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Tin Man
05-03-2009, 12:56 AM
My son has been dying for us to try our hand at building a pole spear for him to use around Wood Guy's place this summer, so today we gave it a shot. Not a home run, but useable, and we learned a few things.

The construction is two layers of carbon fiber / blue fiberglass sleeve over a 1/2" PVC pipe. We turned pieces of PVC for each end, which we glued in place with standard PVC cement. This isn't a big game spear, and we figured the PVC cement should handle the flounder or small mangroves. On the business end, we threaded the shaft and screwed it into the PVC end piece. It actually screws in further than the threaded area on the shaft, so that the shaft is the full 5/16" thickness at the entry. Overall length is 5', and the diameter is just over 7/8".

Things that went well:

Hanging it from the ceiling with a weight kept it nice and straight.
The heat shrink left a perfect finish. Zero sanding.
The threaded shaft can be removed, but it's a tight threaded fit. I don't think it will come loose unintentionally.

On the downside, I would have liked it to be stiffer. The composite layer is less than 1/32" thick. We considered ordering a few more sleeves to add thickness, but the 10 year old member of the design team was anxious to see the finished version . . .

Just need to add a flopper and a band and we'll be good to go.

http://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3451.jpghttp://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3450.jpghttp://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3464.jpg


http://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3452.jpg http://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3462.jpg

http://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3461.jpg http://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3457.jpg

kjflyfish
05-03-2009, 03:34 AM
That's cool! Just do the spin trick and flex shouldn't be too much of a problem. You might also find that it's really buoyant - if that's the case, you could always open it back up and fill with epoxy or something like that.

Tin Man
05-03-2009, 08:48 AM
Kolt - Yep, probably going to be a little light. But as this is his first, I suspect we'll spend about as much time looking for it, as shooting it! If it were buoyant enough for the back end to float off the bottom a little, it might even be easier to find.

classtimesailer
05-03-2009, 03:05 PM
Very Neat.
If you guys can share a trade secret...
I'd like to know how that heat shrink step works.
Brush the epoxy on first, then wrap it in shrink stuff, then the heat gun squeezes out the excess epoxy? Then you cut the shrink stuff off and it hasn't stuck to the epoxy?
Jeff

mikey111k
05-03-2009, 04:31 PM
very neat. I like the blue and carbon braid. I recently made a pole spear with an aluminum tube as the core and two layers of carbon sock. In reference to the heat shrink I did the same thing and it worked well. I wet out the carbon socks then slid Teflon heat shrink over it and started shrinking from the top. As it shrunk it forced the excess resin down. Be careful not to over heat the heat shrink or it could split. I left it on the first few times I used it and once it started to rip I pulled it off and it left a great finish. Again great first spear. Hope your son enjoys hunting with something that he made.

Tin Man
05-03-2009, 05:21 PM
I use the clear PVC heat shrink. Like you said, wet everything out completely, and then slide it through the heat shrink tube. The easiest way that I have found is to pull a string through the empty heat shrink tube before you get started. Then, it is easy to tie it to the wetted out fabric and pull the whole thing through.

I start in the middle, and work towards each end. Never had any issues with the PVC splitting. Although it will chase extra epoxy towards the open ends, the whole thing is probably still a little "epoxy heavy" compared to vacuum bagging or other approaches.

After the epoxy sets overnight, you gently cut down the middle of the heat shrink tube, trying to cut only "mostly" through. Then it just peels right off.

fishizzle77
05-04-2009, 06:46 AM
That's awesome! Where do you get the c/f sleeve & how much is it?

Tin Man
05-04-2009, 09:45 AM
I got it from sollercomposites.com. It was about $2.30 a foot, I think. These sleeves are very thin, though. If I do another spear, I will use a couple of the heavier, plain carbon sleeves first, with just the top layer colored.

LunkerBuster
05-04-2009, 10:10 AM
ou oh,,we got a little Tin Boy in the mix too, will the inventions never stop?!?

looks great Jeff, I like the look and it seems like a nice littel reef slayer too

why are you going flopper instead of para tip? just curious

Tin Man
05-04-2009, 10:54 AM
ou oh,,we got a little Tin Boy in the mix too

Be afraid . . .


Actually, the intent of the threaded shaft connection was so that we could change out the business end to play with balance, different tips, etc. A paralyzer would probably be a perfect choice, but I didn't have one handy at the moment.

Here is a mock up view of how we did the shaft connection, although the real thing was a good bit longer. For the real 5/16" shaft, the hole is about 1-1/2" deep, with the threads removed for the first 1/2" or so.

A standard tap has a tapered nose, and therefore does not cut fully formed threads all the way to the bottom of a hole. Because of this, a threaded shaft, screwed in completely, will wedge itself into the area at the end of the hole where the threads are incomplete. Maybe not the best idea with metal to metal contact, but a stainless shaft in a plastic bushing ends up working like one of those lock-nuts with nylon inserts. It can be removed, but it's very tight for the first full turn or so.

Secondly, you can see from the cut away model, that we drilled out the threads near the openning of the hole. This allows the shaft to remain its full diameter at this point, which is where any bending stresses are greatest.

http://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3467.jpg http://i172.photobucket.com/albums/w32/Jeffs_network_pics/Pole%20Spear/IMG_3470.jpg

Aimrite Tko
06-16-2009, 08:16 PM
Im really dying to try and make one

phil herranen
06-16-2009, 08:26 PM
when i made a couple i used s solid 1/2" od fiberglass rod and 3 layers of carbon to get the stiffness right for a 7' spear
phil

Tin Man
06-16-2009, 08:31 PM
We made a second one, using one layer of heavy carbon fiber sleeve and then a cosmetic layer of green fiberglass/carbon fiber. It was notably stiffer than the first spear using only the two layers of fiberblass/carbon fiber. Fine for a kid's first 4'-5' spear, but certainly not stiff enough for a longer one or one intended for bigger fish.