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Thickness for bending bloodwood binding?
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10101&t=50214		 Page 1 of 1
Author:  Paul Burner [ Sat Jan 20, 2018 1:59 pm ]
Post subject:  Thickness for bending bloodwood binding?
I'm going to be bending some bloodwood binding and am pondering how thick I should take this down to for bending.

Any input from the gallery would be appreciated.

The age old dilemma of wanting to keep it as thick as possible but thin enough to not crack at the waste.

Thanks!
Author:  Rodger Knox [ Sat Jan 20, 2018 2:26 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
I've done 0.08" binding with bloodwood, bending was not pleasant, but possible. Thinner would be better.
Author:  Glen H [ Sat Jan 20, 2018 2:39 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
Same here. I broke a few.
Author:  Allen McFarlen [ Sat Jan 20, 2018 3:02 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
My uke binding is .07" thick and I couldn't get any to bend. Shattered like glass. Good luck.
Author:  J De Rocher [ Sat Jan 20, 2018 3:25 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
I bound a parlor guitar with bloodwood at 0.080". It had fairly tight curves and a bound 3 1/2" soundhole. I bent it on a hot pipe after treating it with SuperSoft II veneer softener. It bent easily with no breaks or cracking.
Author:  Paul Burner [ Sat Jan 20, 2018 3:28 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
J De Rocher wrote:
I bound a parlor guitar with bloodwood at 0.080". It had fairly tight curves and a bound 3 1/2" soundhole. I bent it on a hot pipe after treating it with SuperSoft II veneer softener. It bent easily with no breaks or cracking.


Thanks for the reminder about SuperSoft. I have some and had forgotten about it.
Author:  ernie [ Sat Jan 20, 2018 6:47 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
Bent mine at 2.2mm for binding at abt 87 thou diss aster ! broke . I tried using it as a veneer line in a rosette used it at 1.1mm on alum bender took forever with lots of water but finally worked . Bending 2pieces at 1.1mm would be the way to go IMHO.Where do you get super soft veneer softener ? Have never used it thanks
Author:  Trevor Gore [ Sat Jan 20, 2018 7:11 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
Bloodwood bends like glass, so you need to get it seriously hot, just short of charring, and then it plasticises and bends just fine. Don't use too hot a pipe. You need to get a lot of heat fully through the piece without it charring on the surface. Straight grain helps a lot. On the ones below, sides were bent at 2.2mm, down to ~1.8mm around the cutaway and bindings at ~2.0mm. The cutaway area for the sides was done on a pipe (as per my normal practice) after bending the rest on a Fox bender. The bindings were done on a pipe all round. Bends have to be accurate because the stuff does set like glass. Way too hard to pull in with tape. And you don't get many chances to get it right before it gets all brittle on you. I've used it for B & S on a few guitars and bindings on quite a few more. I didn't use Supersoft and I don't recall ever breaking a piece (touch wood!).

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Author:  J De Rocher [ Sat Jan 20, 2018 8:52 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
ernie wrote:
Where do you get super soft veneer softener ? Have never used it thanks


I bought it in the quart size spray bottle from Veneer Supplies: https://www.veneersupplies.com/products/Super-Soft-2-Veneer-Softener-Conditioner.html

Highland Woodworking also sells it but at a significantly higher price.
Author:  ernie [ Sun Jan 21, 2018 12:42 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
Jay do you leave the bloodwood binding outside in seattle?? before using ? it/s damp like 9 mo of the year ? Thanks for the info
Author:  J De Rocher [ Sun Jan 21, 2018 3:02 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
ernie wrote:
Jay do you leave the bloodwood binding outside in seattle?? before using ? it/s damp like 9 mo of the year ? Thanks for the info


I keep it in a nice dry place, but I could keep it in the shed out back during the nine months of rain/drizzle if that would help...
Author:  Paul Burner [ Sun Jan 21, 2018 4:43 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
Trevor Gore wrote:
Bloodwood bends like glass, so you need to get it seriously hot, just short of charring, and then it plasticises and bends just fine. Don't use too hot a pipe. You need to get a lot of heat fully through the piece without it charring on the surface. Straight grain helps a lot. On the ones below, sides were bent at 2.2mm, down to ~1.8mm around the cutaway and bindings at ~2.0mm. The cutaway area for the sides was done on a pipe (as per my normal practice) after bending the rest on a Fox bender. The bindings were done on a pipe all round. Bends have to be accurate because the stuff does set like glass. Way too hard to pull in with tape. And you don't get many chances to get it right before it gets all brittle on you. I've used it for B & S on a few guitars and bindings on quite a few more. I didn't use Supersoft and I don't recall ever breaking a piece (touch wood!).

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Thanks Trevor.

I bend my binding on my side bending machine, so when you say REALLY HOT what temperature range are we talking about?
Author:  Trevor Gore [ Sun Jan 21, 2018 5:58 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
Paul Burner wrote:
I bend my binding on my side bending machine, so when you say REALLY HOT what temperature range are we talking about?

I can't give you a number because I don't measure it. My side bender is double width and heated the old fashioned way by PAR 38s (a reflector light bulb/globe). Total power for it is 800w (that's double width, remember). My typical procedure is to load up the sandwich (SS slat/wood/SS slat), apply heat until the outside is too hot to touch (probably ~60-70C) which means the inside is much hotter, and then apply the screws and pull downs slowly, so the full bend takes about 30-40 minutes (for two sides together). Can complete in around 20mins for easy-to-bend wood.

With heating belts (which I've never used) I've seen lots of horror pics (many on this forum) where the sides have been cremated, it seems by applying too much heat too quickly. So it would seem that one would have to use belts with a controller, just to give enough time for the heat to "soak in" before leaving a funereal result on the outside.

All the "tricky" bends around the cutaways I do on a small diameter pipe (500W) which I made myself from slightly squashed thick walled aluminium tube (initially 38mm O/D). I run that through a lighting dimmer, so maybe operating at more like 300W for sides and less for binding. Again, no idea of the temp. Water sprayed on bounces. Too hot, you don't get the bounce, just instant vaporisation and too cold you just get runs.

Bending wood is very much a feel thing for me. Patience is a virtue. To bend a tight radius you need to heat a zone, not a line contact, so rock the wood on the bender. Apply moisture to the inside of the bend rather than the outside. Let the wood tell you when it wants to bend. You'll feel it relax. Practice helps. That's about all I can tell you. There are no great secrets.
Author:  davidmor1 [ Sun Jan 21, 2018 9:24 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
Bloodwood is tough to bend. Breaks like glass. I've done a few builds with it and have had the best luck with hot and dry. I bend them on my side bender with heat underneath and then a heat gun working slowly starting at the waist, then the upper bout then lastly the lower bout. Once set I let it cook to hold. On my first go-round with bloodwood bindings I broke several doing them the way I do other woods. Tried super-soft and had no luck with it. Dry and very hot on both sides bending one piece at a time works for me.
Author:  Paul Burner [ Sun Jan 21, 2018 10:12 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
I am very happy to report that the bending of my binding went perfect.

Thickness: .072"
SuperSoft 24 hours before
Very light spray of water

Cooked at 305 before I started the crank down the waist on my bending jig to within about ..75"
I wend much slower than I usually do in pulling the waist to that position. Just slow and easy.

I then did the lower bout at the curve is less drastic, then did the upper bout - again slower than usual.

I kept an eye on the temp and tried to keep it right at 300.

I tightened down the waist lastly - and then cooked it for the remainder of the 15 minutes on my time - let it cool to room temp - and then cooked it again.

Just pulled it out and no cracks and nice smooth bends.

Whew!

bliss
Author:  Michael Keller [ Sun Jan 28, 2018 4:50 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
few photos of just finished 12 string with blood wood trim.
Author:  Michael Keller [ Sun Jan 28, 2018 4:52 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
Another photo of bloodwood trim on new guitar>
Author:  sdsollod [ Sun Jan 28, 2018 5:23 pm ]
Post subject:  Re: Thickness for bending bloodwood binding?
That is a beauty Michael!
Author:  jfmckenna [ Mon Jan 29, 2018 8:40 am ]
Post subject:  Re: Thickness for bending bloodwood binding?
That's absolutely killer Keller. Beautiful lines and joinery.

FWIW I just bend on my last guitar bloodwood bindings at .1in thick and had no problems at all. So I guess I am surprised to hear they are normally difficult. I do tend to run my pipe real hot though so maybe as Trevor said, that's why.

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