Outsourcing the finish

The Achilles' Heel of Luthiery
tippie53
Posts: 7011
Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
Contact:

Re: Outsourcing the finish

Post by tippie53 »

I had used Deft early
all those finished check badly.
There is a technique issue for sure and in most cases it is learning to know how much to put on. I see often , and myself was included that too much finish was used and improper sealing.

Here is what I have learned
A proper prep
if your surface is not perfect you finish won't be. Do not sand past 220 grit as you need to allow the finish to have something to bite on to.
B good fill
I found this was one of the hardest parts to learn. I use Pore o Paq from behlen. Also there was a mineral spirit based filler Jasco . I do get natural and color my own but dark walnut filler will work . I then used minwax stain to color and thin the filler. The mineral spirit base thinned the filler. Once I have the color I would then use a plastic fork and whip the filler to about the consistency of Hershey's syrup. Then add a few drops of naphtha for aid in flash time. about 2 drops per tablespoon. I would apply let flash and rub in. 2 coats
C the hard part I would use the filler that was recommended usually vinyl.
I would STAIN SEAL FILL SEAL FINISH The trick is to know how much to get on. For that I would use a piece of foam rubber under the soundhole with a deli cup on top, this sealed the body. Then you can place a business card between the top and the cup. Measure the card and you can get a rough idea on how much build on your finish. I am looking for 8 coats to build .016 of finish. You can mike this on the card. Once I hit this I then let set and cure about 2 weeks.
Then you start the level sand and buffing process. Runs , may occure if you get to heavy a coat so watch out for them. If you get one don't do anything you can sand that down later.

Now that the finish is cured you start the level sanding. I use a cork block start with 600 and go about 1/2 way through the orange peel , then 800 to the level point. 1200 to rid the last of the shiney divots then 1500 2000 and start buffing and polish

I like 3M products and mazzerna

I think learning to finish is harder than building a guitar. It is easy to go past and if you need to you can apply 3 coats if you sand through.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
tippie53
Posts: 7011
Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
Contact:

Re: Outsourcing the finish

Post by tippie53 »

I do outsource my finish. I am doing about 20 guitars a year. My finish guy handles the filling
When you find a good finish guy they are worth every penny.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Post Reply