Bending Black Walnut

[C Herb Hickman]

I'm gathering materials, making tooling, and starting out on building of two F-style mandolins, which I've never done. I've done pretty extensive repair work -- neck re-sets and the like, but haven't tried building an instrument since the 1950s. Now I'm semi-retired.

I have fancy curly maple for one mandolin back and thin maple for ribs (sides), spruce for two tops at least, ebony for fingerboards and headstock overlays, and bridges. I have roughed out two maple necks and two mahogany, have tailpieces ordered and Grovers one gold and one nickel sets. I have some 3/4" thick black walnut that has been on hand for many years, and that has always been one of my favorite woods. So I'm moving toward one maple b&s, maple neck, englemann top and one black walnut b&s, mahogany neck.

Having never bent anything, I'm very wary when I read that black walnut is difficult to bend. How difficult? Are there any special precautions that will make success more likely? The walnut I have is pretty straight grain, board sawn. I have some round pipe-like things I could torch heat, and a pressure-cooker steam generator of rather low capacity (which I could increase). I wouldn't really welcome a side track to build a steam chamber like I've seen illustrated somewhere, made from pipe, as there's so much work ahead already.

Thanks
Herb

[Mike Langford]

It be one o dem stor bought new fandangled plashtek ones!

[Laurent Brondel]

IME black or claro walnut are some of the easiest woods to bend, pipe or blankets. Very forgiving compared to, say, curly maple or some mahoganies. A steam box is not a good idea for bending sides as the thin wood will most probably cup and curl.

[Cliff Morris]

Just adding on to this old post since I am about in this fellows position. I was looking through a Ukulele builders forum and one of the members showed his method of bending using a bending machine and heat blanket set up. The machine for lack of a better word is more like a set of plates to hold a form so that cauls can be attached and pulled tight against the form and material to be bent. He also showed how he placed both sides on a sheet of aluminum foil after spraying with distilled water and folded the foil to keep the steam in. Both sides bent at the same time and looked fairly easy to do. Any other suggestions that might improve this method?

[Bob Webster]

Yes. Wrap it in parchment instead of foil so that the water can escape. Otherwise, you'll see cupping. What you've described sounds like an Everett bender rather than a Fox bender. Either is highly effective.

Bob

[Cliff Morris]

I don't know which is which but this one uses eye bolts hooked onto the through shafts. I have seen another one using springs and a press screw at the waist. Thanks for the parchment tip. I figure I can make something similar to get the bulk of bending knocked out but a pipe would still be good to have for custom stuff.

[Bob Webster]

Sounds like you have the Everett, or some similar incarnation. A heating blanket makes this setup work really nicely, as long as you take your time with the waist.

Bob

[Steve Frost]

Laurent already said this, but to reiterate- walnut bends easily. The phrase, "like plastic", sticks in my mind.I don't think you'll have any trouble!