Weight of CS25 v full fiberglass factory boat

FastEd05 · Post by **FastEd05** » Sun Dec 24, 2023 9:12 pm

Hello, i was wondering about the weight difference between ply glass sandwich and a production chop glass spray/lay up boat, being a CS 25 verses production glass. I think the CS 25 comes in at 900 kg hull less parts , motor etc. My hull i made seems to go very well with a 175 2 stroke, i haven't clocked it yet, but how fast would it go with the max of 250 HP on rear.

cape man · Post by **cape man** » Mon Dec 25, 2023 6:04 pm

Really fast! 50?

TomW1 · Post by **TomW1** » Tue Dec 26, 2023 7:18 pm

I totally agree with Cape Man lower to mid 50's. The finished hull as it leaves the dock will weigh less than a fiberglass hull. You have a very nice boat there sir.

Tom

OneWayTraffic · Post by **OneWayTraffic** » Tue Dec 26, 2023 11:36 pm

It's not that hard to estimate the weight difference between the two materials. Polyester glass has a relative density of about 1.5 though it varies on the quality of build. The typical materials used for these boats are about a relative density of 3/4- 1, depending on the amount of glass and type and thickness of plywood. So about 1/2-2/3 the weight at similar design and structure.

FastEd05 · Post by **FastEd05** » Tue Jan 02, 2024 12:04 am

Thanks for the replies, i was guessing with 175hp i was doing near 30 or a bit more, compared to my 17 ft tinny with a 60 command thrust which does 30 flat out.
I will keep saving for a near new 250 for her. Keep on dreaming i do. Cheers Ed

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