Just for fun tell mr woods you just discovered derek kellsels designs and techniques are completely anamoured. 

I suspect you will quickly learn what he doesn't know about fiberglass. 

Nick

Sent from my Bell Samsung device over Canada's largest network.

-------- Original message --------

From: "StoneTool owly@ttc-cmc.net [harryproa]" <harryproa@yahoogroups.com.au>

Date: 2018-09-03 12:27 PM (GMT-05:00)

To: harryproa@yahoogroups.com.au

Subject: Re: : Re: [harryproa] marine ply

 

    I've pretty much settled on what I intend to build, and there are numerous reasons for the choice.   The alterations involved in installing the Sagitta topside on the Eclipse hulls are minimal, and Richard will provide the drawings / support.    
    The knuckle design offers an efficient profile below WL, while increasing usable space above, and helping with the water flow under the bridge deck.  

    It must be considered that the actual hull shells are only a very small part of the construction of a boat, and it is a one time undertaking.    I'm considering the various options for the lower hulls, including building them using conventional vertical foam stripping rather than cedar strip, or even doing the hull shells entirely using vertical foam stripping.  The knuckle makes a natural break point to go from one material to another / one technique to another.... say H80 to infused XPS.
    The fact is that most of the work in building a boat is done AFTER the hulls are built, and "intelligent infusion" can be applied to a great many of the structures, not just the hull shells.   I'll use what I can of Rob's techniques where it makes sense......... for my specific project.   That may even mean building the entire hull shells using vertical foam stripping............ that remains to be decided.   It may mean cedar strip lowers and infused upper panels, or it may mean some other combination.  

    The KD 860 appealed to me in terms of simplicity of hull design and payload, but it comes with several liabilities.   Inadequate length, no forward view, and not enough space outboard in the hulls.   All of these could be overcome, but that involves designing a new boat for all intents and purposes.   Sagitta offers what I want as drawn (more or less), and with the option of the Eclipse hulls, it's about as good as it gets.   I'm neither a designer nor a naval architect, and while I could probably design a perfectly adequate boat based on what I know now from existing designs, that adds another dimension (and time) to the project.... one I do not want.

    Originally I had no intention whatsoever of building a boat, but found that nothing out there meets my criteria.  Clearly what I want differs from the general market.  What I've found in Richard Woods is a designer I can work with, who is willing to accommodate my needs within his existing stable of designs.

    I would still consider buying if I could find something that met my criteria............ I'm looking.

                                                                            H.W.


On 09/02/2018 08:56 PM, eruttan@yahoo.com [harryproa] wrote:

 

| Realistically, I don't belong on this forum...... hopefully I'll gain some insights and ideas to make my project better, easier, stronger, and lighter.

That is for you to decide, but I would suggest there is reason enough to stay.

| The original question regarded ply construction alternative for an HP hull, something Rob had not offered. I presented the information I had with regard to my own project (intended), without making judgments or any intention of actually equating those specifications directly, just to show what Woods had done. I do agree that it seems excessive, and would suggest that Richard is not by any means "expert" with foam core composite design.

That all is very reasonable. I read your post as suggesting there was little benefit to II when the numbers were ran, which did not match what I see.

| We have a number of suggested substitutions for foam core to plywood, all of which differ, Rob's being by far the lightest, though he offers it to substitute for the plywood only, not taking into account the stringers. Richard's figures replace both ply and stringers with 12mm foam and 900/900 glass. This is obviously not a template for reversing Rob's HP to plywood..... the result would be rather absurd I think. It is simply information to file away, and add to one's "body of knowledge".

I don’t see a problem. Rob’s Infusion plan is for designs like his, that are way up the design spiral. Other designers design for their designs. that's why I chose Robs designs. They are lighter, cheaper, easier and faster to build than anything comparable. If you find something better let me know.

A thing that further complicates comparison is Robs Latest build techniques are even ahead of the latest builds, as the knowledge, skills and ideas iterate faster than the boats are built.
Look at Steinar's WW hull vs his LW hull.

| I am only on this forum to learn what I can to help me construct my boat of choice "efficiently". It should be obvious that if one were to peel the hide off the boat in question and lay it on the floor, while it would lay flat, it would be anything but square. Both the top and bottom edges would be curved, and not in a way that I am capable of calculating based on the plans, and the bow and transom ends would be angles that could not easily be laid out in the flat. I do not yet have the plans.... Things are still evolving. A plywood skinned boat is normally built by fitting each skin panel in place over formers with stringers. There will be no scalable drawings or table of offsets to precut these pieces. What this means is that while making a flat infusion of the hull sides is possible, I am left with the need to create a template that will lay flat so that I can infuse to the final shape (more or less). The other alternative, which you no doubt would agree is absurd, is to make a 30' panel and attempt to trim to fit.

What, its not our good looks and engaging banter?
As to figuring out the shape of the flat, to bend to the hull, if you HAVE to build a frame, to hang everything off, then just mock up what you need. paper of some type, perhaps, laid and cut as you need as a place holder of the spot. then remove and get your measurements. I would guess its close enough.

As I look at Robs designs, I see very simple lines. Your picture has very complicated lines. I am not a Naval Architect, but, if it was me, I would follow the upper hull sides strait down to a flat bottom, probably at the same depth as the drawn hull, with a low radius curve in the corners. You know, like robs designs. Way simpler to build and you can infuse the bottom in one simple mold. Its not like you need a very specific hull line to get your boat to go slow.
Look, just ASK rob. He loves talking about boats.

| The lower hull beneath the knuckle will be done in cedar strip over temporary bulkheads. The stripped lower hull is typically glassed outside, and removed from the form, and glassed inside. Everything above that will be sandwich, as per the option of building them with plywood. My inclination is to use low cost "sacrifice material" for bulkheads, and stringers as needed using the provided offsets for the foam version which has 1/2" foam rather than 1/4" ply. The actual bulkheads would be sandwich, and would be inserted later..... perhaps not even in the exact original locations and shape in some cases.
| Ideally, I would like to generate the data to allow others to do the same thing.... A reference line and table of offsets could allow someone else to duplicate the shape on a melamine table. The design of the Eclipse hull does not have the simplicity of the HP hulls that lend themselves to "intelligent infusion", nor do I have any intention of redesigning the boat itself.

Meh, I think it way simpler to build a simpler design. I mean you are doing a custom boat. You might as well get a custom boat.

|> Why not ask Rob for a design and total package price to meet your Statement of Requirements?

| Rob is not in the business of designing cats

Bullshit! He has done cats. But is it gonna kill you to ASK?

| and an HP does not scale to my requirements realistically.

Bullshit! A HP will do everything you need, except be a 30' cat. It will do it cheaper, faster, and safer.

| Richard has offered me a solution that works for me in the form of Sagitta built on Eclipse hulls

Bullshit! You want an Intelligent Infusion, because you can see the wisdom in it, but your stuck using expensive, complicated and slow techniques. If there is where you wanna draw the line on compromise, fine. But it’s not what you want.

| .... longer than I really want, but it will allow me to easily have the mast where I want it, and leave me with a huge cockpit. The fatter hulls offer greater displacement, and if I build the upper works using infusion, I gain more.

A fat ‘square’ hull all the way to a flat bottom has even more displacement. Build the whole thing in infusion, and gain it all, cheaper. or not. Up to you.