New Boats For 2009 ....

[crfabbro2F]

I believe that the general scarf ratio is 8:1.

[reed28n]

yes....you are correct

I believe that the general scarf ratio is 8:1.

I thought of it when I woke up in the middle of the night!

[Bill Huson]

you are correct . . .

I believe that the general scarf ratio is 8:1.

8:1 is the preferred scarf ratio. The scarfer attachment sold by WEST is 8:1, but it involves drilling a few holes in the skill saw base. Had one all set up on a Craftsman saw and it worked well. Need a nice rigid straightedge clamped to the plywood to run the saw against, and a carbide blade.

[wagner-racing16-s]

Why don't you just do a lap joint with a router?

[mdaspit]

Lap joint

Wow, a lap joint? How much would each side lap? And would each lap be half the thickness of a 6mm sheet? 3mm?

[Bill Huson]

lap joint might work . . .

Why don't you just do a lap joint with a router?

but lap joints do not score high on strength, and the router cut would have to be very precise for the outside faces to match without sanding.

#1 - scarf joint. No appreciable weight gain, strong, and least "stiff" effect when bending the joined part.

#2 - butt joint with backer. Strong, adds weight and creates a stiff area which does not like to assume a graceful curve.

#3 - simple butt joint. Okay if the joint is over a frame member and joined to frame, but rarely used. If the simple butt joint is done in situ and the panels are curved (i.e. boat foredeck) the usual result is an obvious "break" in the smooth curve.

#4 - your lap joint suggestion. Should work, but I wouldn't use this method on a part that takes abuse. I suggest you run break test on the half-lap joint v scarf. Half laps on framing (i.e. furniture joints) are the weakest of the three common joints used in furniture: mortise & tenion, doweled, and lapped.

Stringers can be scarfed with a router. A simple jig of two spaced 8:1 angle pieces and an extended base plate on the router so it can slide down the angle parts and shave the scarf angle on the clamped in place stringers. My method of scarfing stringers since it is near impossible to cut itty-bitty stringers with the WEST rig on a skill saw.

[drbyrne55]

Bump .........

[mercguy]

08 1/2 model year!

not exactly 09 models, but close enough, as they both just got painted for 09 (and only had 2 previous races on them)!!

Darneille DSH/DMH
JDS CMH

got a few more in the shop now...........

[form-e one]

will be raceing george luces form-e hydro,, this year hopefully we wil go very fast,,hehe,,, hopefully see everyone at nats...cheyney street.. kilo holder

[Al Peffley]

Last Month's Picture?

Hey Daren,

That picture of the e-mod hull outside can't have been taken today -- where are the snow drifts? The red paint job on the JDS is really cool.

Al

[mercguy]

Hey Daren,

That picture of the e-mod hull outside can't have been taken today -- where are the snow drifts? The red paint job on the JDS is really cool.

Al

ya, the DSH pic was last month............last night we got another 12" snow!!!!! Thank got I have a heated shop to work in!

heres a "sneak peek" of the 09 Hemp (Davids built) OSY boat..........just got the topside sprayed with epoxy..........now to flip it over, do the bottom, then flip back over and paint..........

note: sponson tips conform to the mod rule.........

[blueskyracer]

Daren, Your boats are looking really nice. If I can figure out how to post some pictures I will post my new MJR. I am almost ready for the bottom.

[blueskyracer]

What is the new requirement on sponson tips? Is there a radius requirement?

[mercguy]

might as well

What is the new requirement on sponson tips? Is there a radius requirement?

the rule does not (yet) apply to STOCK boats Mike, but since you are building a new one, why not conform anyways? The rule is "basically" a 2" radius, but here is the "official" rule in MOD: page 6 of the MOD tech manual

2. All MO hydroplane hulls built after October 31, 2007 will have the foremost points of sponson
pickleforks that meet the following requirements for shape. The foremost points of the pickleforks
shall have a minimum radius of 1" in one view. This minimum radius shall extend at least 45
degrees to both sides of the foremost point. At 90 degrees to this radius conforming view, the
foremost points on the picklefork will have a minimum thickness of ¾". This minimum thickness
shall extend at least 45 degrees to both sides of the foremost point.
3. All MO hydroplane hulls built after October 31, 2007 where the cockpit nose extends forward of
the body of the hull, shall have a cockpit nose that conforms to the same requirements for shape
as the picklefork foremost points described in paragraph 2 above.


BTW: I just "updated" a 2006/7 Hemp hydro and it took me less than 1hr......

[Tom Cronk]

Cowl Nose

Daren
You better check the front cowl nose on your
JDS CMH for Mod rule.
Happy Holidays
Tom