Unsure about staining

[Craig Bumgarner]

Trying to make new work look old. I know, just wait 40 years. Making new work look old is always difficult. Not talking about distressing, just color. Here's the new one side by side the original I copied.

Guitar is spruce top, birdseye maple b/s. My proposed finishing schedule is epoxy fill back and sides and Royal Lac epoxy filled b/s and unfilled top. Maple doesn't usually require grain fill, but these b/s are laminated and there is already some epoxy saturation through the grain, plus, being birdseye, there are a number of little chips in the surface and sanding them out is risky with .022" veneer.

In the past, I've used darker shellacs and some Stewmac Colortone liquid stains added in for the first couple coats after sealing. I pad it on, using straight strokes with the grain, trying to keep it even. This works okay with care, but very hard to keep from the finish even. The darker I make it, the more difficult it is to keep even. I tend to back off before I get it as dark as I would like.

Given my finish schedule, does anyone have any suggestions how to do this better? I have spray facilities if spraying a tinted layer of shellac or something else might do. My guess is for some of the forum members, this is old hat, but staining makes me very nervous, I've never really had much luck with it.

Any experience with an ozone chamber for turning darkening the new wood?

[Robert Russell]

Have a look at using Potassium Permanganate. It isn't a stain but it is brushed on. It is an oxidizer that will turn the wood brown just as it does with age. I have not used it yet but I am looking to do the same thing on my next build and I ran across this a couple of months ago.

Here is a video of Mamie Minch talking about guitar restoration using oxidation chemistry to remove and add oxidation on wood.

She talks about Potassium Permanganate at about the 3:45 mark


https://www.youtube.com/watch?v=tViTWUL8Was


Hope this helps,

Bob

[Barry Daniels]

Using tinted lacquer is pretty much a routine technique for experienced guitar finishers. You can make it nearly any color you want. Matching that old guitar would be fairly easy.

[Robert Russell]

I just re-read your post and noticed you said you have some epoxy saturating through the wood. In that case I think your only choice is to tint the clear because anything you do with the wood will not take on those spots (i.e staining or using the Potassium Permanganate).

Someone may have a better idea about using UV lights to age it but I have never done it so I am not sure if the epoxy would block the UV exposure or not.

Bob

[Craig Bumgarner]

Using tinted lacquer is pretty much a routine technique for experienced guitar finishers. You can make it nearly any color you want. Matching that old guitar would be fairly easy.

Okay, thanks. I'm set up to spray. I spray varnish instead of lacquer, but it works about the same. Spray, let it set up, wet sand and polish. I have some stain powders for oil base as well as Transtint stains. I gather Transtint stains are not really for oil base, but I've used them in testing and they seem to work okay. Not very experienced with spraying tinted coatings, but two cons I can think of are 1) runs in tinted finishes are a nightmare if they happen and 2) the finish ends up being fairly thick as the tinted coats have to be covered with clear before wet sanding or it will come out uneven.

[Craig Bumgarner]

Anyone spraying Royal Lac? I'm might trying tinting and spraying it for a color coat. Would set up faster than varnish.

[Barry Daniels]

The trick I have learned is to use lacquer and mix up my tinted coats with a lot of thinner and just a tiny bit of lacquer. That way the coats end up quite thin. Just make sure not to get any runs. Maybe spray the back or top with the guitar in a horizontal position.

[Robert Russell]

The one thing you have to take care with when tinting the clear is not to try and go too dark or put a lot of coats on or it will start to turn opaque and you will loose the beauty of the wood grain. The other thing it has a tendency to do is when looking at the wood at an angle it will look a bit foggy if you put too much color in your clear.

What Barry said... Don't try to build up the finish in your color coats so more thinner than clear is the way to go. You have to use some finish or your color will want to get blotchy and uneven.

Looking at your pictures I think you may have a problem with it getting opaque if you try and get the finish as dark as the one in the picture so I would suggest you try some test pieces before you spray your guitar. When you test it make sure you put clear on it as well to check to see if it is covering up the grain. You may not be able to go that dark but testing will tell you how dark you can get it before it goes opaque.

Good luck,

Bob

[Jason Rodgers]

Here's the new one side by side the original I copied.

No suggestions on finishing, just compliments on the work. Very nice (but you threw a longer scale on there!).

[Mark Fogleman]

I would spray (not brush or rag d/t splotching w/Maple) on Transtint Golden Brown or Antique Maple (based on what I see on my screen...your white balance may vary) followed with a few coats of garnet shellac or shellac tinted with Brown Mahogany Transtint, then your topcoats. Dye doesn't obscure the grain and Transtint is light fast.

[Craig Bumgarner]

Very nice (but you threw a longer scale on there!).

Thanks! Most of that is distortion from the iPhone camera, but it is indeed 665mm as opposed to 660mm on the original.

[Craig Bumgarner]

I would spray (not brush or rag d/t splotching w/Maple) on Transtint Golden Brown or Antique Maple (based on what I see on my screen...your white balance may vary) followed with a few coats of garnet shellac or shellac tinted with Brown Mahogany Transtint, then your topcoats. Dye doesn't obscure the grain and Transtint is light fast.

I have ColorTone aniline dyes which I "think" are the same as Transtint. The ColorTone colors are different and just now looking at the Transtint color chart, I see some there I like better, but I can probably mix something up with what I've got.

Would you mix the dye into solvent only for spraying or mix it with thinned topcoat as a base? I assume the latter, but checking.

Thanks for your suggestions.

[Robert Russell]

Craig,
I would put a binder (Finish or Sealer) in your tint coat, about 1/4 to 1/3 as much as you would normally use for a regular clear coat. If you don't it will come out blotchy looking. Also don't try to do it in one or two coats. Mix your color up very light and spray thin even coats. If you try to build up the color too fast it will also become blotchy and uneven. I personally would probably apply about 5 or 6 thin coats to get to the shade you are trying to achieve. The advantage to that is you can always adjust the color as you build it up.

Cheers,
Bob

[Mark Fogleman]

I have ColorTone aniline dyes which I "think" are the same as Transtint. The ColorTone colors are different and just now looking at the Transtint color chart, I see some there I like better, but I can probably mix something up with what I've got.

Would you mix the dye into solvent only for spraying or mix it with thinned topcoat as a base? I assume the latter, but checking.

Thanks for your suggestions.

I use distilled water as a carrier for the dye after using a solvent grain filler and use Denatured Alcohol (DNA) or Lacquer Thinner (LT) as a carrier after water-based fillers. If you use DNA or LT, consider adding a retarder in hot weather. You can also add a very small amount of shellac to a DNA or LT carrier to make it easier to see where you've sprayed on dark woods and inside corners but not appreciably seal the surface. Jeff Jewitt has an excellent tech guide on his store's website: http://homesteadfinishingproducts.com/w ... 7-2013.pdf He also has a well run forum with lots of expert advice if you have questions there.

[Jim Ashby]

It's not my call as it isn't my guitar but the spruce/birdseye is one of my favourite combinations - I'd leave it alone and hope I lived long enough for it to naturally age to the colour I wanted.

[Steven Smith]

Have a look at using Potassium Permanganate. It isn't a stain but it is brushed on. It is an oxidizer that will turn the wood brown just as it does with age. I have not used it yet but I am looking to do the same thing on my next build and I ran across this a couple of months ago.

Here is a video of Mamie Minch talking about guitar restoration using oxidation chemistry to remove and add oxidation on wood.

She talks about Potassium Permanganate at about the 3:45 mark


https://www.youtube.com/watch?v=tViTWUL8Was


Hope this helps,

Bob

I did some testing with Potassium Permanganate and found that for large areas spraying works much better (the stuff is not benign so be sure to observe all safety precautions). I used a cheap touch-up gun. Here's a thread with some photos: http://www.mimf.com/phpbb/viewtopic.php?f=8&t=3293. The guitar in question ('49 J45) is now ready to finish and I'm hoping the customer will agree to a burst which is what it had before someone sanded it off and ruined the original top. If they insist on a natural top I will do a light spray with the Potassium Permanganate followed by a few seal coats of shellac then the normal nitro process.

[Michael Lewis]

One point of caution with using chemicals on the birds eye veneer that has some epoxy bleed through, it will resist the chemical from penetrating the wood wherever the epoxy has soaked through. I suggest that if you want the guitar colored to look old you should put the color in the finish OVER the epoxy sealer. Otherwise you will most likely end up with a rather blotchy mess.

[Steven Smith]

One point of caution with using chemicals on the birds eye veneer that has some epoxy bleed through, it will resist the chemical from penetrating the wood wherever the epoxy has soaked through. I suggest that if you want the guitar colored to look old you should put the color in the finish OVER the epoxy sealer. Otherwise you will most likely end up with a rather blotchy mess.

A very good point - I didn't consider the veneer, I would probably not use it on that. Using it to age bracing shows that any glue spots will do exactly what Michael is cautioning against.

[Craig Bumgarner]

So what I did was epoxy filled the back and sides three times, sanded dead flat, sealed the top with shellac, mixed ColorTone dye in shellac and sprayed it. Many light coats until the color looked right. Then sprayed 3-4 coats of blonde shellac over this. When set up, gave it a very light sanding with 1200grit and French polished in the conventional way. Well, I used Royal Lac for the French polish part for quick build and better moisture resistance. Turned out good. Thanks for the help and suggestions.