Official Luthiers Forum!

Hi, I've been building acoustics for a few years now and am not a fan of nitro due to its toxicity so have been exploring some alternatives. I tried a waterbased lacquer by behlen...so disappointing. I recently tried tru oil. I was impressed initially and felt it was almost too good to be true, I felt I need some more practise/experience as far as pore filling etc. though which is to be expected for a first use something new but on the whole it seems a great product. However, after applying around 10 thin coats around a day apart and leaving it to dry for around 10 days after the last. I am finding now it is far too soft, I could draw patterns with my fingernail without much pressure.....I'm guessing this is not right? Anyone able to suggest where I've gone wrong?

Any help greatly appreciated,
Nick

Nick,
I've found that all the varnishes I've tried (including True Oil) seem to benefit from being left to dry 36 hours between coats and for a month after the final coat has been applied. Maybe you just need to set the instrument aside for a while longer?

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George :-)

Gotta agree with George, I like tru-oil, use it regularily, but 10 days to harden is not enough.
My experience is that it continues to harden for months. I would give it more time. 30 days minimum.

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My memory is so good, sometimes I remember things that never happened.

I've been using TruOil a lot in the last couple years with the popularity of flattened finishes, and I can't seem to get more than 2 coats per day. Keep it thin, scuff it back with Scotchbrite every 2 coats, and be patient. Takes about a week to start looking good.

Also - when the humidity is over 50% - let it dry longer. Skip a day.

If you want a fast finish, invest in that stuff that cures with black light.

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"Act your age, not your shoe size" - Prince

I can usually get at least 3 coats of Tru-Oil a day with each scuffed back. I do work in a climate controlled shop at about 40% RH, which allows for scuffing back with a gray Scotch Bright after 3 hours. I do put it on very thin, with no wipe off. Minimum of 12 - 15 coats before anything close to a real finish. The first few nearly go away.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Waddy's right on, and I use TruOil almost exclusively. I posted my schedule on another thread yesterday.
Most of the way down the page. viewtopic.php?f=10123&t=48300

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

Thanks all for your responses. I'm guessing, once properly applied, tru oil is pretty durable/scratch/chip resistant? I'm loving the way it flatters the wood. Putting it next to a nitro finished effort in the same wood I so much prefer it. Is worth waiting for it seems. Hoping to make it work for me. I'll be honest in that I've found the finishing a bigger challenge than the actual making as far as my 'journey' as a wannabe guitar maker- i love wood....hate the array of noxious chemicals you then find yourself having to get into. Tru oil seems so much less so, I like the way it smells even. Not sure why more people don't use it. Thanks again.

Most people don't think to look for guitar finishes at the gun shop (where I buy mine).

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"Act your age, not your shoe size" - Prince

I think you've gotten the answers you need from people who have used it enough to know (I have only done 1 with tru-oil). I just wanted to add that I have heard anecdotal claims that it can dry very slowly (or maybe even never completely) on some oily woods. So if your project is cocobolo or something like that, you may have an additional factor to consider with regards to drying time.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Getting a really good finish is the most difficult part of building, for me anyway. TruOil is relatively easy, relatively cheap, and is not terribly toxic. It's not as hard or durable as a nitro finish, but it's probably more durable than French polish.
It's hard to get that mirror-like shine with TruOil, which I believe is why more people don't use it. I have had trouble with it drying on cocobolo(took twice as long as usual, but did dry) and Pao Ferro (never dried, had to be cleaned off). On the pao ferro, a sealer coat of shellac solved all the problems.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

It's much cheaper if you buy direct from Birchwood Casey!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Or from the amazon link above, via birchwood casey.

I have buffed tru oil after a few months and while it is not the mirror finish of some others, its pretty darn good.

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My memory is so good, sometimes I remember things that never happened.

Exactly. One can proceed more quickly, as others clearly do. Personally, I prefer to give varnish a good long time to start hardening.

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George :-)

Here's an old thread with a lot of discussion about "oil" finishes which may give you some other ideas
viewtopic.php?f=10101&t=31537&hilit=watco

Kevin Looker

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I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

Everyone has slightly different experiences with TruOil, so they have all given great advice. Your finish just hasn't cured yet, and you might need to wait longer between coats where you are working. Also, if working with liquid, stir it before using. If using aerosol cans, shake it before using. The reason: Drying agents can settle to the bottom of the bottle / can, thus retarding your drying and hardening.

I seal instrument projects with wax-free Shellac before applying the TruOil. This will help over oily hardwoods and some pore fillers. On projects such as walnut furniture, I have sanding the first several coats in, forming a filler out of the oil / sanding slurry. Lots of ways to go about this! Be patient and good luck with it.

Mentioned in that old thread was Howard Klepper's post containing the word "film". Patrick has the right idea that the instrument should be sealed before applying penetrating oils. Folks will go to the extreme to apply as thin of a lacquer finish as possible, but have no qualms about slopping on 15 coats of gun or tung oil; the first 2-4 coats will probably penetrate a spruce top easily, totally changing the tonal qualities of the instrument.
I have had 25 years of varnish application to mandolins and always sealed the wood with 2-3 coats of spirit varnish before applying several coats of oil varnish. Then the final "shiny" coats were again, spirit. Spirit varnish can be sprayed and when done, hits the surface almost dry, taking minutes to seal the surface, barely penetrating.
Something to think about...

I really like Tru Oil for its ease of application and the way the guitar looks. I started my first couple using it and then tried a few shellac french polished and have since gone back to the Tru Oil. I usually do between 12- 15 coats. One to two coats per day. It definitely hardens over time.

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Having fun learning every day.

I do this as well.

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George :-)

Here's the section of a "Guitarist Magazine's" review which mentions Johnathan Kinkead's/Kinkade's finish work.

"Although you can get this model in matt lacquer, what you can see from the photos is the painstakingly produced, hand-rubbed oil finish on this particular guitar. While not as protective as polyurethane, polyester or nitrocellulose, its visual and tonal advantages outweigh these shortcomings. The key is in the way the wood is prepared prior to application. After the normal progression from scraper to extremely fine (1200 grade) wet and dry paper, Kinkead moves on to micro-mesh paper invented for polishing Perspex in the aerospace industry – which goes up to an incredible 12,000 grade. This produces a mirror-polished surface on the bare wood, normally unnecessary for other finishes. Then several applications of a substance called Tru Oil, normally used in the gun industry, is rubbed in over several days. Finally, after a week of drying, the guitar is buffed to a shine.

This attractive, tonally transparent coating is not only time consuming, but conceals no flaws, gaps or blemishes, so it is even more of a credit to Mr Kinkead’s skills that the Kingsdown is so immaculate."

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Ken Cierp

http://www.kennethmichaelguitars.com/

I don't know if I can be that immaculate in my skills... Early in my building I used trueoil. It did work pretty good, but I wanted more protection and the ability to drop fill if necessary...

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com