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PAHI construction method

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Anonymous (not verified)
PAHI construction method
Hi, some questions from a newbie if anyone can help: 1. Are Pahi's basically built using ply exopy fillet construction over moulds. 2. How are Tiki's built by comparison. 3. Is there a view as to which is the stronger more durable method. 4. how many sheets of ply would a Pahi 31 consume and what thickness would these be. 5. Is sheathing of the entire hull recommended even when BS 1088 ply is used throughout. 6. How many degrees would one expect a properly setup P31 to tack through in in moderate waves F4, with how much leeway. 7. Wharram designs were recently critised by another well known cat designer on another forum as having too many embellishments, do the raised ends of the Pahi hulls have a demonstrable function. That is a lot to swallow in one go I know, but only the tip of the iceberg I am afraid. Any comments gratefully received.
Anonymous (not verified)
Re: PAHI construction method
Hello Cacaique Well, there doesn't seem to be much traffic at all on this site as yet so maybe I'll just have a try at answering some of your questions, at least as far as my feeble experience goes. That's not much, by the way! 1. Are Pahi's basically built using ply exopy fillet construction over moulds. No, Pahis are built in a similar way to Classics although there is much less framing involved and more reliance on glass tape amd epoxy for the joints between bulkheads and hull sides etc. The bulkheads make up the frame and then stringers are attached and then that "frame" is fitted with the plywood sides, essentially that's it. 2. How are Tiki's built by comparison. The Tikis are built "stitch & glue" which basically means that the hull sides are made up of one piece on each side which is then "stitched" to the bulkheads with copper wire and then finished inside with epoxy fillets and fibreglass tape & epoxy. OK, there's more to it than that, but essentially that gives the idea. 3. Is there a view as to which is the stronger more durable method. They both work, it's just that the older Pahi method is more expensive in terms of timber, and may be a little heavier. 4. how many sheets of ply would a Pahi 31 consume and what thickness would these be. Can't quite remember but I think from memory that it is mainly 9mm ply and around 50 sheets sounds about right, although that may be out quite a bit?? 5. Is sheathing of the entire hull recommended even when BS 1088 ply is used throughout. Yes, plywood "checks", that is, expands and contracts in the sun so the painted surface will break down and very fine splits will let moisture in to the substrata of the ply sheets otherwise. So sheathing with glass cloth stops that happening, at least. 6. How many degrees would one expect a properly setup P31 to tack through in in moderate waves F4, with how much leeway. Don't know, but they are not too impressive in that regard, that's for sure. 7. Wharram designs were recently criticized by another well known cat designer on another forum as having too many embellishments, do the raised ends of the Pahi hulls have a demonstrable function. As I understand it, they act as reserve buoyancy, so that is practical, but how much of a difference they make I wouldn't know. The point being, though, that this is an historically accurate feature of canoes in parts of Polynesia, especially Hawaii and even little Tikopia in the Santa Cruz Islands. That's about all I can say on this topic! GregF
Anonymous (not verified)
Re: PAHI construction method
I'd like to add just a couple little things to Greg's excelent answers. 7.I get asked whether the upswept bows on Manu Rere are decorative or functional often. One way to look at it is the ordinary catamaran of her size would have freeboard higher than the upsweap bow throughout its entire length so the bows are high enough but the whole boat is too high and heavy to sail. Polynesians didn't have engines so they built boats low and sleek; such low boats will bury their bows if they aren't swept up. Storm survival often means turning the stern to the wind so the stern should be shaped to take waves too. There is a prejudice in design today favoring ugliness. Look at the SUV. (A real man only owns ugly things or something like that). 6.I cruised 10 years and 30,000 miles on a pahi 26. During the first year it had the origonal bermudian rig and sailed awfully. When I changed to the wingsail rig the boat was transformed, and was profoundly successful. With the later rig she tacked through 90 degrees eficiently and had very little leeway, even without the boards. The pahi 31 will also sail much better with the tiki rig.
Anonymous (not verified)
Re: PAHI construction method
Glenn, Your outrigger tender is really nice, and it looks like it's keeping you healthy! ;) Take good care
Anonymous (not verified)
Re: PAHI construction method
Thanks Kim. Your too kind. The cruising life is good. My latest blog is on the wharram home page in case anyone else is interested.
bouvier
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Last seen: 3 years 7 months ago
Joined: 04/27/2014 - 06:32
Pahi 31 : suppression des dérives et puits de dérives

Quelqu'un aurait-il Supprimé les puits de dérives sur Pahi 31? N'utilisant pas mes dérives en navigation, j'aimerais Supprimer les puits de dérives. Y aurait-il un Problème Structurel?

mayavidya
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Last seen: 1 year 2 months ago
Joined: 04/25/2015 - 21:54
outdoor construction

What information is available to aid in construction without a roof (barn) for a Pahi 31?

archie.linthorne
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Last seen: 1 year 3 months ago
Joined: 10/28/2015 - 00:43
Wharram designs about plans in aluminum

Time perhaps for wharram desines to look at plans in aluminum aluminum has become very easey for the home builder  more durable less maintenance so much faster to build with most wooden boats here are seen in museums