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  #31  
Old 10-07-2020, 11:23 AM
ac ac is offline
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Well, looking more closely at this website https://hempstone.net/ it appears hempstone may be the overriding company name that makes hempcrete.

You can check the website yourself to see if that seems right. I don't see anything that clearly describes "hempstone", only hempcrete.

Canna may have modified the material in some way. That's always possible. For example, maybe grinding the hemp to a finer consistency would make it a bit easier to form a thinner end material. I'm only guessing since I find no information that provides greater detail either from his site or the Hempstone site.

AFAIK, Canna's guitar body is hempcrete, in some form or another. Hemp + calcium carbonate + water. If there is an epoxy resin involved, that would be interesting.

To my eyes and reading, the use of the words hempcrete vs. hempstone by the supplying company and by Canna, is a difference without a distinction.

It would be great if the builder would join the forum and explain "in detail" what he is actually doing and how that differs from the standard 3 ingredient formula that is found in a number of places when I searched.

It still all a bit of a mystery at this point.
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  #32  
Old 10-07-2020, 11:51 AM
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A mystery indeed. Jakob says you can stand on his guitar. Byut can you jump on it?
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  #33  
Old 10-07-2020, 02:35 PM
Captain Jim Captain Jim is offline
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Quote:
Originally Posted by EvanB View Post
A mystery indeed. Jakob says you can stand on his guitar. Byut can you jump on it?
Is there a demand for that? I can buy a step-stool for considerably less money than a guitar. I'm kinda new at this guitar stuff, but in 56 years of playing, I have never stood (nor jumped) on a guitar. Not even that crappy ol' Recco electric that made my fingers bleed when I was 12.
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  #34  
Old 10-07-2020, 02:44 PM
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BUT YOU CAN'T GET MUSIC OUT OF A STEP STOOL.
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  #35  
Old 10-07-2020, 03:43 PM
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I could probably stand on my Lucky 13 without a problem, but I know it has its limits.

https://www.acousticguitarforum.com/...ight=lucky+mot
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Last edited by mot; 10-07-2020 at 04:06 PM.
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  #36  
Old 10-07-2020, 05:26 PM
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Mlot;

Nice reminder.

P.S. I'm waiting for your check.
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  #37  
Old 10-07-2020, 06:57 PM
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I'm waiting for your check.
It's in the mail‽
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PS If you don't want to invest in yourself, why should anyone else even bother to try?
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  #38  
Old 10-25-2020, 08:16 PM
KarenB KarenB is offline
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It says in the video at one point:
Signal chain—
Neumann KM184 > Focusrite ISA Two > Focusrite Scarlett Generation 2

So it seems we are not hearing the acoustic sound. I’d really like to hear what it sounds like unplugged.
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Last edited by KarenB; 10-25-2020 at 08:21 PM.
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  #39  
Old 10-26-2020, 08:58 AM
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In my various emails with Jakob he argues that there is a distinct difference between hempcrete and hempstone. I suggested that he show up on this forum to explain the difference but he is not a commercial supporter of the forum and has decided to stick closer to home as he develops his version of the guitar--which is probably a good idea.

KarenB brings up a good point regarding the promotional material for Canna--some unplugged acoustic soundtracks would be nice.

I like the exploratory nature of Canna Guitars and I suspect that we'll hear more as time goes by.
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  #40  
Old 10-26-2020, 11:19 AM
Explorer Explorer is offline
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Having read through the two websites (the drum and guitar sites) for instruments made of "hempstone," and reading up on hempcrete as well, yes, there is a difference consisting of hempstone being only the hemp fiber/water slurry with no further additives. It's the hemp equivalent of papier mache.

Reading up on hempcrete, which has additives, it is definitely not waterproof. Hempstone has nothing added to make it any more waterproof than hempcrete. The size/dimension variance between the wet and dry hempstone on the Canna website makes me wonder about the material's dimensional stability. Wood seems to have a stability advantage over hempstone.

I've had more than one of those Hohner Eclipse model guitars with the woven round back, "spherical alderwood," actually made under contract by Axiom Guitars. The woven wood and resin construction was stable and strong, and lighter than the Ovation Lyrachord bowls. I'm not opposed to new uses of wood or methods of construction in guitars, especially if there is a clear advantage over normal wood. I just don't see, given the information provided, how hempstone has such an advantage.

The angle on those tuners, with the outside strings only able to withstand minimum turns before the string falls off the end, needs a redesign, incidentally. I looked at all the models, and they all looked imperiled.

I have no dog to defend in this, by the way. My 12-string Adamas has managed to stand the test of time, even with recent developments, but the Canna is definitely eye-catching.
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  #41  
Old 10-26-2020, 12:22 PM
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Explorer;

Good points. The tuners bothered me as did the structural design of the headstock.

Canna needs a lot of R&D before its ready for the big time. I don't have a dog in this fight, but I have my eyes on it--it's an interesting fight.
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  #42  
Old 10-26-2020, 02:13 PM
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Quote:
Originally Posted by EvanB View Post
In my various emails with Jakob he argues that there is a distinct difference between hempcrete and hempstone. I suggested that he show up on this forum to explain the difference but he is not a commercial supporter of the forum and has decided to stick closer to home as he develops his version of the guitar--which is probably a good idea.

KarenB brings up a good point regarding the promotional material for Canna--some unplugged acoustic soundtracks would be nice.

I like the exploratory nature of Canna Guitars and I suspect that we'll hear more as time goes by.
Just yesterday, I also visited the Canna site and watched one of the longer videos by the guitar builder. He went over in detail how they make the body and you see the process in action. It's very interesting. IMO, the main selling point for the Hempstone material is it's environmental friendliness. Also, right now, anything cannabis related, from fibers to CBD, etc., is very popular. IMO, there are many who will be attracted for this reason alone.

The Hempstone (their version of hempstone) is simply a slurry of highly ground cannabis fibers in water. I think he said the slurry contained 90% water, or something extreme like that. It's sprayed from a hose onto the form. Then it dries over several days and becomes hard like a rock. The shrinkage from drying was incredible and he emphasized this shrinkage more than once.

This left me wondering. If shrinkage from drying is so great, how does the re-introduction of water affect the stability? I would assume it would swell greatly as well. Thankfully, the question of the affect of water on the dry material was addressed later in the video. Stay tuned.

I also now understand the difference in their material versus hempcrete from the source websites I visited.

It's confusing, because the Hempcrete supplier's website doesn't differentiate hempcrete from hempstone--but they use both words. They use the same word on the same page referring to one single process for both names. That product has 3 ingredients: water+coarse canna fiber+calcium carbonate -Tums (minus the sugar!).

The Canna guitars refers to Hempstone and defines it differently than I understood from the Hempcrete site. Canna uses "purified" ultra ground up canna fibers+water. That's it. Since they don't have a source of the purified fibers as raw powder (at least not yet), instead they purchase white canna fiber paper for their base material.

With water, they return the paper back into a slurry of loose fibers. After that, the white slurry is pressure sprayed from a hand held hose onto a mold form to make the bowl. It looked like about half of the spray hit the wall next to the form and then they cleaned that off later with a squeegee.

Now, the mention earlier of papier-mâché was a great comparison. If papier-mâché is a composite, then so, of course, is the Canna guitar body. The only difference is the canna fiber has properties that are just enough different that it doesn't just harden like papier mâché, it hardens like a rock--and stays like a rock--as long as it remains dry.

In the video, he demonstrates how they cut off the bowl from the mold after it's been sprayed and dried. They they begin to smooth it so that it is not so coarse.

Originally, it's so rough that I don't think any one would want it for anything. It's very hard, very rough ugly stuff. He shows just how hard it is by using a power sander. The sander leaves the surface untouched.

So how do they smooth that surface enough to be smooth enough for a guitar back?

He demonstrates just how by using a spray bottle filled with water. He first sprays on the bowl surface. Once wet, a second later, he begins the sanding again. Voila--it's soft enough to become easy to sand. He sprays water, sands, and this water/sanding process is repeated until it's finally as smooth as he wants it to be.

Water is the key for them to be able to soften and work with the bowl guitar body to get it ready for use. It softens the "composite" immediately making it easier to work with.

Most of their many models have wood necks. However, they do have at least one model where it appears they use the very coarse, long raw canna fibers right from the dried plant, and fuse them together with a plastic or epoxy material and form a true composite as we are all more familiar with.

So with that, I would say they do use "composites" occasionally, at least as I define composites. But the use is rare and it's for a portion of the guitar that least needs composite properties.

The neck does look really, really nice though.
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  #43  
Old 10-26-2020, 03:11 PM
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AC;

Nice analysis;

When I first ran across the Canna I figured it would be made along the lines of Ekoa, with pressed hemp instead of linen. And when I first ran across the notion of hempcrete I assumed that hemp fibers had been mixed with an epoxy. In short, my initial assumptions were generally wrong.

However, I do think the classical Canna is somewhat beautiful. I find the headstock fetching (though probably fragile) and I am fascinated by the off-set sound hole in the bottom bout.

I don't envision myself placing an order soon, but I will be keeping an eye on the pilot project and looking for some experienced reviewers to come on line.

I think Kramster should buy a Canna, something he doesn't have in his fine collection.
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  #44  
Old 10-26-2020, 08:36 PM
KarenB KarenB is offline
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I asked some questions of Jakob regarding lower bout depth and width. He said "the lower bout is 38cm wide and about 10cm deep. The depth on the Neckjoint however is 13mm because how the Neck sits on top." I also asked him about unplugged videos, and he said, "The videos of the recordings almost all unplugged." I should ask him which ones.
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  #45  
Old 10-26-2020, 09:23 PM
Captain Jim Captain Jim is offline
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I just looked at their site. The general design of their guitars is reminiscent of Ovation, to me. One thing that concerned me regarding the design: their soundhole in the treble side of the upper bout and the sound-port almost directly across from that on the bass side of the upper bout. I can't say that is an issue, but it seems counterintuitive, with the main soundhole pushing the sound down and away from the player. A style exercise to be different? Then, a sound-port to give some direction back to the player? I totally get the upper body soundholes like Emerald, Journey, and McPherson are using.

I appreciate innovation in guitar design, build, and materials. I'll have to sit on the sidelines for Canna until there are some of them out in the wild and are proven to hold up and give good tone. Hemp is a buzzword right now, but that doesn't mean it is the right material for a stressed string instrument. I guess we'll see.
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