Guidance on using marine epoxy for a flute?

[Cathy Wilde]

Many thanks, everyone, for the clarification and benefit of your experience, particularly Jon for correcting my misperception that what is probably patina on some antiques was some sort of finish. I’m encouraged to leave well enough alone and stick with oiling.

[mandoboy]

Ah, But what oil would you use?

Now that is a question!

Jeff

[highwood]

misperception that what is probably patina on some antiques was some sort of finish

I certainly consider linseed oil, or tung oil to be a finish

Ah, But what oil would you use?

Now that is a question!

[Jon C.]

Well you could call a drying oil a finish, but a drying oil will still allow the wood to breath. Drying oils are temporary, you have to re-apply the oil. I have worked on quite a few antiques and 99% of the time it is just polished wood, the boxwood may be acid stained, but i have not found a hard finish on it. Some later flutes were coated with shellac, you find out real fast when you buff the flute, or apply alcohol!
Linseed oil was probably the oil of choice, there are records of makers soaking the flutes in linseed. Personally I cannot get near the stuff, must be allergic to the stuff! I do use a refined bore oil, but not around the embouchure. I have used Tung oil, It is very think and waxy.

[Loren]

I can't entirely agree with Jon on the use of finishes on antique flutes. While I agree that water resistant finishes were probably uncommon on blackwood flutes from the 19th century, baroque and renaissance instruments, including flutes, made from the softer woods like boxwood certainly were varnished in many cases. I do wonder if any of the boxwood flutes from Rudall and Rose etc., were varnished but I haven't personally come across any myself. Even so, it is not always easy to tell with an older instrument whether it has been varnished or not because it depends on the the varnish used and how it was applied: There are many different types of varnishes, some are not shiny and do not much change the look or feel of the wood, particularly if applied thinly and forced into the grain. And then there's time and wear, both from handling and from repairs: A very thin finish could be virtually unnoticeable so many years later.

That said, it wouldn't surprise me if R&R and most their contemporaries didn't go to the trouble of varnishing their flutes because it would have been more time consuming (expensive) to do for instruments with the block mounted key system. Still, as instrument makers do tend to like being different from one another, and considering the problems with unfinished boxwood instruments, I do find it hard to believe that no makers were varnishing their boxwood block mounted flutes. After all these years it would be difficult to tell though unless the original varnish had been applied rather heavily.

Anyway, antique boxwood and other soft wood flutes were varnished at some points in history, and there are makers doing it on instruments today as well, perhaps not the fully keyed flutes we tend to use for ITM, but certainly Baroque and Renaissance flutes by some modern makers are varnished.

Loren

[Casey Burns]

I've seen several 19th century flutes with a French Polish (shellac), rubbed away in the usual places. Whether these were applied by the maker or by someone later on is unknown.

Jon, are you allergic or sensitive to all Linseed oils including the stuff sold as flaxseed oil in health food stores, or are you just talking of the stuff found at the hardware store? If the latter, then it might be the metal salts that they use as a catalyst. How about flax seeds used in food?

Raw linseed oil is very slow to harden. Something is needed to speed up its polymerization, and a few drops of superglue seem to do this. This is a common varnish used by woodturners. The oil by itself though doesn't form a film in the traditional sense - unless one leaves a bunch on the surface for a very long time.

Casey

[keithsandra]

Oils - Flutemaker Brent Santin recommended I use 100% pure almond oil from any East Indian food supply shops on his flutes. I've had an 8.45 fluid ounce bottle of the GAGAN "pure natural" brand for four years without the recommended refrigeration and it's still good - no emulsifying or thickening in any way. It's thin and runs and adheres very nicely, giving a very satisfying finish. (Good on the hands too ...). I can't remember the price but its not expensive.

K.

[Tonehole]

Tonehole, I used to work at Von Huene

Loren

I'd love to hear more!

How long did they recommend, a coated traverso be played continuously before stopping?

[Jon C.]

Jon, are you allergic or sensitive to all Linseed oils including the stuff sold as flaxseed oil in health food stores, or are you just talking of the stuff found at the hardware store? If the latter, then it might be the metal salts that they use as a catalyst. How about flax seeds used in food?

Raw linseed oil is very slow to harden. Something is needed to speed up its polymerization, and a few drops of superglue seem to do this. This is a common varnish used by woodturners. The oil by itself though doesn't form a film in the traditional sense - unless one leaves a bunch on the surface for a very long time.

Casey

I guess I am sensitive to all linseed oils, I was using raw linseed, that didn't have a catalyst.

[Jon C.]

Just spent the evening buffing off a shellac finish on a Metzler, turns out there was beautiful Couswood hiding underneath the darkened finish... I thought it was kind of synchronicity...

[jackiep]

I am wondering if anyone can tell me the best way to remove what I believe to be some type of hard shellac or polyurethane finish off a flute I just purchased? There is a hairline crack in the body of the flute that I would like to repair but no doubt the finish will need to come off before I do that plus I really prefer having a oiled flute over the shiny look of this flute. So should I start sanding? or would it be a better idea to use a chemical to remove this finish?

[Tonehole]

I am wondering if anyone can tell me the best way to remove what I believe to be some type of hard shellac or polyurethane finish off a flute I just purchased? There is a hairline crack in the body of the flute that I would like to repair but no doubt the finish will need to come off before I do that plus I really prefer having a oiled flute over the shiny look of this flute. So should I start sanding? or would it be a better idea to use a chemical to remove this finish?

Have you found a solution? I mean a wet one, rather than sanding, which seems rather extreme!

You might need to do a test strip using a variety of solvents. I tend to use alcohol, since it is mostly harmless except on Saturday nights. You might find that it needs some rubbing and then, it may strip back the nitric acid stain if you have a stained/darkened colour on your flute, making it less even in colour.

Cyanoacrylate remover is also possible, since this will form organic polymer bonds with the shellac and/or varnish and strip it, although it seems a rather harsh and drastic method. Ladies nail polish remover (because I haven't seen any for gentlemen) should operate on a similar principle, based on acetone (propanone), however as an intense ionic reagent, its effect is going to be very severe compared to alcohol.

If you don't wish to take a risk, it might be best work gently with alcohol, avoiding the harsher reagents. My guess is that most players with antique flutes, aren't too worried about the cosmetics, and the embouchure area, tends to look sullied and flat, compared to the rest of the flute where the finish has been eroded over play. If you are working on the whole flute, rather than just a part, it is more likely that you will have a better matched finish. I say this, because after stripping 150 years of wood dirt and grit off my traverso, I was surprised to discover a flamed boxwood appearance under a chocolate brown stain. I've yet to succeed in stripping off the rest of the stain from the other 3 joints, at the risk of drying out the cinder-relic of a traverso which I started off with.

Good luck!

[Adrian W.]

Back to epoxy for a minute......has anyone tried the epoxy consolidant made by Abatron? Assuming just for the sake of discussion you DID want to seal/harden the bore (not saying you SHOULD), having used lots of marine epoxy and the Abatron product, this is what I would experiment with....it is very thin, designed to wick in to the wood and harden. It will displace water and harden the wood; used for restoring wood you would follow it with a thick epoxy putty that replaces missing wood, but clearly not applicable to flutes. Anyway, it's an excellent product and I've wondered about it for a while as a bore sealer, but haven't got to the point of experimenting yet.

[Tonehole]

Hi Adrian,

I looked up Abatron and it seems like a rather fantastic product which doesn't require as much expertise to apply as marine epoxy proper (is this correct?)

The images on their website mostly demonstrate outdoor, weatherbeaten items, like wood posts and housing, which have been restored using this kind of epoxy. My traverso doesn't look quite as terrible as these! In fact, it's starting to look rather handsome after weeks of slow oil seep. If I could find a cheaper flute to experiment with the Abatron, I'd love to see what happens when the bore is sealed in the way you've described. It seems no more unusual than varnishing or coating the bore of a flute, to prevent the moisture damage?

Many thanks for your helpful suggestion. I'll think over it whilst making a cup of tea.

[Adrian W.]

The Abatron epoxy is a great product; I have used a lot of it for the main purpose it was intended for....restoring decayed and sometimes wet and rotting wood. The system is supposed to be formulated also to move in a smilar way to solid wood, which is why it is preferred for restoration work to polyester fillers. They don't seem to have them on the Abatron website, but you can get smaller kits also, though you wouldn't need the putty part. The Liquidwood is what I am familiar with; they may have better products avaialable that I don't know. For sealing bores, I would experiment with thinning Liquidwood with Abosolve; it is already thinner than marine epoxies I have worked with, but could stand some more thinning. maybe try it on some bamboo or something like that rather than an instrument to see how it works?