Builder's block and finish questions.

[Br1ck]

Any advice for me? I've been stopped at the point of binding channel routing since before Christmas. I even went so far as to buy an old Stella arch top guitar to practice on. I removed the back on that to do a cheater neck reset, glued and trimmed the back, and since the binding was painted on, bought the Stew Mac Dremel attachment a router bit and bound the front and back. It came out fine. I even did a refret, on it. I keep telling myself to just do it when I feel I'm having a good day, but that hasn't happened yet. I'm building an Arches kit that is already routed around the scroll and headstock, so the really hard part is done. I'm even being very flexible on top color. It's fine if I need to use filler and go blacktop with it. I just have that first time on the high diving board fear thing going.

Speaking of finish, I bought an assortment of alcohol dyes and some maple boards I sanded to 220. I'm not doing a sunburst, but want to play with shades of brown or amber, or very dark brown to hide flaws. What is the best way to measure dye and alcohol mix so as to be able to duplicate something I may like? Drops from a pippette?

Does the dye go on bare wood? I'm going to use shellac and try to french polish at least the top coats.

I know my fear is irrational and the answer is just do it. I'd love to hear stories of the first time you did scary to you at the time stuff.

[sliebers]

Generally, the dye goes on bare wood. That's the hand rubbed process anyway. It's a lot easier to do on maple than spruce. It sounds like you have some practice boards of maple. I would strongly suggest to get some pine boards 1"x6" or something like that. Glue them up so you have the body width of your mandolin. Cut them to the shape of your mandolin and start practicing your stain and finish on those before you touch the real thing. Stains can also be sprayed, mixed with a light cut of shellac, lacquer, whatever your finish is going to be. Pipettes are good for measuring out stains, I use them and count the drops. Write stuff down, come up with a recipe so you can recreate it. You could even practice your binding routing on the practice boards. It's normal to be scared to cut into, or start staining an instrument. Lots of hours of work and expense to get to that point. Do the practice boards, get some confidence, and then just do it.

[rcc56]

Measuring dye: If the dye is liquid, you can use a syringe. If it is powdered, you can use a scale. Use only grain alcohol from the liquor store. Denatured alcohol can wreak havoc with colors and drying. I recommend mixing only small amounts of dye at one time, because the alcohol can evaporate from the bottle during storage, confusing the proportions.

Some people dye the wood, some the finish, some both.

[rcc56]

I'll also add that some will first wash coat the wood with one or two coats of a very thin shellac/alcohol mixture, allow to dry thoroughly, and follow this with stain. Lightly sealing the wood this way gives you more control over the depth of the color and helps to avoid uneven spots, but the color build is much slower.

Whatever you do, allow long drying time after applying color, no matter how you do it. Any coat that follows color should be done quickly and lightly to avoid disturbing the color directly underneath. Once you have one or two clear topcoats over the color, you don't have to be as delicate about adding more finish if you need to.

On French polishing: It's a great technique. It does take time to learn how to master it. I have found that you have to be careful not to use to wet a pad; you have to know when to quit for the day; that when in doubt, double the drying time; and finally, that if you try to build the finish too thickly, it will become cloudy. I get better results when I wait at least two days between polishing sessions.

If you're going to use shellac, you can only get away with brushing it on for a wash coat or an initial sealing coat. Avoid the canned stuff available at the hardware store. Make your own with shellac flakes and pure grain alcohol. The flakes are available from violin suppliers, some of the luthiers' suppliers, and from Woodcraft. The best deal I've found is from International Violin Company. Shellac flakes have a limited shelf life, not much more than a year or so, so don't buy in huge quantities.

[Drew Streip]

I'll also add that some will first wash coat the wood with one or two coats of a very thin shellac/alcohol mixture, allow to dry thoroughly, and follow this with stain. Lightly sealing the wood this way gives you more control over the depth of the color and helps to avoid uneven spots, but the color build is much slower.

This was my method on the ukulele I just built, and to nobody's surprise but my own, my spirit-based stain interacted with the wash coats of shellac. The result is that my planned cherry-to-dark mahogany burst turned into a more uniform "dark cherry."

I'm still quite happy with the finish because, as rcc56 said, the color builds very slowly. But it's definitely something to plan for.

Because I got scared after that, I decided to finish with a wipe-on poly instead of French polishing shellac. There was very little disturbance to the finish, but I did have to re-stain a slim rectangle where I had mis-located the bridge. The alcohol in the stain left some blushing in the adjacent poly. So I had to scuff out the poly, build the thin area again, level-sand, and final coat.

The result is virtually invisible:

[j. condino]

"Shellac flakes have a limited shelf life, not much more than a year or so, so don't buy in huge quantities."

Where did you get this information??????????????????? Shellac mixed with alcohol has a limited working lifespan, in that it gets funky and does not work very well after about five months, but I have never heard of shellac flakes or buttons going bad.

Have you seen this color and finishing video? Fine woodworking seems to have put a membership block on it, but you can watch it direct here (the mandolin one on the top of the page, not the bass video):

http://condino.com/skoolin/

[rcc56]

I got that info from half a dozen places. Frank Ford was one. I don't remember the others off the top of my head, but they were all reputable. I also know it from experience-- I have found that when the flakes no longer will dissolve completely overnight, the finish is more likely to cloud or dry poorly.

Oil varnish, many other finishing materials, yellow glue, and most other liquid glues also have a shelf life. I learned some of that the hard way. Hide glue flakes seem to keep almost indefinitely, though.

"I can make my own mistakes without your help, thank you." --Ron McKernan

"The only thing that bothers me more than having to redo somebody else's work is having to redo my own work." --Me