Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com

Zpoxy Crack/Grain fill on knotty pine.

Discussion in 'Finely Finished' started by Phil Gerke, Apr 14, 2015.

  1. Phil Gerke

    Phil Gerke TDPRI Member

    30
    Oct 26, 2012
    Hey all,

    So I've got a knotty pine tele body that I am prepping. Around the knots there are several fairly narrow cracks. I was planning to hit them with Zpoxy and sand back to flat. A couple questions.

    Firstly does this sound like the right product for the job?

    Second; I know pine is not typically grain filled, but if I'm whipping up the zpoxy and filling cracks, would it be a problem to just go ahead and spread it all around and "grain fill" the entire body? I know its more work for sure. The reason I'm considering it is because on an experiment body a while ago I grain filled the top but not the back. It was wood that did not need filled as it was a tight grain but I filled the top anyway for un related reasons. The top definitely finished flatter as a result, even though I think "technically" it should not have mattered as it was such a tight grain.

    What do you all think?

    Also the plan is the seal with shellac and follow up with Tru Oil for a few coats as I like this look then I'm going to do a brown burst with Behlens rattle can tinted nitro and top coat with Behlens rattle can instrument lacquer.

    Thanks a lot for any feedback!

    Phil
     

  2. drmcclainphd

    drmcclainphd Tele-Afflicted

    I've not used Zpoxy, but I've used similar epoxies on rocketry builds and composite lay-ups. The only epoxy I considered good enough to use on a guitar is Premium No-Blush from Epoxy Products http://www.epoxyproducts.com/ It's non-hazmat, so safer to use, it dries crystal clear, and is a very slow cure. That last is most important. You don't want epoxy going tacky before you're able to get everything covered the way you want, and 30 minute cure hobby epoxies give you maybe 5 minutes. I built a strat style 12 string and finished it with nothing but kona stain and this epoxy on top. It's bullet proof now. It came out glossy, not quite what I wanted, so I put on another coat and wiped it with a microfiber cloth with DMSO on it. It came out a nice satin.

    That's the other thing. I only use DMSO for thinning/cleaning epoxy. Low odor, non-toxic, zero flammability. I buy it at farm supply stores, where it's called horse linament.

    Now, as for all that other stuff. On top of epoxy? No way. Do everything else first, leaving the grain/cracks open, then fill and top coat all in one with epoxy. If it's good epoxy, stuff you put on top will scrape off easily. It it's cheap epoxy it's a PITA to finish smoothly.
     

  3. Jupiter

    Jupiter Telefied Silver Supporter

    Jun 22, 2010
    Osaka, Japan
    I'd consider doing it, if only to toughen it up so it won't dent so easily....
     

  4. DrASATele

    DrASATele Poster Extraordinaire

    Jul 6, 2012
    North of Boston
    Sounds like a fun project Phil. I might skip the Tru-Oil if you plan to do the burst in lacquer. I see Tru-Oil as more of a clear coat. You can get it's slight ambering qualities of the Tru-Oil with 3 or 4 drops of Amber/Yellow and 1 Brown in 8oz of shellac. It's very subtle mix. The brown eases the brightness of the yellow/orange effect, giving it more of that vintage amber look.
    Just my opinion though. More than one way to skin that cat :D
     

  5. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

    Age:
    71
    May 1, 2003
    Jacksonville, FL
    Use thin CA... and an orbital sander.... wet the area that needs attention with the glue... the CA will wick down into the cracks, eliminating 'em as a source of concern.. then the sander with a medium grit paper, around 150.. will produce enough powder to blend with the still wet glue, and fill the cracks, invisibly..

    You can use old used sandpaper because the wet glue and sanding dust will load up the paper rapidly..

    try it on scrap. it only takes a time or two to get the hang of it.

    For more pronounced cracks.. the epoxy and heat gun are the way to go..

    Ron Kirn
     

  6. Mike Simpson

    Mike Simpson Doctor of Teleocity

    Age:
    61
    Mar 19, 2006
    Gilbert, AZ (PHX)
    A couple of years later you will probably be able to see where the knot is in the finish no matter what you do. The different expansion rate of the knot vs the surrounding wood will eventually show to some degree in the finish. Guess how I know that....
     

  7. Phil Gerke

    Phil Gerke TDPRI Member

    30
    Oct 26, 2012
    This is great input guys! I think between Ron Kirn and DrAsat I got a plan.

    I'm going to forgo the epoxy all together. I had completely over looked CA glue, but thats what I'll do. Also after consideration I'm not going to grain fill this body. I'm confident its going to be plenty flat and finish up just fine. I'll be missing the potential "hardening" benefit which is unfortunate. However its more time and further sanding which is a factor as I am barely home at all this spring and I want to get this going!

    As for the Tru Oil. I know it seems unnecessary, however I feel that it imparts something to the look that is unique to Tru Oil, call me crazy. If it was not compatible with shellac or lacquer I'd lose it in a heart beat, but they all play nice so I'm gonna go for it. I did some tests that got me pretty excited.

    Thanks a lot everyone! I'll definitely be posting pic's, thoughts and questions on this project.

    Cheers!
    Phil
     

  8. Phil Gerke

    Phil Gerke TDPRI Member

    30
    Oct 26, 2012
    Drmcclainphd


    Thanks for the links and insight. The DMSO is a great tip (I grew up with that stuff around) I'll do some tests with it next time. I'll definitely look into this epoxy in the future as its hard to find one that stays clear.

    That said, my initial thought was not to use the Zpoxy as a top coat, only as a grain fill, which is a fairly common practice and you can still finish however you'd like. I'm also keen to try Brownells glass bedding epoxy for this some time as well.

    Thanks again!
    Phil
     

  9. Phil Gerke

    Phil Gerke TDPRI Member

    30
    Oct 26, 2012
    Hey Ron Kirn,

    Any further tips on the CA glue? I'm finding that because its so thin it really wants to seep in all around the cracks, then the sanding spreads it around even more. Is there a better way to keep it localized to the crack? Or do I just embrace it and sand the hell out of it? My concern is that the glue "stains" will show through too much.

    Also, I attempted this on some end grain. Holy hell, instant saturation. Fortunately most of my CA spots will be obscured by dark brown if its a problem.

    Thanks again!!!
    Phil
     

  10. Jupiter

    Jupiter Telefied Silver Supporter

    Jun 22, 2010
    Osaka, Japan
    I'm not Ron, but I do know that there are all different degrees of viscosity for CA. Maybe you want medium vis.
     

  11. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

    Age:
    71
    May 1, 2003
    Jacksonville, FL
    what I do sometimes on loose knots is wet it with thin CA, then add medium Viscosity .. wetting it with the thin facilitates the thicker goo's ability to soak further into the cracks before it begins to harden.

    once it's on the body, you cannot let it sit for more than a nano-second ... hit it with the sander immediately which will blend it evenly into the surrounding surface... you won;t see a thing...



    rk
     

  12. Phil Gerke

    Phil Gerke TDPRI Member

    30
    Oct 26, 2012
    You guys are great! I have the "thin" variety of CA, I may grab some medium tomorrow just to have it. That said I think the thin stuff will work, if I actually do it right! My problem is I waited too long and then attempted to hand sand. Tomorrow I'll do a drop, then immediately hit it with the sander as Ron said. Again, in a brief moment of insight I did my first attempts in places that will be a very dark brown and left the ones that will show for tomorrow.

    Thanks again!!
    Phil
     

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