dixieangler
Registered: 06/11/09
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Reply with quote | #1 |
I have only one type of preferred wood here where I live that I know of and that is Mulberry. I have not been able to find any yet. Ironwood is only available here if I go way back into a hammock and even then I am not sure I would be able to get any. Is it possible to use another more common wood such as Maple (being Red or Florida Maple) or Oak (we have various kinds but none are White Oak) or would there be too much string following with those types of woods?
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prariewolf
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Reply with quote | #2 |
Primitively I wouldn't be too concerned about string follow. Making the bow would be the priority. I have used cottonwood and willow - sure light weight with string follow but bows none the less. The very advanced bowyer can make a bow out of about anything from a toothpick to a broom handle if he knows what to look for and the basic rules of tillering. If he wants a bow that stays straight and is using a wood that has a reputation for string follow he will use his knowledge (ie: wider, with reflex) so that the finished product is a straight bow.
The beginner/novice should worry more about how to make any piece of wood bend properly so as to shoot an arrow about 1/2 the length of the bow at full efficiency (+-). Any wood will work for this.
Myself I enjoy using the best woods available on occasion to make fine bows but I get great enjoyment on choosing any stick and turning it into a usable bow in short order using just a knife (sometimes stone tools).
In your case I would experiment with the maples and oaks. You might be pleasantly surprised. I have used oak in the past and found it to be a good enough material but I have no hands on experience with the maples. I'm thinking that Tim Baker has worked with maple in the past.
j
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dixieangler
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Reply with quote | #3 |
Thanks for replying, John. I will do that. Would it be possible to back the bow with pine pitch and Yucca fibers instead of sinew and hide glue?
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dixieangler
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Reply with quote | #4 |
Something else I wanted to ask besides the Pine pitch and Yucca fiber for backing was would it be possible to take a green stave, cover (seal) the ends to prevent splitting, and tie it to a straight solid rail (back facing up) with blocks inserted to shape it while its green and let it cure (season) so it holds that shape? Maybe placing a small block eight or so inches in (between the back and the rail) on either end to shape the ears (ends tied off to rail) and tying the center to the rail. There would be no need to heat shape the bow this way if it cures to its final curved shape, just removing wood from the belly and sides, notching, and also tillering.
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prariewolf
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Reply with quote | #5 |
Besides the sealing, that is exactly how I illustrate in my bow & arrow video. A trick I learned from Jim Riggs - oh, so many years ago.
I seal ends of rounds and thicker staves. If the stave is thin enough to shape then it should be thin enough so that it would not split/check. Checking is primarily caused by moisture leaving the stave at varying speeds - heartwood vs. sapwood - thicker areas vs. thinner.
Work green stave to about 25% of finished tiller being cautious to not overbend - which means no bending of it at all - just feel to see if it has “give”. Once green fibers are stressed (over stressed) to deformation, they cannot be repaired. In this stage it can be tied to 2x4 or rail and shaped with ears and/or reflex.
The main purpose of the backing is to absorb the 50% stress (tension) of the outer 10% of the of the compressive side of the bow. Other materials besides sinew (12% {+-} stretch vs. 1% of wood) work also: ie. nylon, bamboo. So, maybe yucca fiber might have some stretch but off hand I would think not. Maybe worth the try? Pine pitch for the adhesive gives me doubt. If used raw it would be too runny/sticky and at the other extreme if overheated it would be too brittle. Control of the heatiing/preparation of the pitch (and mixing w/charcoal) would be difficult to control primitively (note I don't say impossible). In a primitive lifestyle, If you have pitch you would likely have hide/sinew/other scraps to make hide glue which is easier to control - tho primitively difficult in itself to make - but possible.
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dixieangler
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Reply with quote | #6 |
Thanks, John. That helps a lot. Guess I need to hurry up and get the DVD series. LOL I was thinking Yucca because I wanted to keep all natural materials for the backing but it probably is not very good since I don't believe it has much stretch either. I don't really want to use bamboo or sinew since I don't have any of those unless I ordered some. So I will just keep thinking about a natural source for backing material. I guess I will just have to use some hide glue instead of the pine pitch also. I can always get some squirrel hide (road kill). LOL
One more question.....so far. LOL Thick vs. thin wood. I know I should save the thick wood. How do you save only the heartwood (inside) if it is thicker without removing (splitting) the back (outside) sapwood of a stave, say for instance Oak wood?
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dixieangler
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prariewolf
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Reply with quote | #8 |
Thick vs. thin wood. I know I should save the thick wood.
Thick vs. thin? Sorry to be a bit getting back but things around here keep me busy - and not much of it “Primitive” unfortunately. Not certain what you mean by thick/thin. Assume that you refer to heartwood/sapwood.
In some cases heartwood is thicker than sapwood as with Osage but with others such as ash and hickory the sapwood is quite thick. Generally with the white woods (hickory/ash) the bow is made from the sapwood (outside wood nearest the bark which is white in these cases). Those with thinner sapwood (osage orange) the bow is generally made from heartwood. I have worked very little with oak.
I have left the sapwood attached to the heartwood in a coupla osage bows with good effect. Some bowyers have stated that the sapwood becomes too brittle but by keeping my finished bows greased they held up for years.
Generally one would remove the sapwood down to one of the outer layers of the heartwood. For the quick drying referred to earlier I then remove wood until the bow is “almost” finished - bendable.
With the white woods I will split away the heart from the sapwood retaining the outer sapwood for the bow.
If taking not to a “thin” stage but to simply an average stave I will make it the size of a 2x4, coat the ends to keep moisture from leaving too fast and then hanging by a rope in a shady spot protected from the elements.
How do you save only the heartwood (inside) if it is thicker without removing (splitting) the back (outside) sapwood of a stave, say for instance Oak wood?
In this case I would remove the bark and coat the ends and hang as above. (Bark will attract bugs that may tunnels into the wood deep enough to hurt.) This will create some checks in the outside but should not effect the heartwood. Some bowyers have placed the log under water for extended periods (?) and the natural moisture will leave without warping or checking. I have not done this.
Hope that this helps to clarify some.
j
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dixieangler
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Reply with quote | #9 |
Quote: Originally Posted by "prariewolf"
In some cases heartwood is thicker than sapwood as with Osage but with others such as ash and hickory the sapwood is quite thick. I have left the sapwood attached to the heartwood in a coupla osage bows with good effect. Some bowyers have stated that the sapwood becomes too brittle but by keeping my finished bows greased they held up for years.
Generally one would remove the sapwood down to one of the outer layers of the heartwood. With the white woods I will split away the heart from the sapwood retaining the outer sapwood for the bow. For the quick drying referred to earlier I then remove wood until the bow is “almost” finished - bendable. Hope that this helps to clarify some.
I was referring to heartwood/sapwood. Yes, that does help a lot. That is exactly what I wanted to know. I did not see anything on the "how to" separate one from the other in the book (especially the heartwood separation) and it was kind of an enigma (question mark) with me. No problem on replying. I know you are busy and I am not in a hurry. I can't cut any staves until winter when the sap is low anyway.
Quote: Originally Posted by "prariewolf"
Besides the sealing, that is exactly how I illustrate in my bow & arrow video. A trick I learned from Jim Riggs - oh, so many years ago.
Yeah. Duh. I completely missed that section in the back of the book under "Tools" (p. 364-371) where you and Geri used that method of shaping a green wood Juniper stave to make a primitive Juniper bow (photos) using stone tools. The DVD on it will be nice to show the entire process.
John, if I use nylon to back the bow, what is the best to use or what you would suggest? Nylon string (thread) or nylon stockings?
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Robert M. |
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dixieangler
Registered: 06/11/09
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dixieangler
Registered: 06/11/09
Posts: 72
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dixieangler
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Posts: 72
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Reply with quote | #12 |
Bump means that I bumped the topic or topic question back up the to the top of the topic list for a reply. Did not mean to confuse anyone.
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Robert M. |
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prariewolf
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Reply with quote | #13 |
Yeah, I guess that this got buried didn't it? I have only heard of one fellow, whom I trust, state that nylon had worked for him on at least one occasion. Whether it was strapping, material (such as from pants/jacket) or threads I can't recall - tho a material seems to come to mind. I also do not recall what glue he used with it. If I was to try this I would use something that I could stack at least 1/16 or 3/32 of an inch. Threads would likely work also same as sinew.
Remember, I have only heard of this somewhere and have not done it.
The back of the bow is stretching, attempting to tear apart (with wood that's after about 1%. (Also bear in mind that all bow woods, everything else being equal, will fail under compression first.) Remembering our bow physics, 50% of the thickness is devoted to each, compression and tension. At the mid point where these come together there is a plane of nothing - neither of these forces is acting (tho there likely is a shear force of sorts). So, from this point (0%) where nothing is happening, the increase to 100% of that force is graduated resulting in the outer 10 % thickness of it's half of the bow (either tension or compression) absorbs somewhere around 50% of that particular force.
So - sinew (@ 15-16%) stretches more than wood. By attaching this to the outside of the bow, the thickness of the limb is increased. That critical 10% w/50% of forces is moved into the plane of the sinew - sinew now becoming the outer 10%. The back of the bow will now stretch much more than wood alone.
Eskimos braided sinew into a cord, maybe finger thickness, and attached this round braided cord with a complicated series of knots to the back accomplishing the same.
Note - that this process allows for the back of the bow to bend further before it will fail. It does nothing at all to help the belly which will yet fail if stressed beyond it's limit (1%+-).
Sinew and hide glue weigh in more than wood so being heavier, the working of the bow limbs are slowed somewhat by this process - tho you won't notice it. Application of sinew will have tendency as it dries to pull the limbs backward into a reflex thereby adding efficiency to the limbs.
Whew! More than you asked for, huh?
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dixieangler
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Reply with quote | #14 |
Quote: Originally Posted by "prariewolf"
Yeah, I guess that this got buried didn't it? I have only heard of one fellow, whom I trust, state that nylon had worked for him on at least one occasion. Whether it was strapping, material (such as from pants/jacket) or threads I can't recall - tho a material seems to come to mind. I also do not recall what glue he used with it. If I was to try this I would use something that I could stack at least 1/16 or 3/32 of an inch. Threads would likely work also same as sinew.
Remember, I have only heard of this somewhere and have not done it
That's okay. At least your idea of it gives me some idea. 1/16" thick? Woven nylon stocking would probably do that and I wouldn't have to strip a nylon string down into threads. Guess I would have to experiment first with some different glues and the nylon before putting it on a bow.
Yeah. I recall the physics of it from engineering courses but its great that you can refresh my memory. The physics of formal bow science didn't deal with backing at all if I recall correctly. Thanks for replying and I appreciate the in depth review of it.
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Robert M. |
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dixieangler
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Reply with quote | #15 |
Hi John,
Theoretically, I could take a measured weight of water to use for measuring bow draw force such as:
1 pint (pt.) of water (at room temperature 78 deg. F) = 1 pound (English/US lb.)
2 pt.s = 1 quart (qt.)= 2 lb.s
8 pt.s = 4 qt.s = 1 gallon (gal.) = 8 lb.s
Once a set number of pound(s) is measured on the bowstring from starting point (giving an increment from initial point to final point after the weight is added), further increments can be made (by distance measure) thereby establishing a pound scale of force on the bow as the bowstring is drawn for tillering.
Have you used this method of measure? Seems to me like this would come in handy for measuring bow force in a primitive situation (making a bow in the wilderness) when water is available and provided that there is a premeasured container.
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Robert M. |
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