PDA

View Full Version : UV Lacquer?



Pete Howlett
07-13-2018, 04:31 PM
Were you using UV lacquers 7 years ago? I saw two guitars with a failing UV finish from separate famous and respected luthiers who will be. quote "Refinishing guitars for the rest of (their) lives".

There is no getting away from it - the building part of making a uke is a fairly straightforward piece of wood engineering. The truly scary part is finishing. It is the hard part.

Agree or disagree... and I am not trolling or poking the bear here because I am currently having my fair share of woes in this department at the moment. It is a tough one to get consistently right.

sequoia
07-13-2018, 07:52 PM
Your not poking Pete cause you are right: The achilles heal of lutherie is the finish. It is easy, but it is hard if that makes any sense. Today I encountered a twist on the situation in that I was changing out tuners and restringing a really nice classical guitar for a friend when I noticed several dings in the finish. I approach finish repair like a person would approach a poisonous snake: Just turn and run away. She didn't care and said they gave the finish "character". I readily agreed if you know what I mean. I don't do finish repairs.

All that being said, I have only one thing to add: Shellac, shellac, & marijuana. :rolleyes:

Pete Howlett
07-13-2018, 09:37 PM
Shellac and marijuana? Now that is a new finish for me. bro :) and one that would be illegal in the Nation State of the UK!

DPO
07-14-2018, 10:18 AM
Shellac is my absolute favorite finish. Easy to apply, fast drying, serviceable and so easy to repair/refinish. It's all I use now.

jcalkin
07-14-2018, 03:28 PM
In the first years of Huss & Dalton two finish makers changed their formulas without notice. The finish turned sticky after delivery. Hundreds of guitars had to be refinished or top coated. It was no fun.

sequoia
07-14-2018, 06:33 PM
In the first years of Huss & Dalton two finish makers changed their formulas without notice. The finish turned sticky after delivery. Hundreds of guitars had to be refinished or top coated. It was no fun.

Definition: Nightmare.

Michael N.
07-14-2018, 08:51 PM
Pretty much every type of finish has it's problems. Nitro is inherently unstable and is very prone to finish cracks. I've literally seen hundreds of guitars with Nitro cracks and some of them not that old. In the early stages owners tend to think that their guitar has a crack in it - the wood that is. Shellac is fine until you meet the person who can strip the finish off, down to bare wood, in a matter of months. Something to do with their sweat apparently. Oil varnish is hard to beat in terms of how it pops wood grain but tends to be a little softer than some other finishes. It is possible to get a hard oil varnish but you come up against the hard = brittle/chippy problem.
Nitro was never an option for me. I didn't like the health warnings and I haven't got the room for full extraction. Personally I really like oil varnish but I tend to use shellac more.
I think we've just got to get over this 'new forever' syndrome. There's going to be wear, there are going to be scratches, there are going to be dings. Treat the instrument with respect, don't abuse it but more than anything play the thing. If you pick up a few dings along the way, big deal, it's a tool for a musician.

Pete Howlett
07-14-2018, 10:21 PM
I have seen one of my ukes so 'stripped'... yes there is no solution that really works is there? In truth, the whole process is one of constant compromise.

Michael N.
07-15-2018, 11:43 AM
I once had a French polished instrument come back after just under 3 months. It was worn down to wood in two small areas, on the back and on one of the sides. I've frequently heard that this is down to some folk having alkaline sweat. I'm no dermatologist but human skin is supposedly slightly acidic, part of it's defence mechanism but perhaps some people tilt towards being alkaline. I don't know. Shellac has no problem with acidic solutions. It certainly does have problems with solutions that are alkaline though. The odd thing about this returned instrument was that the finish on the neck was perfectly intact, no sign of any real wear.
Somewhat confusing as it's the skin that comes into direct contact with the neck, not so on the back/sides of an instrument. I just wondered if it was sweat or perhaps down to what the person was wearing. I do know that washing powder is alkaline. There could be a clue there but in truth I really don't know what causes it. Sometimes I wish I was one of those who does wear through finishes quickly (I don't). That way I could do some testing.
BTW. I've heard that it also happens with nitro and oil finishes. I've also heard that some oil finishes stand up to it better than others. I don't know if any of this is true, it's just what I've read from other makers.

Pete Howlett
07-15-2018, 01:22 PM
And there's the 'rub' so to speak. We have no empirical data to help us make better informed decisions and observations about what we do.

sequoia
07-15-2018, 05:25 PM
I agree with the poster on always hunting for the next, best thing in finishes. Been there. Done that. Still hunting. Maybe there is no silver bullet, although I'm intrigued with what Allen is doing with his polyurethane(?) finishes down there in the down under... As for wear on instruments I present the following scientific definition: Entropy.

2 a : the degradation of the matter and energy in the universe to an ultimate state of inert uniformity
Entropy is the general trend of the universe toward death and disorder. —James R. Newman
b : a process of degradation or running down or a trend to disorder.

I will still stick with shellac. It ain't perfect but it won't kill me.

Michael N.
07-15-2018, 10:53 PM
There's just so many variables and I'm pretty sure that no one has done the testing largely because it's a pretty small percentage of the population who do seem to wear through finishes.
I know for a fact that shellac is susceptible. What I don't know is how the modified shellacs hold up and there are a few different types of those. Oil varnish is another. The term just donates some type of resin in some type of oil. In that sense it's a fairly meaningless term, there are dozens of variables in the type of oil, how it's been treated, the type of resin and how that has been treated. Any one of those variables could have consequences in terms of how it reacts to body chemistry. I seem to recall Al Carruth mentioning the oil varnish that he uses holds up quite well. I looked it up and I think it was only available in the USA, can't remember the name of it. He will know of course and he's probably got a fair idea of how it reacts over time.
Another snippet of information. A week or so ago I came across a forum posting where someone had said that they had worn through the french polish on a neck in two years. He then went on to say that he had it refinished in gunstock finish (almost certainly tru oil) and 8 years later no sign of wear. Tru oil is certainly a little softer than shellac but clearly the hardness of shellac wasn't helping in his particular case. Years ago my own personal guitar was finished in Tru oil - the whole lot, neck, soundboard, back/sides. I used it for around 10 years. It held up well but then again I'm pretty careful with my instruments and my 10 years is the equivalent of a more regular players 3 years.
No one wants the finish on one of their instruments to wear out after just a couple of years. Having said that there comes a point where it's just down to the natural wear and tear of materials. No point in putting it down as a guarantee for endless years. Even relatively soft shoe leather wears away stone eventually.

Pete Howlett
07-16-2018, 09:36 AM
Each to his own. I like cellulose lacquer and understand it. My clients do also.