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I saw you Peruvian Walnut on LMII today. Turns out it's not a true Walnut, so it may bend differently. Anyone with specific Peruvian experience?

My bet is hotter is better on this species. What's the temp reading on the thermometer?

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http://www.dickeyguitars.com

Heath, how do you have your blanket rigged up?

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Aoibeann

im curious to see if there is anyone with experience working with peruvian walnut as well. good call bruce. it is, however, if i understand correctly, a true walnut. juglans neotropica. the wood i was having a problem with was the oak, however. my practice stuff, if you will. the temp reading on the thermometer never reached 300 degrees. i had the blanket on for quite some time. its still a bit of a mystery to me, but i have a feeling there will be a little more light shed when i give it another run.

Lillian, the blanket is a john hall jobber with the heat control (router speed control) and a digital thermometer he sends with the bunch. sides were bent blanket on top of slat/wood/slat.

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sweat the small stuff.

Hang in there brother you are doing fine... I haven't even purchased my bender yet. Keep with it and I'll have you bend some wood for me.

Best of luck
walter

I have bent .125 butternut to this shape, this is .185 flatsawn oak. I bent both soaking 10-20min then a bowl of water a rag a hot pipe and an outside strap.

I have bent claro to much gentler curves and Suspect it is very similar to peruvian but sorry no cut away.
I have not used black walnut yet.

There is a story behind thinning the oak with a router.

Flatsawn oak likes to tear along the grain sort of like figured maple.

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"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

I would like to try English walnut.

Not relevant but had a dream about making a bog oak Peruvian harp.

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"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

Ahh, never reached 300.

I have a Minco heater runs around 800 Watts on 110Volts and will hit close to 500 degrees so they say. My thermometer only makes it to 400.

I use a 1000 Watt Commercial dimmer to cut back once everything is bent, just a switch and duplex outlet mounted on a board. Before using that control, I did like Jim Olson and used the plug and unplug method, it works too.

You might want to get a second thermometer in the kitchen gadget section at Walmart. John Mayes turned me on to it. About 12 bucks. This will give you confirmation that your thermometer is correctly indicating.

And well, you are right on the Juglans comment. I got on the Mayan by mistake at LMI:

Black Walnut, Mayan Walnut and Peruvian Walnut are three species new to the LMI catalog. Each offers a great value to beginners looking for a quality tonewood at a great price. All three share qualities of our familiar and popular California Walnut . They are dark in color, bend easily and offer a clear, open tone with excellent depth and strong trebles.

The Black Walnut (from the Eastern United States) is gray in color, often with contrasting tan center strips.

The Peruvian Walnut is a nice, dark chocolate brown color, often with interesting, broad, dark lines. Most sets will have some small, subtle gray mineral spots. The Peruvian variety is slightly more dense than other Walnuts, which may increase volume and/or projection.

The Mayan Walnut (not a “true Walnut” from the Juglans family) is even-colored and straight-grained, and is very easy to work. The color is a light-mocha (decaf anyone?) with contrasting dark gray grain lines. Most sets have a very subtle flame figure, and many sets also have an attractive blonde sapwood center.

I like the Easy to BEnd part!

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http://www.dickeyguitars.com

    http://www.bluescreekguitars.com/tut orial10.php

Here is a tutorial on bending. In a nut shell most peple tend to over cook or over wet the wood.
   If you are not done bending your wood to the pattern in 6-8 minutes you are waiting too long. I set the thermometer between the blanket and slats. Usually I am bending the lower bout in about 2-3 minutes at full power then then I do the upper bouts. The waist is done last so that the sides are "pulled" onto the bending pattern. Once I see the 200 degree mark I am checking the wood for relaxing.
    I never use softening products but if you feel you need them go ahead. The temp range for a good bend is 250-375. The staining can be either iron migration or water staining. I do see that once in a while on African mahogany. I think it may be something from the water chemicals or maybe even iron in the water.
    You have a good bit of spring back. This can be attributed to taking it out too soon or not heating it enough. I use 375 degrees for 3 minutes then 200 for a full 15 to dry out the excess water.
     Again check out the tutorial as you can get bneind instructions there or call me and I will be happy to help you. Never use the blanket without a controller . they will scorch wood.
   The full pattern you made will absorb a great deal of heat from your wood. That is why you see the patterns with the tubes. The heat isn't pulled off the wood and into the pattern. It becomes are large thermal mass.
john hall
blues creek guitars

Hi John, tips from the master.

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http://www.dickeyguitars.com

"and the additional support from the form means that even thin slats perform well."

Uhmmm, the idea is that you need the support while the wood is bending but not yet in contact with the form (as occurs doing the waist and cutaway areas). So I don't see how having a solid form is going to make up for the lack of support from thin slats. Sorry.

Pat

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There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

OK, I know I'm a dinosaur here but I would strongly urge folks to get a hot pipe bender and learn how to use it. I just purchased one from Stew Mac after using a piece of iron pipe (flattened in an arbor press) and propane torch for thirty years or so.

Hot pipe bending is easier than you think, produces sides with little or no spring back and frees you up to build many sizes and plantillas that you don't have to make a bending jig, or even a form for if you "free build". A luthier friend of mine who already knew how to pipe bend purchased  a Fox style bender from a supplier and after using it a few times, it collected dust for several years and he sold it on ebay. Meanwhile, the many side sets he bent were all produced the old way.  

Even if you are commited to the bending machine approach a hot pipe bender can help you refine the results.

   Bending machines are designed to work with building molds and forms. Free building as Dave is mentioning is mostly for both but free building without molds you need a pipe.
   The bender gets you close and the mold does all the refining of the shape
john hall

Todd,
I agree with your point about the value of a solid form helping to reduce cross grain ripple. In the form I made to go with the spring steel slats I made it "semi-hollow" which is to say I added a middle board. So there's only about 1.75" gaps  across the form  between the boards.  I think the  spring steel is rigid enough that  I won't have any  rippling  over that distance. For some reason, the area I was was having the most breakage was the first inside curve closest to the neck in the cutaway. So for me, it seemed important to get good wood support under the ram as it pushes into the cutaway. So if I was making a choice, I would have the thicker slat on the bottom. For the other tight curve to make the horn, you already get support on the inside as you press on the form and you can provide it on the outside with the bar that is doing the pressing. That's my theory, but it may well be wrong. Personally, I would prefer to have support on both sides using "strong" slats so that I could move the ram out over the cutaway early without having to think about using to support the outside of the wood while doing the horn area.

Hesh,
With respect to using "regular" stainless steel slats you are right. I don't know what I am talking about since I have never used them so in that regard people should take what I am saying with a grain of salt. However in making your recommendation you described the stainless slats as "whimpy" and from that I took that they offered less support than the spring steel. If stainless provides all the support you need and they flatten easily after use, then I would agree, use them to reduce staining. I think part of my reaction has been my joy at finally finding a method that gives me good consistent results and I wanted to share what I think have been the reasons.

This may be awkward for John Hall since he sells both, but I know that he has done a lot of experimenting with different slats with respect to thickness etc. So I'd very be interested in his opinion on their relative merits just with respect to the support they provide the wood and if that's really all important.

Pat

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There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

things i will do differently next practice run:

1.  possible work indoors (if the wife smiles on it ) as the temperature is a bit warmer and the humidity probably lower.

2.  after the bend is complete, cook the side for twenty minutes or so at a lower temperature to dry things out.

3.  probably use foil and craft paper this time. i just realized that on the second side i bent (the worse of the two), i wrapped the side comletely in foil with no way for moisture to escape.

anything else?

as for bending with a hot pipe. i gave it some thought and then decided on the heating blanket. i figured i would probably end up using a blanket eventually anyway, so why not just start with it? maybe it would have been a good idea to get started with a pipe, but since im $200 deep on blanket/slats and hours in the shop making molds and forms, i think ill stick with my current method. thanks for the advice though.

david, i just laughed really hard because i looked at you profile to see what your first name is and noticed your occupation is "museum exhibits." was it a figure of speech, or are you really a dinosaur?

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sweat the small stuff.

H,

That is funny! (though unintentional........!?..). I do work at a Museum and have been building now for 41 years and sometimes feel like a dinosaur in that I that I started at a time when there was one place to buy wood, one how-to book and Martin guitars <REALLY WERE> hand made. Just wanted to chime in with another perspective.

Best!

John,
Excellent post! Reminds me of how much I miss building..better get by butt in gear.
Thanks for the great post.

Mr Laplante
    you are not a Dinosaur as having the privilege of meeting you through Steve and at Asia you had given me some valuable advice. Those of you that don't know David , he is very experienced in luthiery. He was very helpful to me when I started.
      Things have progressed since the "old days" and the internet has made information so available from the few things that we could gleen from just a few years ago.
     I believe there is more than 1 way to do this and you as the builder need to find your own path. I have been at this now for about 10 years and have learned a lot. Often because of a failure or I was lucky enough to get to meet some knowledgeable people like yourself.
     I know if you use the machine aluminum is not the way to go. Steel either stainless that is tempered or spring steel will have more than enough strength to support the wood.
    Warping on bending can be from a few things. Too much water , pulling out the side when it is still warm or sometimes it is the wood. That is why quality wood isn't always the cheapest but is often the better buy.
   Hopefully we all learn from each other and can agree that this is why we are here , to share what we know.
john hall
blues creek guitars

well, this is my third try. it seems like im getting worse with each attempt. not sure what to do now. guess ill try again, eh?

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sweat the small stuff.

If you were bending using a pipe I would be telling you wait for the wood to relax that you can feel it when it does.

Not having form bending experience limits my ability to help.

It does sort of look like you bent the waist first and cooked the bouts dry before you got to them. It is easy to be wrong just looking at a pic though.

I think you should describe the order of operation and a rough time line.

_________________
"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

YOU WILL get the feel for your method just keep at it.

_________________
"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

Perfect opportunity to make a Venetian Cutaway though......(hope it's the treble side....)