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Stevelele
11-28-2011, 08:14 AM
Just wondering whether this type of finish could potentially impair the ability of an uke to 'open up' or whether it could have an adverse affect on the sound. I really like the look, but if it means sacrificing sound, I wouldn't do it

PhilUSAFRet
11-28-2011, 10:04 AM
It's an ongoing "debate" but the consensus seems to be "not so you'd notice." I like it too.

Doc_J
11-28-2011, 10:55 AM
Just wondering whether this type of finish could potentially impair the ability of an uke to 'open up' or whether it could have an adverse affect on the sound. I really like the look, but if it means sacrificing sound, I wouldn't do it

You might want to check in the Luthier Lounge forum.

Kanile'a and Taylor Guitars use UV-cured Gloss Polyester finishes, so I don't think it is a problem. I love my Kanile'a (gloss finish) but sometimes wonder if the a thinner non-gloss finish could be better sounding.

Stevelele
11-28-2011, 11:30 AM
sorry guys--I should've used the ole' search function! Don't mind me--just passing through

Rick Turner
11-28-2011, 05:21 PM
Properly done, thin gloss polyester finishes are no more tone-damping than nitro lacquer of the same thickness.

And before anyone says, "Oooooh, but it's plastic!", just what do you think nitrocellulose lacquer is? Oooooh, it's plastic...as in celluloid.

specialk13
11-28-2011, 07:27 PM
I think nitro is cool in that it will get harder over time, an instrument finished with a polyester finish won't get nearly as hard.
The UV cured poly finish is supposedly very thin but my Kanilea seems to have quite a thick coat on it.
Basically, if it sounds good.....play it.

OldePhart
11-29-2011, 12:40 PM
I think the real issue is if more "filled pores" vs "non-filled pores." If you're putting any finish on thickly enough to completely fill the pores in the wood and leave a mirror finish my gut feel is there has to be some impact on the flexibility of the soundboard and thus the tone and volume. However, compared to things like wood thickness, quality, and, most importantly, build details this impact is probably fairly small. I.e. a superb ukulele with a "mirror" finish is still going to sound better than a merely good ukulele "naked." The big question is would the superb ukulele be even more superb with a thinner finish and I suspect the answer is yes, but it would be really hard to tell since there is going to be some variation in individual samples even from a very fine luthier.

Rick Turner
11-29-2011, 03:13 PM
Nitro does NOT get as hard as polyester whether the poly is UV cured or MEKP cured. Sorry, but I work with this stuff every day...hands on, and I would love to see fewer comments on finish from people who don't do it for a living. There are enough myths out there without adding to them.

Also, pore filling is a separate issue from finishing, though the finish can be a part of that process.

I can tell you what I do for a thin gloss uke finish:

2 coats of brushed on and wiped off epoxy for pre-seal and pore fill
lightly sand
2 coats of Simtec "Adhesion Promoter" two part urethane
lightly sand and maroon ScotchBrite for an even scratch pattern
3 coats of Simtec "Easy Sanding Sealer" polyester catalyzed with MEKP
sand dead flat
3 coats of Simtec "Clear Top Coat" polyester catalyzed with MEKP
Wait 24 to 48 or more hours, sand with 400 (if needed), 600, 800, 1000, 1200, then buff with Menzerna polish on a 14" to 18" wheel.

The resultant finish is much tougher and scratch resistant than any nitro lacquer finish ever sprayed, and when done correctly, it comes out at a similar film thickness to a decent nitro job.

I've probably sprayed over 2,000 instruments with polyester now, and it's fantastic stuff.

specialk13
11-29-2011, 05:39 PM
I think it's prudent to say there are many finishes available and equally as many ways to apply them. What really matters is in the end is the sound of the instrument as a whole and whether it works for the consumer that purchases the instrument.

FWIW I think a poly finish does look nice, I just prefer the feel and look of nitro. I like that nitro will age as my instrument does and show the wear from being played and loved over the years that I own it. I think it sounds better too, but then that's just extremely subjective again......

peewee
11-29-2011, 06:33 PM
Semi Hijack alert: What if a Kanilea Polyester finish has a tiny pit in the back, like uncooked couscous grain small. Is there a way to fill it that a non-woodworking idiot like myself might be able to manage?

Rick Turner
11-29-2011, 06:42 PM
No.

And I could show you a five year old uke of mine and tell you it's nitro, and you'd believe it. Sorry. And this bit about aging and showing it is...well, I think it's crazy. The fact is that nitro instruments will someday have to be refinished. Nitro starts going down hill the day after it's sprayed. The stuff is chemically unstable. I'll take the look of any pre-lacquer Martin finish...shellac and/or varnish...any day over what the 1930s finishes look like. You want a great look? French polish. And it will scratch if you look at it sideways, but it's what lacquer wishes to be in terms of depth and look. And long term, it protects better.

Plainsong
11-29-2011, 07:25 PM
Ok, dumb question time: is polyester only for gloss finishes or is it used on satin finishes as well? I have my glossy kanile'a, and it fills the need in me for glossy ukes. I ultimately just prefer satin. My gloss uke doesn't sound dead or horrible in any way because it was done right. No regrets there. I'm just more comfortable with satin.

I could ask Rick this in PM, but why not let everyone else into the conversation. I can't be the only clueless one. What's your take on how to do a nice satin finish? Or is there such a thing?

Edit: my husband just used shellac (among other things) on a pipe he just made for himself, his first one.

specialk13
11-30-2011, 04:04 PM
Plainsong, I would love to give you my opinion but I fear the backlash even though Im fairly certain that having a personal opinion is what a forum is all about.
I'm wary of anyone that thinks they have all the "right" answers.

southcoastukes
11-30-2011, 07:35 PM
Plainsong, I would love to give you my opinion but I fear the backlash even though Im fairly certain that having a personal opinion is what a forum is all about.
I'm wary of anyone that thinks they have all the "right" answers.

Rick's bark is worse than his bite. Go ahead with your answer. He'll probably give you some grief, but buck up! You'll get a lot of great info from Mr. Rick.

That said, just like he loves his polyester, I love my nitro, and my background includes a lot of time spent in the finishing profession. At one point, I helped my company develop a nitro based Musical Instrument Lacquer, and I still like it better than anything.

Rick's finish is excellent, but none, including mine is perfect. I think ours is much more repair friendly, his more durable. Ours is more flexible than a typical nitro, and would have a slight edge in sound properties over an epoxy / polyester procedure. Thickness would weigh into that equation as well, and I also think our finish can give a nice job with a thinner coat. I think ours gives a nicer look as a polished satin, but if you like a filled gloss, then you might as well go Rick's way. Any slight acoustical advantage ours might have would be mostly lost, and his finish looks gorgeous buffed out.