# hull thickness



## marv (Jan 22, 2004)

can anyone tell me the average thickness of a kayak hull?


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## farp (Nov 4, 2003)

About 379 micrometers in the bow and it tapers to 263 micrometers in the stern to provide for better schematic or asterior control. Never buy a boat with a hull thickness of more than 660 micrometers because it throws off the mid-center tenier balance and the boat will not be stable.


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## marv (Jan 22, 2004)

micrometers? What the hell are you talking about? Do you mean thousandths of an inch. How do they get that taper effect from a roto mold? Can anyone give me a answer in inches?


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## mescalimick (Oct 15, 2003)

Yah, a few years ago I had a boat with 720 micrometers in the hull and it was a real problem. I got it really cheap, now I know why. Damn mid-center tenier balance ratio, I won't get burned again on that.


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## erdvm1 (Oct 17, 2003)

I didn't want to tell anyone this but since we're all purging ourselves............I got burned too. Hull thickness is a lot more important than I thought. Thanks to Mountainbuzz and it's members I know better for next time. Thanks guys.


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## earthNRG (Oct 24, 2003)

Uh, farp, you may want to check your units. 379 micrometers equates to 0.379 millimeter, or 0.015 inch. A typical piece of 24 weight office paper is about 0.005 inch thick. So, your kayak hull is only about three sheets of paper thick! :shock: Your numbers sound somewhat reasonable if you meant to say thousandths of an inch. 

I did find one manufacturer who specs their aluminum canoes with a hull thickness ranging from 0.030 to 0.050 inch. Of course, marv, if you are wondering about a whitewater kayak, the numbers should be quite a bit larger. Farp's numbers (0.397 to 0.600 inch) sound somewhat reasonable (probably a bit thick), so long as you read micrometers as thousandths of an inch! As a visual guess, my Blitz Special is about 3/16, or 0.1875, inch thick at a far aft point on the stern deck. I found that out by installing an aftermarket drain hole and plug (had to drill a hole). I would expect the hull to be thicker, but probably not by too much. Hmm...upon further thought, I think farv was just trying to be funny and made up some numbers. Realistically, I think his low end number (about 3/8 inch) is more likely a maximum hull thickness. Much more than that and you would never see the hull flex like it does. It's likely that we'd need some means of transport other than our shoulders for our boats, too (more material -> heavier boat).

Marv, I think you ought to take my thoughts here with a grain of salt. I have never actully designed or built a kayak. Heck, I haven't even broken out the calipers to make an acurate measuement of hull thickness. I'm just a lowly Physics and Engineering junior with an eye for practicallity and a tendancy to over design. :roll:


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## farp (Nov 4, 2003)

Check out Mr. Wizard. Do you have pocket protectors for your PFD? All those big brains have got to make you a little top heavy in your boat. Might want to check out a 1,295 micrometer thick hull to balance out all that extra weight and eliminate some flux on the center beam chafe resister.


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## earthNRG (Oct 24, 2003)

Yea, I figured that's why I spend so much time with my head underwater when in the river, but have learned to cope with it. It seems coping skills in general are really lacking in our society. Anyway, I have tried to "check out," but mis-calculated; it just wasn't my turn or time yet. I'll see what I can do about that flux issue, since flux through a support structure such as the center beam chafe resister is a major problem. Maybe we all should replace our chafe resisters with new, impervious versions.

Mr. Wizard :roll:


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## stiff (May 23, 2004)

In case it's not obvious, 
farp and others are just having fun with a load of bull.


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