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Luthier
Mar-12-2004, 10:47am
This is a bit off from mandolins but I need some help with getting a matte finish on a Martin guitar I just repaired. There were three massive cracks in the back as a result of being dropped on its tailpin. #I managed to repair the major damage, I have matched the wood with stain, filled it and I am ready to do a touch up spray. #I am good with gloss but I don't know how to do a matte finish. #I know there are great luthiers in here and I was wondering if I could pick your brains? # #Don #(My ENTER key is not working today)

sunburst
Mar-12-2004, 2:09pm
If you can find a flattener, just add it to your regular lacquer and finish as usual. A flattener is a suspension of small particles (plastic? stone? ground glass?) it makes little difference what material, I suspect. I don't know where to find it, but I might be able to find out if you can't. Let me know if I need to look.

Anyway, to do a flat finish correctly, the flattener has to be suspended in the finish. A rubbed surface, steel wool or whatever, will look similar, but will wear to a gloss with use. A true flat finish, on the other hand, cannot even be buffed to a gloss because of the refraction of light within the finish caused by the suspended particles.

If you're good at gloss, you'll likely find flat to be a piece of cake.

Luthier
Mar-12-2004, 2:12pm
ok...I'll take any help I can. #I know the steel wool will just bring out a sheen but this pup is matte. #Do I just look where they sell finishing supplies?

Don

sunburst
Mar-12-2004, 2:20pm
That used to work, but it's getting harder to find stuff like that, and I usually encounter people in paint stores and suppliers that don't even know what I'm talking about when I ask for stuff that's not used regularly by their usual customers. It's worth a try tho.

I have a friend who works for a manufacturer of clear coatings for wood and he can probably get me some, but I am not at home right now so I don't have his phone number to call and ask.

Luthier
Mar-12-2004, 2:24pm
Thanks. #I will also do some checking around. #I was thinking rottenstone might work or pummice but I think even with a satin nitro, I will still not get the flatness I need.

sunburst
Mar-12-2004, 2:33pm
I found this. They aparently use it but don't list it as being for sale separately.McFadden (http://www.gelfinish.com/lacquers.htm)

Luthier
Mar-12-2004, 3:40pm
sheesh....burial caskets too.....I'm doing some cheking with some other sites as well. #Bound to hit on something somewhere.

Luthier
Mar-12-2004, 3:51pm
http://www.meritindustries.com/lvf.htm#laf This may work. So does this need rubbed out after it is sprayed on?

thistle3585
Mar-12-2004, 4:49pm
A friend of mine is a Martin authorized repairman, whatever that means. He said that Martin's finish is very difficult to touch up and that he has had to deal with this same problem in the past. Here is his number. Maybe he can help you. He's in Indiana.

Jim at Bennett String Instrument Repair 812-375-9383.

Andrew

mandoJeremy
Mar-12-2004, 5:11pm
Luthier, I will check when I get home but I used to have a quart of Dupont's laquer flattener and R-M's flattener from my days as a salesman in a paint store. If I still have I can send it to you because I have no use for it anymore. I did use some of it one time in some nitro and acrylic laquer and it worked great. I will post later this evening and let you know.

sunburst
Mar-12-2004, 5:51pm
So does this need rubbed out after it is sprayed on?
It can be done with or without rubbing. The trick is to do whatever it takes to match the old finish as closely as you can. If you get a good level coat without any dust or gnats or whatever you might be done.

Good luck and let me know how it turns out!

Luthier
Mar-12-2004, 6:05pm
Thanks much, #You folks are great. #Like I said, you taught an old dog a new trick.
I needed the gnat to help me hold the crack together while it dried. #This guy is fortunate to get his guitar back. #I will need to throw in the "how to take care of an instrument lecture" when he gets it.#

Don

sunburst
Mar-12-2004, 6:05pm
He said that Martin's finish is very difficult to touch up
well, yes and no. A lot (most?) Martins have a high gloss lacquer on the body that is really pretty easy to touch up. I have some lacquer of the same exact formula that I got for that purpose, but McFaddens guitar lacquer blends in just as well and I find it easier to work with.

Martin necks are a different story. Early ones had a flattener added to the last coats of lacquer, and later ones are a cross-link finish that is not a lacquer at all. Some of the newer ones with flat finishes, I don't know what they are.

Luthier
Mar-12-2004, 6:21pm
I just got an email from an aquaintance I have at Taylor Guitars.
<http://www.gelfinish.com/>
It is Mcfaddens.
Jeremy, if you want to get rid of that, give a yell. I'll take you up on it. Is it worth a free set of my OM plans I am coming out with??
This is where they get theirs. #I am glad folks share what they know.

Don

Michael Lewis
Mar-13-2004, 2:06am
Hey Don, dealing with the finish on Martin guitars is a bit difficult when they use the semi matt finish and spray it fairly dry. It makes tiny bumpy texture that is only achieved by spraying, and is very difficult to blend for a touch up. I generally make any repairs that are called for and do as little as possible to the surrounding finish. If that isn't a reasonable possibility I sand the entire surface with 800 grit and buff it with the brown Menzurna compound. This isn't the original surface texture, but it is more even in appearance than a shiny area where the repair was done. This is a judgment call each time.

The flattening agent in lacquer is usually stearate, the same white stuff that coats 'no clog' sand paper.
By the way, I'm a service center for Martin, which means I take care of most warranty problems like neck re sets, re gluing bridges, pick guard cracks, finish seperations, etc.

Luthier
Mar-13-2004, 4:20am
A few years back they asked me to be a service agent but I don't have a tax ID number just yet. #(Repairs have gotten beyond keeping up with so I may have to go that route soon.) #That is why I have kept my teaching job during the day. #The repairs and building and kits are my relaxation. #This guitar was real bad. #Three major cracks up the back and separated from the bottom two back braces. I didn't want to take the back off. (I didn't even want to do the repair...LOL). #The splits were clean and everything is great but the finish. #Even without touching up the finish, it will go back to him 100% better than when it came to me. #I just want to try if I can to get it as close to its original condition.#I have all the spray equipment. #I was Tom Loprinzi's finishing department in 1978-80 til they closed. I learned a whole lot during that time!! #All I did was nitro water clear gloss lacquer so this is a new bear for me. # We will figure something out. Would Sherwin Williams or an auto body place carry the flattening agent as well? Heck....maybe I should just mist it??

grsnovi
Mar-13-2004, 12:19pm
Are you familiar with this place?

Instrument Refinishing Message Board (http://www.reranch.com/)

Luthier
Mar-14-2004, 5:54am
Nope...I wasn't but I am now, and I thank you

Don