Finishing Advice

[johninCR]

I'm a noob when it comes to wood finish, but I want to do a top notch job with the baffles of my set of Planet10's Frugelhorns. I'm using multiple layers of real wood for my supra-baffles. While my camera didn't do the raw wood justice, I really want to bring out the depth of grain without too much darkening. I read with interest the thread a while back about using boiling linseed oil, followed by flame treatment once it is hardened. Has anyone tried it, and is it easy enough for a beginner to get great results?

[Bob Barkto]

What is the wood?

The linseed oil finish you mention is not what I would call beginner friendly.
It takes a lot of work to get it right.
It's high risk too. Flame treating can cause burns or scorching...
Also I have only ever seen it done on very tight grained, lighter colored hardwoods like curly maple. There it can look spectactular.

Your wood looks like teak or possibly walnut (the camera didn't do it justice!)?
Judging from the darkeness and texture I would expect the wood to get very dark with linseed. Especialy after a few years when you've quit re-applying it and it starts to oxidize. Most oils, especialy non-drying, have a tendency to darken the wood. The more open, porous, soft and dark the wood the more the oil will darken it.

You can get great looking results using more forgiving materials like plain old or rub on polyurethane, polymerized tung oil, acrylic or nitro lacquers, etc.
Stains and dyes can at times be really helpful in bringing out a woods potential character. Dyes especialy can add great depth even under modern lacquers.

I would test some finishes on scraps before proceeding, that is some nice woodwork...

[jcmjrt]

I don't know anything about using a flame treatment on wood but my favorite finishes for beautiful wood are boiled linseed oil or a 50/50 mix of boiled linseed oil and tung oil. The thing about blo and blo/tung is that it takes time. The basic mantra is one coat/day for a week and one coat/week for a month. I don't always follow that exactly but the idea is multiple coats with time to dry in between each coat. I rub in the oil well, leave it for about 20 minutes and then wipe off the excess with a lintproof cloth. The first coat, you can rub in a lot of oil and you may want to thin it with mineral spirits to aid it soaking into the wood. You don't have to. The blo/tung mix does dry a little quicker than the plain blo. I typically give a light sanding with 0000 steel wool in between coats. Use a tack cloth. If you feel that you need a more spill proof surface then at the end you can put on 3 coats of satin Arm-R Seal and it will basically just look like an oil finish but will be more waterproof. This isn't a difficult finish at all but it does require some patience.

[Cal Weldon]

I once used a propane torch with a flame spreader attachment before I did the finish on pine.

I used Watco Danish "Fruitwood" after a good sanding. Looked very rustic.

[johninCR]

The wood is called cenizaro, which is in the mimosaceae family. It's a medium density with a wide range of color in the grain, almost black in places. It sounds like one of the modern clear finishes is the way for me to go. I'll buy a few different things and test on scraps.

I was lucky enough to find a local plywood factory that had some pretty good plywood with cenizaro as the outer laminate with amazing color too, so my side panels will be a good match with the baffles.

[Bob Barkto]

No wonder the wood wasn't quite recognizable!
It's very nice.
Don't find that commercialy around here. Koa maybe? I think it's the same family. Might even be an alternate or local name for Koa? Just thinking out loud...


If you like the ease of use aspect of oil;

Test some polymerized tung oil (sometimes called tung oil varnish or tung oil finish). It does a good job of protecting the wood and is very moisture resistant yet is easy and forgiving to apply. It dries hard so application can be controlled to not penetrate as deeply so you won't get as much darkening as with other oils.

Wipe on poly will come close to the oil effect with even less darkening and more protection.

Originally posted by johninCR
The wood is called cenizaro, which is in the mimosaceae family. It's a medium density with a wide range of color in the grain, almost black in places. It sounds like one of the modern clear finishes is the way for me to go. I'll buy a few different things and test on scraps.

I was lucky enough to find a local plywood factory that had some pretty good plywood with cenizaro as the outer laminate with amazing color too, so my side panels will be a good match with the baffles.

[Willitwork]

Originally posted by Bob Barkto
The linseed oil finish you mention is not what I would call beginner friendly.

"Flame treatment" doesn't sound particularly innocuous either

[poobah]

That wood is beautiful as is...

Unless you want a glass finish, or have severe humidity changes, I would go with an oil... and then keep them AWAY from UV (sunlight).

I'll bet that wood feels waxy/greasy as is. A Linseed/Tung oil thing should do fine.

BTW... Nice!

P.S. An Orangutan is now living in a refridgerator box because of that wood... and the woodcutter's little kids are eating. Treat it with respect.

[Bob Barkto]

I think that's the part that makes it tricky...

Originally posted by Willitwork


"Flame treatment" doesn't sound particularly innocuous either

[johninCR]

Originally posted by Willitwork
"Flame treatment" doesn't sound particularly innocuous either

I wish I had another need for a mini torch, because I'd like to try the boiling linseed finish at least on some scraps to see what happens. After it dries it becomes cloudy, then you hit it with the flame to polimerize it and clear up the cloudiness with great depth of grain.

Bob,
I live in Costa Rica and visit a couple of local lumber mills every once in a while to see what kind of exotic logs they have on hand. This stuff is from some choice planks of 1.25" x 20" wide by 4 meters that I've had curing for over 2 years, straight, flat, and no cracks through 3 rainy seasons and 2 dry seasons. I've got some other stuff, almendro, that even 16 penny nails won't go through, which I may use for the bases. It's difficult to work with though and just chews up router bits and saw blades. I did a big coffee table sub top with it, on which even a belt sander had almost no effect. I routed and planed and sanded on that top for 2 weeks. It's so hard, I haven't even needed to apply a finish.


Poobah,
No orangutans here and plenty of tree huggers in CR, so the exotic stuff is managed with special permits needed for the cenizaro.