tru-oil finish - ?

Merlemantel · #1 12-01-2023, 09:09 AM

What can you tell me about a tru-oil finish. Pros and cons?
Thanks

Rudy4 · #2 12-01-2023, 09:19 AM

Cons? It takes WAY too many coats to build a finish, and it can be problematic on softer woods because it does not offer the degree of protection that other finishes do. Anything beyond building the occasional instrument means taking far too much shop time to produce an acceptable finish.

Pros? It's often recommended by home shop folks who make one or two instruments a year because it's relatively foolproof. Once a builder gets a little more experience under their belt they usually move on to a more professional finish.

Merlemantel · #3 12-01-2023, 09:22 AM

Quote:

Originally Posted by Rudy4

Cons? It takes WAY too many coats to build a finish, and it can be problematic on softer woods because it does not offer the degree of protection that other finishes do. Anything beyond building the occasional instrument means taking far too much shop time to produce an acceptable finish.

Pros? It's often recommended by home shop folks who make one or two instruments a year because it's relatively foolproof. Once a builder gets a little more experience under their belt they usually move on to a more professional finish.

Thank you. I am looking at a Macassar Ebony + Cedar crossover built by a young but talented luthier. Was wondering about the finish. The guitar sounds and looks amazing, but the finish concerns me.

BradHall · #4 12-01-2023, 10:39 AM

I am one of the afore mentioned one to two builds a year. I used Tru Oil on my first 6 builds and found it ok, forgiving of minor mistakes, and durable. I moved to Clear Coat filler and water based wipe on poly and like it a lot more. It dries quickly so building coats is much easier. Less of a tendency to put it on too thick like I did with Tru Oil, although I still use it for necks.

GillanderGuitars · #5 12-01-2023, 06:27 PM

Have a look at Ken Parker’s archtop series on YouTube. There’s a lot to be said for TruOil if applied properly. Of course, any finish can be applied poorly. It goes on very thin, has a warm color to it, and is repairable. It can create a nice satin finish or be buffed carefully to a nice shine.

rick-slo · #6 12-01-2023, 06:57 PM

I built a few guitars back about fifty years ago and used Tru-Oil on all of them.
Mainly used it because relatively foul proof and easy. Not as much wood protection from scratches as some other finishes and not as shiny. Don't have to worry about temperature change finish cracks as you might get in lacquer. A good finish sonically.

srick · #7 12-01-2023, 06:59 PM

I just used tru-oil on the neck of my first build. The neck was a very open pore mahogany which I filled with GluBoost fill and finish CA (with a small amount of their brown tint). Excellent result.

I also finished the peghead with it, and that was problematic. It was very hard to get the flat glossy finish that I was looking for.

If you think about it, a gunstock is all curves, so a guitar neck is a perfect match.

koolimy · #8 12-05-2023, 01:08 PM

I think it's unfair to call tru-oil a less professional finish. Yes it is popular with hobbyists because of its ease of use, and yes, it doesn't offer as much protection as some other finishes, but as with any finish, it has its uses and can be perfectly fine for a guitar, as long as the application warrants the use of tru-oil.

I have used tru-oil on the necks of all of my builds and it works wonderfully. It is easy to apply, looks very good, and provides adequate protection. Most importantly, it feels very good to play. I would not hesitate to buy a custom guitar that uses tru-oil on the neck.

I have used it on the body of 1 acoustic guitar (and 2 electrics), and it worked fine for me. The body is more problematic because it gets bumped around more and can develop scratches easier. If you want more durability in your finish, tru-oil should not be the choice. But if you are a home player and you are okay with a few bumps and scratches here and there, tru-oil can be a viable choice.

I think the most controversial application of tru-oil is on the top. I have heard that oil based finishes can increase the damping of the top. I'm not sure if tru-oil is actually oil based, but there is the distinct possibility. Of course, increasing the damping of the top might not be a bad thing. It's all about the design goals. It will be more susceptible to bumps and scratches, but at the same time it'll be one of the thinnest finishes you can have. So there's pros and cons everywhere.

Regarding your guitar, if it has tru-oil on the top I would probably pass. You use cedar so that you can have low damping (Cedar has lower damping than Spruce), but tru-oil would mitigate that effect. Tru-oil on the B&S and neck I would probably be okay with, but it depends totally on your use case. If you want a more glassy finish and if you don't want scratches, it probably won't be your thing.

GillanderGuitars · #9 12-05-2023, 05:17 PM

I think the amount of dampening caused by truoil would really depend on how it’s applied. Again, any finish will dampen to a point, and that point will again vary due to how it’s applied. Truoil is a polymerized linseed oil. To reference Ken Parker again, he likened his application to the finish process of the violin world. The wood is sized traditionally with a protein base and then oil varnish is applied over it. The process he uses substitutes epoxy for the protein and truoil for the varnish. Both are applied so thin that it takes roughly 20 coats of truoil to get to .001”. Most consider .003” to be thin. The epoxy stops the truoil from penetrating the wood, thus minimizing the dampening effect. The more coats you build of truoil, the more shine can be achieved, and if you’re careful, it can be buffed. Also, similar to shellac, you he stuff is nice to work with and won’t kill you in the process. There is a lot to be said for truoil, if done properly and patiently.

jt1 · #10 12-06-2023, 05:35 PM

Quote:

Originally Posted by GillanderGuitars

...To reference Ken Parker again, he likened his application to the finish process of the violin world. The wood is sized traditionally with a protein base and then oil varnish is applied over it. The process he uses substitutes epoxy for the protein and truoil for the varnish. Both are applied so thin that it takes roughly 20 coats of truoil to get to .001”. Most consider .003” to be thin. ...

Thanks for referencing Ken and his guitars. I currently have one of Ken's guitars that he was kind enough to loan me. Everything about the instrument is extraordinary, including that micro-thin finish.

GillanderGuitars · #11 12-08-2023, 10:07 AM

Quote:

Originally Posted by jt1

Thanks for referencing Ken and his guitars. I currently have one of Ken's guitars that he was kind enough to loan me. Everything about the instrument is extraordinary, including that micro-thin finish.

That is very kind, but he’s that sort of guy! I have a huge appreciation for guys like Ken that are so willing to share all they know, especially when they’re as knowledgeable as Ken. Enjoy that guitar, they are incredible.

Side note, if this is John of the Kalamazoo Girls book, it was great to meet you and chat briefly at Woodstock!

Merlemantel · #12 12-08-2023, 10:40 AM

Quote:

Originally Posted by GillanderGuitars

I think the amount of dampening caused by truoil would really depend on how it’s applied. Again, any finish will dampen to a point, and that point will again vary due to how it’s applied. Truoil is a polymerized linseed oil. To reference Ken Parker again, he likened his application to the finish process of the violin world. The wood is sized traditionally with a protein base and then oil varnish is applied over it. The process he uses substitutes epoxy for the protein and truoil for the varnish. Both are applied so thin that it takes roughly 20 coats of truoil to get to .001”. Most consider .003” to be thin. The epoxy stops the truoil from penetrating the wood, thus minimizing the dampening effect. The more coats you build of truoil, the more shine can be achieved, and if you’re careful, it can be buffed. Also, similar to shellac, you he stuff is nice to work with and won’t kill you in the process. There is a lot to be said for truoil, if done properly and patiently.

Thank you. Great information. Very interesting.

GillanderGuitars · #13 12-08-2023, 10:52 AM

Quote:

Originally Posted by Merlemantel

Thank you. Great information. Very interesting.

You’re very welcome!

jt1 · #14 12-08-2023, 01:33 PM

Quote:

Originally Posted by GillanderGuitars

...Side note, if this is John of the Kalamazoo Girls book, it was great to meet you and chat briefly at Woodstock!

I am indeed that guy. It was great meeting you and your guitars!

Bluemonk · #15 12-10-2023, 08:33 AM

Quote:

Originally Posted by jt1

Thanks for referencing Ken and his guitars. I currently have one of Ken's guitars that he was kind enough to loan me. Everything about the instrument is extraordinary, including that micro-thin finish.

John, which of Ken's archtops do you have on loan? Congratulations. As you say, they are extraordinary.