Severe Belt Buckle Rash

The Saint · #1 10-08-2014, 08:59 AM

I've decided to take on this project of refinishing the back of my Takamine EN-10C acoustic. It has a mahogany back and some wear from my belt buckle that has broke through the lacquer and is exposing the bare wood. It has a satin gloss. I must admit I've never done this before but figure if I get the proper instruction I might be able to do a decent job refinishing this as I am meticulous when doing other projects.

If you have experience in this area I would love to hear your process, supplies I will need and of course your advice. This is a one time repair so I'm not looking into high costs or buying materials that I won't use again.

Thanks

charles Tauber · #2 10-08-2014, 09:14 AM

My advice is, "Don't".

It will be waaaaay more work than you can imagine and the chances of it looking even remotely "professional" are slim. I'm not casting doubts regarding your abilities, just that high quality finishing work is an art unto itself and requires a fair bit of knowledge and experience to look like much more than slapping finish on with a paint brush.

The Saint · #3 10-08-2014, 09:41 AM

Quote:

Originally Posted by charles Tauber

My advice is, "Don't".

It will be waaaaay more work than you can imagine and the chances of it looking even remotely "professional" are slim. I'm not casting doubts regarding your abilities, just that high quality finishing work is an art unto itself and requires a fair bit of knowledge and experience to look like much more than slapping finish on with a paint brush.

I'm retired and have got the time so I don't care how long it will take. I don't plan on just slapping finish on with a paint brush either.

I plan on doing it myself and I plan on doing a quality job (to the best of my ability). The process I'm somewhat familiar with as I have done lots of wood working projects. What I am unfamiliar with is the material used.. ie.. lacquers vs nitrocellulose, dyes, pore filling... etc.

I want to do it the right way and would appreciate someones expert advise on the key issues in refinishing the back of the guitar other than "don't".

The only "don't" I want to hear is the "don't" concerning products to use or tools to use.

Thanks

Frank Ford · #4 10-08-2014, 09:51 AM

It'll be like refinishing any other guitar, so I suggest you start reading about finishing in detail - it's the single most frustrating part of guitar making, so be prepared for something of a steep learning curve if you want to make it look professionally done. You will find myriad texts, illustrations, materials, etc. recommended, so it will be a challenge to figure which method will work best for you before you start.

With that preamble, I'd say the biggest problem at first will be surface preparation, and, as with painting a plastered room, it's the key to a good job. Getting the old finish off can be problematic because it's likely to be a catalyzed polymer that will resist any solvent you have available. I'd start by trying regular heavy-duty paint remover, being certain to keep it off the binding, etc. Then light sanding to get everything level and smooth.

You'll want to investigate stains and fillers to get the right combination to match the sides, decide on the surface coating and method of application. Lacquer is customarily sprayed, where other finishes might be wiped or brushed. Spraying is by far the easiest way to build a full surface finish, and these days good lacquer can be obtained in aerosol cans. Oil finishes can be attractive and very easy to apply over a good surface, although they don't yield the same look as lacquer. Some folks will insist that French polishing is quick and easy, but I have no idea of where they got THAT idea - it takes lots of practice to get good at that process.

Every so often I see very professional results from first-timers, but those are by far the exception.

Be patient, persistent, willing to start over (and over) and go for it if you'd like a challenging project!

Ned Milburn · #5 10-08-2014, 01:01 PM

Agreed on both Charles' and Frank's points.

The finish removal will be nearly as much of a job as putting on the new finish.

Are you intending to refinish the WHOLE instrument?? Another option would be to refinish ONLY the back and sides, but the challenge would be making a nice seam at the neck.

It really is a tough job - not just time consuming. But other people do it, and it can be done, so if you really want to, go for it.

A scraper can be your friend in the finish removal process. I have only ever had to refinish one guitar (soundboard only) and I did it completely with a cabinet scraper. Use a dust mask if you use sand-paper and a palm sander.

BTW, a "brush" is a fine way to do the refinishing, if you choose to do so. Whether you choose brush, spray, or rub-on finish, you will have choices of finish to use (nitro, poly, oil, shellac) and each method and medium tends to have its own strengths, weaknesses, and idiosyncrasies.

So, your research should include the following before you begin:

1) removal
2) choice of finish
3) choice of application method
4) final polishing & shining

The Saint · #6 10-08-2014, 02:42 PM

Tried to upload a pic but just wasn't able to.

Like I mentioned, I've got the time and I'm patient so I look forward to doing this. My concern is limiting the frustration and capitalizing on other people's experience. Even if you have some good links to point me to, that would be great. I can find snippets of what I'm looking for but no "start to finish" illustration... i.e. removing the finish..sanding...pore filling..applying stain/lacquer..thinning lacquer..re-applying lacquer..sanding..waxing

BTW...I'm only doing the back and it will be a satin or semi-gloss. As mentioned it's mahogany. Thanks

pics can be found here https://www.flickr.com/photos/739831...57648121400940

B. Howard · #7 10-09-2014, 06:27 AM

The fact it will be satin really doesn't make it easier. A gloss finish that is leveled and buffed will remove lots of errors. With a satin you must get a good look off the gun. It is likely a poly finish on that guitar but you should test it first to be sure because if it is a lacquer it may be easier to repair than refinish.In the pic it appears to have a acid cured sealer/filler as it's base, something to keep in mind if you intend to match the finish. An epoxy may be your best bet if you have no experience with post cat finishes. If you strip it you will need to stain it a bit to get the new white wood to match under finish as the rest of the mahogany has darkened with UV exposure.

John Arnold · #8 10-09-2014, 07:13 AM

The fact that the color came off with the finish means that the wood was not stained. The color is in the finish. That makes it easier to prep the bare wood, but it may be hard to get the same look by staining the wood itself.

The Saint · #9 10-09-2014, 09:47 PM

Quote:

Originally Posted by John Arnold

The fact that the color came off with the finish means that the wood was not stained. The color is in the finish. That makes it easier to prep the bare wood, but it may be hard to get the same look by staining the wood itself.

So what do you suggest I do concerning this. Do you mix a dye with a lacquer?

B. Howard · #10 10-10-2014, 06:24 AM

I doubt there is any color added in the finish. While the bindings could be scraped easily, the white back strip not so much. All wood darkens when the finish is applied. Wet the bare spots with some naptha or even water and you'll see it is actually close. Looks like a typical low end import finish with a thick post cat poly sealer/filler and a clear over it, likely a conversion varnish. As I said earlier you may need to adjust for the fact that the mahogany has darkened under the finish due to UV exposure and you will be exposing "white" wood when you prep to re-finish.

The Saint · #11 10-10-2014, 11:34 AM

Quote:

Originally Posted by B. Howard

I doubt there is any color added in the finish. While the bindings could be scraped easily, the white back strip not so much. All wood darkens when the finish is applied. Wet the bare spots with some naptha or even water and you'll see it is actually close. Looks like a typical low end import finish with a thick post cat poly sealer/filler and a clear over it, likely a conversion varnish. As I said earlier you may need to adjust for the fact that the mahogany has darkened under the finish due to UV exposure and you will be exposing "white" wood when you prep to re-finish.

Would you suggest taking a paint remover to this?

Bowie · #12 10-10-2014, 01:06 PM

I've done a lot of finishing work. That wood may be a problem if the damage went past the stain as you'd never get it to match. If it hasn't eaten past the outer stain then you should be ok. Can't tell from the pic.
You're probably not going to be able to match the satin. Meaning, you'll have to re-texture the entire back to either a very fine grit paper or just gloss it.
To make it near invisible, you'll have to spray it pretty liberally to fill the gouges. After that, very carefully cut down the high spots and possibly spray and cut again until the low areas are filled.

Personally, I'd CA glue the wood-damaged areas and just sand and buff the entire back to the desired gloss. It will make the problem less obvious and save you many hours of work.

The Saint · #13 10-10-2014, 03:35 PM

Quote:

Originally Posted by Bowie

Personally, I'd CA glue the wood-damaged areas and just sand and buff the entire back to the desired gloss. It will make the problem less obvious and save you many hours of work.

That's sounds like it might work. I'm wondering how much of the wear will show through.

Bowie · #14 10-10-2014, 04:10 PM

Quote:

Originally Posted by The Saint

That's sounds like it might work. I'm wondering how much of the wear will show through.

CA can be pretty much invisible against a clear coat, the main question will be the raw wood, whether that has been chewed past the stain. You can try a drop of CA and see how it looks when "wet". The clear coat itself will make the wood look darker and you may end up having no issue whatsoever.
Let us know how it goes.

Ned Milburn · #15 10-10-2014, 04:40 PM

FWIW, I don't know what all the rage is about using CA for finish repair.

If you are just doing the back, you should be able to do a decent job without too much difficulty. I asked earlier how much of the guitar you intend to refinish. As someone pointed out, it will be very difficult to exactly match the satin texture. Hence, doing the sides and back only is a fine option, since sometimes guitars have different finish on the Soundboard or neck.

Grab a scraper and some sandpaper and go for it!