Bow Build-a-long , picture heavy | SouthernPaddler.com

Bow Build-a-long , picture heavy

dawallace45

Well-Known Member
I think I mentioned some time back some one on the Archery forum I frequent asked me to do a build-a-long on my next bow , I've posted it there and thought some here may be interested in seeing it


First off the some details

The bow is 68" nock to nock , 70" all up

The Riser is Zebra wood , 16"

One tapered lamination and three parallel laminations
Taper is Coffee Bamboo .103"

Parallel laminations
2x .064 " Coffee bamboo
1x .101 " Tulip wood

Fibreglass laminations
2x .040 " Black

Draw Weight 40# @ 28"

First off I cut and grind my laminations , I use a attachment I made up for my big belt sander
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I then mark out and cut out the Riser on my Band saw then grind to the line on the big belt sander
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My bench is set up with a roll of Brown paper on one end , when I go to do a new bow I roll it out and tape down one end , when the bow is finished I cut off the old paper and roll out a new lot , makes it cleaner for epoxy work
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I double check the laminations and the riser tape up the face side of the fibreglass strips with 8 day masking tape then do a dry run by putting the lot into the bow press and inflating the air hose , if all is well it comes out again and into the hot box to warm up ,
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While that is happening I set out the bench with all the stuff I'll need for the next step , I set out the epoxy , I use smooth on , I make it up to a 110 gm batch , that seems to work out just right for me , I use a 40 mm plastic scraper to spread it , I always put several pair of rubber gloves on the bench handy and make sure the press is set up and the glad wrap , tape and such are handy and a covering of Glad wrap is on the bow form
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Once the laminations are warmed up I put them on the bench , mix the epoxy and start work , when all surfaces are coated it's in to the form with the riser held into place with filament tape , more glad wrap goes on the Lamipanel strips I use between the bow and the air hose , I then put more Filament tape on the very ends , flip the mudguard washers along the form into place and nip them up to hold the laminations in place evenly and then use a plastic film hand dispenser to wrap the form from the ends to hold the lot into place evenly , the air hose then goes on and the top form and it's all bolted up tight and the air hose inflated slowly with a gap of 30 seconds or so every 10 psi , then into the hot box

Next morning out it comes and the plastic wrap comes off and then the epoxy dags are ground off on the big belt sander
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Then the straight edge goes on and the centre is marked , then the bow marked out ,
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Once it's marked out I cut it out on the Triton Bench saw , I used to use the Bandsaw but it's too expensive on blades , with the triton I get 10 bows from the one blade instead of just one
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Then back onto the big belt sander to grind almost up the the marked lines for the limbs and the riser is ground to the correct width , I have made them 1 1/4" but prefer to make bows 1 1/8" wide
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Then into the vise and sanded down to the line by hand
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At this stage I then File the string nocks ,
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string the bow and check for limb twist , check the draw weight , check both limbs are bending equally and check tiller , mark the top limb and mark out the shelf , I make the main cuts for the shelf with a tenon saw then take it to my smaller linisher and rough out the shelf , then back to the vise and the rasp , once the shelf is pretty much rasped out I take the bow back to the big linisher and rough shape the riser , then back to the vise and rasp ,
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after the rasp I start with a block of wood that has one edge slightly rounded and I wrap that with 80 grit fabric backed sand paper , I use that to finish shaping the riser grip and shelf , I like the shelf to be slightly curved on all faces with no corners to create weak spots , I go from 80 grit to , 120 then 180 , 240 and then 400 grit ,
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I then epoxy on some Zebra wood strips for the string nock overlays and into the hot box
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next day I grind the overlays close to profile on the linisher and then start with the rasp ,
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After the tips are roughed out with the rasp I clamp the bow to the bench and start working with strips of fabric backed sandpaper in a shoe shine style to final shape and sand the tips , seems to work out a couple of hours work in each one to get just right
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at this stage I sand the tips , sides of the limbs and riser again with 400 grit and take it out into the sun to check over again for any sanding marks ,
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I then apply sanding sealer with finger and let dry
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when dry I sand with 1000 grit wet and dry and fine steel wool , then another coat of sanding sealer and let dry , more fine sanding and then the tape comes off the limbs and then I sand the glass with 150 wet and dry then 240 and 400 grit , not a lot of sanding , just cleaning it off basically , I sand the corners to give a nice rounded edge and then use a paint pen to mark the draw weight
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At this stage I would normally clear coat but it's raining and has been for the last few days and may be for the next few day so since I haven't of yet made my self a spray booth I'll have to wait , I now use a Acrylic clear coat that gives a bit more gloss and a harder finish than the old clear enamel I used to use

David
 

dawallace45

Well-Known Member
Jack

Tiller is the difference between the upper limb and lower limbs measurements from the bowstring to the belly at the fadeouts. Bows are generally tillered to produce a stiffer lower limb , the bowstring to belly measurement on the lower limb is less than the same measurement on the upper limb.
Tillering is the adjustment of tiller by removing material from a bow limb or limbs. Most bows are tillered to approximately 1/8" - 1/4" positive measurement on the upper limb, when the bow is to be shot split fingered. I mostly tiller my bows even for a 3-under shooter. mostly with a bow tillered for three fingers under you have a low nocking point , mostly 1/8" to a 1/4" but rule of thumb is to check out he bow with the arrow you are shooting and move the nocking point up and down to see what works best for that particular bow , arrow , hold combination

From what I can see most bows are considered to have propper tiller with in limits if with in 1/4 " positive to 1/4" negative

Of course to tiller also comes into the even curve of a bow limb

David
 

dawallace45

Well-Known Member
Well really they are pretty close to it ,

As I said if a bow is with in 1/4 " positive to 1/4" negative tiller it's considered fine , or at least it is for commercial factory made bows , my bows are 1/8" positive to Zero tiller because I shoot three fingers under

David
 

Wannabe

Well-Known Member
Apr 5, 2007
2,645
2
on the bank of Trinity Bay
David,
If a bow had the shelf on the right and was shot with a thumb ring, would the upper and lower limb lengths be the same? The thumb ring would contact only a single point on the string instead of being spread over several fingers. Am I understanding this properly?
Bob
 

dawallace45

Well-Known Member
Bob

Sorry to take so long to get back to you been busy

Now what I know about thumb rings can be written on the head of a in with a three inch brush so I really can't be of help , there is a few guys on the archery forum who are interested in that sort of stuff and make the Saracen and Hungarian style recurved bows , what I do know is because the thumb release twists the bow string in the opposite direction to the three finger release, Asian archers place their arrows on the opposite side of the bow handle. A right handed Asian archer will put his arrow on the right side of the bow. well at least that is the story I've heard

Yes a thumb ring only contacts a single point , well a single point slightly wider than your thumb , as for upper and lower limb being the same I really don't know , I've only seen two Hungarian style bows , one had a upper limb that was about a inch or so longer than the bottom and the other bow seemed to be even in each limb , I don't know if this was normal or not , I really didn't get to speak to the guy with the first bow long enough to find out , and didn't get to speak to the guy with the second bow at all , I do know that due to a dislocated thumb when I was 11 that never went back into place properly a thumb ring is right out for me so I really haven't looked into them at all

One interesting thing I did notice was that the guy with the thumb ring also put a loop of cord on his bow string and engaged the thumb ring through that instead of the string it's self , the idea was to eliminate the twisting of the string , this guy built the bow him self and put the shelf on the left as for a normal right handed shooter , he reckoned that while he liked the style of the Hungarian bow he'd been shooting long bows for too many years to be able to change from his canted style of holding his bow

David