I am not trying to be controversial or open a whole can of worms but I would like to hear peoples thoughts and comments on keeping the great Wharram design principles (I totally buy into) but build them with more modern, lighter composite materials ... without mentioning brand names here I am talking about the panels/sheets that have already glass on the outside but weigh about 1/3.
I get it that composite panels present challenges for the amateur builders and cost more per sqft but I believe they have come a long way in terms of usability and they do save time in terms of labour compared to glassing plywood.
I also get it that this isn't all in line with the philosophical "green" aspect of Wharram boats but then again we are all about "live and let live", right ... :-)
First, this is a completely open forum. It is completely OK to post links, pictures, names, brands, and just about anything that is not vulgar or in bad taste. You can even post and talk about competing sites and forums. There shall be no hiding of good information on this site, regardless of its source.
Composite Wharram's have been built, so it can be done. Other than material costs, I personally do not see any real downside if the choice was to use pre-skinned panels. However, for cross beams, I would probably still choose to use the lumber method. There would be a few considerations that would need to be addressed depending on how much composite material one would want to use and where, as well as overcoming some mounting/clamping issues that do not arise with ply/lumber. Glassing the plywood, in my case, has not presented any issues or concerns, and was not difficult nor time consuming to do. I think prepping the plywood - sanding, epoxy coating, sanding, coating again, turning over, sanding, coating, sanding, coating, sanding, etc. is by far the most time consuming part of building a Wharram.
Otherwise, from some past research it seems that a foam core Wharram is about 30% lighter and can therefor carry more cruising load without adverse effects.
Permalink Reply by Tom on February 1, 2009 at 6:59pm
I've been wondering about using honeycombed pannels too. They would sure save some weight! I haven't used them due to cost, but if I had the cash I think I would have made my bunk level flooring out of them, as well as my engine boxes, my bowsprit frame, some of my galley cabinetry, some general shelfing, some lids, hatches, decks...it would be easy to get carried away :)
I'm not sure if the substitution of panel for ply would be much of a time saver. You still have to prep and glass them (at least the honeycomb one's I'm thinking of). More glassing work is required to achieve strength equal to or in excess of wood's strength. If your wife/SO does most of the glassing as mine does, perhaps this is an added beneift? Another cost addition, but still under the weight of wood (the panels I mean).
There is a lot of math to do here. Getting the flexibility right would be a neat trick. Wow, you could completely change the hull design and retain only the external hull shape.
Anyway, I bet you could save significant weight by making a hybrid wood/honeycomb Wharram that would retain the aesthetic warmth of a wood boat.
boatdesign.net has a few interesting threads regarding composite construction, but screwing around with the materials is way more fun, ah? haha
You could always write a letter to James Wharram Designs and ask the guru what experience he has had or knows of regarding the composite panels. Sounds interesting for those who can afford it. But a major weight saving idea is to use aluminum alloy pipes instead of wooden masts. They are WAY lighter and the Wharrams have already done the calculations on which size for each design. Some builders are clubbing together to buy alloy masts in a group and thus reduce prices.
We saved weight by using Okume or Gaboon ply when building our Tiki 46. It is lighter than the design recommended eco ply made from Douglass Fir and our timber merchant said we saved over 1000 pounds over Douglas Fir and 2000 pounds over Meranti ply. Okume is lighter in color also, very pretty, and is a marine plywood. We got ours in England but my son got some nice Okume from California. It is more costly than the design recommended Douglas Fir ply.
Keeping the boat light is of major importance to reduce stress and improve speed. Going fast really comes to mind when outrunning stormy weather. Ann and Nev
Hello all, We have sold two Tiki 26's and will build them of foam cored fiberglass in a female mold. There are many people in the world who just don't want a wooden boat. Wood is truly the miracle fiber but it does rot. Fiberglass is also crappy stuff to work with IMO. But we build custom boats and we work in all materials. David www.boatsmithfl.com
The molds for the Tiki 8M have left England on their way to Florida. About weeks should see them in our shop ready to go.This won't be building of composite sheets, but laid up in a female mold. Our test panels indicate stonger and lighter. David www.boatsmithfl.com