W1TEF wrote:
On Mon, 30 Aug 2010 14:26:49 -0500, Jim wrote:

W1TEF wrote:
On Mon, 30 Aug 2010 07:21:18 -0500, Jim wrote:

Best advice you got so far was to weigh the boat to see if the foam is
waterlogged.
I don't know if you remember Jim, but I found out that my Ranger bay
boat is about 870 lbs over published weight putting the whole rig
right on the edge of trailer capacity - 4,980 lbs for a 5,000 lb
trailer.

The foam isn't waterlogged. I called Ranger about it and they didn't
have an explanation either.

I got to thinking about it. A gallon of water weighs 8 lbs. To have
870 lbs of extra water weight, the boat would have to hold 109 gals of
water.

That's a lot of cubic feet of water to have in foam on a 20 foot boat.
I've seen where some weigh their new boat and find it a couple hundred
pounds over. The manufacturers always claim it's because different
workers lay glass differently than others, especially in how much resin.
And that makes sense if you're talking 10% weight or so.

Funny you should mention that. Back when I was in the market for a
32' CC I thought about a custom designed CC from Blue Fin over in
Bristol, RI. We took a trip over there, met the design crew, took the
manufacturing plant tour (which was really interesting) and just
generally got comfortable with them - great folks by the way.

Anyhow, I asked about weight (because of the Ranger) and the design
guy told me the weight spec could be off as much as 10/12% to the plus
side and never on the other side. For exactly that reason - extra
layer of glass, little more mat in strength areas, density of the core
material and how it absorbed the resin under vacuum - he listed a
bunch of things that would cause the extra weight.

So you're right on that score.


Heard that numerous times.
The manufacturers don't talk about it much though.
Here's a Merc/Rude/Yammie 250 test done in 2003.
They used "identical" factory new Stratos 201 Pro XL hulls.
http://www.bwbmag.com/output.cfm?id=943489
with just 3 hulls the weight variance was a bit over 5%.
80 pounds for a 1550 lb hull.
Easy to think it could go higher if they weighed more hulls.
Every glass layup is different.
Boston Whaler supposedly puts overweight boats aside to find what went
wrong. But I don't know what their variance limit is.
Glastron uses a "VEC" process that supposedly eliminates hand-laying
and weight variance to 1%. There's argument whether it's "better."
Most boats are still hand-laid.
A different source of foam could change the weight.
I heard two guys with the same boat but different years talking about
why one's transom was 1 1/2" thick, the other's 2".
Either glass difference or the maker changed the transom board.
The specs should still tell if you're waterlogged - except in the case
of your Ranger of course. Never heard anything like that.
Might make a good movie.

Jim - Mysteries are pretty boring when explained.