Would like to be proven wrong so please post up the results if anyone gives it a go.
Hey Dwardo,
I wrote to the bloke in those Vids, his name's Nick and he lives in Hawaii. Anyway I contacted him earliar today and here's my email and his reply. Pretty cool bloke replying straight away and so candid about it too. Read on:
Hi Nick,
I belong to a Bushcraft forum and a member today posted a message asking about home made bows, so naturally I remembered seeing your channel on Youtube and posted a link to one of the simpler bows you'd made as an example of what he could make.
Then I had a look through all your vids and saw the small take down bow that you did on Aprils fools day and LOVED it! So I posted a seperate thread praising this.
See here:
http://www.bushcraftuk.com/forum/showthread.php?t=92818
Then someone posted about the speed of the arrows dropping off through your chrony which made me wonder about the longevity of the bows. So here's my question: How long would you expect the life of a bow out of a PVC pipe to be? I know this is very much in the vein of how long is a piece of string? But that take down long bow of yours, for example, how long have you had that and how often have you shot wth it, does it seem to have suffered over time and usage?
I'd be interested to know, If you're able to reply I will copy and paste your answer over at that forum.
Thanks for your time..
Aaron
He replied at 8.20pm French time today with:
Hi Aaron,
When I shot that video I was honestly expecting the bow to blow up (that video was the first time I had ever done or even seen a takedown bow with a connection point on a working limb), so each time I did draw a little less and less. But normally the speed does drop a little shot to shot. I notice that as I'm shooting a bow it will get a little slower each time I shoot it. If I put it down for about five minutes it picks up speed again and then drops slowly. If I unstring the bow for half an hour or so it usually returns to its orginal speed. I'm not sure exactly what is going on, but I think it has something to do with the heat from my hand softening the plastic just slightly. I've noticed that even a couple degree change in temperature can change a bow's speed by as much as 5 fps. Like a selfbow with an elastic wood, the bow will take a lot of set after shooting and it will slowly spring back to its original unbraced profile.
I try to get 100 arrows through that bow every day, part of about five bows I've been tracking to see how long they do last (My house looks like a cross between an archery museum and a plumber's nightmare). It's weight and speed has dropped a couple pounds since the video but seems pretty much fixed at about 33 pounds and 140 FPS with a 10 gr/lb arrow. I made the mistake of painting it black, so if I'm shooting in the sun the speed drops pretty quick. If I take it inside the speed goes back up. I think temperature is key with PVC considering it is a thermoplastic.
My takedown long bow is about a year old now and was doing fine till about a week ago. It had about five thousand or more (I lose count after about 3 or 4) arrows through it before I accidentally cut into the front of the handle when putting a new arrow rest on it. When I strung it up and drew it back, the cut started a crack that snapped it just under the handle. I have the top limb on my wall now, I might re-make a bottom limb to go with it and give it new life. I personally think it would have lasted a few years or more of being shot every day if I hadn't tinkered with it.
You can check out this video by somebody who's been messing with PVC bows in Texas.
http://youtu.be/l0wtbJzQ7nI He chronographs a 45 pound PVC bow doing about 195 FPS with a 9.5 gr/lb arrow. It's awesome to see others are getting similar results in other parts of the country.
Thanks for the compliments! I'll keep the videos coming. If you have any suggestions for future videos, I'd love to hear them!
-Nick