Are Ten Layers of Fiberglass Strong?

[s/v Jedi]

Ah, we're now getting into why we need frames, bulkheads, stringers etc. Also, strength, what is that? A Kevlar vest is that strong because it stops a bullet (no puncture)? I can easily bend it double, so am I strong? I can't bend a 3/4" plywood panel double but most bullets will fly right through it, so is plywood stronger than Kevlar?

What I wanted to demonstrate is that stiffness is important even if our boats aren't racers (stiffness equals speed). Flexing a fiberglass laminate is the worst you can do to it. West System did tests that showed that a laminate looses 40% of it's strength after exposing it to a thousand hours or so of sailing in average sea conditions. How much hours you sail your boat per year? Is 60% strength left enough? I have been reading thousands of pages about that and can't tell....

cheers,
Nick.

[GordMay]

Originally Posted by s/v Jedi

... strength, what is that? A Kevlar vest is that strong because it stops a bullet (no puncture)? I can easily bend it double, so am I strong? I can't bend a 3/4" plywood panel double but most bullets will fly right through it, so is plywood stronger than Kevlar ....

As NicK suggests, “strength” implies a number different flavours of resistance to stress/strain.

Ie: See these “Wood Strength Definitions” for some examples:

➥ Wood Strength Definitions

[goldbeard]

Thanks all for the replies.
I stopped receiving email notifications after the forth post. I didn't know the crowd was still posting.

Pblais, S/V Jedi, silverp40 and the rest excellent points.

I have experience on 47 foot motor life boats in extreme heavy weather i.e. 20-30 breaking surf. The hull is constructed of marine grade aluminum between 3/16 to 1/2 inch. More important may be the frame spacing. The boats have been abused for over 10 years. The aluminum plating has been made concave inbetween the frames and longitudinals (it reminds me of a sagging bimini with rain collected on top)

I have seen pictures of 47s high and dry on rocks and coming out fine (spade rudders hella stout stocks and reenforcing in the hull, but spade non the less)

I say all this because it would be like stepping out of an armored truck and getting in a old sports car.

The challenger 32 seems to be a fine boat, I sailed it down from the Puget Sound across the Columbia river. I encountered stustained 25knot winds from the South(even though the forcast call it out of the NW, of course) I made less than 3 knots motoring into the 4-6 foot chop. When I put the engine in neutral and made my rounds of the engine compartment I would come back to the wheel and behold, the boat turned itself around and was crusing down swell at between 5 and 6 knots bare poles.

When I was coming across the bar there was a 4 foot 16 second swell, I was able to surf her to 10.1 knots.

Opps, to much sea-story time...back to my old sports car bit...I have no idea how much punishment a challenger 32 can take. I bought it because it had a fin keel/skeg combo and a flat bottom, you know the speed/strength combo. But I really can't say how much she will take.

I have seen the 47mlb take waves, I know what it can do.

I guess what I'm getting at is sea stories. How big of seas/winds have you been in. Have you been pooped, broached, taken sea breaks(god forbid, real breaks).

Tell me about the boat, construction, techniques...etc...

how did the boat come out? Better than this guy I hope...

YouTube - PTUK ~ Yacht capsize plus rescue

[Maddog]

Originally Posted by goldbeard

Thanks all for the replies.
I stopped receiving email notifications after the forth post. I didn't know the crowd was still posting.

Pblais, S/V Jedi, silverp40 and the rest excellent points.

I have experience on 47 foot motor life boats in extreme heavy weather i.e. 20-30 breaking surf. The hull is constructed of marine grade aluminum between 3/16 to 1/2 inch. More important may be the frame spacing. The boats have been abused for over 10 years. The aluminum plating has been made concave inbetween the frames and longitudinals (it reminds me of a sagging bimini with rain collected on top)

I have seen pictures of 47s high and dry on rocks and coming out fine (spade rudders hella stout stocks and reenforcing in the hull, but spade non the less)

I say all this because it would be like stepping out of an armored truck and getting in a old sports car.

The challenger 32 seems to be a fine boat, I sailed it down from the Puget Sound across the Columbia river. I encountered stustained 25knot winds from the South(even though the forcast call it out of the NW, of course) I made less than 3 knots motoring into the 4-6 foot chop. When I put the engine in neutral and made my rounds of the engine compartment I would come back to the wheel and behold, the boat turned itself around and was crusing down swell at between 5 and 6 knots bare poles.

When I was coming across the bar there was a 4 foot 16 second swell, I was able to surf her to 10.1 knots.

Opps, to much sea-story time...back to my old sports car bit...I have no idea how much punishment a challenger 32 can take. I bought it because it had a fin keel/skeg combo and a flat bottom, you know the speed/strength combo. But I really can't say how much she will take.

I have seen the 47mlb take waves, I know what it can do.

I guess what I'm getting at is sea stories. How big of seas/winds have you been in. Have you been pooped, broached, taken sea breaks(god forbid, real breaks).

Tell me about the boat, construction, techniques...etc...

how did the boat come out? Better than this guy I hope...

I have had my Challenger in 25knt winds and 8' seas in the Santa Barbara Channel. It was a wild ride and I never felt unsafe. I was worried more about my abilities at the time than the boat coming apart under my feet. If you have made it down from the PNW to the Columbia River you are in good shape and ahead of the game. Rig your boat properly,(whatever that means) and take care of it, The Challenger will take care of you. PM if you like, I've done a lot of work on mine.