Jump to content

Polyurethane Only In Bad Guitars?


Recommended Posts

According to their service department (phone call 2 years ago), they use an "acrylic urethane" clearcoat - I was under the impression (from a DuPont news release several years ago) that they were using the DuPont ChromaSystem® production clearcoat (7600S?). Of course, I could be mistaken, or the factory might have changed processes.

<EDIT>Sorry, it looks like it was the 4500 clear - this is from 2003:

http://www1.dupont.com/dupontglobal/corp/d...pmag/DPM303.pdf (3+MB download)

Edited by lovekraft
Link to comment
Share on other sites

I use Poly Urethane exclusively. Many companies use Polyester because it's very fast cure and very hard. Poly Urethane is a more durable and deeper looking finish (durable in that it doesn't chip as easily as Polyester). Both are brutally deadly to spray though and have a steep learning curve in the spraying. Polyester is also popular in use due to it being useable in an electrostatic booth which most major companies use now.

Link to comment
Share on other sites

well Lgm, your guitars are awesome, but what do you think about all brands like fender, gibson, etc ect about Nitro and the sound, and they say that polyurethane stop the sound, the wood cant breathe and 1,000 things.

The Viola, violin, cello, Luthiers talks about the same thing, the coat that they uses its from a tree, and very very thin, even they dont use any kind of nitro, poly or other.

And my cuestion its because i love Poly, very easy, very strong, and protects very good your guitar, but what about the sound guys?

Excuseme for my bad awful english :D

Link to comment
Share on other sites

Some people say that thick finishes effect up tone, but I think that's ridiculous on solidbody instruments. Even if it does effect tone (minutely) there's no way to use it to control the sound of the guitar. Neither Gibson or Fender uses nitro as far as I know. I've never looked into it much, but I seriously doubt they do.

Link to comment
Share on other sites

well Lgm, your guitars are awesome, but what do you think about all brands like fender, gibson, etc ect  about Nitro and the sound, and they say that polyurethane stop the sound, the wood cant breathe and 1,000 things.

The Viola, violin, cello, Luthiers talks about the same thing, the coat that they uses its from a tree, and very very thin, even they dont use any kind of nitro, poly or other.

And my cuestion its because i love Poly, very easy, very strong, and protects very good your guitar, but what about the sound guys?

Excuseme for my bad awful english  :D

The ironic thing about many companies, is they are run by traditionalists who never want to advance technologically. The 2 part Poly Urethanes IMO are a better finish for tone for a few reasons.

1. Poly Urethane, although it gets rock hard, still moves, it remains semi pliable, this is why you can paint a car with it and not have the paint crack from winter to summer. So, when wood moves, the paint moves with it, when wood vibrates, the paint vibrates with it. Nitro Laquer gets hard, and brittle, it does not move. This is why finish cracks occur, also, over time, the laquer continues to shrink until it finally cracks on it's own.

2. Poly Urethane looks deeper with fewer coats. 10 coats of poly = 30 coats of laquer. The thicker laquer is, the better it looks, it also cracks easier. On an acoustic instrument, the poly can be applied thin, still offer great protection, and look deep. Check out this finish on this acoustic I built http://www.lgmguitars.com/images/guitars/c...gsa1/gsa_06.jpg that is 3 coats of Poly Urethane. Find me a laquer that will look like that after 3 coats.

3. As for the wood not being able to breathe, that's a crock, you seal any wood, I don't care if it's a french polish, poly, laquer, or dried snot from a monkeys head, it's not going to breathe the same. Temp and humidity will still affect it, so why wouldn't you want to use a finish that will withstand all those variables?

IMO the 2 part Automotive Poly Urethane is simply the best finish out there. The only finish I haven't personally sprayed is Poly Ester because I simply can't get it here. As for killing tone, well, breedlove, Larrivee, they are 2 premier acoustic manufactures, and they use Poly Urethane. Part of the problem in this industry, is you get sooooooooo many people who are traditionalists and unwilling to more forward with technology. That is sad really. If nobody tried anything new, then I guess the world would still be flat :D

Link to comment
Share on other sites

Lets see...

Gibson acoustic uses Nitro. Taylor uses Poly. Tacoma uses Poly. Martin uses mostly Poly and some nitro, near as I can figure.

While I am not a fan of Taylor, they do not make crappy guitars, in fact, quite the opposite. Tacoma makes nice guitars as well.

And Martin? They make fine guitars.

I think that the real question should be: Who makes a good guitar.

BTW: I currently own a Gibson, Tacoma, and Martin. I used to own a Taylor.

Guitar Ed

Link to comment
Share on other sites

From what I understand PRS uses a polyester sealer. The advantage of polyester is that it cures fast and has an extremely high solids content. It's tough to sand, but doesn't gum up your paper as much as nitro or polyU. Also polyester sealer will shrink less than polyurethane.

Most production shops seal with polyester, shade/color with polyurethane and either clearcoat with polyester or polyurethane/acrylic polyurethane.

In my experience polyester clearcoat is much tougher to buff out, but it resists scratches better so passes through assembly without being sent back for touch up buffs. And I can feel confident that it will survive in the stores longer without looking worn and beat up.

The polyurethane clearcoats I've used in the past were easier to buff (acrylic polyurethane being the easiest) than polyester, but also easier to scratch. After several months it hardens up OK, but I'd go out of business if I had to let instruments hang for several months before buffing. Yeah, you can try and force cure polyurethane with heat, but even low heat dries out the wood and causes the gluelines shift slightly.

Edited by ddgman2001
Link to comment
Share on other sites

As far as wood breathing.. I too think that is a crock. Take any guitar and strip off the nitro, the poly, the tru-oil, whatever exotic sounding finish you want and what's underneath?? sealer and pore filler!! The only way to leave your wood that free of finish is to do a light oil finish. Be prepared for a lot of maintenance though :D

To me, for a project guitar, Nitro is the best value and if you want your instrument to age naturally in a classy sort of way, nitro is perfect. If you're deadset on the hardest finish possible and the most age resistant.. the finishes LGM mentioned are the best, but are out of reach of most project builders. Might be able to talk your local auto painter to shoot you a clear coat for a fee. What's a guitar for them.. they are used to painting things a couple hundred times the surface area..

well Lgm, your guitars are awesome, but what do you think about all brands like fender, gibson, etc ect  about Nitro and the sound, and they say that polyurethane stop the sound, the wood cant breathe and 1,000 things.

Link to comment
Share on other sites

Yes, PRS does use Dupont ChromaPremier system, I posted about it in 2003 when the magazine first came out, they was kind enough to let me borrow it for a while. I later found out the web link for the online magazine later and posted the link to download it, same as LK gave you guys.

Dupont PRS link

To answer your question about PRS paint methods nowdays. They still to this day use the Dupont, because I have the 20th Anniversary PRS Guitar Player Magazine that came out a couple months ago, and it showed a picture of the Dupont painting ChromaPremier system they use.

Link to comment
Share on other sites

To answer your question about PRS paint methods nowdays.  They still to this day use the Dupont, because I have the 20th Anniversary PRS Guitar Player Magazine that came out a couple months ago, and it showed a picture of the Dupont painting ChromaPremier system they use.

Ditto, they have a factory tour and all. PRS's shop has a RACK full of different colors.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...