Scratch-Built Hydro

[FloatDaBoat]

Scratch-Built Hydro:

I drew up the plans for the hydroplane I’ve been wanting to build over this past Winter. The itch just kept getting worse, & I’ve finally purchased the building materials to begin construction. She’ll be run on 4S1P, & I’m leaning towards the Leopard 4074/ESC TBD for power.

Dimensions:

Length - 29+ inches [dependent on how I decide to shape the sponson tips]
Width - 16 3/8 inches
Height - 3 inches + ??? [dependent on how I design the hatch canopy, which will be the last step in completing the hull]

The hydro will be fabricated from:

1. 1/8” 5 ply Birch Plywood
2. 1/16” 3 ply Birch Plywood
3. Various widths & thicknesses of Basswood strips (at least that’s what I ordered -appears to be Spruce though, which is what I was actually wanting)
4. 4 ounce high quality fiberglass cloth, 3:1 mix ratio laminating resin, Alder Green (Teal) pigment, & Phthalo Blue transparent pigment

Attached is a pic of the jig building board, one of the rough-cut “Sponson Spines”, frame ends for the right half of the boat, & fiberglass building materials. Oh, & don’t forget to take note of my ‘Laser Cutter’ … 54 teeth per inch razor saw … works like a champ for precision cutting of plywood - - HAW !!!
　

[FloatDaBoat]

Progress Photo

Frame Ends attached to Sponson Spines, Outside Stringers for Sponsons in place, & the Jig Building Board trued with a few shims of poster board paper to make the hull square.


Ready for the Transom & Structural Cross Members to be epoxied to the Sponson Spines.


To be continued . . . .

[v-spec]

That's awesome! Can't wait to see you get it finished!

[JimClark]

1/16th and 1/32 would be just fine, 1/8th is way overkill

[FloatDaBoat]

Off Da Jig

Sponson Spines attached together with Transom & Lateral Cross Members.

Next step is to epoxy in the remaining longitudinal stringers, then the FUN part begins - - a “Boat Load” of careful sanding to achieve the final shape of the hull in order to apply the skins.

More later . . . .

[FloatDaBoat]

Clamped & Strung-Out

Checked my Sandpaper Inventory … time for a 60 grit re-supply for sanding blocks & also acquire the coarsest Dremel sanding bands I can find [I don’t think the 120 grit ones I have now will put much of a dent in 5 ply, which is where I’ll need them most in order to speed the shaping process along].

Lots of Elbow Grease (tempered with patient diligence) ahead . . . .

[Shooter]

Wow. Nice work! Perfect size too! (30x16). That tunnel looks pretty deep.

[FloatDaBoat]

Takin' a Break

Been sanding my Tail Feathers Off . . . .

That tunnel looks pretty deep.

Yeah. Actually, I designed the sponsons deeper than what would be considered “Normal” for a couple of reasons. One is to raise the sponson tips higher, thus reducing the chances of them catching a wave & causing a submarine encounter. Another is to get the flat surfaced bottom above any chop interaction that would create an imbalance of ride attitude.

This feature may result in not enough air getting packed through the sponsors ... EDIT: *Sponsons*; I could use the financial assitance of a few *Sponsors* ... (this will cause the COG to be higher also, but not significantly enough to be a major ‘Worry Factor‘), in which case I’ll add Air Traps to free up any nose heavy planing tendencies.

This design has ample room inside to adjust the Center of Balance, so that may not be necessary - - only the running will tell.

[JimClark]

did you build it on a jig?

[FloatDaBoat]

did you build it on a jig?

Yes, Sir. If you'll take a look at post #2, there's a photo attached.

[FloatDaBoat]

Sanded

Rough sanding to shape’s been completed [Photo 1]. It was easier than I anticipated - - didn’t need to use the 60 grit Dremel sanding bands I’d purchased, just kept refreshing the 60 grit paper on my sanding blocks frequently.

Ready to fit & install the hull bottom. I placed strips of Scotch Tape between the Jig support rails [photo 2] and the Sponson Spines, in case of runs or drips of epoxy during assembly … it’d really suck to end-up with the rails attached to the inside of the hull.

Time for a nap . . . .
　

[FloatDaBoat]

Bottom Sheeting Begun

Progress on the build was slowed considerably when DaBug decided to strike - - slept fourteen straight hours due to a bought with bronchitis, but am feeling better & have managed to get three of the seven bottom skins attached. The dreaded Compound Curves of the sponson bottoms took some additional prep time, but I was pleased with the overall results.

Had to place my Desert Storm Coin on the hull to get the camera to focus.

Pressin’-On … even though my tail is still Draggin’ . . . .

[Shooter]

Yikes! Hope you feel better. The boat is looking great! I like the suttle angle and curve that the sponson will hit the water. Should glide on the water nice. Can't wait to see how that deep tunnel works out. Several of my boats will nose dive for no apparent reason in rougher water. This might be a solution.

[j.m.]

...slept fourteen straight hours...

HA! I do this almost every friday and saturday!

Boat's lookin good! Your really doing this one perfect, have you considered taking a mold from it?


Jon

[FloatDaBoat]

The boat is looking great! I like the suttle angle and curve that the sponson will hit the water. Should glide on the water nice.

I wanted this Hydro to look like ONE!!! The curve lines are natural, as I utilized a bent piece of Spruce strip to draw them.