding some pores all the way back and potentially pulling material out) vs. leaving a complete thin layer of epoxy (risking leaving too much material on, potentially leaving some unevenness and/or affecting the sound of the guitar).
This may be a topic for a different thread.
-j.

_________________
“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

Another Tru-oil question. How long between coats? I've seen discussions of a max of one a day to 3 or 4 per day. What's everybody think?

The only reason I could see for unlevelness if you leave the film on the body would be if you don't level sand the film after the cure

The only reason I could see for unlevelness if you sand back to wood and wash coat with the 60/40 cut would be is if you don't level sand out any high ridges you may have left after the wash coat. Which should be near none anyway

I keep reading of concerns that sanding back to wood risks pulling out the zpoxy from the pores. Out of some 30 or so guitars that I have zpoxy filled, including open pore woods, medium pore woods and tight pore woods, I have never had the zpoxy pull out. On some open pore wood I have sand too much and exposed pores That I had to refill, but that was my fault not the media.

When I sand back to the wood I am not concerned about removing all the zpoxy from the surface. But rather eliminating film thickness and leveling out. Once I have achieved this, I do the 60% alcohol/40% Zpoxy wipe down. this is so very thin it leaves no detectable film thickness. It only evens any color disparity

So I have some trouble seeing why you would ever have varying thickness of the Zpoxy prior to over coating unless you did not level the surface. Be it leaving some film thickness or sanding back to wood and adding a wash coat.

I can understand sanding through the top finish to the zpoxy if you leave a film. but this is no different than sanding through any finish. As soon as you see a sand through starting stop and work in other areas. Add more finish, cure and level again.

I've done 4 with Z-poxy and have never had a problem either, I just know some people had.
I watched a documentary once on surfboard building. When the guy was sanding level prior to his finish, he had an entire room dedicated to it. The raw board was elevated a little below chest level and he had a series of small floodlights on all sides of the room at the same level of the board and no overhead lights. This, he said, showed all of the flaws, highs, lows, and scratches. I tried it out at home. Dark room except for a couple lamps real low shining accross the guitar instead of down on it and man, does it work like a charm. My finish prep has been a breeze since I adopted that method.
-j.

_________________
“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

[QUOTE=MichaelP]The only reason I could see for unlevelness if you leave the film on the body would be if you don't level sand the film after the cure



The only reason I could see for unlevelness if you sand back to wood and wash coat with the 60/40 cut would be is if you don't level sand out any high ridges you may have left after the wash coat. Which should be near none anyway [/QUOTE]

Thanks for the reply, Michael.  Yup, I jumped the gun a little and simply didn't sand enough.  Well actually, I used "finishing pads" and steel wool because it doesn't load up like paper, which I now see to be a mistake.  When I hit it with some 320 paper, all those high spots pop right out....which you otherwise can't see when "white".

I was actually trying NOT to take it all the way back to bare wood but leave a thin level film...that's a good trick in itself.  Next time, back down to bare wood and then the wash coat, I'm sure it will turn out better as you described.

I'm learning!  Thanks again for the pointers.

[QUOTE=SStallings]Another Tru-oil question. How long between coats? I've seen discussions of a max of one a day to 3 or 4 per day. What's everybody think? [/QUOTE]

The tutorial on the LMI site says to "let dry for a few hours" between coats....I can vouch for that, although it's usually not even that long. That being the case, I can get 3-4 coats on in one evening.  Final curing time is one to two weeks, they claim.

A little tip here. don't try to sand to where you have bare wood everywhere. Instead sand till the thickness of the film is near nothing. This will probably leave you some places you have sanded through the zpoxy. Don't worry about that. the 60% alcohol/40% zpoxy wash will color the sanded through areas. If you try to sand till all the wood is perfectly bare of zpoxy everywhere you are likely to expose new open pores as it is hard to reach bare wood everywhere at the same time without sanding on the wood. Sand till the thickness in almost gone and level and do the wash. Then very lightly sand the wash coat with 320p just to add a tooth for your sealer and knock off any ridges you may have made when you did the wash coat.

As you get more experienced with using the finishing resin you will see why we all say during application work into the pores and scare off all excess zpoxy. Makes for far less work leveling out.

[QUOTE=MichaelP] A little tip here. don't try to sand to where you have bare wood everywhere. Instead sand till the thickness of the film is near nothing. This will probably leave you some places you have sanded through the zpoxy. Don't worry about that. the 60% alcohol/40% zpoxy wash will color the sanded through areas. [/QUOTE]

In my experience, this is true for woods which, if they oxidize to a darker color, were sanded just prior to the pore-fill. I had a mahogany neck which was sanded a couple weeks prior to pore filling. I ended up sanding through in a couple of spots and when I applied a little epoxy the color was different. Those spots still show up several years later.