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Oil paint as colour coat under Tru Oil

Discussion in 'Finely Finished' started by Matthias, Aug 30, 2015.

  1. Matthias

    Matthias Friend of Leo's Gold Supporter

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    I just came across this on YouTube... Using linseed oil-based paint as a colour coat beneath Tru Oil. Is this an established method? Has anyone tried it? It's certainly an interesting idea.

    I'm wondering if you could combine it with a Tru Oil wet sand to grain/pore fill as well.



    Cheers all.
     
  2. piece of ash

    piece of ash Friend of Leo's

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    TruOil is essentially linseed oil (highly purified) with some tung oil tossed in. So yeah... that would work.
     
  3. Matthias

    Matthias Friend of Leo's Gold Supporter

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    The white followed by Tru Oil might be a good alternative to whitewash for rubbed blonde finishes. Painting on board, it's quite easy to get an even finish with oil paint so I wonder if it's the same rubbing it in. Doing my first rubbed finish over the next couple of weeks so might need to experiment with this for my second.
     
  4. Cat MacKinnon

    Cat MacKinnon Friend of Leo's

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    TruOil is a "modified oil" wiping varnish. It's been processed and has a lot of additives, and is quite different from pure linseed oil. It's also meant to absorb into wood to give good adhesion, so I don't know that it would work over a "solid" layer like dried oil paints.

    If I were OP, I'd absolutely do some test pieces first. It might work, but it also might go horribly wrong (I can see the TO potentially peeling off the oil painted areas, but maybe not.) Another issue I see is that artist's oil paints can take a loooong time to dry, and I don't think putting multiple coats of TO over undried paint (of any type) is a good idea.

    Lastly, artist's oil paints tend to go on really thick, so at the very least they'd need to be thinned quite a bit. It may still be too thick to bury without having a mile of TO on top, but again that's something OP would have to experiment with.

    One thing that might work (I stress "might", because this literally just popped into my head): OP might be able to mix the raw pigments into the TO and use that as the carrier. Better art supply stores often carry the dry pigments for mixing up your own oil paints, so that might be something worth looking into. I haven't painted anything (on canvas) in years, and I don't really know anything about mixing my own oil paints, so OP is on his own there; I'm sure there are loads of resources online though, so it shouldn't be too hard to find a starting point for experimentation.
     
  5. Matthias

    Matthias Friend of Leo's Gold Supporter

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    I found some other people using it. I think I have heard of people adding a bit to Tru Oil to tint it before, but this is a bit different.



    Now, drying time is long on oils but that's not normally in a situation where its rubbed on then rubbed off again... and it's normally used on a primed surface not an absorbant one. I wonder how long it would take to dry in practice.

    I'm quite intrigued by the possibility of getting rub on finishes with a certain amount of opacity (like some of the Wudtone kits appear to have). But I'd wager the success could differ from colour to colour, brand to brand and situation to situation with the paint.

    Well, it's a cheap experiment and I have some spare planed pine somewhere...
     
  6. Meteorman

    Meteorman Tele-Afflicted

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    I have mixed dry pigments into Tru-Oil quite a bit in the past.
    Specifically, bone black powder, and as well as burnt umber pigment powder.
    It's done to add "aging" to reproduction longrifles.
    The darker areas on this piece are created with pigmented TruOil, and then faded into surrounding "high wear" areas (the wrist) with lots of rubbing.

    [​IMG]

    It's not a terribly permanent coloring process as is.
    It requires several overcoats of clear TruOil to lock it in.
    And if you're hand rubbing on the subsequent coats, the color coat can soften and lift and rub away.
    Spraying on subsequent coats of TO might be different.
    Myself, I wouldnt want to try hand rubbing this coloring technique on a guitar body.
     
  7. Cat MacKinnon

    Cat MacKinnon Friend of Leo's

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    I wonder if it's due to a lack of binder? I know the three main ingredients in paint are typically pigment, binder and a carrier (solvent). The binder is what keeps the pigment in place, so maybe that's an issue? I dunno, like I said I've never mixed my own oil paints before, and my level of knowledge about oil paints kinda stops at "squeeze the tube" :lol:.
     
  8. Matthias

    Matthias Friend of Leo's Gold Supporter

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    I was thinking about this further. I wonder if the drying agent in the tru oil penetrates and speeds up the curing time of paint. The fact the oils don't dry quickly might actually be a benefit, as the first tru oil coat will mix with it when you rub it in.

    Of course, you could pre-mix the two, as suggested in the video page and I guess to a fairly thick consistency.

    I reckon this is only better than dye or stain if it allows you to build greater opacity of colour to mimic a blonde/semi-transparent laquer look. If it doesn't, this feels like a bit of a waste of effort.

    For the future projects I'm plotting, two-part bleach -> stain/dye -> Tru Oil is looking like a more predictable route to mimic that blonde/semi-transparent look... Or maybe some of the semi-opaque Wudtone colours. But certainly not having to deal with bleach would be nice.
     
  9. Matthias

    Matthias Friend of Leo's Gold Supporter

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    Well, I'm going to give this a go on some scrap and see what results from it. As luck would have it, the paints were half price so why the heck not?

    They all have a linseed oil base except the white, which is sunflower oil. Having stuck with acrylics for most of the painting I've ever done, that was a new one on me. Apparently the stuff they use in paint isn't the type you get in the supermarket... :)

    Not so much luck finding any Tru Oil in stock... I'll need to get that online.

    I'm not sure what to expect. The more research I do, the more I find references to people using this method (successfully) but even pics of the results are elusive.

    Whatever, gives me a chance to have a play with Tru Oil at the same time.
     

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  10. DrASATele

    DrASATele Poster Extraordinaire

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    I've had the same problem only with wipe on polyurethane. I Keep finding similar references to a similar application (mixing the artist paints of the same medium into the wipe on poly to creat semi transparent colors and shaders.
    I'm very curious what your results will be. I may have to conduct this same experiment with the minwax poly in the not to distant future.
     
  11. Matthias

    Matthias Friend of Leo's Gold Supporter

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    Experiment #1: straight from the tube, pigmenting stage before Tru Oil

    Medium: Pine plank, grain raised and sanded to 400 grit (a bit high, but the theory I'm testing here is I want to be able to wipe a lot of the oil off but leave the pigment in the wood).

    Method: Straight from the tube on to a home-made dauber (kitchen towel wrapped in T shirt rags). Wipe on, work in and spread out with some pressure. Wipe off excess. On the black, I put more paint on and then wiped it off with a separate cloth

    Schedule: I'm making this up. I'm going to give the oil 48 hours between coats of the oils. See how that works. Remember this is a much, much thinner layer than you'd ever put on canvas.

    First coat results: The colour goes on VERY solid and is easy to work, but it's also hard to get it on evenly. I'm anticipating that due to the solid pigment, this will even out with subsequent coats.

    Verdict so far:
    - White: Sunflower based so least likely to work... Shame as it could could make a nice white blonde and a less watery look than whitewash
    - Red: Cadnium Red tends to be a very solid colour from memory, so this may build to be quite opaque. Once this goes on, it's perhaps the most stubborn to wipe off
    - Black: long working time so easiest to work in. This could look pretty epic with a light sand then a tinted Tru Oil on top.

    I have two rectangles left on my plank, one for a plain Tru Oil control subject and one to try tinting.

    It'll never work :twisted:
     

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  12. Matthias

    Matthias Friend of Leo's Gold Supporter

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    One more, showing how intense that red is.
     

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  13. Matthias

    Matthias Friend of Leo's Gold Supporter

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    24 hours of drying... erm, drying? What's that? As could be expected, this is still rather wet. The drying time alone makes this rather unappealing when compared to staining or dying.

    I'll check again tomorrow. I'm very interested in how that white turns out.
     
  14. DrASATele

    DrASATele Poster Extraordinaire

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    Nice!
    When you do the mix can you please list the ratio of TO to Paint color?
     
  15. Matthias

    Matthias Friend of Leo's Gold Supporter

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    Second coat results: It was *mainly* dry, so did another coat. This really does build up. It looks like the wood is sanded too finely for the pigment to stick to some of it, with the exception of the red that's building quite an opacity. It goes on very thin and level. Excuse the electric light/slight reflection in the photos.

    Verdict so far: Just makes me want to experiment with wood dye. I think the guy in the video had more patience than me... I think this method could take months to properly dry. However, my Tru Oil arrived today. If I can get a nice tint to that, it might make all this messing around worth it...
     

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  16. Matthias

    Matthias Friend of Leo's Gold Supporter

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    Will do - I'll post pics of what I mix.
     
  17. DrASATele

    DrASATele Poster Extraordinaire

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    I think an initial wipe followed by tinted layers of color would make for an amazing finish. I agree the 2nd coat of color makes it too solid.
     
  18. HotDan!

    HotDan! Friend of Leo's

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    I'm not a builder so I'm not implying any expertise in that realm but I do have experience with oil based paints. As has been mentioned, these are linseed oil based. The pigment (color) is suspended in the oil and is combined with a solvent (these solvents can vary in types and quality as well). When referring to 'drying' it's not really that, in the normal sense, but rather polymerizing. The oil base properties remain but as the solvent evaporates, it solidifies. So...Think of the linseed oil simply as a transfer vehicle for the pigment. It will react differently depending upon what it is applied to and that has already been shown to be the case with the test blocks.

    I would suggest that the pigment (oil paint) should be applied in stages just as you would do a tru-oil finish, not allowing it to totally polymerize until the desired shade is realized. Applying tru-oil will not re-suspend the pigment since there is no solvent present...Just a thought that may be helpful...
     
  19. Matthias

    Matthias Friend of Leo's Gold Supporter

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    Thanks HotDan! - that's interesting.

    I think it's clear that a rougher surface (perhaps sanded to 240) would be better. I suspect I missed a spot sanding the black area, hence the better penetration of pigment on the near side in both close-up pics.

    I think this would work as well, if not better, thinned. I'd probably use mineral spirits as that's the same thinner recommended for Tru Oil. I'd be tempted to use a little to mix the paint and the Tru Oil for the tinted finish, but not to too thin a consistency.

    On to the tint...

    If everything indeed mixes smoothly, I think the tint might work best using a coat or two of Tru Oil to seal and grain fill, then build on top. Then the wood will be sealed and the oil will work like a proper tinted varnish rather than a stain. I think there are three big challenges I see here:

    - Getting a good mix in the first place
    - The tinted Tru Oil going over the plain Tru Oil OK
    - Applying evenly. I think the French polish method is likely best here and a lot of thin, even coats, only knocking the finish back with wire wool every 3 or 4 so not to rub through the tint. It will help to keep the colour mix consistent on each coat, too. That's the theory anyway! :/
    - Any other more experienced opinions more than welcome :)
     
  20. HotDan!

    HotDan! Friend of Leo's

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    You are correct in your assumption here. The more open (rougher) the surface is, the more pigment penetration you should have. Also keep in mind that some solvents don't like each other so you should make sure that what you use as a dilution agent is compatible with what is listed on the paint tube. I also agree with your idea of using the French polish method but not your willingness to employ wire wool. It's okay to use as an intermediate finishing tool but not for final finishing employing oil. Bad choice (IMO) because it will impregnate it's tiny shads of itself in your finish as it deteriorates through usage. I'd think that wet 5000 or 6000 grit sandpaper may serve you better...

    I'll add that, as a player, I prefer an oil finished neck over any other. Poly and lacquer are 'shell' finishes and when they begin to wear, your only alternative is to refinish them..An oil finish requires only a cleaning and an oil application to turn them back to as new...
     
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