Making whistles out of Bubinga (wood treatment ?)

[earthjig]

Hi everyone,

I'm in te process of starting to make whistles and flutes out of Bubinga-wood.

Now, I have lots and lots of that wood.

I'd like to know if you could help me by telling me how I should treat the wood.

What steps do I need to take.
I think I read somewhere to use raw linseed oil, but I may be mistaken.

Thank you for your help

[chas]

When I'm not sure if a wood will take the moisture, I use linseed oil. I dip the finished part in it (not the windway of the whistle, though), stand it up and let it dry overnight, then swab out the bore and buff the outside. If it's really porous wood, I do this a second time.

Ralph Sweet uses tung oil to good effect.

[earthjig]

Hi,

Thanks for the answer. A little extra question though : does the oil need to be heated, and for how long are the pieces dipped into the oil.
Or is it just a coat that needs to be applied?

[chas]

I don't heat anything. I just do a quick dip -- the oil is quite thick, so a lot of it sticks to the surface. I let them dry/let the oil soak in for a day, then wipe dry, paying especial attention to the rings and slide. I once got a flute from a reputable maker that had linseed oil all beaded up on the inside of the tuning slide; had to use mineral spirits and acetone to get all the gunk out. Then let them sit for at least a week at room temp to allow the oil to begin to polymerize before doing any further work. It really takes a month or more for the oil to really harden to the point that one can use polishing paper if necessary. For some reason I've come across a few woods that just don't want the oil to dry to any kind of sheen.

This is only my process that I've arrived at through trial and error. Ralph Sweet soaks his flutes for quite a few hours in tung oil. The tung oil I got congealed not too long after I got it; probably too many polymerizing accelerators in it.

Hopefully Feadoggie and some others will ring in with their experiences.

[Feadoggie]

Hopefully Feadoggie and some others will ring in with their experiences.

Chas, my experience is similar to yours as far as the oils go. You've described things well IMO.

I'd prefer to just leave the timber alone if it polishes well. Many timbers require something more than that. So we oil, we fill grain sometimes and we lay on polishes if needed.

I don't like tung oil. What tung oil I have used remained gummy for a long time. But I do not really think I ever used a "pure" tung oil.

The Bubinga I have on the shelf needs a finish/sealer IMO. It has "moved" more than many other woods that I use. Some pieces have twisted and warped after being milled to working blank sizes. YMMV. I'd like to chalk that up to the particular boards I bought and that particular wood seller. Well seasoned wood is the best starting point in any case. It would not be unusual for blanks to acclimate for several years before initial turning in my shop. Wood can take time.

But that's all so 19th century. What I am working on presently is wood polymerization. The finished material retains the look of wood with the stability of a polymer. Or at least that's the theory.

Geoffrey Ellis is using a similar process for flutemaking. As it happens Geoffrey just posted a photo of a Bubinga flute that used that polymerization process to treat the wood. Take a look at his photo at the bottom of the thread. viewtopic.php?f=2&t=101188

I am sure that's more than you wanted to know. But it is where my thinking is these days.

Paul Busman has offered Bubinga whistles. Perhaps he will share his thoughts. I recall him mentioning tung oil way back when but it would be best to hear it from himself.

Feadoggie

[Tunborough]

I've used tung oil successfully a number of times, on oak, red cedar and figured maple (none of them whistles). I used pure tung oil, applied many thin coats, and buffed each coat part way through the curing process. The result has a nice sheen to it, and highlights the grain well. I never had a problem with gumminess or failure to cure.

With pure tung oil, thicker coats produce a matte finish. I haven't tried polishing this finish with a mild abrasive like wet-and-dry or pumice. That might have produced faster results.

[brewerpaul]

I made a few Bubinga whistles quite a while back with good results. My wife owns a Bubinga soprano recorder which is quite nice.
As with nearly all woods, I don't apply any finish at all until the whistle body has been final turned and bored. On the harder, smoother grained woods, all I use is this for the outside:

https://www.woodturnerscatalog.com/p/14 ... ystal-Coat

For woods with a rougher grain that doesn't sand out really smoothly, I apply a sanding sealer first:

https://www.woodturnerscatalog.com/p/42 ... ing-Sealer

I use a couple of coats of that, letting it dry in between. It dries quickly. Then I sand it right on the lathe and apply the Crystal Coat.

For the harder woods I don't apply anything to the bore until the whistle is just about done. Then it's just a couple of LIGHT coats of almond oil. On some of the more porous woods like birdseye maple and walnut, I'll seal the bore before turning the outside. I've used several different things for this. Linseed or Tung oil work well, but take a long time to try. Water soluble polyurethane works well. I hold the tube vertical with one finger over the bottom end. Pour in some of the poly, plug the other end with another finger and tip it back and forth for a while, then drain out the excess . It's sometimes surprising how much has absorbed. I leave the tube vertically on a rack so any remaining excess can drip out. Depending on the wood I may repeat the treatment. In any case, the tubes need to be re-reamed after treating the bore.

[chas]

Paul, would you apply urethane or linseed to the bore of bubinga?

[earthjig]

Thank you for your advice everyone.
I'll try it this weekend.
Let's hope everything turns well.

[Loren]

I hold the tube vertical with one finger over the bottom end. Pour in some of the poly, plug the other end with another finger and tip it back and forth for a while, then drain out the excess . It's sometimes surprising how much has absorbed. I leave the tube vertically on a rack so any remaining excess can drip out. Depending on the wood I may repeat the treatment. In any case, the tubes need to be re-reamed after treating the bore.

This was essentially the process we used at VH, although not with poly. Messy work, particularly when doing 50 instruments at a time

[brewerpaul]

Paul, would you apply urethane or linseed to the bore of bubinga?

Probably not. My test was to cover one end of the tube and blow hard into the other end. With some woods you can feel that it's not totally airtight. Those are the ones I treat. You need to turn the tube down nearly to the final OD before you try this.

[Timothytiptoes]

Acknowledging that linseed oil has been used as a wood finish for hundreds of years, I would like to point out that in its unaltered form it never really dries or hardens. So, just a heads up if you are not experienced with linseed oil's use. Respectfully, tim

[brewerpaul]

Paul, would you apply urethane or linseed to the bore of bubinga?

Probably not. My test was to cover one end of the tube and blow hard into the other end. With some woods you can feel that it's not totally airtight. Those are the ones I treat. You need to turn the tube down nearly to the final OD before you try this.

I just realized that I answered a question about poly vs linseed with a "no".
As I recall, Bubinga was dense enough not to need poly. When the whistle is finished, I'd just use the oil of your choice. Don't use a lot. A thin film in the bore is really all that's needed. Avoid the blade area.

Speaking of the blade... on woods which are prone to grain rising or are relatively soft, I coat the top and bottom of the blade with thin CA glue. This functionally turns it into plastic and protects it from the moist high velocity air directed at it.

[Tunborough]

Acknowledging that linseed oil has been used as a wood finish for hundreds of years, I would like to point out that in its unaltered form it never really dries or hardens. So, just a heads up if you are not experienced with linseed oil's use. Respectfully, tim

We should distinguish between raw linseed oil and "boiled" linseed oil, which has been through a heat treatment process to start the polymerization. Although I don't have experience with it, I gather boiled linseed oil will harden.

[Timothytiptoes]

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[quote]We should distinguish between raw linseed oil and "boiled" linseed oil, which has been through a heat treatment process to start the polymerization. Although I don't have experience with it, I gather boiled linseed oil will harden.[/quote]

I believe you will also find that BLO will not harden. My suggestion would be to experiment with a chosen product on a scrap of wood before finishing a completed whistle. There are likely linseed products available with added hardening agent. IMO if you want a completely hard/dry finish there are better products for that purpose.

I have used BLO as a hardwood finish with good results and an attractive quality to linseed oil is the ability to later put a few drops on a soft cloth to reapply to an existing linseed oil finish on an item that is heavily handled....ie. re-fill the wood pores and buff to a sheen.