On Mon, 30 Aug 2010 20:53:41 -0400, W1TEF
wrote:

On Mon, 30 Aug 2010 18:12:19 -0500, Jim wrote:

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%.

I wonder how much environmental issues like humidity and air temp
during the layup/resin process add to this?

Be interesting to look into.

That might be a factor also but I've heard that the biggest variable
is the amount of resin used. Resin is heavy, almost 90 lbs to the
cubic foot, 50% heavier than water. It adds very little strength to
the hull since its primary function is to bind the layers of the
laminate together. Anything more than that is wasted but the
tendency is to use more than necessary because too little can lead to
delamination down the road. As a result quality control is very
important as well as techniques like vacuum bagging which squeeze out
excess resin before it cures.

On Aug 30, 9:52*pm, Wayne.B wrote:
On Mon, 30 Aug 2010 20:53:41 -0400, W1TEF
wrote:

On Mon, 30 Aug 2010 18:12:19 -0500, Jim wrote:

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%.

I wonder how much environmental issues like humidity and air temp
during the layup/resin process add to this?

Be interesting to look into.

That might be a factor also but I've heard that the biggest variable
is the amount of resin used. *Resin is heavy, almost 90 lbs to the
cubic foot, 50% heavier than water. * It adds very little strength to
the hull since its primary function is to bind the layers of the
laminate together. * Anything more than that is wasted but the
tendency is to use more than necessary because too little can lead to
delamination down the road. * As a result quality control is very
important as well as techniques like vacuum bagging which squeeze out
excess resin before it cures.

Ya, I've seen those broken boats that used less resin....reaaaaaaaal
strong.