Bending Black Locust

[Airplanenuts]

Hello!  I'm building a red spruce and black locust OM, and I'm writing to ask if anyone who has experience with lack locust (BL)  (robinia pseudoacaci) is willing to offer advice?

Intentions:

 *Back thickness 0.110"

 *Side Thickness 0.085"

 *Kiln dried, currently at 10% moisture content.

I'll bend the BL sides over a 3" o.d. hot pipe.  Is immersion, steam,  or spritzing beforehand the most successful method using my technique?

Any other helpful information regarding this wood for guitar-building would be very much appreciated.  

I selected it carefully, basing my decision on John Arnold's comments and the sound properties I prefer.

If a reader happens to be looking for some, or some red spruce I highly recommend a very nice, helpful vendor in Canada I found online last week, who has more (as of this writing)  here:

https://edcofinewoods.com/en-us/product ... 2f6a&_ss=r

Best wishes!

-Rich
Go Army!

[Stray Feathers]

Ha! I thought I recognized your Black Locust set - I have been watching them on the Edco web site for some time now. I bought one set from Ed a while back when he was still involved with Bow River Woods (now called Cascadia) but he is on his own now. It made what might be my best sounding guitar overall, an OM, which has been sold (my first sale) pending a small lacquer repair. I am looking for more Black Locust to do another. Having only worked with the one set, all I can say is that I had no difficulties with it except that it splinters a bit. Seems to bend fine on my Fox-style bender (I'm not very good with a hot pipe) with no special procedures, same as for rosewood say, and on the Tonewood Data Source web site the account says it bends well. Good luck with it - I hope you are as pleasantly surprised with it as I was with mine. Bruce W.

[Airplanenuts]

Hi Bruce!

Thank you for your information. I'm glad to read you like it, as well.

I haven't used a Fox bender, but have seen one at the local guild. I believe that's how the members bend their sides, too.

Do you bend it dry, and heated up beforehand?

Best wishes!

-Rich
Go Army!

[Airplanenuts]

Hi Bruce!

Thank you for your information. I'm glad to read you like it, as well.

I haven't used a Fox bender, but have seen one at the local guild. I believe that's how the members bend their sides, too.

Do you bend it dry, and heated up beforehand?

Best wishes!

-Rich
Go Army!

[Airplanenuts]

Hi Bruce!

Thank you for your information. I'm glad to read you like it, as well.

I haven't used a Fox bender, but have seen one at the local guild. I believe that's how the members bend their sides, too.

Do you bend it dry, and heated up beforehand?

Best wishes!

-Rich
Go Army!

[Stray Feathers]

I pretty much follow guidelines from John Hall and another luthier named John Mayes. They are similar and both seem to work. Others develop their own special ways to bend sides and I don't think there are hard and fast rules. I don't have enough experience to advise on temperatures for different species - I rely on the experience of others. I don't preheat the sides, and I spritz both sides with Windex with ammonia just before bending. If I have learned anything, it is to work fairly quickly through the bending - too slow and the wood can dry out and break. I never seem to be able to get the wood hot enough quickly enough on a pipe, though I sometimes use it to tweak springback. The locust guitar I made is here if you are interested:

viewtopic.php?f=48&t=9921

Bruce W.

[Airplanenuts]

Thank you for your advice, Bruce.

I am interested! Thank you for the link. I will check it out.

Best wishes!

-Rich
Go Army!

[tippie53]

why are you bending at .085? When I started I did.095 then when I learned Martin does them much thinner I started checking into this . .075 is fine. Many guitars that I check the sides are often .065 and I have seen a lot less warp also I know have learned 285F is fine for temp to bend often the high temps create warpage.

[Airplanenuts]

I posted those numbers hoping for comments, not having handled black locust nor understanding it's potential characteristics under stress.

From my notes, from an owner's post in an old thread on UMGF:

"This is again from a spring 1930 pyramid-bridge OM-28.

Back thickness (measured directly opposite the soundhole, near the back strip): .111 inches 2.81mm
Side thickness (measured near the waist, bass side, a bit towards the lower bout): .068 inches 1.72mm"

So, 0.068" is a target. Finding someone who has successfully bent BL at 0.068" is an obstacle.

Best wishes!

-Rich
Go Army!

[tippie53]

bending for 20 years I have learned a good bit and I am happy to share. Locust bends similar to many rosewoods.
I like to use Windex with Ammonia D ( ammonia is a cell softener ) and since I started using PID controllers I went to straight 285F for my bending. This seems to work very well.
I have learned that too much heat and water can add to the warping issue. Martin bends at 425F but do it in less than 6 min. they also have the bending done all CNC controlled.

Hope this into helps you and please feel free to ask all the questions you need to we are here to help