WLP, I refinished my Mustang to a natural finish...it was my first attempt at refinishing and I learnd a lot that I hope will help you.
The biggest challenge is you don't know what's under that paint. Likely Poplar or another wood that may be "pieced". That is two or three different pieces of mismatched wood glued together to make the body. Even if it's a single piece of wood, some woods like Poplar have gray, brown, tan, and green streaks...not as pretty as you might want in a natural finish.
So while disassembly and sanding are a challenge, exactly how to refinish a less than uniformly grained and colored body in natral finish is the hard part...the ARTISTIC part, if you will. So here's the article I wrote about what I learned...the photos won't copy & paste with the text.
Refinishing a 1965 Fender Mustang Poplar Slab
by Doug Pratt
This is a description of what I learned from my first ever refinishing project. Actually office furniture was my first project a few months prior and I’d learned a bit from that, but not as much as I learned from this guitar project. The guitar refinishing was much more complex than I could have predicted. Fortunately, I got lots of advice from woodworking specialists, from my luthier, and from a vintage guitar expert along the way. I digested a lot of information and discovered a few little tricks, so I hope this report is helpful to some guitar lovers who face refinishing challenges.
This now-natural beauty came to me as a
battered Dakota Red refinish.
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The Plan…and the Challenges
I got my 1965 Mustang (pre-CBS) in 2009 with lots of dings & scratches. It had already been refinished and, even though the refinish was in the correct original color, Dakota Red, about 1/3 of the vintage value was irrevocably lost in that refinishing. I noticed one day that the fret markers on the side of the neck are brass dots and they looked really good next to the amber neck. The red paint worked against this subtle aesthetic and I began to picture the slab in a natural wood tone matching these little markers, the neck and the headstock.
I knew most original Mustangs had been made of Poplar, a light wood, and a rare few were Mahogany. When I stripped my guitar, I discovered not only a Poplar slab but all the surprises Poplar has to offer! Poplar, it turns out, can be challenging to work with for several reasons.
First, there are typically two predominant colors in any one slab, blond and dark brown. These are assymetrically variegated and have steaks of yellow, gray and green. Opaque finishes are no problem, but Poplar’s eccentric variegations make it hard to predict what the wood will look like after translucent color or natural stain is applied.
Second, Poplar is soft and porous wood. Softness means sanding can easily leave uneven spots. The porousness means paint absorbs deep into the grain. So there’s a double challenge in that it takes a lot of sanding, after stripping, to get down to where paint has not penetrated, and this sanding has to be done with great care to keep an even surface. Were I painting this slab, there would be no problem. However, to achieve an appealing natural wood finish, there’s a substantial challenge: porosity and variegation together mean liquid stain absorbs unevenly.
I knew I could easily paint my Mustang any color. Poplar absorbs paint very well. So I selected T.V. Yellow as a default plan. But I’d decided the natural finish with the pearloid pickguard and brass fret markers was the look I wanted, so I decided to press on with my vision.
Preparation: Surprises, and a Few Tricks
I used a wood stripper to get through the two layers of red paint. After letting generous amounts of the stripper sit for 20 minutes, I scraped gently with a plastic scraper and then hand sanded with 100 grade sandpaper till I got down to mostly bare wood. Then, to remove most of the red saturation in the grain, I used Formby’s refinisher, a gentle stripper with conditioning agents, and rubbed that with 0000 steel wool.
I saw how well the Poplar had absorbed the paint in several sections where red was embedded deep in the grain. It was clearly more than some careful cleaning wth a dental pick dipped in stripper could remove. Aggressive hand sanding might have left indentations in the soft wood. So I used an electric block sander with very fine grain sandpaper to take off enough wood to remove the imbedded red.
An experienced woodworker would have been faster, but my preparation of the slab took about 12 hours, double what I’d planned. Overall, it was good that I went slow, modulating the muscle I put in, and mustering lots of extra patience… eventually all the saturated paint and almost every ding were gone, leaving only one deep battle scar visible
Finishing: More Surprises, and a Few More Tricks
When the slab was completely prepared, highlights of yellow and green between the blond and dark brown sections of Poplar became obvious. This was not pretty wood and looked almost like several species had grown together. I was clearly hooked by the challenge, however, because I persisted in my vision of a natural wood finish…if only I could mute these dramatic contrasts.
I learned from some woodworking specialists that a liquid stain would soak into the wood. My goal was to lighten the dark wood and darken the light wood until both match. Stain that soaks into the wood wouldn’t achieve that goal. What I needed was a stain that would sit on top of the wood and allow me to gradually build up the color.
I applied Butternut Gel Stain to the brown wood to lighten it a bit. Gel stain, I’d learned, tints the surface instead of being absorbed like liquid stain. Then I applied Autumn Gel Stain to the blond wood to darken it just a bit. The Gel Stains tinted the surface of the Poplar more evenly than a liquid stain could have and brought the blond and brown each closer to an amber.
Applying coats of gel stain on top of each other didn't have enough cumulative lightening effect. So I sprayed Fender Neck Amber (from Guitar ReRanch, Texas) in very thin coats. Then I was able to apply another coat of either Gel Stain, to further lighten or to darken. Three repetitions of this process brought the brown and blond sections much closer together, nearly matching the headstock. This was the look I was shooting for.
Finally, I applied a Satin Nitro Tinted Clear Coat (From Guitar ReRanch) which is tinted just 20% as much as the Neck Amber. This further softened the blond-brown drama and sealed the finish (Fender Neck Amber is not a final seal). The body is now a near perfect match for the neck and headstock, exactly what I’d hoped for.
My battered old Mustang now looks healthy and strong enough for hard rockin’…not a classically beautiful piece of wood, but to me it’s a handsome axe aging gracefully.
You can see the body and neck are an almost perfect match.
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Three Brands of Gel Stain
To Even-Out Variegated Grain, Coloring
Gel stains compared to thin-bodied stains: Because gel stains lie on a wood surface instead of soaking into it, they uniformly color porous and nonporous areas alike. That makes them relatively goof-proof, and a great help to novice finishers. And, because they don't run or splatter, they're especially handy for applying to vertical surfaces.
Nevertheless, gel stains do have certain drawbacks. We avoid them on projects with lots of tight corners and crevices because the stain collects in these tight spots and is hard to remove. Thin-bodied stains don't have this problem because they wick into tight spots and the areas adjoining them. And, because gel stains don't penetrate as well as thin-bodied stains, they don't bring out the "depth" of the wood grain as well as thin-bodied stains. That's why we prefer thin-bodied stains for porous woods such as oak, ash, mahogany, and walnut.
When it makes sense to use a gel stain: Sometimes you can't avoid combining woods of slightly different coloration or mismatching grain patterns in the same project surface. For example, various red oak boards may vary from pale white to pink in tone, and they may have flatsawn or quartersawn grain patterns. If economics dictate that you must use such boards together, you can help give the surface a uniform appearance by using gel stains…Species such as pine, maple, cherry, and birch have relatively nonporous surfaces…grain pops to the surface so you can get splotchy areas of light and dark because of uneven absorption of liquid stain. Gel stains help you achieve uniform coloration on these woods.
The three brands we tried: The three gel stains we tried varied considerably in thickness. The Minwax product was just slightly thicker than the Bartley product, and the Wood-Kote stain was considerably thicker than the other two. So, the Wood-Kote product possessed all of the qualities-and drawbacks-of a gel stain to a greater degree than the others.
For example, the Wood-Kote did the best job of masking uneven wood coloration and graining, but it was also the hardest to apply and wipe off. Removing it from crevices was a chore.
 Wood Magazine, online woodmagazine.com; also Teri Masaschi in Fine Woodworking, Oct., 2002
Hey everyone I have a white 65 ri mustang that im hoping to sand down and stain to make it look like this Its the image below the black mustang at the top