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Longbow Build along (Page 2) (Part 9-22)

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Rancid Crabtree:
So, enough waiting already. Time to glue this bow up. I promised a local grade school I would give them a few hours on Friday so I took the whole day off and worked on the bow in the afternoon.

I laid out everything I needed since the dry run a few days ago. Then I put both quart containers of the epoxy in a basin of hot water to warm them up a bit.




Next, I cleaned all the wood and glass surfaces and laid them in the order in which I would glue them.



1. is .050 clear glass

2. is .020 kingwood vernier

3. is .090 thick hard maple taper (two pieces glued together to make one long piece)

4 and 5.  is .065 thick hard maple taper (two pieces glued together to make one long piece)

6. is a piece of hard maple .060 parallel from the piece of wood my Dad cut. (two pieces glued together to make one long piece)

7. is .020 kingwood vernier

8. is .050 clear glass

Missing from the picture is the riser.


Fast forward to a completed glue up with the warmed epoxy. Due to the mess and the fact that I was working alone, I did not slip out of my sticky rubber gloves to take pictures along the way. What a slippery mess to work with. I used a combination of spring clamps and rubber inner tube strips to compress all the layers. I had more C-clamps at the center (on the riser) but I took them off once I realized that they stuck up higher than the sides of the box and the cover would not lay flat. So much for a complete dry run. I should have tried the lid of the box also. Oh well. live and learn.



Here is a close up of all the layers and all the extra glue that oozed out. I also learned that I used too much glue. I think I could have built two bows with what came out from between the seams. Once again. Live and learn. The gold colored layer on the top is a strip of aluminum that will help spread out the load from the clamps. I was the old track from a shower door that I cut into two strips for this project.



Here is the oven box doing it's job of keeping the bow at around 160F. I will unplug it before I go to bed and let it slowly cool down over night.

Rancid Crabtree:
It was a day of ups and downs on the bow project. It took a solid hour to free the bow from the form. Removing the spring clamps was easy, The epoxy covered strips of inner tube proved to be a bit tougher. The form cleaned up easy because of all the tape I used to protect it.




The bow was a little tougher. The extra epoxy was everywhere and held bits of the inner tube captive.



To save on a mess in the shop (and because it was a nice day) I took the bow out to the back patio behind my shop. The breeze would blow all that nasty fiberglass dust away.



I learned that I need to place a layer of plastic wrap between the last layer of glass and the aluminum pressure strip. I didn't do that with this bow and needed to sand away the excess epoxy to free it from the bow. This also gave me my first look at the glue lines between the layers of wood.



after sanding both sides I could pry away the aluminum pressure strip.



Then I just had to peel away the tape to see how the Kingwood looked under the clear glass.



And the other limb.



and finally the back of the bow. Everything looked good.



Then I worked on the riser. there was a lot of epoxy to remove.



The risers looks good and so do the skive cuts that joined the strips of maple





I then made a line on each end of the limbs that was 34 niches from the center point of the bow. (68 inches overall length) I used a fine tooth hacksaw to cut the ends off.





Both ends measured the same thickness.



Then I used the washers to string the bow before I cut the string grooves.



Here is is strung but with a bow string that is too long so the brace height is only about 5 inches. I used the string from my longbow. It is the only string I have for that bow. (that is an important point that will be realized a bit later.



To check for limb twist, I wanted to look at more than just saw cuts at the ends of each limb so I took a carbon fiber shaft and taped it in place on each limb. I made sure they were at 90 degrees to the limb.



With the washers in the measured center of the limbs, there looks to be no twist in the limbs.



I marked the centerline of the bow along the entire length and used a strip of wood to mark a straight line for the limb taper toward the string nocks.





Just as I was marking the last line on the other limb, all hell broke loose, Something whacked me in the finger and the bow jumped up off the table. When I figured out what it was, I had to search high and low for both washers. The bow string (my only sting for my bow) had broke. My guess is that I left too sharp an edge on the inside of the groove and it cut through the string. Now I have no string for either bow. Time to scramble and locate a 64 inch string for my bow and a 63 inch string for the new bow.

Rancid Crabtree:
Today was a better day. If there is such a thing as a good time for a string to break, I guess I am lucky. I have a lot of work to do before I need a string again.

I used my belt sander with a 50 grit belt to grind down the limbs to the lines I scribed. My lovely bride got a picture of me at work.





Next, I marked the location of the string grooves in the ends of the limbs.



Using a chainsaw file I made the beginnings of the string grooves. This will help me locate the tip overlays. when they are installed, I can finish the grooves.





For the overlays, I want to use Bloodwood and antler. The Bloodwood will match the accent strip in the riser and the antler is just something I wanted to try. I had a section of antler left over from a knife handle I made. I will use the longest tine as it has no pithy core. It is solid all the way through.



Using the belt sander, I created a flat spot on the antler that will run against the rip fence of my table saw. I am using a carbide tipped finish blade so I get less chipping and a smooth cut.





I made the strips about an 1/8th of an inch thick.



In order to get the best adhesion with the epoxy, I needed to rough up the shiny surface of the clear glass. I used a hacksaw blade as a scraper. I did the same to the bloodwood and the antler.



I used the same epoxy, I used for the rest of the bow build.





I used only one bulb under each tip and some of the left over insulation from the hot box. Not much I can do except make the tillering tree.

Rancid Crabtree:
With the antler and Bloodwood overlays glued in place. I began shaping the tips. I still have the very first fiberglass longbow I ever owned as a kid. It is a 25 pound bow and I wanted to make the tips of the new bow look something like my old bow.





I sanded all the edges flush and continued the string grooves I had already started.



The rest really needs no explanation.



















The groove has to have enough room so the string does not kink at full draw. I used the good end of the broken string and approximated the string angle.







It's a slow process and I only finished one end tonight.

Rancid Crabtree:
I've been a bit busy lately so time spent on the bow project has been short. I did get a replacement string from a very kind young man on a traditional archery site where I have been keeping this same blog. He sent not one but two strings for Josh's bow. I offered to pay him and he would hear nothing of it. Trad folks are really good people.

He even matched the colors of the riser.




Before I could use the new string, I needed to build a tillering tree to check the limbs for even bending. I had a section of treated 2x4 up in the rafters of my garage for a few years so I knew it was good and dry. I drilled a series of 3/4" diameter holes at a 15 degree angle in the edge of the 2x4. The holes are 2 1/2 inches deep. In those holes, I glued short sections of 3/4 inch wooden dowels. I then sanded them to round off any sharp edges.



And marked off the distances along the side.



This is the bow holding end of the tree. I use a piece of leather to protect the riser when I clamp the bow in place.



I attached a plywood base so it would stand by itself.



With the string grooves filed and the tillering tree finished, I strung the bow for the first time. and drew it back. It was a good feeling. I then put it in the tree and drew the bow to a few different lengths to see if the limbs were flexing equally. Here are the pics.







I can see some differences in the flex of the limbs. I will sand away certain areas to make the limbs act the same.

Lessons learned. I could have left out every other wooden peg. I really don't need one at every inch.

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