Flaps

[Blaise]

Hi Guys,
I know that the fairings most call flaps is not a new subject. But being the longest (probably) owner of a 37 cutter, I have some insight. The fairings were originally delrin. They did work well and the boat is defininately faster with them on. Untill they get hard and don't move. Then they are a speed brake. They are really scarey when you are in reverse. They open up about a foot wide. If you cruise, you probably don't care, but I race my boat and try to get everything I can. Twenty or so years ago I took the old ones off and used them as patterns and had my sailmaker make new ones out of two layers of heavy dacron sailcloth with a layer of mylar in the middle. They work great and last about ten years. They are cheap and effective. John Cherubini put them on for a reason. He originally drew the boat with a skeg hung rudder like the 30, because it was fashionable but Hunter wanted a balenced spade because it was cheaper. Boy did we luck out. By the way I have helped two friends with 30's cut their skegs off and convert their rudders to balanced spades. What an incredible difference it makes.

 

[rardiH36]

Blaise:

Thanks for the insights and background on the fairing "flaps". I had figured that Cherubini must have had a performance reason for incorporated them as original equipment. But as a recreational sailor, my now permanently flared out flaps I expected were probably causing problems. Not knowing if replacing them with new plastic (of unknown type) would yield a similar flared out result in short order, I was just easier to do away with them.

With your background and being successful with your replacement, I will keep in mind replacing them again with the next haulout. I only filled in the screw holes on removal. I didn't fill in the recess at the end of the skeg that the fairings fit into. So restoring the fairings to original design won't be a problem.

If it doesn't take you too much time, can you provide more detail about the sail frabric mylar sandwich? How thick is the mylar plastic? Why is the dacron even necessary? Is the sail dacron glued to the mylar? Are these fairings relatively stiff that press hard against the rudder, or is it the flow of water that keeps them against the rudder. Are your replacement fairings protected with anti-fouling paint?

Again thanks for your post.

regards,
rardi

 

[Ed Schenck]

Right after I purchased my H37C in 1998 I had to replace those "flaps". After some searching for the right material I settled on two hard rubber stair treads. Those lasted until October 2008 when I removed them forever.

 

[Jim Legere]

Replaced mine

I am definitly not a "performance sailor", as one look at my bagged out old mainsail will tell you (...maybe next year...sigh), but I replaced my flaps last year. I think I paid about $15 at the local plastics shop for an off-cut of white PE (or maybe it was nylon?) of the right thickness. I cut and drilled a pair in about ten minutes using the old ones as templates. After a year in service, they are as good as new - definitely stiff enough that I don't need to worry about them flairing out in reverse. And I have enough plastic for a lifetime supply of flaps. I guess I am somewhere between Ed and Blaise in the Great Flap Debate: probably don't need them but feel good about having them ;-)