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Standard Sail Upgrade $7.00
http://www.hobie.com/forums/viewtopic.php?f=32&t=7158		 Page 2 of 2
Author:  Soyjer [ Sat Jul 21, 2007 5:45 am ]
Post subject: 
Kepnutz - or other experimenter - which diameter and material sail foot stiffening rod did you find to be the best as far as upwind and downwind sail shape, etc.?
Author:  kepnutz [ Sat Jul 21, 2007 7:41 am ]
Post subject: 
Hi Ya Jer.. :D
Author:  tracker [ Tue Jul 15, 2008 10:35 pm ]
Post subject: 
Kepnutz (or anyone else experimenting with boombats),
You mentioned in your posts about possibly using a fishing blank. Did you ever try one? I was looking for a rod with variable thickness that might work better than the 5/16 inch fiberglass rod I currently am using, as I think that is just a little stiff for upwind sailing, as the sail doesn't curve at the bottom. Boats with real booms keep the sail straight on the bottom, but I wasn't sure with this sail shape is that is preferred...there isn't much sail to have any inefficiencies (unless the stiff boom helps the air flow in other ways, which would make the rest of my post moot.)

I thought a variable stiff rod might give the sail better shape sailing upwind (putting the tip toward the mast, allowing more curve near the mast), but give the sail stiffness to keep the sail out more when going downwind because the latter half of the rod would be rather stiff.

I'm shooting for the shape shown in the article:

http://www.arvelgentry.com/techs/A%20Re ... Theory.pdf

which shows an "ideal" shape of main and jib sail config as the following:
Image

Sailing with the 5/16" rod (below in 6 mph winds), the rod stayed straight instead of allowing any bend.

Image

I have three examples below for rods:

The first is my existing 5/16 inch rod under pressure ($7)

Image
(Too stiff? There isn't much shape near the tip)


The next example is a 6 foot solid fiberglass fishing rod ($11):

Image
too much bend on the tip?

Next is a whip that I bought at Fleet Farm for eight dollars:

Image
Is this one just right?

Unless someone else had already experimented with this, I think I'm going to unravel the threads from the whip to thin it out and try it in the sail. I'll keep it a little long, and if it's too flexible at the tip I can cut the tip off to stiffen it up a little more.

Unfortunately I probably won't be on the water for another couple weeks at the earliest. :(

-tracker
Author:  kepnutz [ Wed Jul 16, 2008 12:28 am ]
Post subject: 
Hi Tracker..
Author:  tracker [ Thu Jul 17, 2008 12:27 pm ]
Post subject: 
Hi Kepnutz,
Thanks for the info! After removing the fiberglass rod from the whip, the tip diameter measured 1/8" and the handle measured 5/16". The whip is 16" too long, so if I decided to cut it to length by cutting the tip off, the new tip would be 3/16". These diameters are very close to the merger between your thinner batten and your thicker boom, so I think I'll try it out and see if it makes any difference compared to my thicker 5/16" boom.
It's just something else to play with while sailin' around :)

-tracker
Author:  kepnutz [ Thu Jul 17, 2008 3:55 pm ]
Post subject: 
Hey Tracker :D
Author:  tracker [ Thu Jul 17, 2008 6:17 pm ]
Post subject: 
Hey ya Kepnutz!
I think you are right on the jib. :) I'll post your thoughts on the jib post along what I found out from a one of my buddies from work that does a lot of sailing of standard sailboats.
Author:  kepnutz [ Thu Jul 17, 2008 6:56 pm ]
Post subject: 
Hey Tracker
Author:  idavis [ Thu Sep 04, 2008 9:55 am ]
Post subject: 
I am curious about the boombat. Does it curb some of the incessantly loud flapping when you release the sail? I have found that on the lake I sail on, when I let go of the sail, the flapping noise isn't just loud, it carries. I am hoping to try and cut down on the noise, as I trolled last time out and managed to catch two nice sized fish. The trick was as soon as the fish was on the line, I needed to stop sailing, so I just released the line, but the sail flapping was like somone hitting you in the head with a hammer.

Other than the noise when there is no tension on the mainsheet, I do love sailing my kayak.
Author:  tracker [ Thu Sep 04, 2008 7:35 pm ]
Post subject: 
idavis,
It's been my experience that the boombat removes all of the sail flapping when you release the line. The sail will just rotate instead of flap and snap. It would seem like the perfect solution to your fishing ventures...plus you'll like the improvement in sailing in the medium to higher winds. :)
In my testing last week, I didn't see a noticeable difference in performance between the tapered boombat and the 3/8 inch uniform fiberglass rod. I'll probably continue to use the thicker rod.

-tracker
Author:  idavis [ Fri Sep 05, 2008 8:38 am ]
Post subject: 
Thanks. Looks like I will be visiting OSH this weekend before I head out to the lake.
Author:  Revo_1756 [ Fri Oct 03, 2008 1:11 pm ]
Post subject: 
I found my 1/4" dia. fiberglass rod at my local bicycle shop. A bicycle safety flag 1/4" dia. x 6'-0" long for $7.00 and in stock so no shipping. I cut to length 1-1/2" longer than the bottom of the sail using a dremmel tool with cutting wheel. I used the same wheel to taper the end to slip more easily into the slot in the sail hem.
I used a pointed soldering iron to make the slot in the hem. I then took a large wirenut and screwed it onto the other end. I have yet to use my new boom batten but eager to try after hearing all the good results.

The boom batten is a great idea and easy to make. Thanks
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