Need some help from those of you with fiberglass experience

Will M

Will M

Active member
Looking to build custom flapper boards for my db13. I want to continue the 100% composite construction the boat currently has so wood is not an option. What would be the ideal cloth and epoxy combination to use to construct them? They won?t be very tall, maybe 12? in height and the longest would be about 24? long so they won?t be very big
 
Good morning, Will~


I have no experience with Coosa Board (or similar products). Living where I do, price and shipping have scared me off.


I'm not sure of your design for your flapper boards, but I have been impressed with the stiffness added to a layup by Coremat:



http://www.uscomposites.com/specialty.html


It is a very light foam that gets sandwiched between 'glass products - all with polyester resin. I have made some spray shields and cockpit hatches by placing the 2mm Coremat between two layers of 1708 - the biaxial with mat. Much stronger than the factory spray shields I see on South Bays. I through-bolt my thatch rails with no problems - as the CoreMat gets saturated during the layup and cannot compress.


All the best,


SJS





 
I simply epoxied two sheets of FRB (fiberglass reinforced board) and cut the boards out. I used full length aluminum piano hinges to spread any loads and provide added edge support. They have held up well.

Next up, I want to make silhouettes out of the doubled sheet. IMHO a single sheet just isn't stiff enough for either application.

Scott
 
Scott~


Interesting idea, but....what's FRB ?


A quick search taught me lots about the Federal Reserve Board - and I see numerous panels at Lowe's and Home Depot.


Got a good link?


SJS

 
D'oh! It's FRP, as in Panel. Link Of course just to confuse me Home Depot calls it White .090 FRP Wall Board. It's smooth on one side and pebbled on the other. The pebbled surface breaks up the flat reflective surfaces, while the flat sides epoxy together nicely.

Scott
 
Thanks, Scott~


I can imagine this material as a time saver. Because it's stiff but flexible, I could see avoiding the need for a jig. I wonder if polyester resin and mat will bond to it - worth an experiment or two.


Although I now feel "irrationally exuberant" - I will not have to appear before the Federal Reserve Board.


All the best,


SJS

 
Photos of the boards. Note my first boards were made from fir marine plywood coated with epoxy. The same design held up well when sitting on a wood deck but the flat aluminum deck held water against them and they rotted away in about 6 years. The FRP in the photos (taken today) is 4.5/5.5 years old sitting on the same aluminum deck and they are holding up great. It was pointed out to me that write-ups on the FRP note for interior use only, I assume that's because they are not gelcoated and are susceptible to UV attack. Nothing that a good primer and coat of paint can't protect from.



View attachment FRP Sideboards down.JPG



View attachment FRP Sideboards up.JPG

And just for giggles this is an earlier picture taken on a RI salt hunt with Fastgrass rolled down both sides. Not fancy but remarkably effective.


View attachment FlipboardBlind.jpeg
Scott
 
That?s guys. Steve I think I?ll try your suggestion. Can the core mat be bent at a 90 degree angle
 
Will~


Yes - once the Core-Mat is saturated is loses all stiffness. The biaxial resists really tight bends - so you may have to cut it or otherwise manage it at a 90-degree.



All the best,


SJS

 
You must log in or register to reply here.
Back
Top