Monday, December 2, 2013

Interesting New Project

I recently received an email from a fellow named Allan.
Allan had a Korean bow and was looking for bamboo arrows for it. A Korean arrow maker had quoted him $35 each for arrows but I figured I could do a little better than that.
After quite a number of emails back and forth we settled on what Allan wanted and I got started on his arrows.
I'm using the bamboo shafts I got from China. I have very few of these shafts left and I doubt I'll be re-ordering them. The Chinese manufacturer kept wanting me to order 1,000 shafts or more and become his American distributor. Well, that's not going to happen and when he realized that my orders would be for a couple hundred shafts rather than a couple thousand he lost interest in me and became somewhat difficult to work with. There are other bamboo shafts available from Asia and when I get some free cash I may check into them. But for now I won't be dealing in bamboo shafts when the few I have left are gone.

Luckily I do have shafts available for Allan's project.
The traditional Korean bamboo arrow has a wood nock glued into the end of the shaft. I'd gotten some nock blanks from 3Rivers and this was the perfect time to use them.


I'm actually quite unimpressed with these nock blanks. The quality control on them is horrendous with the tenons varying in size from one nock to another and few of them cut square on the ends. Some of the tenons were off center to the nock body and I had to put those aside for the fireplace. The next time I do a project like this I'll find a way to make these myself.
Before I glued the nocks to the shafts I cut in the preliminary string slot. I'll refine this later once I have the nock and shaft together but it's easier to do this first cut with them seperate.

 

Many people advocate taping two or three hacksaw blades together to do the string slot on self nocks. I don't really care for that method so long ago I followed my friend Sal's advice and got one of these tile saws. The blade is round and cuts going forward and backward. The cut width is almost perfect and needs very little enlarging to fit the bowstring properly.


The end of the shaft needs to be drilled to accept the nock blank tenon. I chose a drill bit size that would fit most of the blank tenons but was still small enough to use on the bamboo shaft. Some tenons were pretty loose and some needed to be sanded smaller to fit in the hole. Did I mention the poor quality control on these nock blanks?
When you drill bamboo like this it's important to wrap the end of the shaft with masking tape to help keep it from splitting during the drilling. Equally important is to not force the drill bit. Let it find its own speed down into the end of the shaft. If you're one of those guys who pushes a drill as hard as possible while you're drilling, you're going to have some big problems on this step.

 

 
After the hole is drilled and the drilldust tapped out, it's an easy step to glue the tenons down into the hole. I used the same epoxy I use for tips on this step. I know it's a good glue, it's easy to work with, and I have it in big bottles. I rest the shafts with the nock blank down while the glue sets so any glue settling inside the shafts will be up on the nock tenon rather than down in the shaft where it won't be doing anything constructive.


 
 
After the glue is dry I used the Woodchuck tool to give a rough shape to the nocks. I'll refine the shape with small files and sandpaper. At this time I'll also refine the string slot with the small files. If you're careful here and take your time you can get just about any nock/string fit you want. Korean arrows are typically somewhat loose on the string so that's what I'll go for.

 
Sanding will let me fare the nock down into the shaft so there is a pleasing transition from shaft to nock. This area will be wrapped with thread but the profile will still be obvious so there won't be any hiding of shoddy workmanship here.

The large nocks won't let me use my regular gasket lacquer as a finish so I'm using spar varnish in a spray can. The spar varnish is actually a better coating than the gasket lacquer so Allan won't be getting shorted on the arrow finish. The reason I don't normally use spar varnish on arrows is that it just doesn't lend itself to production work.


I got three coats of finish on the shafts before I ran out of it. I had to wait a day before I could get to town and get another can. The instructions say to recoat within 1 1/2 hours. If they can't be recoated within that time then I need to wait 72 hours before adding more finish. I'll work on getting the fletching ready in the meantime.

 
Korean arrows typically use a very low fletch height. The cut isn't something I can buy pre-made and it doesn't fit into any of the choppers I have. It's time to break out the feather burner.
The feather burner has a wire that gets red hot when the machine is turned on. Rotating the fletched arrow on the tool puts the feathers against this red hot wire and they are burned to the wire's shape.
I got the wire shaped as I wanted and gave the burner a try on a sample bamboo shaft that I've been using to try different techniques and procedures with this project.
Good thing I tested first because there was an issue.
While the bamboo shaft spins well and pretty straight on my spin jig there can be little bumps and whoops along the length of the shaft. If these bumps and whoops are in the area of the fletching they can cause the feathers to go in and out as the feathers rotate into the cutting wire. On the sample arrow I had one perfect cut, one that wasn't that great, and one that was horrible.
Obviously, this wasn't going to work.
Then I had a brilliant idea: I'd tack glue the feathers to a straight wood shaft, burn them to shape, pull them off the wood shaft, clean the base of the feather, and then glue them on the bamboo shafts. Perfect!
But then I had an even better idea: I'll use an aluminum shaft for this preliminary gluing and shaping. Aluminum will release the Duco glue even easier.
Then I had to find a straight aluminum shaft. See, I don't use aluminum arrows. The only shafts I have of that material are some I've picked up in the field to repurpose for arrow finders. Out of the three metal shafts I have in my scrap bucket only one was found to be suitable for this task. But that one shaft is doing a great job.


 
After some initial fiddling to get the wire right (it expands when it's heated so that needs to be taken into account) I've finally got this step going in the right direction.
Four little dabs of glue are just right to hold the feather on the shaft while it's burned and the feather is easily stripped off afterwards.


I think I'll put the point tapers on these arrows next. I frequently glue on the points as the last step in making the arrows but this seems like a good time to do the tapers.
Bamboo shafts have a hollow center but it's easier to work with the point taper if the bamboo is solid.
So we'll make it solid.
I drilled out the end of the shafts for an inch or so and glued in bamboo bbq skewers. These come in different diameters so choose a drill bit suitable for the skewers you use. You can also use hardwood dowels from the hardware store. I just use regular wood glue for this step. Be sure to wrap the end of the shafts with masking tape before drilling them. There is a little bit of variation in the diameter of the bbq skewers so while they all went into the hole far enough, some went in further than others. I'll trim the ends before tapering for the field point.

 
Here's how the tip taper looks if you don't fill in the bamboo with a skewer or dowel.
 

While this is a bit of an extreme example you can easily see why the shaft will be easier to work with when the center of the bamboo is filled.

Once the glue is set the ends of the shafts are tapered for the field points on the Woodchuck taper tool. With bamboo you need to use a sanding-type taper tool. The pencil sharpener style of taper tool won't work on bamboo.


Because there is variation in the diameters of bamboo shafts the field points won't all fit on the shafts the same. Some will be fine and some will seem a little large for the shaft. We just need to accept that and put them on the best we can. I find epoxy easier to work with than hot melt glue since it's easy to adjust the tip to ensure it's on straight. You can use hot melt if you want to. Whatever glue you use for the tips be sure to clean the inside of the tips of any oil or grease from the manufacturing process. No matter what glue you use, if the tip is oily the glue will not stick and you'll lose tips in the targets.

These arrows will be shot off the hand. The bow doesn't have a shelf to rest the arrow upon so the archer's hand takes that place.
Consequently, it's a good idea to treat the front of the feathers in a special manner so they don't cut the archer's hand as they rush off the bow. For applications like this I like to wrap the front end of the feathers with some thread. Luckily, this fits with the asthetic of the Korean arrows, too. While I'm at it I'll also wrap some thread back on the nock and catch the back end of the feather. While I don't think it will be needed on these arrows wrapping thread on the wood nock will strengthen it and help keep it from splitting from the pressure of the bowstring.

 
Here's what the thread looks like with a bit of finish and some gold trim.
 
 
 
 
Remember how I said the tips will fit on each shaft a little different? Here's a good example of one just a little large for the shaft diameter.
 
 
With the thread wrapped, finished, and trimmed, and the tips glued on, these arrows are all done!
 
 
This has really been an interesting project. I've learned a lot and had a great time making them. If I do another set like this I'll do a couple things differently, but not much. I'm quite happy with how these have turned out. I hope Allan is just as pleased with them.
 
Thanks for reading this long post.
As always...
Happy archery!