I am making a Mandolin out of some 16th” curly maple vaneer. My plan is to use the vaneer as is , not glued to any other wood. I have seen articales on how to finish regular thick boards, such as dyeing then oiling then sellac as a topcoat. Now my question………. I have not done any thing to the wood exept for sanding it smooth , is it to late to add a dye to accent the figure my concern is re-raising the grain after all the sanding left me with less than I started with. My hope is to dye it then use Tung oil, and finilly amber shellac as a finish. Any help will be rewarded with a big thanks and my 1st born. I am sending pics of the vaneer as well as the top of the Mandollin finished withe straight poly.
Replies
Any finish is going to raise the grain to some extent. You can reduce grain raising from dye by using a NGR dye(Non-Grain Raising) instead of waterbased dye. These don't dry as fast as just using an alcohol based dye, but I'd still spray if possible. (It would be essential with alcohol based dye.) Even so, if applying by hand you want the retarder for diluting the dye. The problem with fast drying dye is that when you overlap wet dye onto an area that has already dried you will get a dark streak that is a real bear to remove. You will likely want to substantially dilute the dye as it comes from companies like Behlen unless you want a fairly dark color. YOU MUST TEST dye on similar scrap to get the right dilution. Also note that dye by itself tends to look awful and nothing like the final appearance. You need to work the full finishing schedule (or most of it) over the dye to see how it will turn out in the end.
A common method of really enhancing the figure in curly maple would have you sand off surface leaving dye only in the more porous areas. Obviously you can't do that in your situation. This means the dye won't dramatically "pop" the figure and will mostly just change the overall coloration.
I would recommend using boiled linseed oil instead of tung oil. Tung oil takes quite a while to dry and I'd bet you wouldn't see the difference. Remember you don't need to flood the wood, just dampen, let penetrate and wipe off excess fully.
curly maple
Thanks for your input I shall listen to what you say.I have 1 quick question about shellac, Do I need to dilute it, and if so to what degree? I tried working with it as is and it dries fast leaving me with a short work time is this normal I am new to these ways of finnishing.
Shellac does dry pretty fast, due to the rapid evaporation of alcohol. For that reason, it is pretty hard to apply with a brush. Thinning it doesn't make it dry slower, unfortunately. Even if you thin with isopropanol (which is slower to evaporate than methanol or ethanol), you will only gain a small number of seconds before it dries.
What shellac are you using? I'm going to guess Zinsser SealCoat or Shellac, but please let us know.
Shellac sprays well, if you have access to spray equipment. The fast dry time works to advantage here, in drying dust nib-free, allowing for faster recoat time and preventing runs and sags. Both of the Zinsser products will spray straight from the can, although it is pretty easy to lay on too heavy a coat. For that reason, I prefer a bit thinner cut (1.5 pounds).
If you don't have spray equipment, Zinsser also sells the Shellac in an aerosol can. For a small job, that might be ideal.
If you are stuck with applying the shellac by hand, you can use the padding method. There are plenty of threads here (and elsewhere) on how to do this, so I won't repeat them - search for "padding shellac". It involves nothing more complex than the shellac, some alcohol, and lint-free cotton rags. One caveat with padding - if the finish underneath the shellac is at all alcohol-soluable, padding may not be the answer. The alcohol in the shellac and the alcohol you use while padding will cause an alcohol-soluable finish to smear in a big way.
curly maple
I am using Zinsser Amber shellac. I plan on using the pad method, that's why I was wondering how thin I can make it because I have time, I'm disabled, so I want to put on several coats to build it up. You made me nervous when you asked about what was underneath, I want to use Tung oil wait the 3 days for it to drfy then put on my shellac.
Shellac over Tung oil
You would have no problems padding shellac over tung oil, provided the tung is truly dry. If you are considering pure tung oil, keep in mind that it takes a long, long time to dry (way longer than 3 days), so you might want to consider boiled linseed oil (BLO, for short). BLO has metallic driers in it to speed the drying process to somewhere around 3 days. Less expensive, too. And, you probably couldn't tell the difference once dried.
You also don't want to build up too thick a shellac finish. Because shellac dries fairly hard, movement in the underlying wood can cause the shellac to crack over time. The thicker the layer of shellac, the more likely this will happen.
So, if you want to use the Zinsser Amber, thin it 1:1 with alcohol, and pad on no more than 3 layers. If you mix your own, go with a 1.5 lb cut, 3 layers.
Mkornell has pretty much covered the ground on shellac. I do like to use a brush, but for me I like watercolor wash brushes made with Taklon gold synthetetic bristles. These are very fine bristles, and the brushes flat with very little reservoir. The secret is moving quickly, but steadily, essentially only brushing in one direction and NEVER going back for a missed spot or overlaps. With these I can apply very thin coats and cover misses on the next coat. Overlaps just "average out". I use them with shellac mixed at about 1 1/2 to 2 lb. cut.
Others like a very different brush, opting for a mop brush made of very fine bristles. This holds a lot of shellac and again the message is to move quickly and spread the shellac to a thin coating. This works well for them.
I agree that padding is a useful fallback position. About 1 1/2 lb. cut is about right for this too.
For serious projects I try to make the effort to mix my own shellac from flakes instead of using the liquid shellac from Zinsser. This ensures freshness and also allows using some of the shellacs that have a bit more interesting tints than the orange of Zinsser Amber. See http://www.homesteadfinishingproducts.com for lots of good info on shellac flakes. This is especially important since Zinsser apparently has regressed an is now only dating their cans in code rather than the much more useful open dating. Even with the date, I prefer to use Zinnser shellac long before it's "official" expiration date.
Let me first say that I know nothing about finishing musical instruments. And that may be the exact point. I think musical instruments require certain finishes which may even affect the musicality of the instrument. have you considered looking on the internet for advice for this.
I respect Steve TOTALLY, let me stress. And I am sure his idea for finishing maple is excellent.
Shellac is among the finishes used by modern luthiers (which I think includes makers of mandolins). Gretchen is exactly right that stringed instrument makers do tend to be obsessive about finishes. There is much on line about such matters, but I expect that until all issues about the shape, thickness of top, and nature of braces have been resolved the finish will be a relatively minor factor in the over all tone or brightness of the instrument. If your manolin derives closely from specific plans then pay lots of attention to the ideas of the plan maker. I've pretty much assumed that that was where you decided on shellac.
I am using my own plans for my Madolin, I know what a very good one sounds like and then I come up with the plans and just pray that I was right, you are right about the finish it is just a final step to make wood look as beautyfull as you can
This forum post is now archived. Commenting has been disabled