Long term care of Tru-Oil finish advice please

Discussion in 'Finely Finished' started by rze99, May 29, 2019.

  1. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    the only questionable part of that is they generally have no idea how much material is actually being applied. Very few measure wet film thickness.

    I have no problem with Tru oil - but it's not a "coating" like lacquer or polyurethane. It's an extremely thin oil-based varnish stain, but should not be compared to varnishes either - it provides just a fraction of the protective film a varnish does. Only 14% of the content is resinous oil (the rest is solvent) and part of that oil evaporates as well. About 10% of what is applied to the surface stays there - the rest evaporates.

    It's a decent material as long as it's being used within the scope of its capabilities.
     
  2. Chunkocaster

    Chunkocaster Friend of Leo's

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    I don't know the percentage of evaporation etc. I do know that you wipe it on and when dealing with a maple or rosewood neck, glass, plastic etc the first coat stays put and already starts to create a shine that then builds with each additional coat. It highlights the figure in wood much better than a sprayed lacquer or poly due to the separate layers creating chatoyance similar to laying many sheets of glass upon each other and light reflecting through those layers. It has lasted years of daily playing on my necks and is much preferred by me due to the look, feel, low cost and ease of use.

    If something grazed it you can just lightly sand and apply another coat easily. I have never had to do that. You can also tint it and apply to shade different areas of the neck etc with it sitting in your lap with no drop sheet while watching tv. You can't do that with most other finishes. The last neck I used it on I managed to fill a dent that was quite deep in the face of the headstock. It disappeared under the tru oil and is now invisible.

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    Last edited: Jun 2, 2019
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  3. El Tele Lobo

    El Tele Lobo Friend of Leo's

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    Here's one of mine. 30 coats of Tru-Oil on the body, 15 coats on the neck. It's darkened to a nice deep honey color since I first applied it. Love Tru-Oil...

    20170716_183217.jpg 20170716_183314.jpg 20170716_183347.jpg 20170716_183404.jpg 20170716_183716.jpg 20170716_184234.jpg 20170716_184545.jpg Jazzbo new pup 3.jpg Jazzbo w:TV Jones 2.jpg Jazzbo new pup 1.jpg
     
  4. Chunkocaster

    Chunkocaster Friend of Leo's

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    Here's a pale rosewood fretboard that had a horrible failing ebonizing job done on it over a already lemon oiled finish. The neck was never sanded or treated to remove oil remnants before using a wood stain pen to ebonize it. The stain felt tacky and wore off over a years use. I re stained it with the same wood stain pen, let it dry a few weeks and sealed it with tru oil when it still had some tackiness to it.

    Although its not perfect looking it looks better in person than in this flash pic and has lasted a year of daily playing with heavy bending etc since then with no visible signs of wear. I doubt many other standard finishes would have even taken to the neck.

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    Last edited: Jun 2, 2019
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  5. rze99

    rze99 Poster Extraordinaire

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    Here's the mock-up un-wired build with Tru-Oil finished neck...
    IMG_1640.JPG


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  6. El Tele Lobo

    El Tele Lobo Friend of Leo's

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  7. El Tele Lobo

    El Tele Lobo Friend of Leo's

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    I feel like we need more pictures...
     
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  8. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    The reason you can do those repairs is that it is a wipe-on, penetrating oil stain.

    It brings out color in the grain because of the stain properties; the chatoyance for the same reason plus the small amount of varnish-type hardening resin - which also creates the soft sheen you see.

    Yes, it's easy to apply, easy to maintain and can be (in some cases) moisture resistant. As long as its properties are understood and there are not expectations of performance equal to that of a true "film building" surface coating like polyurethane of lacquer, great. It has low abrasion resistance and very low impact resistance; very little solvent resistance; has very limited tinting capabilities (tinting is actually not recommended, although some do it anyway); can't normally be combined with other products into a "protective coating system"; and because of the low abrasion , impact and solvent resistance regular maintenance is to be expected.

    For these reasons I used it periodically on necks but would not use it on bodies. Owner expectations are usually too high despite what they say they understand about it.

    It's not available here at all now so I'm not concerned about it myself. I just want to ensure others understand that it's simply not very different than Danish Oil. From the late 70's-about 15 years ago Watco (and other) Danish oils were the rage for all the same reasons. The look eventually became dated and the maintenance a pain in the backside - and several years ago things came full circle in the guise of "gun stock treatment".

    I find it kind of funny as long as users don't expect too much - especially when younger users talk about the "new" type of finish...that has been around for centuries (and called "Danish" since 1946)!
     
  9. Chunkocaster

    Chunkocaster Friend of Leo's

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    I would not call it a penetrating oil stain. I have drop filled on a poly finish with tru oil to eliminate deep dents in the back of a neck and on acoustic tops. I have coated glass with it and it sets hard and doesn't flake or peal off easily. It is closer to a varnish than a oil stain. It takes several layers to begin to add color and even after 20 layers the color added is minimal on maple or anything other than a white finish. I did a strat neck 6 or 7 years ago and it looks the same today as it did then with no maintenance other that an occasional clean and polish.

    I don't know about tinting recommendations as I have not seen any mention of that by Birchwood Casey. I know tinting works great for me when adding Colortone wood stain undiluted straight to the tru oil. Depending on who you ask applying tru oil over a decal on a already nitro finished headstock would also be advised against but again it has worked fine for me. This is where real world application and experience using it in a particular situation is preferable to guess work or manufacturers recommendations. The only time I guess is when I trial it myself. If it works it works and it has worked great for me in the applications previously mentioned.

    It's my preferred finish choice but I am not going for a thick, tough as nails poly type finish. It adheres to most things very well. I can't imagine trying to shoot a lacquer over a tacky wood stained fret board like on the rosewood acoustic neck above on a cold day and expect it to stick and last for a years worth of heavy use. I think even poly would probably turn out looking and feeling a mess trying to do that and what a pita it would be to apply it.

    New decal applied to thinly finished nitro headstock and buried with tru oil.


    20190603_140053.jpg

    Colortone tinted tru oil to create fade on maple neck.

    20180826_154414.jpg

    Both look the same today as they did when freshly done.
    One coat applied every 2 to 3 hours, sanded and final coat applied, buffed and polished next day with Gibson pump polish. Both on relic guitars so stopped short of perfection. Better results possible if you want to keep going with coats and polishing.
     
    Last edited: Jun 12, 2019 at 6:23 AM
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  10. rze99

    rze99 Poster Extraordinaire

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    Very nice looking. I'm looking for a stain like the US colortone than is compatible with Tru Oil in the UK. Anyone used one on this side of the pond?
     
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  11. Chunkocaster

    Chunkocaster Friend of Leo's

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    I have read online that TransTint is the same product but I don't know if that's true or just someone guessing or making it up.

    The small bottles of Colortone seem expensive but they last a really long time. A few drops goes a long long way unless you are tinting tru oil. When tinting tru oil the coat goes on thin so a really dark exaggerated color is needed to achieve most targets. Think something like coca cola color to achieve the typical ambered lacquer look on maple. It will take a few coats of the exaggerated tint to achieve the ambered look. In most cases using the colortone diluted with water and applied to the unfinished neck/ wood is the way to go if you want to save material.

    That faded neck above was lightly tinted using water diluted colortone applied to the neck first, Then straight tru oil, then the darker areas are tinted tru oil over the top but not over the light areas you see. The edges and color look a little dodgy in pic but that's the phones camera messing with the look. In person it looks more even and less exaggerated. You can add more tint as you go to darken to exact color you want. Just keep applying coats until you are happy with it and stop.
     
    Last edited: Jun 12, 2019 at 6:29 AM
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  12. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    What you "would not call it" is, though, exactly what it is. Read the MSDS - the hazardous (and critical) ingredients are solvent, modified oil, and linseed oil.

    The "modified oil" is a polymerized type - a varnish. If you filled "deep dents" by drop filling either they were not as deep as you thought or - if say, even 1/32" thick - it would take 100 or more coats to fill that dent flush based on the product's solids by volume. It's simply not physically possible to "drop fill" deep dents in a few coats with a very low solids product, and Tru Oil has a fraction of the solids content of lacquer, polyurethane, shellac or brushing-grade varnish. We'd need very specific measurements/test data to back these things up, but they never seem to be available.

    Coating glass is called "free film testing" and is done to test 1) adhesion of the raw film and 2) "pencil hardness" using specific ASTM test methods. It "sticks" because the remaining - very thin - film is a chemical combination of linseed and polymerized oil - "varnish". Flaking and peeling (note spelling) properties are irrelevant unless you 1) measured your film thickness and noted dry time 2) performed adhesion tests using an established test method, 3) had some standard as a basis of comparison, and 4) performed the same test repeatedly to establish a meaningful sample size.

    And glass application has no relevance when talking about guitar finishes applied to wood surfaces - even when applied over itself some of the previous Tru Oil coat thickness is lost due to "rewetting" properties - and the thickness of multiple coats varies widely depending on the applicator and application method.

    But you're not measuring at the wet film thickness of a coat with a $5 gage at the very least - so you have no idea how much material is applied to the surface.

    And without an understanding of how to calculate dry film thickness - or access to very expensive test instruments - you'll never know whether you have a shiny varnish film 1/10 the thickness of a SINGLE coat of gloss lacquer or 1/10 the thickness of a complete clear lacquer-over-dye-system.

    It does a nice job for what it is, but please don't imply that is a substitute for lacquer, polyurethane or even conventional varnish as a "protective coating system". The simple fact that i is only "water resistant" and not "waterproof" puts it in a different class.

    Tru Oil was not designed by Birchwood Casey to perform like multiple-coat finish systems and the products most similar in application, performance and appearance are Danish Oils. Like Danish Oil, Tru Oil is a penetrating oil with a small amount of hardening varnish resin that can - when applied "off label" (i.e. not per the manufacturer's published instructions) provide a very thin surface film. I've performed lab and "real world" tests comparing it to other oil finishes for decades and used the product on guitars. And I've provided tech support for Tru Oil and many other brands of penetrating oils (some labeled as "Danish Oil" - some not).

    Don't exaggerate the product's performance. If you can prove your claims and provide measurable test data great. If not....:rolleyes:
     
  13. Chunkocaster

    Chunkocaster Friend of Leo's

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    You keep telling me it wont do what I have done and do with it. You can pool it in a deep dent and it will dry hard. You then keep adding it and because it doesn't melt into the previous layer it will build. The dents I drop filled with it on the back of a poly finished acoustic neck were deep enough to annoy when playing. Steaming them did little to help. For a really deep dent you can drop super glue in the dent and finish over the top with tru oil until completely smooth and polished. The dent in that teles headstock was clearly visible and you could catch your nail on it. I dropped a few spots of it on the dent and 30 coats over the whole face of the headstock filled it completely and it needed that much anyway to bury the decal because it was so thick. I'm not interested in the formula breakdown or assumptions based on that. Are you expecting me to deny the fact that it worked based on the formula breakdown despite the fact that it did work? It's their own formula, not Danish oil.

    I find it's protective qualities to be similar to nitro. Nitro is a sturdier finish but both require similar levels of care to be taken with it. I don't plan on submersing my guitar in water. If basic care is taken with the instrument tru oil provides enough protection for me. A belt will wear through a tru oiled body but same applies for nitro.

    Using tru oil on wood is not a new invention. It's only become more popular in recent years because with the internet people are being exposed to it. Prior to the internet people were using it but not advertising the fact they used it and they had no way of sharing their experiences with the masses. Once you use it on a gunstock it just makes sense to reach for it again when you have another wood project requiring a nice clear finish without the need for the hassle of sourcing more products or the process of spraying etc.
     
    Last edited: Jun 12, 2019 at 9:06 PM
  14. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    If you do chemical analysis or understand coatings/varnish/stain formulas, testing and performance the basics are the same.

    Superglue wasn't mentioned in your previous posts - those are high solids products that fill voids easily (if you understand "solids" in a formulation as it was explained earlier this would be clear)

    If you find it similar more power to you.

    Please don't tell others that the performance is the same though - it's not They require similar levels of care if you are very careful to avoid impact or abrasion of Tru Oil. That's where differences show up - you might see no damage on lacquer or polyurethane but a scratch or dent on Tru oil that you need to touch up.

    Those are quite different levels of care.

    I'll repeat - because you seem to be missing it - I'm not saying it's a lousy product or doesn't perform well. It performs great at the job it was designed for. But NOT the same as film-building coatings like polyurethanes or lacquers.

    That's like saying "I don't care if it's water or oil based - I'm going to ignore your statements of fact" - not assumptions, BTW.

    I think it's obvious you don't understand the concept of coating thickness and volume solids. Or measuring wet film thickness. So you're tossing out and choosing to ignore facts simply because you don't understand them, apparently. Knowing how deep those depressions were is a critical factor in understanding what the product could - or could not - do, no matter what you *think* it did. Do you use the depth measurement pat of your micrometer to determine what you're actually trying to "drop-fill", or how high a decal protrudes above the headstock surface??

    If not you're guessing at how much material to use and/or what you're trying to achieve. When you're dealing in thousandths...or fraction of thousandths...of an inch just how do you expect to "guess" your way through the process? That either takes a ridiculously long period of trial and error time - or a huge amount of luck.

    No - and as stated I've used, tested and compared it to other finishes for decades in both real world and lab environments and understand what it is and how it compares to similar oil/varnish products and "film building" products.

    I think we should end this here - because you need the right tools to discuss this. Not only the ones the work is performed with, but the knowledge and understanding of basic coatings formulations, solids and how they apply to each process. And it seems like the tools aren't at hand.
     
  15. Chunkocaster

    Chunkocaster Friend of Leo's

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    I don't need to know the chemical breakdown and I don't need to break out the microscope or know the exact thickness of the tru oil on my neck. Sending the guitar off to nasa and having them measure the depth of the dent before considering how I would fix it was not an option. All I need to know is that it works for my intended purposes and as shown it does that just fine. If I worried about the lab tests and recommendations I would not have tried it on my freshly applied decal on nitro finished neck. Which worked great. I would not have tried it on the tacky ebony stained rosewood board which also turned out fine. The 4 guitars I have here that have had tru oil finishes for many years would not look the same as the day they received the tru oil but they do.

    People reading this should know these things are possible and easily achieved by a novice or pro alike. Not be told that the product will fail and is unsuitable when that's clearly not the case. Sure there are tougher more scratch resistant finishes out there but I think most people using tru oil are not going for ultimate durability.

    As for the not mentioning super glue, I did not use super glue on the back neck repair, only tru oil, same as the headstock dent. On the back of neck I taped around the dent creating a dam, then dropped a good amount of tru oil in the dent, waited to dry and repeated until nearly level. Then removed tape and wiped more tru oil on until level, then sanded, applied another final coat and polished. I used superglue on a hole in acoustic top and on dented binding, then applied tru oil to blend a gloss finish with the surrounding poly.

    Look at the crust that builds around the cap of tru oil bottle. Its not a oily mess, its hard boogers of tru oil so of course it can build a thicker finish than what you typically wipe on.

    You can build tru oil as thick as you like by applying more coats. When level sanding the finish does not shrink back into the dent so after enough coats the dent gets buried.

    Try it yourself. No micrometer required.
     
    Last edited: Jun 13, 2019 at 1:59 AM
  16. Rumblur

    Rumblur TDPRI Member

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    it's just liquid plastic, the oils in your hand should keep it nice for years.
     
  17. Silverface

    Silverface Poster Extraordinaire Ad Free Member

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    No, it doesn't shrink back after it dries - but it will take a hue number of applications to fill anything other than a VERY thin mark.

    First - it's impossible for the thickness of the wet film to be the same as the thickness of the dry film.

    Second - the dry film ends up about ONE TENTH as thick as the wet film.

    Sorry, but it's very clear you don't understand how coatings actually work - how thick you REALLY can build it up based on how much you apply. And both a micrometer ((or depth gage) and wet film gage are very common tools when making coatings repairs. Without them (and possibly a dry film thickness gage) AND product data it's impossible to know the thickness -wet or dry.

    So here are some REAL numbers to consider:

    Because of Tru Oil's light viscosity (thickness as a liquid) it runs if applied at over about one mil (.001") thick wet. That's about a tenth the thickness of a high-E string - say, a 10 thousandths - .010") plain string. It's also the average thickness of a human hair.

    And because roughly 89% of Tru Oil consists of evaporative solvents that completely "leave the surface" the actual DRY thickness of one coat is close to 1/10 mil - .0001".

    So it would theoretically take TEN dried coats or Tru Oil just to reach the thickness of...a hair.

    A thin lacquer system - sealer, 3 color coats and 4-6 clear coats - might be about 2-3 mils thick dry . It's difficult to apply a good looking system that thin but it would be a good looking protective coating if done right. Factory polyester and UV cure systems are often about that thick.

    *IF* it was even possible to add one full coat of Tru Oil to each preceding coat - which it's not, as about 1/3 or more of the previous thickness is lost in "rewetting" - you would need 200-300 coats to build it up - if that's (your words) "as thick as you like". And because of rewetting, in reality it would take more like 300-450 coats to build a 2-3 mil thick dry film.

    That's not practical, very labor intensive, slow, and all you would have is a very thin varnish system (which only outperforms shellac and regular "paint" in durability) - so that's NOT what it's used for and not how it's applied.

    It's used as a penetrating oil with a small amount of polymerized (hardening, or varnish-type) oil - which provides a very thin film and some shine, moisture resistance better abrasion resistance than raw wood - and a finish that's easily maintained and repaired. Applying 20-30 coats takes some time and effort but can result in a nice looking, easily repaired finish if you like the natural wood look with some sheen to it.

    But it does NOT result in much of a "protective coating system".

    So again, please - let's drop the non-debate. It is what it is, and because of your lack of education in coatings technical terms, formulations and methods of comparison any disagreement is pointless. And it's NOT your fault nor is any insult intended - it's just info you have either never been exposed to or decided to learn. But please do not fault me for explaining things to you and other thread readers - Tru Oil is a very misunderstood product.

    As long as users understand the characteristics and capabilities of Tru Oil (and can obtain it legally) it has some excellent uses.

    But it's NOT equal in thickness or durability to traditional film-forming coatings - and it important not to mislead newcomer, into possibly thinking along those lines.

     
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