Primitive Archer
Main Discussion Area => HowTo's and Build-a-longs => Topic started by: yazoo on February 17, 2010, 02:38:04 pm
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here are the tools of the trade,, bow form, wedges, c clamps, shims, spacers, oil(http://i16.photobucket.com/albums/b34/m5555/101_1517.jpg)
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the bow form the most inportant tool,,this one is made out of two 2x4s and a 2x6,,cut the reflex part out of the 2x4s,,this one produces about 3in of reflex,,you can cut the reflex out several ways,,take your 2x4 6ft long,, mark the center at 36in take a flexable yard stick,,hold one end at the center with the other end held at the bottom of the tip and trace the arc,,then do the same at the other limb,,or you can measure out from the center and drop 1/4in every 4 to 6in for the reflex,, then saw out on bandsaw or jigsaw,,I use two of these nailed together then nailed to the 2x6,, as I work a lot of very crooked wood and they wont fit on a 11/2 in piece,, so I nail two together for more working room,, shims are used around knots and very stiff spots,,to insure uniform reflex, wedges are used to remove twist,,spacers are used to over bend a very crooked spot, oil to prevend browning and to even out heat,, and the heat gun for our heat source also lots of c clamps, if you have any questions during this how to please ask,
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Thanks for posting this Mike. Lots of folks will pick up some good info. 8)
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I will be posting some more tonite,,the first bow we will do is real simple it has a slight dog leg, the blank is shaped sorta like a bannana,,then we will work our way up to some more complicated twisted and crooked pieces of osage,,
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Thanks for posting this mike. I have a hickory to straighten so this will help alot.
Tell
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this is our first blank to straighten ,it is shaped like a bannana,,a gradual crook from the handle out on both limbs,the blank has been taken to the floor tiller stage, and coated with shellac,,slide the blank against the back of the form to use as a straight edge to deterimine where the crooks are,,as you notice this one is a gradual bend from the handle to tip,,once we deterimine where the limb leaves the form this is where we will add spacer,this will allow us to over correct in the oppsite direction of the bend,,since this one starts at the handle we will put out spacer in the center of handle and bend in the opposite direction,,(http://i16.photobucket.com/albums/b34/m5555/101_1523.jpg)
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any questions,, I will post more tomorrow sun is down and to dark in my shop for photos,,,
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now we have the blank in the form and have our spacer in the center of handle because thats where the bend starts,,if the crook would have started in the center of limb we would have slid the spacer to there,I always set the bow up and start the opposite bending before I start heating,now that everything looks good I will spray with oil and start heating,,I will heat the entire section to be bent till it gets hot the wait 15 min,,this allows the heat to soak in to the center of wood,,depending on how thick the wood ,,then come back and heat it good,,use the back of your fingers, the soft part to see how hot it is,,it needs to be to hot to touch, but not burnt,,very light brown will not hurt and will scape off,,if you dont allow this heat soakin period the wood will feel hot but the center will not be to temp and can cause cracks or very distressed wood,,which will hurt performance,,now we wait to cool about 4hrs if you are not sure overnite,,then check,it will take a couple times or more to get it perfect,,so dont worry if it is not straight the first time,,I always do the final heating when the bow is near finished,,(http://i16.photobucket.com/albums/b34/m5555/101_1526.jpg)
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now I have removed the clamps and we now have a straight piece of osage,,if you notice that you get the bow straight then the next day its crooked again, the wood is not dry enough,, if not it will revert to its natural shape,,,also this is why I dont use kerfed or sawn wood,, when you clamp them in the form and begain applying pressure in the opposite direction of crook puts a lot of pressure on the longitutal grain,,if you have a big violatiion in grain it will crack while you are straightening it,,(http://i16.photobucket.com/albums/b34/m5555/101_1532.jpg)
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that one was and easy one, the next one I will start tomorrow will have a 45degree twist which we will take out first then straighten and reflex..also If you notice we could not do this work with a caul which i see a lot of people use,,nearly impossible to remove the crook and twist form wood,,but all you need to do is add a back to a caul and you have got a great bow form,,
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This will be very helpful to me. Thanks for doing this.
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this is the one that has more problems,, it has a severe twist,,we will correct the twist with the use of wedges,,simple wood 2inlong , 3/16 on the thick end tapered to point,, one limb of this bow has no twist,,clamp it to the form very soild,or when we put the pressure on the other limb it will give,,if the twist in one small area one wedge will be enough, this one has a gradual twist all the way out the limb, so we will use two,,put the thick end of wedge on the low side of the bow limb,,so we can over correct in the opposite direction, now we preheat the entire limb so the heat can soak in,,now we put our clamps on the high side of limb as close to edge and it will stay, this will give us the most overcorrection in the direction we want(http://i16.photobucket.com/albums/b34/m5555/101_1529.jpg)
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here is the photo of with the clamps on, as the gap closed between the limb and wedge you will notice the limb twist in opposite direction,, clamp er down and spray with oil , preheat , and lay the heat to it,,and let set over nite,then without taking clamps off heat again and let set another day,,, I like to double heat a severe twist before I un clamp,,(http://i16.photobucket.com/albums/b34/m5555/101_1530.jpg)
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Great "bend along"!!!
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Thanks for posting these. Keep 'em coming, they are very helpfull.
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Thanks for the How-To Mike but I have to ask what is the point of shellacing the bow when using dry heat???
I understand why ya shellac the wood when using wet heat but don't see the point with dry heat.
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its just for insurance,,better safe than sorry,,,this is my only source of income I dont take no chances,,from the time I split em out till they leave they are coated with shellac ,,I made over 600 osage blanks last year I had 4 crack while heating,,thats pretty good odds,,, by the way dana its time to plant those collards,,I dug some out the snow last week ;D
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Thanks Mike but I won't be planting anything for at least 6 to 8 weeks, ground is froze solid for several feet :'(
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... clamp er down and spray with oil , preheat , and lay the heat to it,,and let set over nite,then without taking clamps off heat again and let set another day,,, I like to double heat a severe twist before I un clamp
QUick question, may seem stupid, but im a bit lost.... ???
When you say you pre-heat the entire limb, is this just slowly going over the limb with your heat gun or are you using a heat box? It seems like it would be a little difficult to have all of the wood for the entire length of the limb hot enough to bend at the same time.
I guess im asking if you would do a really dumbed down sequence of "pre-heating" and "laying the heat to it"
Im probably making this more complicated than it needs to be, but I appreciate the help. Thanks again for doing this, great info here.
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the preheating is with a heat gun,,just go over the parts to be bent put some heat just to give the heat time to soak in to the center of wood to make sure it is heated through,,and by laying the heat to it,, it just means to heat it very well,,I use the back of my fingers to test heat as the underside of fingers and hands are not as soft,,it needs to be very hot to the touch,,but not scorching the wood,,,, sorry if my wording confused you,,instead of a spell check on my computer I need a hillbilly check,,because I live here deep in the tn mountians,, I will add some more this eve,, time to work now,,, thanks mike
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What I do sometimes is to preheat the area to be bent(straightened) wrap it with aluminum foil to hold the heat in and allow it to sink into the wood well. Then remove the foil and continue heating and clamping as needed.
Mike, this is a great build along. Thanks for posting it. 8)
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that is a great idea,,I think that a lot of people who have bows crack while bending recurves are due to the wood not being heat competely through,, when I finish this bow I will do a recurve more tonite,, I am splitting osage today in the rain,, :(
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When I'm bending recurves I place the form in the vise at a steep angle so the stave sticks up when in the form. Set the stave in the form, clamp the support strap, oil the wood and begin heating. I heat all sides slowly until the weight of the stave begins the bend the heated area. Then I know it is heated completely through and it is very plastic so it bends easily.
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Mike, thank you for this "bend along".i have a osage bow that is floor tillered but the string is tracking of quit a bit.
now i have great new mindset to getting it tracking center ;)
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THANKS YAZOO!!!! you don't need to change the way you explain!! I got that loud and clear!!! I just wish there was osage my way!!! you say 600 staves?? man I gota talk to you some time!! thanks for the bend-along keep it comming Jeff w
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I will do a recurve tomorrow,,very bussy today, getting ready for bow class in florida,,
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the twisted limb bow is finished,, it has quite a bit of snakey curves , be sure when you straighten one you dont take all the snake out of it,,just line up the tips and handle,,(http://i16.photobucket.com/albums/b34/m5555/101_1534.jpg)
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(http://i16.photobucket.com/albums/b34/m5555/101_1535.jpg)
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in the photo above we are ready to start recurve,, the bow needs to be near finished tiller or finished,,as the thinner the wood the better it will bend,I also like to work the belly to a ring on the parts to be recurved to help prevent pulling splinters,,spray down with oil and preheat very well,, as you start applying heat pull down on the bow real easy when it reaches the right temp you will feel the wood give,, then we will start clamping do the first clamp then heat more between each clamp
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now we have brought the wood up to temp and tightened the clamps slowly one at a time,, now all we need to do is wait till woods cools , if you are not sure wait overnite,,once it cools do the other limb and your finished
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(http://i16.photobucket.com/albums/b34/m5555/101_1536.jpg)
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Mike, you said that the bow should be near aor at fully tillered before recurving the tips.
wont this effect tiller?or are you only bending the non working section at the tips?
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I am usually only bending the tips,,but It will probablly mess with tiller,, and may need some work after the recurves are put in,, but our main concern at that point is thinning the tips as near as possiable to finished thickness , to prevent cracking while we are bending tips,, the recurves may need to be tweeeked form side to side,,each one comes out alittle different,,once the limbs are recurved the hard part is over,,
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(http://i16.photobucket.com/albums/b34/m5555/101_1538.jpg)
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above is the bow with both tips recurved and ready to turn in to a bow,, any questions anyone has I will try to answer ,,or anything else they would like to see, I will try my best to explain,, I would like to see how everyone else does there straightening,,please feel free to add to this, all of us are capable of learning, mike
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Mike, here are a few of my forms and my straightening techniques.
The first pics is for flipped tips and not necessarily recurves.
(http://i5.photobucket.com/albums/y199/PatBNC/forDon002-2.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forDon010-2.jpg)
The next are straightening out a crooked stave
(http://i5.photobucket.com/albums/y199/PatBNC/forpa053.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forpa054.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forpa060.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forpa069.jpg)
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...and finally for adding reflex and tempering the belly
(http://i5.photobucket.com/albums/y199/PatBNC/forDon006-1.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forDon007.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forDon005.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forDon010-1.jpg)
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I have never tempered the belly of a bow, how deep does the browned wood go in the belly,,I blew up another heat gun today,,next time I may get the insurance , just not tell them I run it 10hrs a day,,
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The scorching only goes just below the surface but the hardening of the wood goes deeper. It is not as effective on osage as it is on whitewoods but you can still notice a difference.
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again, fantastic info here guys...thanks for putting this up
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WOWed!
Another article for the folder.
Nice & thanks.
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thanks great info
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Well, I just applied Osage Bending 101.
I'll see if I graduated in the morning.
Already know it helped. Just not sure yet how much.
Heated with olive oil 1/2 after a preheat, let cool and repeated.
I'm fully expecting to need to repeat it again tomorrow.
A little concerned with too much too fast to be honest.
It went nicely so far though. (I think)