Thread: Modified Bolger June Bug

I'm not sure what you mean with "decent foils", but I don't think you'd be able to notice the difference from hunks of rounded leading edge plywood, to NACA sections on this design. She performs the best she can as designed. Even very well designed multiple NACA sectioned blades will not produce more then a 1/10th of a knot. Her limitations are not appendage related.


Increasing the sail area from 59 to 75 sq. ft. will make a huge difference in the potential of the design. The SA/D will go from a very lively 21.06 (@ 300 pounds) to 26.78 (again @ 300 pounds). This will provide considerably more power, but I'm fairly sure you don't need it on this boat. She'll probably be on her ear so much that you'll sail with a constant reef in the 75 sq. ft. sail. Her limitations are not sail area related.

The hull shape is also better suited to leeboards then dagger or centerboards. Unlike other appendage hull forms, the choice of leeboards forces the designer's hand in hull shape decisions and appendage location. This is much less so in other forms of appendages.

Is there a reason for these changes?

Thanks Paul,

As far as the daggerboard mod, I just like the cleanness of the setup vs. a sliding leeboard. I also like a balanced lug sail and I suppose I could set a smaller one to keep the SA/D down to designed specs. Leeboard setup is easier to build I suppose, it just looks cheesy to my eye :P. I was under the impression that good foils are beneficial to handling and responsiveness, but if it won't give me anything with this boat I can do the quick and dirty I suppose.

Originally Posted by PAR

I'm not sure what you mean with "decent foils", but I don't think you'd be able to notice the difference from hunks of rounded leading edge plywood, to NACA sections on this design. She performs the best she can as designed. Even very well designed multiple NACA sectioned blades will not produce more then a 1/10th of a knot. Her limitations are not appendage related.


Increasing the sail area from 59 to 75 sq. ft. will make a huge difference in the potential of the design. The SA/D will go from a very lively 21.06 (@ 300 pounds) to 26.78 (again @ 300 pounds). This will provide considerably more power, but I'm fairly sure you don't need it on this boat. She'll probably be on her ear so much that you'll sail with a constant reef in the 75 sq. ft. sail. Her limitations are not sail area related.

The hull shape is also better suited to leeboards then dagger or centerboards. Unlike other appendage hull forms, the choice of leeboards forces the designer's hand in hull shape decisions and appendage location. This is much less so in other forms of appendages.

Is there a reason for these changes?

This boat (June Bug) was initially intended as a burdensome yacht tender, that could still row well. This means it's a fat row boat, a skinny sailboat and a load carrying dinghy. Of course it can't do any of these things particularly well, because it's trying to be too much at once. Think of this as an identity crisis.

I too like the centerboard or daggerboard arrangement over a leeboard. You could use them on this design, but other then "cleanliness" you'd gain little if anything in performance. If you where to change the rig, keep the new one 65 sq. ft. or less, which will give you a modest performance boost, but not make the boat unmanageable in all but light air. Another tip would be to build an overly long dagger board slot. This will permit you to move the board around to find the sweet spot and suit different wind conditions.

I'm assuming this is your replacement for the GIS you can't keep at home any more, correct?

Have you thought about car topping the GIS? I think it can be done, with a little helpful engineering to load and unload, she's light enough to wheel to a beach or ramp. Maybe some cantilevered arms with tackle to lower it to the ground from the other side of the car.

Originally Posted by PAR

I'm assuming this is your replacement for the GIS you can't keep at home any more, correct?

Have you thought about car topping the GIS? I think it can be done, with a little helpful engineering to load and unload, she's light enough to wheel to a beach or ramp. Maybe some cantilevered arms with tackle to lower it to the ground from the other side of the car.

I'm with Paul on this one. Just set your truck up to take the GIS and use wheels to get her from the car park to the water.

Richard

This isn't a *replacement* for my GIS, just a boat to get me on the water until such time that I have room for the GIS. Car topping the GIS is problematic for me, my lumber racks on my pickup are too narrow to allow the GIS to ride without extensive modification to the rack, or replacing the rack with something I use just to haul the boat, which is a problem because I need the lumber racks as-is for my work. It's all a colossal PITA just to go sailing after work!

I don't expect the June Bug to be a barn burner, but I do like to tinker and I do like the shorter spars for a balanced lug. I'll draw up a smaller sail and see what it looks like.

G'day Rick

you are going down the exact same path as I did with my Bolger Teal.
In some ways, I've got a better boat for it. In other ways, not.

I made a NACA012 profile dagger-board & rudder. In my opinion, NACA0012 is
not worth the effort. Since you have the plans already, suggest you make a
set of GIS foils & use them. Far easier, & you won't be able to pick the
difference in performance between them & NACA. Also, if Teal is anything to
go by, the as-designed lee-board is too small.

With June Bug's plumb sides, you could probably do an in-board leeboard, but
PAR's suggested overly long dagger-board slot would be easy to do, and give
extra rigidity to the bottom.

Agree with what PAR said about the sail size. I actually went smaller for Teal,
as Sth Oz is generally a very windy place. Using MIK's OzPDR plans as a
guide, I came up with a balanced lug that behaves very nicely indeed,
although it is under-powered in light air.

Finally, why June Bug? At 14ft x 3ft3in she is a short fat canoe, with
penalties in weight and performance. unless you use her as designed - to
manage marina moorings. In my opinion, you'd get an easier handling &
possibly a more useful boat at half the weight and price if you did MIK's
Eureka with the optional sail rig. Add outriggers if found to be a bit tender.
It would still be a lighter & more flexible vessel than JB.

cheers
AJ

Hey Rick, you want light, unusual (anyone who wants a Bolger wants unusual, even if they don't admit it to themselves) and fun ... why not build Mik's Beth (the sailing canoe). It certainly won't be out of place as a stable mate to the GIS when you finish that.

Richard