My Riva Aquarama Plans

[CaptScot]

Tad, I enjoyed your posting on 10-23-2007 on this thread since it is a refreshing professional accessment for correct high speed craft construction rather than just building a boat by rule of thumb. For me you answered a lot of questions I have often thought about particularly in a Riva type boat's construction. In your comment about frame gussets being a sound solution "abeit ugly" to an otherwise weak lap joint, I having the same opinion what do you think about the pocket created between the plywood gussets and frame as being an ideal place to catch debris and moisture during the vessel's life? These have always seemed to me to be a source of rot waiting to happen. The only factors I can think of is that epoxy over the joint even with glass may not seal it, the sawn frames can be cut so that no pocket exists, and lastly if a chine longitudinal is knotched in along each frame joint then perhaps a lap joint would suffice since once the monocoque hull is built the gussets no longer contribute to the strength of the hull. Bottom line, the moisture/ rot potential of gussets, plus being plywood has never seemed right to me. Thanks, Scott J.

[Tad]

Cuda,

Thanks for the clarification, as you know...any engineering advice found on the interweb is worth about what you paid for it! Which is a way of saying I know nothing about your construction method and the engineering behind it, so I should refrain from criticizing. I will say that "plenty strong" becomes a engineers nightmare when the boat is leaping off waves at 40+ knots.

In cold-molded construction every part is contributing to the overall structure and thus no part can be viewed by itself. Each part sizing must be understood with a view to it's supporting structure. Most scantling rules address this in some way. One method is to treat stiffeners (longitudinal or transverse) and skin panel edges differently depending on "end fixity". This is why I like the transverse plywood bulkheads, as their depth is infinite; they are considered "fixed" ends. If one is using frames of a nominal size, end fixity is considered "floating", i.e. there will be some deflection. A thicker skin and larger stiffeners for a given load will be required in this case.

I think you may have trouble fastening your second planking layer to the first if both are only 1/4". The inner layer may bend quite a bit between frames and you have nothing to clamp to. Poke sticks from the ceiling and plastic staples might help, but vacuum bagging would be best. Plywood strips inside and out with screws between may also work, but leave holes to fill.

Capt,
Good maintenance is of course the key to long life for any structure. In my opinion if the gusset is properly sealed in epoxy, along with every other part of the structure, rot is unlikely to be a problem. But good air circulation throughout the interior is important. Some fit blocking between the gusset sides, to fill the cavity. This is more needless weight.

Sorry I don't understand your statement "a lap joint would suffice since once the monocoque hull is built the gussets no longer contribute to the strength of the hull." The stiffeners (no matter their makeup) support the skin, and are absolutely required throughout the life of the vessel. I would agree that the chine log supports the outside edge of the bottom panel, but the athwartships stiffeners (frames) require a strong connection at either end.

Tad

[cudashark]

Good Morning Tad,

Constructive criticism is welcome. I will be adding .5 inch X 1.25 inch Douglas fur battens 6" on center as an attachment structure for the first skin of .25 inch mahogany. Each layer after that will be vacuumed bagged.

I have tested composite staples from Raptor and although they jam the gun from time to time they work well enough to fasten the first layer. Being a plastic composite I won't have to remove them. I'll fair right over them.

As soon as the battens are on ( a couple of weeks ) I'll post more pics.

PS She will go 50+ knots....twin 5.7 liter V8

Ray Cuda

[Pericles]

Cuda,

Douglas fur battens. Hope they are strong enough?

Regards,

Pericles

[cudashark]

Hi Pericles,

Here are the battens I spoke about.

Also 1063 board feet of South American Mahogany for the veneer. These will be milled into 2800 liner feet of 3/16 inch veneers.

The battens by the way are 5/8 inch by 1 1/2 inches. They serve as attachment points for the first corse of veneers.

Ray

[Pericles]

Coming along nicely. Raptor sell their own gun if jamming really becomes a pain.

http://www.raptornails.com/english/firstframe.html

Keep up the good work.

Regards,

Perry

[cudashark]

Latest pics of the first of four 3/16 inch skins.

Ray

[pedroportugal]

the plans in this site http://classicwoodenboatplans.com/
of aquarama are yours? if you live in uk dont anderstand how i have to pay more $60 to send -me to portugal?
i dont understand.

[cudashark]

No they are not my plans. I live in Stuart Florida USA. The plans you mentioned are not real boat plans. They are some files for a model boat that are beingsold as real plans.

Don't waste your money.

Ray

[jomor]

Gentlemen, Can anyone direct me to a source for credible plans or a kit to build a Riva/Chris Craft style boat? I have been thus far unable to obtain anything.

Cheers

Paul

[cudashark]

Glen-L maybe

There are no real useful or “full set” of plans for building the Riva type boat. I drew in cad my own set so I could make patterns via a CNC router. Then I used a shaper to make the ribs, and other components. The rest is carpentry.



One major reason plans don’t exist is that using veneer over frame is not a common method for this type of construction(plank on frame). Cold molding is, and plank over frame is, but my method is a combination of the two.



I also use “plastic staples in my glue –up so I don’t have to remove them and I can sand over them.



I will attach some various pictures to give you some Idea of what I have done. From start to where I am not of actual work time took me 6 months. But over two years.


More pictures can be found in the Gallery under Cudashark


Ray



If you are interested in using my cad files call maybe we can work something out.

[Bondovian]

Cuda, Looks beautiful and cant wait to see the updated pics. Keep em' coming. I too have been looking for a set of plans for the Riva Aquarama style boat with no luck. I think through research on the net and through pictures of restored Riva projects, one can get a pretty good set of plans formatted to your own liking. cant wait to see your finished project. Do you have a launch time estimated yet?

JB

[pistnbroke]

glen L certainly does have plans for this type of boat www.glen-l.com single and double cockpits and inboard or outboard

[TMG]

Cuda,

Nice project you have there! I've been thinking of building a boat in the style of the 24' RIVA Super Aquamarine. I have been studying the plans and hull design for the Glen-L Gentry design as previously posted and was considering using this as a basis and scaling the design to produce a 22 footer with an 8'6" beam. I would then re-layout the cockpit to be similar to the RIVA. Glen-L does specifically say not to increase the beam of the boat, though I'm not quite sure of the consequences. I'm also not quite sure how the hull design will perform in rough water. I'd like a boat that can be used in weather conditions other than mirror flat waters.

You mentioned you have a cad file of the boat you are building. Did you create it yourself, or did you acquire the file from some other means. I'd like to do the same, the problem I have with starting from scratch is that I have no idea how to shape the hull for proper performance. I'd like to acquire a basic hull model and from there design the cockpit / interior. Any advice on how to do this?

Thanks

[cudashark]

TMG send me your e-mail and I'll send you my phone number.

We'll go from there.

Ray