Birchwood Tru-oil Finish?

[H R Fisher]

  I have heard that some use tru-oil over oil varnish than polish with 8000 grit micro mesh for their final finish.

i would like to hear your thots.   Thanks  Henry

[Violadamore]

6 minutes ago, H R Fisher said:

  I have heard that some use tru-oil over oil varnish than polish with 8000 grit micro mesh for their final finish.

i would like to hear your thots.   Thanks  Henry

It's great for gunstocks.  I wouldn't put it on a violin.  

[Marty Kasprzyk]

24 minutes ago, Violadamore said:

It's great for gunstocks.  I wouldn't put it on a violin.  

Why not? 

Is it ok to use it on violas?

[Dr. Mark]

1 hour ago, Marty Kasprzyk said:

Is it ok to use it on violas?

Can't anything be used on violas?

[ke0777]

2 hours ago, H R Fisher said:

  I have heard that some use tru-oil over oil varnish than polish with 8000 grit micro mesh for their final finish.

i would like to hear your thots.   Thanks  Henry

Tru-oil is very interesting and easy/quick to apply (especially if we compare it to french polishing for example). I've tried using it as a finishing step (I dilute it with a bit of OMS) and so far it seems like it is doing okay, but I'm not sure how stable it is long term. I think it's worth to test it out and see if you like it! 

[HoGo]

Many mandolin makers use Tru oil as their main finish. It's a bit on the lean side making more flexible film than typical old school oil varnish but nothing really wrong. Can be applied thinly and can be colored and also brushed. It certainly won't crack or chip anytime soon.

I think Michael Darnton showed herea a violin he varnished with TO few years back. 

[Rico Suave]

1 hour ago, ke0777 said:

Tru-oil is very interesting and easy/quick to apply (especially if we compare it to french polishing for example). I've tried using it as a finishing step (I dilute it with a bit of OMS) and so far it seems like it is doing okay, but I'm not sure how stable it is long term. I think it's worth to test it out and see if you like it! 

Wood is wood. 

I finished my first Fiddle with TO over 25 years ago, which still have and use. I recently started to repair the finish with TO to fill in some fingernail scratches/dents that followed some belly growth rings which were imparted by my bored kid in in Middle School and/or HS Orchestra Class.

TO has held up to near daily use on this fiddle with a few breaks over the years. 

I like the ease of use and durability for both my (mostly) Curly Maple Flintlock Longrifle Gunstocks and mixed wood Fiddles.

I typically dilute TO with a little mineral spirits, usually applied with a fingertip and sometimes a brush, then rub out the dried glossy finish to a soft sheen with a 3M Ultrafine Pad, then wax with Carnuba.

[Don Noon]

It's pretty much colorless, so you'd need to either use it as a clear final finish, or somehow add colorant to it.  I haven't used or tested it, but it's pretty widely used for gunstocks, and there may be a good reason for that.

[Rico Suave]

8 minutes ago, Don Noon said:

It's pretty much colorless, so you'd need to either use it as a clear final finish, or somehow add colorant to it.  I haven't used or tested it, but it's pretty widely used for gunstocks, and there may be a good reason for that.

Good point - Since TO is Boiled Linseed Oil based,  I use a toothpick's tip amount of Artists (linseed) oil paint to tint when I mix in the mineral spirits. It dries slow enough that I can usually overlap areas before it starts to dry too much. Elsewise, I'll thin the next section with a little more mineral spirits - I use a pipettefor for adding mineral spirits.

[ke0777]

2 hours ago, Rico Suave said:

Wood is wood. 

I finished my first Fiddle with TO over 25 years ago, which still have and use. I recently started to repair the finish with TO to fill in some fingernail scratches/dents that followed some belly growth rings which were imparted by my bored kid in in Middle School and/or HS Orchestra Class.

TO has held up to near daily use on this fiddle with a few breaks over the years. 

I like the ease of use and durability for both my (mostly) Curly Maple Flintlock Longrifle Gunstocks and mixed wood Fiddles.

I typically dilute TO with a little mineral spirits, usually applied with a fingertip and sometimes a brush, then rub out the dried glossy finish to a soft sheen with a 3M Ultrafine Pad, then wax with Carnuba.

Thanks for this info, so far I have used it as a final coat on one instrument that is being used daily, but only 4 months of use have passed so far (without issues). 25 years is very impressive! 

[Brad Dorsey]

4 hours ago, ke0777 said:

…OMS…

What does “OMS” stand for?

[ke0777]

2 minutes ago, Brad Dorsey said:

What does “OMS” stand for?

Odorless mineral spirits - I use the one from Gamblin. 

[Marty Kasprzyk]

I've used it for about 65 years on gun stocks, violins and violas.  The only problem I've run into is that the narrow bottle is easy to tip over.  So I glue the bottle onto a small wood plate to make it more stable.

[HoGo]

I will add that I used it on half dozen gunstocks I finished for a friend and four or five mandolins as main varnish coat with french polish overcoat for gloss. Worked well and aged nicely.

The last bottle of TO I had, got to stage of half rubbery jelly and I used it as a sealer/filler/basecoat on a poor stripped fiddle I got and I managed to create beautiful smooth satin surface for color varnishing by rubbing that jelly on and rubbing off any excess. It took nice amber color after some suntanning.

I've also used BC tru oil sealer/filler (I don't know exact name but it is in the same bottle as regular TO - I think I still have it somewhere in boxes of old varnish stuff) that is suposed to have more solids doesn't seem too different for regular TO but I heard from gunstock folks who mix the two together to get something with more "body" for quicker buildup of first layers.

[lorenzo fossati]

I used it to varnish my electric guitar, in my experience, after only 2 years, the parts more prone to playing rubbing, thats mainly where the picking fingers touch the body, deteriorated the varnish. I am not sure because the guitar top is a very oily wood (thuya burl), but it is definitely not as much wear resistant as amber varnish, and I think also oil colophony varnish is much more wear resistant. the plus side is the beautiful finish, and ease to apply

[lorenzo fossati]

I think there is also a "recipe" to make it yourself, if I remember it right it is 1 part of wipe-on poly, mixed with 1 part of boiled linseed oil

[Michael Darnton]

Ultimately I rejected the stuff. It didn't act like real varnish; it acted more like sheet of Saran wrap.

[Marty Kasprzyk]

If you do a search on Maestronet for "Birchwood Tru-oil Finish"   you will see many discussions on it going back to 2001.

[Jay Higgs]

I used True Oil as part of my finish on my violin #10.  This can be found in my "Contemporary Makers' Gallery" thread, with a Word attachment that details all that I did, right and wrong.  I still play this violin in orchestra and love it.  The consensus opinion of others, however, is that it is not dark enough.  

[Marty Kasprzyk]

On 5/8/2026 at 12:43 PM, lorenzo fossati said:

I used it to varnish my electric guitar, in my experience, after only 2 years, the parts more prone to playing rubbing, thats mainly where the picking fingers touch the body, deteriorated the varnish. I am not sure because the guitar top is a very oily wood (thuya burl), but it is definitely not as much wear resistant as amber varnish, and I think also oil colophony varnish is much more wear resistant. the plus side is the beautiful finish, and ease to apply

What ever colored varnish Stradivari used had poor wear resistance.  It looks terrible when it wears away and leaves the lighter colored wood to show through.

Polyurethane varnish probably has the best wear resistance for avoiding this failure.

[Will Turner]

I have literally used gallons of True-Oil!   It is absolutely fantastic as a very low VOC finish as I poured each can out on my floor.

My house literally sings with the unlocked resonance this secret of Stradivari finish brought to my…..

hardwood floors.

Sings “every step you take”

[lorenzo fossati]

1 hour ago, Marty Kasprzyk said:

What ever colored varnish Stradivari used had poor wear resistance.  It looks terrible when it wears away and leaves the lighter colored wood to show through.

Polyurethane varnish probably has the best wear resistance for avoiding this failure.

I like tru oil, I use it on the inside of the violin soundbox, for protection against climate changes and such. I am just saying, it wore off quicky in my guitar, it may well be because of the oily wood that dissolves onto the varnish while drying, making it weaker and softer. I am sure it would have happened the same with other oil based varnishes, since they share same solvents. I have used, on half the maple back and ribs of six strings viola, a bicomponent polyurethane (stuff sprayed on electric guitars, I brushed, 1st and last time I do that  ), and there I confirm the fact that polyurethane is a very strong nice, unmatched transparency in my opinion, and flexible varnish, probably stronger than amber or other copal based ones. But wipe-on poly is not the same stuff, so I stay away from it, a bit because I don't trust as much as I do with amber and copals, and a bit because it is not "philological varnish" (whatever strad used, it was not poly for sure)

[Marty Kasprzyk]

I used Tru Oil on all the 53 violas and violins that I've made.  None of them have ever shown any evidence of wear on their finish.  

But maybe that's because none of these instruments have never been used. 

[lorenzo fossati]

Just now, Marty Kasprzyk said:

I used Tru Oil on all the 53 violas and violins that I've made.  None of them have ever shown any evidence of wear on their finish.  

But maybe that's because none of these instruments have never been used. 

I fail to understand the reason why, me stating my personal experience, is taken as a direct attack towards the use of tru oil, it is not. I just said what happened to me, said that there is chance that the problem was caused by the wood and not by the varnish, yet here we are...

[HoGo]

I don't think Marty was responding to you at all. I actually like his funny remarks, mostly pulling his own leg.

1 hour ago, lorenzo fossati said:

(whatever strad used, it was not poly for sure)

Chemically his varnish was a product made from pine resin and drying oil (linseed) that dries by polymerisation with oxygen with some added resins as plasticizers.

A bit oversimplified, "Poly" finishes are typically products made of alkyd modified urethanes which are products made from oils (linseed or modified soy or tung or others) and alkyd resins with added plasticizers.

So not too far from each other...