Primitive Archer
Main Discussion Area => Bows => Topic started by: Shiloh on January 09, 2013, 08:42:12 pm
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I've got a red oak board that will (hopefully) be turned into a hunting/training bow for this fall. My question is, with the #48 or so that I'm hoping to get out of it, do you think I could get away without a backing on this one, or should I fork over the cash for linen?
(http://s2.postimage.org/71652jxah/DSCN1112.jpg)
(http://s13.postimage.org/mx9todpuf/DSCN1113.jpg)
(http://s14.postimage.org/58kp6dqtd/DSCN1114.jpg)
(http://s7.postimage.org/ux367hkln/DSCN1115.jpg)
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Linen wont help. Grain is everything with boards.
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You can get away with it as long you sand it nice and smooth then put lots of clear shellac. I'm no expert but that's what i did with my last red oak pyramid now that didn't have perfect grain.
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it looks just fine to me. The grain looks as if its fairly strait i dont see why you cant get anything out of it.
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You can get away with it as long you sand it nice and smooth then put lots of clear shellac. I'm no expert but that's what i did with my last red oak pyramid now that didn't have perfect grain.
What??????
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what ive experienced is that so long as the grain is close to strait it will be just fine, if its slanted diagonally then it might be a problem, but it looks fine!
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You can get away with it as long you sand it nice and smooth then put lots of clear shellac. I'm no expert but that's what i did with my last red oak pyramid now that didn't have perfect grain.
What??????
x2
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as to you two and not quite understanding him, i believe what he means is that by getting the backing to a very fine point with absolutely no rough edges then there shouldn't be any splinters unless the bow wasn't going to be one anyway. As to the shellac i have no clue what hes talking about lol ;) :D
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Don't listen to me lol. I was thinking of potential splinters lifting by the run offs but even then it doesn't really make sense.
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Iconic muffin understands my weirdness lol. As for the shellac, it makes sense in my head that a splinter would have a hard time lifting though a thick layer of clear.
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Shellac will protect the back the same as air
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Thanks for the input guys, I'll just sand it nice and smooth, round the corners, and be REALLY careful during tillering. ;D
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Grain is far from ideal. However, I think that with a linen backing that bow could easily survive, as long as its well tillered. I think no amount of sanding and shellac will stop grain violations and run-offs from lifting splinters.
Gabe
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That sounds like a good idea.
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My phone isn't that great to see the detail of photo posted,are pics 234 edge shoots or on the flat?
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On the flat, on the soon-to-be back.
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what size board is that?
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If I took a chance on it, I would probably use rawhide.
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so you guys are telling me that the grain is terrible? i use boards like that all the time! i just finished one up that had grain run offs and its going strong at 50 lbs at 26 inches! its a bit long but no matter.
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I'm no expert but I just recently made a 50# red oak and it held up without a backing and the grain looked similar.
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what size board is that?
A home depot 1"x2"x6'
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A board bow can survive with grain run offs. Lower weight bows survive them better. The angle of the run-off generally determines how much a problem they are. The steeper the angle the more likely they are to break. Also, the different types of wood are more likely to survive growth ring violations (which is what a runoff really is). Red oak is not a wood that tends to survive with significant grain run offs.
If the board you showed us if flat sawn or plain (not rift sawn) I think you should look at the edge grain. The run offs on the edge grain are what represent growth ring violations. However when the back grain moves from one side of the board to the other this generally means you will have grain runoffs on the edge.
The board you showed will have pretty decent run-offs. It could survive without backing, depending on how "high stress" the design is, but those runoffs are a big liability. Backing a board bow with runoffs (in my experience), with a low stretch fabric such as linen or silk, can greatly improve its safety.
Id say, keep the bow long (68") and a bit wider than usual, and keep the weight under 50lbs. But given the option I'd back it with linen.
Gabe
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Thanks, I'll err on the side of safety and back it.
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OOPS! One other question; does anyone have experience with recurving/heat-bending board bows? I've got a cousin who's begging me to make her a recurve, doesn't have to be a static recurve or anything to fancy, but she's really into those.
ETA: Whell, turns out it's not going to be my bow after all! Someone just commissioned me to make them a #35 target bow with a linen back. Methinks this board is a good candidate. ;D
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Forgive, and correct me (anyone), if this comment is out of line:
I'm a little concerned that there are people giving advice here that shouldn't be, that there are people who are giving advice here that should be and are not being taken seriously. Also, if you have ever seen a bow explode or seen some of the injuries that result from it you might be a little more concerned with the integrity of the bows you are making, especially bows you are making for others.
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as to you two and not quite understanding him, i believe what he means is that by getting the backing to a very fine point with absolutely no rough edges then there shouldn't be any splinters unless the bow wasn't going to be one anyway. As to the shellac i have no clue what hes talking about lol ;) :D
So lets cut some slac and admit that sandig it fine is helpful, on a grain violation bow....and about shellac. Have you guys ever tried dry shellac flakes or is all this based on spray can shellac and pre-mixed shellac? if you mix fresh shellac flakes in alcohol...thick cut, it is like glue. Used as a pore-filling finish on an extremely porous oak board bow, it seems would provide additional backing protection. Heat it up a bit and it plasticizes.
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Does shellac have tensile strength? Because that is what is required on the back of a bow. Compression or shear strength will be useless on the back of a bow. While shellac might act as a glue, it does not offer tensile strength. According to your theory, a layer of wall paper glue would even function as a bow backing, right? Shellac could be a good finish for a bow, but it does not serve as a functional backing.
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A board bow can survive with grain run offs. Lower weight bows survive them better. The angle of the run-off generally determines how much a problem they are. The steeper the angle the more likely they are to break. Also, the different types of wood are more likely to survive growth ring violations (which is what a runoff really is). Red oak is not a wood that tends to survive with significant grain run offs.
If the board you showed us if flat sawn or plain (not rift sawn) I think you should look at the edge grain. The run offs on the edge grain are what represent growth ring violations. However when the back grain moves from one side of the board to the other this generally means you will have grain runoffs on the edge.
The board you showed will have pretty decent run-offs. It could survive without backing, depending on how "high stress" the design is, but those runoffs are a big liability. Backing a board bow with runoffs (in my experience), with a low stretch fabric such as linen or silk, can greatly improve its safety.
x2, this was well explained, Bub
Id say, keep the bow long (68") and a bit wider than usual, and keep the weight under 50lbs. But given the option I'd back it with linen.
Gabe
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Shiloh, you can steam or use dry heat but I've had more luck steaming in recurves than dry heat, but if you haven't got a lot of experiancejust flip the tips a little, or you can do a glued on reflexed tip, Bub
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Why dont you want a backing?
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I wouldnt recurve and hence make a more stressed design of an already questionable board. You are asking for trouble with it breaking. It very may well survive @35# but still, its not going to be your bow. I know somebody who had to have stitches in his head from a bow that blew up, even after he owned that bow for ten years. If you give that bow away, make sure its got rawhide on it and you shot it a lot!
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If you don't find a straight grained board with possibly 3 or 4 run outs, walk away. If you must use it do back it. I would have never taken it out of the yard. I'm pretty picky about boards. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/index.html
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I wouldnt recurve and hence make a more stressed design of an already questionable board. You are asking for trouble with it breaking. It very may well survive @35# but still, its not going to be your bow. I know somebody who had to have stitches in his head from a bow that blew up, even after he owned that bow for ten years. If you give that bow away, make sure its got rawhide on it and you shot it a lot!
sleek I thought he was talking about a different build, Bub
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Why dont you want a backing?
I was just wanting to try something a little different, but there's always more boards.
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Also, I'm not recurving this one, I'm just thinking of future projects.
@George: I've made succesful bows with more grain run-off than this one, each one backed with either linen or drywall tape. Mine rarely go above 50#, so I've found that for the style of bows I crank out proper tillering and good, tight grain are more important, at least in my case.
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My misunderstanding, I'm sorry...
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No problems. ;D
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Does shellac have tensile strength? Because that is what is required on the back of a bow. Compression or shear strength will be useless on the back of a bow. While shellac might act as a glue, it does not offer tensile strength. According to your theory, a layer of wall paper glue would even function as a bow backing, right? Shellac could be a good finish for a bow, but it does not serve as a functional backing.
Dark Soul. I am not saying shellac is a backing material, but I do think it can increase the tensile strength of fibrous material such as wood. For example, last night I finished a couple dozen arrows with shellac applied with a paper towel. This morning I took the dried out shellac'd paper towel and attempted to rip it. It took significantly more effort to rip this paper towel than one without shellac. I am not saying it is a backing material, but sanding a board bows back and applying a number of coats of shellac is better than say, a back left a bit rough and finished in oil.
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Well, then I respectfully disagree with you :)
A paper towel soaked in oil is easier to tear than a paper towel coated with shellac, right? So that would mean an oil as a finish for a bow would actually weaken the wood?
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Shiloh,
Lay out your bow on this board. Looks like the worst of the run out is on one end. Not a great picture of the other end of the board. If you went with a 68” bow you could 4” off of the worst end and get a bow out of this board.
If were me asking the question on whether to back it or not….. The advice from several experienced bowyers has been to back it. I would follow that good advice.
1” x 2” x 6’ only gives you 1.5 inches. Red oak is recommended to be 2” wide. You have already extra stress with a less than optimal width on this bow.
Keith
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Well, then I respectfully disagree with you :)
A paper towel soaked in oil is easier to tear than a paper towel coated with shellac, right? So that would mean an oil as a finish for a bow would actually weaken the wood?
That is fine. I am not trying to be an advocate for shellac "backing". I just felt that if the bow was not going to be backed, then it is a good idea to sand the back very smooth and that coating the back with a strong bioadhesive polymer, such as shellac, would provide some level of splinter lifting prevention, i.e. backing protection.
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The 1-2#'s of pressure a splinter may generate would rip through 3 coats of shellac as if it wasnt there. I have seen splinters push through sinew wraps and hide glue and that tell me shellac wont do a thing in prevention or holding of splinters.