Diversion: PVC bows

Well, it's not woodworking, but it still pertains to bows and how they bend...

I decided to undertake making some PVC bows with an eye toward supplying those who don't have access to archery bows with something cheap and relatively quick to make. I got the idea this summer after visiting Raptor Archery. My kids were handed one of the bows -- which of course have flashy paint jobs and come in cool shapes (more than half of the appeal, if you ask me) -- and I was told that the store had a book about it. It was inexpensive, so I picked it up. (For those interested, it is Simple PVC Pipe Bows, by Nicholas Tomihama.)

For those who don't know, the basic premise is to take PVC pipe and heat it with a heat gun (or other heat source), then to flatten parts by clamping in a simple caul. The flattened sections are weaker, so allow more bend, while round sections are stronger and allow less bend. In essence, it is very easy tillering, since the material is homogeneous.

It seemed like a good way to try them out was to make them for the kids. The youngest (age 5) is pulling #9 @ 16" on our Martin all-fiberglass 50" bows. The oldest (age 9) is drawing about #16 @ 22". Hopefully I could make something that has just a slightly stronger pull at the same draw weights, partly as a way of allowing them to grow as archers and partly as a way of increasing their performance and minimizing arrow "bounce-outs."

My first try with 1/2" PVC had the usual learning-curve problems -- I heated the PVC too much/too fast, cooled it down too quickly so that it split the tube while clamping, etc. The second go was more successful, yielding a stylized "horse bow" of about 46" ntn length, #32 @ 26 on the tillering tree (though I did bring it to a full draw of 28" while shooting). This was made using 3/4" PVC, and I must admit it looks pretty cool. Sadly, it took about 3-4 hours of time (more time than I had wanted to spend on it), though that is fast compared to working with wood and probably not too bad for learning the process.

"Horsebow" at brace...

...and at 22" on the tillering tree.

At 28" draw.

A third try was made using 1/2" PVC salvaged from the first go (I cut out the bad sections.) The overall length was of only 40", yielding 39" ntn length, in "longbow style" (i.e. no recurves) and with narrowed tips (made by cutting out a section, heating to move the tips together, and then gluing the split tip back together). Of interest: Each section taken out of the tips removed about 175 grains of weight -- a significant weight savings, though it was offset by the noxious nature of the glue. This little bow ended up coming in exactly at #9 @ 16" and #16 @ 22", pretty much identical to the Martin fiberglass bows, with the downside that the PVC ended up both slower and lacking in the stability that a longer limb-length gives.

Short "lonbow" at brace.

At 20" on the tillering tree.

How did the kids take to them? All were wowed by the shape of the horse bow but complained that it was way too strong. They all liked the smaller bow, as it seemed comparatively easy for them. Interestingly, they all thought it was easier to pull than the Martin fiberglass bow, even though it is exactly the same draw weight and despite the shorter limbs creating more finger pinch. I'll have to assume that it was either a) the novelty of it creating a more favorable review or b) the comparative ease of drawing it after trying the heavier bow [or c) a combination of the above].

How do I feel about PVC as bow material? Well, it was an interesting project, and I see both the positives and negatives:

Pros:

• it requires little time commitment
• material is minimal, cheap, and accessible
• little expertise is needed
• being able to get bows into the hands of non- or would-be archers
• being able to fancifully decorate a bow (and not feel guilty about covering up beautiful wood)

Cons:

• the end product might not be durable and is not something I would want to pass on
• short limb length means less stability
• dense, sluggish material gives poor cast
• material is inorganic and creates a plastic "saw dust" that clings to everything
• possible negative environmental impact?
• skills are not very transferable to real bows

By this last point, I mean that this is a one-way street. Based on my knowledge of bow building so far, I would say that everything I have learned about the way real bows bend and work can be applied to the PVC to make a decent bow, but there isn't a single thing I learned from the process of working with the PVC that would assist me in making a real bow. So if you are thinking of trying to make your own PVC bow, just know that this is the case. PVC bows might make you an archer faster, but they won't make you a bowyer any sooner. 

Quick and inexpensive they may be, but it was a sad task working with a lifeless object with the personality of putty. There is something sacred about working with wood, knowing that nature has provided one with a bit of itself; and that this bit is a good bit compared to all the other wood that had to be rejected. Working with wood and thinking about it in this way forces one to slow down and treat the material with reverence. PVC, not so much. (Ok, so I reused the failed bow from the first trial, but only because I can't stand the idea of waste. Even my offcuts make their way into projects when I can.) Yes we can work fast, but as Dean Torges put it best, "Let's not punch time clocks in our sport as though it were indifferent to our best efforts, at least not until we also value loving and praying as fast as we can."