Does anyone have any recommendation about the thickness I should use to coat the bore of a boxwood traverso flute with marine epoxy?
I was thinking of the http://www.dove-medows.co.uk/# product.
Does anyone do this to their well used flutes, or is it bad in the long run for the sound quality?
I don’t know one way or the other.
But, I’d contact the maker before making any radical and irreverasable alteration.
Question: Where did you get the idea to use marine epoxy on a completed flute?
Loren
Not recommended… I heard John Gallagher uses a linseed oil/ CA glue to seal the head joint in his flutes.
Jon,
Marine epoxy actually works quite well as a bore sealant, but where you apply it in the flute making process is critical because that stuff is HARD. I mean so hard that unless your reamers are extremely well hardened themselves, you can’t ream the bore to spec once you’ve epoxy coated it. I know of no way to apply marine epoxy to an already completed flute without major complications (including screwing up the tone holes) that would likely ruin the instrument from the playing perspective though. This is why I asked the OP where he/she got the idea, perhaps someone has worked it out, but we always had to do it early in the instrument making process and we refused to apply ME on completed instruments.
Marine Epoxy is a bitch to work with anyway and I really wouldn’t recommend it’s use outside of the professional workshop environment.
Loren
I am also considering treating a boxwood flute and haven’t found a great deal of information the subject here. Many antique boxwood flutes seem to have a finish, perhaps light varnish or French polish/shellac? Though most modern makers don’t seem to do this, any ideas on how such a finish might be replicated if one wished to stabilize and protect boxwood (bore and exterior), while not drastically altering its tonal qualities, would be very appreciated.
Whats the point of having boxwood, if you seal the bore. might as well make the flute out of delrin… 
Except that Boxwood is much prettier than Delrin. Also, in time, Boxwood and other woods warp ever so slightly out of round which is beneficial to the tone (this is based on observation). Properly cured and heat treated Boxwood won’t warp any more than other woods.
Sealing the wood is a consideration, especially in drier climates. I’ve occasionally used epoxy for this purpose but have found that it is difficult to apply. One needs a way of spreading it evenly and thinly which is contrary to its highly viscous nature, even with marine epoxies. I do use it to seal the sockets and tenons on flutes with tuning slides.
A better alternative for a waterproof seal would be some sort of polyurethane sealer such as is used for exterior decks. I’ve had good results with this.
But mostly I treat my flutes with linseed oil, and then recommend oiling. This seems to work fine for most.
Casey
What Loren said. While I’ve never used it on musical instruments, I’ve used it often for boat bits and repairs and would bet you can’t apply it thin/smooth enough and/or finish it to the required spec. without destroying your flute in the process!
…And I’m just picturing him daubing SikaFlex all over his flute. shudder I use it to absorb shock in the handle of my sword.
I have not found any antique boxwood flutes that have varnish or french polish/shellac.
But, I’d contact the maker before making any radical and irreverasable alteration.
Thanks - I’d like to contact the maker but he has been deceased for over 100 years. Sadly I just don’t have those sorts of connections.
Loren - are you familiar with the high end baroque traverso makers who use marine epoxy? von Heune, Boston Massachusetts use this principle..at a cost which is beyond me. I asked a luthier if it was possible to apply marine epoxy to an aged traverso (“anything’s possible…but it might be no good”).
Now that I know no one has done it here, maybe it is too specialist to try.
JJW - there is a difference between varnish vs shellac. Most of the older boxwood traverso makers used insect based shellac before synthetics came around. Casey’s point about oiling is far more common as a practice - dipping in tung oil/linseed oil for 24 hours or just leaving an oil finish on some flutes. I’m just an amateur, so I’m still trying to work out what the best option is for preserving what I’ve got without letting it disintegrate further. It seems safer to just oil and re-lubricate over time, however Eujene Crijnen and Simon Polak’s advice wards against developing the rubbery oil residue which forms when the oil dries on a flute after excessive oiling.
Thanks for the help everyone.
Tonehole, I used to work at Von Huene 
Loren
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.
Vindication at last! 
Ah, But what oil would you use?
Now that is a question! 
Jeff
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!
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.
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