Flybridge noise

[JimmyG]

Ok i'm finally in Cape May after a 84 mile jaunt from Waretown NJ and that being the longest trip yet with the new refit and motors and everything was great except the noise, creaking and cracking coming from the flybridge floor in a NE heave OMG it was annoying! When i bolted in the new helm chair pedestal I backed the floor from underneath with a 2'x2' x 1/4" SMC (fiberglass) plate that Is glued and screwed in. Any thoughts?

[CaptPatrick]

Jimmy,

Did the noise abate when you were standing, not sitting in the helm chair?

[JimmyG]

Yes, its only when sitting and the boat is rocking, I also used 5200 before screwing the pedestal down…..dont know what else to do

[CaptPatrick]

Jimmy,

I know it'll be a royal pain in ass, but I'd suggest that you dig out all of your backing materials and replace them with 2'x2'x3/8" aluminum plate. Epoxy the plate into place. Drill and tap the plate to match up with the pedestal. There's just too much flexibility and lack of strength with the 1/4" fiberglass backer...

[mike ohlstein]

2'x2'x3/8" aluminum plate.

Exactly what I did for my old fighting chair (now just a rocket launcher).

[MikeD@Lightningshack]

Mine was noisy even with the Aluminum plate. A fair amount of bending stress on thin composites causes a serious amount of transverse shear stress between laminates.

It can't hurt to drop several screws in from the top. You have to stop the 2 subrates from walking across each other. Drill through holes and tap the FRP for 1/4" screws. Then drop a fair amount of flat heads from the top to pull the two pieces together. If you don't like the look of the screws, fill and repaint the non skid.

Other option is starting over with thicker aluminum. No matter what you do the chair flanges are not large enough to keep the 2'x2' backing plate from moving. The stress is two high for the epoxy, so fasteners from top in corners may be a necessity.

The original fiberglass laminate is very thin, and even with the FRP completely secured a 1/4" extra may not provide enough strength for the stresses involved.

Stainless fasteners can be noisy. Sometimes I'll lean towards bronze to avoid squeaking in lumber. Unfortunately In this case the problem is not about the fasteners squeaking.

Hope this helps.

Mike