Hi all,
Dominic Allan writes that he uses a “cellulose based wood hardener” to strengthen his pearwood student flutes.
Since my project pearwood flute comes closer to its final shape, I’m wondering what he could mean by that. Any ideas?
Don’t know what Dominic Allan uses for wood hardening, but I have found that a liberal coating of Cyanoacrylate glue (CA or superglue) works extremely well to harden wood. It also waterproofs it, makes it more brittle and will attach to your skin immediately. If you do decide to try a coating do it in a well ventilated space and wear gloves. For my money though pearwood is plenty hard enough on its own.
here is some info from woodworkers on hardners: http://www.woodworkersinstitute.com/forum/forum_posts.asp?TID=3375&PN=1
Good luck
Rob’s image doesn’t show for me for some reason (broken link?)
nope…shows here, for me
I often don’t see some links from work, (can’t see Rob’s right now), but have no problems from home. Probably a firewall thing?
The stuff I use is for treating wet rot in household woodwork : http://www.screwfix.com/prods/63540/Paint/Wood-Care/Ronseal-Wet-Rot-Wood-Hardener-500ml
You probably get other brands in the states.
Once the billet is bored and reamed I plug the small end, stand it up in a vice and fill with the hardener. You’ll see little bubbles rising , sometimes some oozes out through pores. I leave it to soak until I’ve prepared the next joint, 10-20 mins.
I do ream the joints again so it’s debatable how much remains in the finished product , but it certainly finds and fills any pores.
Sanding Sealer works quite nicely, too. I’ve used it on maple and plumwood, and it does what it’s supposed to do.
Sanding sealer is (can be) a nitrocellulose product, like the wood hardener above. I’ve used both. The difference is that the sealer is designed to build on the surface, to conceal the smallest kind of sanding mark and tack down any wood fibers raised by the sanding process, while the hardener is designed to penetrate wood and freeze in place.
I’m no flutemaker, but of the two I’d say the wood hardener has the kind of characteristics you’d want in a bore sealer.
Rob
Cool, I knew the forum could tell 
Kinda hoped that Dominic was reading, too 
I did already have a discussion with my teacher on finishing with linseed oil or varnish. He says it’s either, not both, and that his personal preference is with varnish, because linseed oil takes long to dry and may soak the wood a bit, which put some of his more fine-bore bagpipes quite out of tune.
He normally runs thinned varnish through the bore (with holes already in place, I believe) to leave the tiniest layer. Says it seals the wood, too.
So I saw Dominic’s approach was to use hardener + linseed oil; would you guess hardener would also help in combination with varnish? Or generally, what improvements do you notice from using hardener on top of varnish / oil?
(I’m in Holland by the way. And I don’t know if it’s a Dutch thing, but googling for a product called “bonda” yields some very strange results here…) 
Thanks all; much appreciated!
i don’t know anything about this stuff, but enjoy reading it (maybe some day… : ) and would also like the thank Dominic for contributing.
anyway, the only thing i would say is that the only flute i’ve ever returned (i pretty much have loved every flute i’ve ever tried : ) was a rosewood sweetheart; he had finished it with what i’m guessing was a varnish that coated the wood and made it shiny?
i hated it. 
it sounded bad (maybe other reasons for that) and i thought it made it look cheap… unless i was going to use it for a table leg.
i’ve tried other sweethearts, in particular that walnut D i sold on this board, that i thought were great flutes. but that rosewood C… no way.
but i’m sure there are different types of varnish as well?
anyway, good luck with your flute.
cheers,
eric
I just can’t believe it. Where are all the jokers? You know the guys that can take a perfectly innocent question and twist into some pun or joke. I thought you wood be all over this!
The answer is obvious.
Viagra 
Here’s an interesting idea, could be overkill:
Knifemakers sometimes use the Minwax wood hardener to condition the wooden handle scales in a similar way to what you are doing with your flutes (looks like the Minwax and Ronseal products are essentially the same, by the way). For maximum grain penetration, the scales are soaked in a vacuum, presumably to draw out any air from the pores.
Not sure if you want to get the hardener on the exterior of the flute parts, but it could be an interesting approach.
Rob
That’s right, but - it works nonetheless. The sealer also penetrates the pores deep enough, I even had it build up blobs on the outer surface of a few flutes. Doesn’t work as well if the bore has been sanded or otherwise polished, though. The sealer should be filled into the bore right after most of the reaming has been done. Leave it in for half an hour, then pour it out, let it dry and ream the last few shavings out. Works perfectly.
I got the idea from Jonathan Swayne, uses a thin epoxy mixture on his pipes. He fills the bored joint then plugs in his compressed air line to force the mixture in. He reams them again ,turns them, then soaks in linseed.
The finished parts are given a final ream to remove excess dried oil.
I was thinking of trying this in a vacuum. I have a vacuum table used for casting, it will force the stabilizer into the grain, kind of the apposite of compressed air…
“I was thinking of trying this in a vacuum” - have you spoken to NASA?
@tuscon_whistler, about rather not using varnish:
That’s how I felt as well in the beginning, and that’s why I’m asking so many questions about it, because I’m also quite sure that this wood needs some kind of finish, but I have no idea what would be common. My teacher did say that he wouldn’t expect problems with linseed oil on something so big-bored & holed as a flute, though.
You can use linseed oil on anything (even the narrowest of pipe bores) provided that you remove any residue when the oil has dried.
All of my pipe chanters (and drones) are soaked in linseed for two weeks. The only problem is that you can’t tune the pipes until the oil has dried.
Linseed oil takes ages to dry on dalbergia species timber, i.e. blackwood and all of the true rosewoods. But other than that, it’s fine.
There are many that doubt if linseed even penetrates african blackwood. In my experience raw linseed will be taken up in any pores in the wood, I swab my flutes out with it after reaming. I have experimented by sanding the outside of some flute joints to leave a matte finish on the outside then carefuly putting a layer of raw linseed inside. After a few days some of the joints do have a few small spots appearing where the oil has found it’s way through.