Determining adequate wood thickness

    Im sure many of you are familiar with the thread on the bluewater gun I am building. I am currently planning the shape of my blank and I am running into some Unknowns. I would like to incorporate a taper into my gun. But I am pretty much at a loss for determining the limitations of a laminated teak speargun blank and how much I could get away with tapering.


    The first gun I built was simple fat and short. So it was easy to build it robust enough. Now I am planning a 63" 4 band gun, with a blank thats starting out 66"L x 2.25"W x 1.5"H


    I know at that height a vertical taper isn't possible. I am wondering if I can taper it 1" along its width and go to 1.25 x 1.5 at the muzzle. But im guessing that with 4 bands Its going to need to stay close to the size its at now and any taper will give me a bow. But this is just a safe assumption.


    Can anyone give me some advice on determining the strength of the vertically laminated teak blank?


    Edit: Also this thread title was not meant to be funny :laughing:

    Edited 2 times, last by Reefchief ().

    Quote from tufual

    why not follow the minimum thickness of an adequate Riffe standard model like the #5 Baja Plus


    Wishihadgills helped me out. He used the riffe euro to guess that even at its full dimensions im pushing the limits for 4 bands. The riffe euro is 1.6" W x 1.0" H and uses 2 bands. As he said, im not nearly doubling the wood, but im doubling the bands. So I may need to go thicker.

    i see , maybe you can leave it uncut and test it with the four bands until you are satisfied with the taper , although that does mean loading the gun out of the water [ be careful ] but i think its best to go slow and taper then test and so on because each blank is 170 a pop if i remember correctly . Good luck with your build by the way . looking forward to seeing the end results .

    Be safe ... Happy hunting .

    your'e probably right , four bands is a lot of force and teak is not the strongest of woods . better to be safe , but isn't three bands enough, then again more bands is almost always better .

    Be safe ... Happy hunting .

    I don't think you'll have to add wood. I took off a decent amount of wood while shaping my build and still needed to add a significant amount of lead just to get it to ballast the way I wanted. Looking at the dimensions on paper may make it seem a bit small, but you've got a pretty big blank there.

    Quote from Reefchief

    At this point i think the taper is out. It more a question of maybe adding wood.


    Sorry I'm late to the party, yes I agree with 4 stout bands the taper is out. If it were my gun I would use 3 hot
    5/8's with the 5/16. Or start adding some fared in wood at the middle to add stiffness


    Cheers, Don

    "Great mother ocean brought forth all life, it is my eternal home'' Don Berry from Blue Water Hunters.


    Spearfishing Store the freediving and spearfishing equipment specialists.

    I remember reading somewhere a while ago that you should aim for 3-4 pounds blank per band (unrigged), that weight was to help manage recoil - can't verify whether that is correct but hope it helps.


    Jono

    Quote from Reefchief

    Seeing the riffe bluewater mid-handle gives me some more confidence in my dimensions.


    Riffe Blue Water speargun


    I wish I knew the dimensions of it. But it looks similar in height but much less thick. And its 67" and shoots 4 bands.


    I added 7lbs of mass (side stocks) to my bluewater to get it dialed in. It does have the thickness to handle 4 bands as is without flexing but your band shaft configuration will be limited. Good luck on your build.

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