Author Topic: New heat treating method??  (Read 61308 times)

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Offline DC

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Re: New heat treating method??
« Reply #285 on: December 31, 2019, 03:29:25 pm »
I doubt any two of us do it exactly the same.     You'd have  to prove how much a variation of placement and duration really matters to the end result.

 I've done all sorts of variations and the net result is hairsplitting in difference.
Agreed. It sure would have been a boon if all of us had kept detailed accurate records over the years. It's hard to know ahead of time what records to keep though and it can be so time consuming that it's easy to just forget it.

Offline PatM

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Re: New heat treating method??
« Reply #286 on: December 31, 2019, 04:02:17 pm »
In case anyone didn't read the above link.  Here's the Science synopsis.



"During heat treatment changes occur within the cellulose, hemicellulose and lignin components of the wood. Cellulose undergoes some reduction in molecular weight, but cellulose crystallinity can increase. Hemicelluloses are the most thermally reactive cell wall constituents having lower thermal stability due to their lack of crystallinity, and during thermal
treatment carbonic acids, mainly acetic acid, will be formed as a result of cleavage of the acetyl groups. The formation of acetic acid further catalyses carbohydrates cleavage, causing a reduction of the degree of polymerisation. Acid catalysed degradation results in the formation of formaldehyde, furfural and other aldehydes as well as some lignin cleavage. The decomposition of hemicellluloses results in the reduction of the number of available hydroxyl groups and a lower concentration of reactive sites will therefore decrease the equilibrium moisture content of heat-treated wood and thus improve the dimensional stability. In addition, the acetic acid that has formed depolymerises the cellulose microfibrils in the amorphous area. Changes within the lignin are equally complex. During the treatment bonds between phenylpropane units are partly broken but condensation reactions occur also. The longer the autohydrolysis time is, the more condensation reactions occur. Auto-condensation of lignin is believed to occur through the formation of methylene bridges connecting aromatic rings. The extent of these reactions is mild but they lead to an increase in cross-linking with consequent improvement in its dimensional stability and decreased hygroscopicity of wood. In summary heat-treated wood has reduced hygroscopicity and improved dimensional stability because the cellulose microfibrils are surrounded by a more firm and inelastic network due to cross-linking within the lignin complex. The microfibrils have decreased expansion possibility and less capacity to absorb water between cellulose chains. This results in a lower fibre saturation point and a higher resistance to biological decay. The cell wall hemicellulose is transformed into a more hydrophobic network.
Timber species and applications Northern European softwoods including Scots pine, maritime pine, the spruces and white fir have been the predominant species used in the process and have found applications in cladding, decking, flooring, door and window frames and garden furniture. In many of these applications the warm brown colour, imparted by the process is seen as an initial aesthetic advantage. Poplar is probably the most important hardwood to receive attention and has found application as cladding/siding. Other hardwoods with a history of treatment are beech, which it is claimed will match the durability of teak after treatment, and ash and birch. Juvenile teak has also been heat treated to improve stability for furniture applications, thereby improving the utility of small diameter plantation grown materials."

Offline Marc St Louis

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Re: New heat treating method??
« Reply #287 on: December 31, 2019, 04:23:42 pm »

I see this type of comment over and over. Not giving credit to Native American knowledge, just because its not written out in a book somewhere word for word that they did this or that.

You are talking about a culture with more knowledge of wood than you and I. You are talking about a culture who uses fire more than you and I. You are talking about human beings with the same cognitive capabilities as you and I. Of course they knew what prolonged heat exposure did to woods. Out where I live (Sierra Nevadas) natives labor was preferred over other ethnicities to build (not engineer) the massive tressels the logging railroads needed to span across huge creeks and drainages because their craftsmanship with wood was superior.

No one on this website nor this fella Shannon has done this first - guaranteed without evidence ; )


Some of those statements are debatable but it's cute that you think that.
Home of heat-treating, Corbeil, On.  Canada

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Offline PatM

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Re: New heat treating method??
« Reply #288 on: December 31, 2019, 04:43:07 pm »

You are talking about a culture with more knowledge of wood than you and I. You are talking about a culture who uses fire more than you and I.

  I love Native American Culture as much as anyone  but their knowledge largely  relied on the "just enough to get by and not an ounce more".   There was no need to do more.

 And I say that with no disrespect to them.

Compare what other cultures have done with wood, stone and fire and you'll understand.

Offline Azmdted

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Re: New heat treating method??
« Reply #289 on: December 31, 2019, 05:02:41 pm »
Hey guys!!  Long time no talk!

  I was shown the technique and filmed it.  I have a pretty good idea of how it's done, although there are still some trade secrets that Keith hasn't divulged...even to me.
         

Hi Billy,

Thanks for chiming in.  I downloaded the video and thought it was pretty well made.  It’s clearly not a how to build and fire harden a white wood bow video, though it does give some basic information on his fire hardening and I appreciate the data at the end where you mentioned the temperature.  I am concerned though about what you said above. What’s the point of paying almost $30 for the video if it isn’t a ‘how to’ of his technique for fire hardening?  If he’s withholding information critical to successful fire hardening using his method then I’m concerned?  What did I buy, a 30 buck infomercial for his bows?  No thanks.

I’m pretty sure I remember him on this forum earlier saying the dvd would explain everything.  I greatly appreciate this forum with its free advice and knowledge. Likewise, I don’t begrudge others who wish to earn money from their efforts.  No one forced me to pay for it.  But as I said, if it doesn’t include all the info necessary to replicate his results then I really question the point of paying for it.  And, I think that will harm his reputation..

Offline wstanley

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Re: New heat treating method??
« Reply #290 on: December 31, 2019, 05:07:21 pm »
[quote author=PatM

  I love Native American Culture as much as anyone  but their knowledge largely  relied on the "just enough to get by and not an ounce more".   There was no need to do more.

Hmmm, just barely enough to get by huh? Is that your quote? Anyhow, I don’t think anyone is being disrespectful to natives either. I just don’t think they get the credit on many of these discussions.

Since this is only a bow discussion page, I won’t begin to comment on your “just enough” perspective in which you greatly generalize vast cultures that existed across millennia in what we call America as of only some 500 years ago. I’m starring at an intricate California burden basket right now pondering your comment.

Marc: my comments can be backed by references if you would like me to provide, and I’m flattered you find them cute ; )

Offline PatM

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Re: New heat treating method??
« Reply #291 on: December 31, 2019, 05:19:06 pm »
Largely and not  "barely".   The statement is not  inaccurate.

Offline wstanley

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Re: New heat treating method??
« Reply #292 on: December 31, 2019, 05:52:35 pm »
What you describe as cultures which “largely just get by” I would describe as simple. I think you may agree to that? What’s problematic is your “just get by” perspective is narrow minded because your disregarding that their is a reason to be simple: survival. If your in a survival situation today are you building a bow or making something more simple to “just get by” such as cordage to survive? That cordage will take less energy to make and be more efficient in procuring meat than making a bow - snare. See where your “just get by perspective” fails to see this point? To me heat teating wood for a better performing bow is a simple step to take to improve it. There is nothing earth shattering about it. To think that no southeastern tribes heat treat their wood is plain silly.
« Last Edit: December 31, 2019, 05:58:00 pm by wstanley »

Offline billy

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Re: New heat treating method??
« Reply #293 on: December 31, 2019, 05:56:14 pm »
Ok let me clarify....  Keith didn't withhold any info on how to actually make the fire hardened bow.  There are a few little tricks he does that are his own way of doing things that are not shown in the video.  That's what I meant.  These are things that he's learned, even since we were done filming the video that were not included in the DVD, but it's not as if he left out any information to trip anyone up.  Everyone will have their own way of fire hardening, so take the info you got and run with it.  Experiment with different techniques on different wood species and see what happens.  You may come up with a better or more efficent way to do it.  If so, great!  We wanted to create this video to spur people to take this info and learn to make a fire hardened bow.  Once you grasp the basic concept, let your experimenting mind and imagination run wild.  We can't answer every question, cover ever single topic, or even foresee what people may encounter when we make a video.  There isn't enough time or space for that.  Keith's technique for making the fire hardened bow is covered and that's enough for anyone with some basic bow building experience to take to make their own fire hardened bow.  We made this video with the assumption that people have already made white wood bows and would be interested in taking it to the next level.  There's PLENTY of info in print, on the Internet, YouTube, and other social media platforms showing how to make a basic wooden bow out of a tree.  To cover that entire subject again in our video would be redundant.  This video is not how to make a wooden bow, it's how to make a fire hardened bow, so we focused more on the actual fire hardening topic, the science behind it, moisture content differences between raw, heat treated and fire hardened wood, and finally chronograph tests of the finished bows showing their performance.  I'll edit that last post about the trade secrets being left out because that's not quite what I meant.  I don't want to mislead anyone into thinking the video is in some way leaving out vital info that would lead to failure.     
Marietta, Georgia

Offline billy

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Re: New heat treating method??
« Reply #294 on: December 31, 2019, 06:02:32 pm »
Yes, it was the fact that fire hardening made the bows hydrophobic, and they would retain consistent performance in high humidity environments that Keith was originally trying to solve.  He wasn't doing it to enhance performance, he was trying to make them more moisture resistant.  He lives on the GA coast where humidity is high almost year round. 
   
Marietta, Georgia

Offline Azmdted

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Re: New heat treating method??
« Reply #295 on: December 31, 2019, 06:06:40 pm »
Thanks, good clarification. 

Modification:  i wasn’t expecting a bow building dvd, so no issues there.  If there were some designs better suited for this method than others that would be nice to know, but I assume it will work on typical designs.
« Last Edit: December 31, 2019, 06:10:35 pm by Azmdted »

Offline Marc St Louis

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Re: New heat treating method??
« Reply #296 on: December 31, 2019, 08:47:36 pm »
Quote
You are talking about a culture with more knowledge of wood than you and I. You are talking about a culture who uses fire more than you and I. You are talking about human beings with the same cognitive capabilities as you and I. Of course they knew what prolonged heat exposure did to woods. Out where I live (Sierra Nevadas) natives labor was preferred over other ethnicities to build (not engineer) the massive tressels the logging railroads needed to span across huge creeks and drainages because their craftsmanship with wood was superior.

No question they knew a lot about wood but I don't think their knowledge of wood included the building of trestles.  Most likely they did the work because it was one of the few things the Europeans would hire them for.  Up here in the early 1900's many of my family would not be hired unless they hid their native heritage
Home of heat-treating, Corbeil, On.  Canada

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Offline PatM

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Re: New heat treating method??
« Reply #297 on: January 01, 2020, 01:01:17 am »
What you describe as cultures which “largely just get by” I would describe as simple. I think you may agree to that? What’s problematic is your “just get by” perspective is narrow minded because your disregarding that their is a reason to be simple: survival. If your in a survival situation today are you building a bow or making something more simple to “just get by” such as cordage to survive? That cordage will take less energy to make and be more efficient in procuring meat than making a bow - snare. See where your “just get by perspective” fails to see this point? To me heat teating wood for a better performing bow is a simple step to take to improve it. There is nothing earth shattering about it. To think that no southeastern tribes heat treat their wood is plain silly.

 I think you're trying to put words in my mouth.   

Offline wstanley

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Re: New heat treating method??
« Reply #298 on: January 01, 2020, 09:27:53 am »
Not at all. Just pointing that your “just enough to get by” rationale has holes in it. These societies led to cultures such as the Hopewell tradition (I’m sure your familiar) - massive trade routes with elaborate artifacts and stunning effigy mounds, the civilizations of the southwest, Cahokia, Povery Point in Louisiana, Machu Pichu, Mesoamerica - all these civilizations rose from hunter gatherer societies - are their achievements “just enough to get by.” By the time Europeans arrive these societies have risen and fallen after several millennia.

PatM you say yourself on this thread state the Cherokee fire seasoned trees? My initial comment was to Marc as he said their is little written record to state the southeast Indians heat treated their bows.

Now we are this topic of native cultures as being simple ... I will never agree and I don’t think you will either.

John Muir has a quote about natives he witnessed out in the Sierras during his travelings. By that time native folks had been transformed and living in povery and just surviving.He said he has never seen such a sorry race, their skin resembling the cracked surface of the rocks, wanderers across the land. This is paraphrased of course. This has always stuck in my mind, because the very beauty of the Sierras was largely attributed to land management practices of California Indians. Muir himself fails to see this because he casts them of as degraded humans (also he was simply a man of his time who shared the same sentiment toward Indians as other whites did) Their are many reason for the catastrophic fires out here, but it all begins with the abandonment of fire as a tool for managing the land (United States government policy ). Kat Andersons breakthrough book “Taming the Wild” (I’m a bit off on the title) gives countless accounts through ethnographic work, writings from explorer, and elder native knowledge. Again, these societies are much more sophisticated than you are making them out to be. See beyond their simplicity, their is much more to them that we don’t even know because that knowledge is gone.
« Last Edit: January 01, 2020, 09:33:20 am by wstanley »

Offline PatM

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Re: New heat treating method??
« Reply #299 on: January 01, 2020, 09:42:49 am »
Yep, exceptions in certain areas but by and large  there was little time for extra innovation.    Sticking to the subject of bows in the area mentioned, the bows were still simple bows, even with heat treating.