Question about aniline dyes over pore filler and more

Discussion in 'Finely Finished' started by alexinhow, Sep 26, 2020.

  1. alexinhow

    alexinhow TDPRI Member

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    Hello everybody,

    I have recently been working on my first project which, after a couple months, turned out okay-ish. Learning from my numerous mistakes (poor sanding in some hard to reach parts, difficulty in wet sending the sealer etc.), I have decided to start a new one, but I'd really appreciate if any of you (undoubtedly more knowledgeable than me) could shed some light on the doubts I have.

    First of all, how does aniline dye react to pore filler? I have seen many projects mixing them togheter, but could I simply use wood color pore filler and then apply my water diluted dye like normal? Or does it tend to not assorb it as well?

    And to achieve a high gloss through wet sanding, should shellac (spray or wipe on?) suffice or would something more specific like a cellulose sanding sealer be better?

    Thanks in advance for your answers c:
     
  2. Freeman Keller

    Freeman Keller Friend of Leo's

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    The answer to your first question is - it depends on the wood, the dye (stain) and the pore filler. It depends on the order in which they are applied, and the philosophy behind your staining and pore filling. I stain woods first to change their color. I then typically apply the pore filler (assuming it is a porous wood and needs filling like mahogany or rosewood). I have experimented with both water and alcohol as solvents for the stains, I prefer alcohol. I then seal that and apply my finish. I also want to be clear that I do not seal before I stain which flies in the face of some of our other finishers here - I've tried it both ways, this works best for me.

    After experimenting with a number of different materials for pore filling I have settled on a finishing resin that both fills the pores and enhances grain. I will typically experiment on a piece of scrap of the same wood to make sure I am getting the effects that I want.

    I seal the pore filler with either shellac or vinyl sealer. I don't expect a gloss from this, mostly its to keep color from bleeding and to give a foundation for the finish.

    For your second question, I typically finish with nitrocellulose lacquer. I have experimented with some water born finishes but I come back to lacquer. I follow the usual finishing schedule - 12 to 20 or so coats, usually three a day, a wet flow coat, two or so weeks of drying and the usual wet sanding and buffing from 800 or so to fine compound.

    I just did my first hand applied shellac finish in the French polish method - shellac dissolved in 95 percent grain alcohol applied with a pad and olive oil. I was not satisfied with the final gloss but I blame that on the cook, not the ingredients. The build is fine its moderately glossy but the "spiriting off" step just didn't have the gloss I wanted. If I was ever going to do a FP again (and I might) I would take time to buy one of the good videos on that technique (Robbie O'Brien, Eugene Clark, one of the people who really know what they are doing).

    The bottom line is don't just read what I (or anyone else) does and try to duplicate it. Experiment on scraps of your wood with your materials until you are completely satisfied, then commit to your guitar. Good luck
     
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  3. Freeman Keller

    Freeman Keller Friend of Leo's

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    Alexinhow, clarify for me what wood(s) you are using, what color(s) you wish to stain them (and what effects you want - popping grain, sunburst, etc), what pore filler you intend to use and exactly what finish you'll put on top.
     
  4. alexinhow

    alexinhow TDPRI Member

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    First of all, I thank you for your exhaustive answer. I am currently "exercising" on a couple of very cheap (30$) candlenut bodies bought off ebay, before committing to anything more serious. From what I can tell, it looks like a very soft, light and porous wood. So far I have tried (and surprisingly succeded) in using a generic wood tint (the vendor doesn't specify anything about the content), but for the next body I was considering either aniline dyes in water or Angelus leather dyes. I have been trying to achieve a popping grain effect, previosly through the common "black dye and sand technique". Regarding pore filling (which is where I have been having most of my problems), to avoid possible incompatibilies with my choice of dye, I thought about using either shellac or a nitro-based sanding sealer above the dye, followed by wet sanding and ultimately by several hands of possibly tru-oil (I have really enjoyed this product so far, even if it seems to apply very thin), but due to me trying to achieve a high gloss, I am willing to experiment with spray nitrocellulouse or wipe-on poly.

    Thanks in advance for your answers.
     
  5. telepraise

    telepraise Tele-Afflicted

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  6. Freeman Keller

    Freeman Keller Friend of Leo's

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    Well, I may not be able to be much help. I looked up Candelnut in my wood data base, sounds like its a pretty non descript soft wood, but it does say that it is "diffuse porous to ring porous" (whateve that means). I would assume that it will take stain well but nothing dramatic will happen - I would think you can change its color but not do a lot of highlighting or grain enhancement. Doesn't hurt to experiment however.

    As far as pore filling, there are literally a dozen ways to do this ranging from pumice in shellac to paste fillers to epoxys and super glue. The idea of pore fillers is just that - the little open pores on the surface of some woods need something to fill them or your finish will just sink back into the wood and not be smooth (you would think that a bazillion coats of finish would fill 'em but it doesn't. My experience is only with tropical hardwoods like mahogany and rosewood and I have only tried paste fillers, epoxy, superglue and shellac. They all work, I have settle on the epoxy because I like what it does with colors and grain.

    While I have experimented with several other finishes, I keep coming back to sprayed nitrocellulose lacquer, but certainly not for filling pores. Lacquer is relatively easy to apply as long as you mind the cautions, it does give a nice high gloss when buffed out. Other finishes can do that also, I just can't recommend from experience.

    Maybe someone else with more experience with similar woods will chime in.

    Ps Telepraise mentions my use of Zpoxy, I did do a little write up about it. I'm sold on it for the woods I use but I'm not sure its right for yours

    https://www.tdpri.com/threads/zpoxy-for-pore-fill-and-grain-enhancement.940522/
     
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  7. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

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    You can use it to TINT the filler in most cases.

    But you should use dye BEFORE filler; then tint the filler. This is the sequence:

    Preparation

    Lacquer sanding sealer/light sanding. Bot pshellac or regular lacquer. Sanding sealer has specific clear picgmenbts and fillers that slow dye and stain penetration so you can control color depth by wiping with a solvent dampened cloth in areas that start to go too dark.

    dye or stain

    Grain filler (aka paste wood filler - not the "pore fillers" in a tube hanging on a rack in a hardware store)/sanding

    Sanding sealer (again)/light sanding

    Then you apply your color or toner coats and clears.

    There is no wet sanding unless you applied finish coats too thick - they should be one in multiple passes (usually 3) and a single coat should be transparent. With lacquer, flow and coverage starts at about the third coat.

    You should go straight to butting with vertical cloth wheels and stick-type bugging compound when lacquer is dry (about an hour after the last coat is applied.). Each coat of lacquer dries in 30-60 minutes unless you are using a "lacquer enamel" blend like Colortone or Deft - they dry VERY slowly.

    But lacquer does not "cure". It dries only by evaporation.

    Sanding sealer has NOTHING to do with topcoats. And shellac should not be used if you're using lacquer. See above.

    It sounds like you're unfamiliar with the products and application sequence. If you are using lacquer, use the sequence listed above - that's the standard system for conventional lacquer. And wet sanding is a REPAIR procedure. It's only needed for small runs - or MAJOR mistakes.

    Otherwise, you buff after the lacquer dries - and it should be dry in an hour.

    You can do prep/sealer/filler/sealer one day; color and/or toner coats and clears the next - or put the clear off until the third day. Then buff later the third day or do it the 4th day.

    And you're done!

    And how you GET to that point is by applying the entire system on scrap wood until you get the desired results. You don't learn by applying things for the first time on your guitar - that gets REAL expensive as you have problems, sand coats off or strip the whole mess and so on.

    Lacquer is NOT paint, and the procedures are very different than painting.

    Work everything out on scrap FIRST until you can apply the whole system smoothly in 3 days at least 2-3 times. No stopping in the middle, removing something and restarting.

    THEN you're ready to work on the guitar. Finish work is like anything else - practice makes perfect. And because of the multiple products/coats involved you have to practice the application and learn the quirks of each one, including how they react with each other.

    The most common cause of finish work problems is impatience.
     
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  8. alexinhow

    alexinhow TDPRI Member

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    Thanks to everybody for sharing your experience. I'll make treasure of all you've said
     
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