Just a Thought - Any Interest ?

MultiHulls General Discussions (MultiHull/MultiOne)
21

Yes carbon is expensive, but it’s properties, make just a few layers of the stuff equal to, the use of more of the other materials.

For eg. The amount of layers of carbon of a given weight, to rival the stiffness of glass of a given weight, is not as much. Because there is fewer layers, there is less resin used. The costs just about match up overall.

Also, this is how using carbon makes things light, because not much of it is needed etc.

As for making boats expensive, it’s not the materials. It’s the time spent on the nessesary steps, to making craft to very high calibers. With carbon, the structural reinforcement is seen, and to build with the stuff to have good strength, and good looks, makes the craft tricky. An easy way is to hide it all with a thick gelcoat. Then the extra care in using the fibers is not needed (prices drop down).

Molding the parts is easy, building them together in the right places, and the the fine tuning of the assembled parts (fairing, alignment, and such), is what makes a product expensive.

I had some one ask me to caculate making them a rig, like the ones on my personal boats. There’s to much hourly detail work to sell them. The spars and the fishing hardware supplies are cheap, but filiment winding them into place, with all the wee bits, and micro-fairing the wee fillets, is a lot of hand work.

Bond some slabs of balsa together is one price. Sanding, shaping, sculpting, and finishing the surface to reflect one’s image is another.

Ya dig…

22

absolutly, like I said I know there is a definte art to it…, but again if we are tryingto build a class thats “easy for the average person to get into and compete”, the exotics (carbon, kevlar, glass) are out of most peoples grasp…both in experience and $$$

Hell I’m not smart enough to build (from scatch) my own boat that will sail with out sinking, I’m 2 for two…:slight_smile: so I have to take existing hulls and play with em…

I applaud those with the skill., but having deep pockets shouldn’t be a determining factor.

Heck look at teh Victoria. a $99 kit, and all you use are the hull, fins, and bulb. everything else is garbage more or less…and you end up dropping another 2 bills just to be competitive.

I’d love to have your skill, and maybe as I slowly get my shop(dungeon) together I may dabble in the composite arts…I just did lay up a multi layer soling boom made of basswood and 1/64th birch and it turned out pretty good using a homemade vaccum bag…

yo do great work, and Iknow oneof th elocal guys was thinking of getting one of your 100% carbon labjabless(sp) but when he got the price, I think he had a coronary…but like you said, and i agree, its an art, and it takes time to learn…

23

What skills I have, are from doing just like you(s). Messin in the dungeon.

I can relate it to what I’m trying to do these days. Learning to play guitar.
My fingers won’t go where my mind tells them. My friend (teaching me) who has been playing many hours, everyday, for the past twenty years, can do any combination of sounds imaginable. Practice with a mind willing to learn is the way.

A full carbon version is more expensive to make yes. The pricing reflects the time spent, and somewhat to dicourage it’s sale, as my own attempt to somewhat control sky-rocketting in the class. If anyone does want to have that kind of thing built for them, that’s their right. Their really is no performance differance between the two versions, just one is expensiver (if that’s a word).:wink:

24

Dick

sicne the vic is 30" long… what would the optimum pontoon length be, and how wide should the tri end up?

it looks like the pontoons are a smidge shorter than the hull(looking at pics) and the width=length more or less…

Again all hypotheticalll, but I juts don’t see myslef building a purpose built tri just yet… any links to any good plans???maybe I shuld just jump in and build a purpose built tri…, just add another boat to shipyard…:slight_smile: and tryto learn the artof composites while I’m at it…

although i think a convertable vic would be interesting to say the least…

Marc(toomany ideas in my head right now)

25

Mark -

you certainly could go with a “square” platform of 30" x 30" but I would think 30" x 24" would be a good starting point to begin experimenting. Remember that tacking (whether a cat or tri) is often difficult since you are crossing the “eye of the wind” with three hulls - not just one. Thus narrower may be better for a starter. Floats can be 30" in length with enough width and depth to provide buoyancy to assist in supporting the boat as it starts to heel. If you did 115% buoyancy, I think it would look pretty ugly, so maybe shoot for something in the 70% range of main hull weight to start. That part will be the hardest, since it will be a balancing act (literally) to allow the hulls to break free of the water surface, and still support the weight on only one hull.

I really wanted to do two attachments today - one a photo of the UK 1 Meter floats made from round closed cell pipe insulation with a pointed end (bow) and also reduce the lines for my 1 Meter trimaran to RG-65 size. Unfortunately, I may have shot myself in the foot, as my local hard drive file folder contain those ( and many other ) photos and info may have been accidentally deleted. It’s a folder and I can’t find it in my “wastebasket” - but hopefully it went to some temporary file and can be recovered. Will know tomorrow - and I didn’t shut the PC down tonight in case there is a chance. Some photos date back to 2000 when we tried to get the F-48 class up and running.

I hope for the best, but fear for the worst.

My own boat drawings I have here at home and have posted them below. If you print one page - check the scale line. If it’s an inch long - you are fine for a 1 meter boat - so might try a copier reduction to 75% for station templates, and then space as necessary to meet the 65 cm length. That way you will keep buoyancy but on a shorter overall length length.

The drawings, as you will see are minimal - and were designed for shaped foam hulls from which either a cat (use two of the main hulls) or a trimaran (2 floats and 1 main hull) were envisoned.

As for the Vic - iit will be afun project. I suggest using house foam insulation of 2" thick if you can get it. You can rough shape, then sand and finally cover the foam with plastic packaging tape while you use them for testing and experimentation. Don’t waste time and money covering with glass for first effort - just try to get both floats “close” to being similar. If you can find commercial construction site - foam may be free (look in dumpster) as around here most contractors place it against exterior of basement wall - if you have to buy it a HUGE 4’x8’ sheet at a local big lumber yard may runt around $16.00 or so. I have yet to buy any - seems I can always find stuff somewhere. Maybe even ask at lumber yard if they have broken sheets at a discount ( or maybe free) You only need enough for two floats for the test - 2 pieces 30 " long x 2" wide x (probably) 3" high.

Good luck

26

dick

thanks.

I did send an email to a guy who has plans for a nightmare Mk 7 saw it an another website…but its a mini-40…

I work at a college so we have a lot of the pink foam you are talking about. in fact I have several pieces at home right now for my footy stuff…

I was actually thinking of using some 1/64 ply/veneer and soaking/ wraping it around a d-cell maglight, and as i near the end cut and trim the ply so it forms a stem/stern, kind of an “origami” it would have a knife edge bow kind of like “flatfoot” in the footy world… and it may be a bit less messy than sanding all that foam to shape…:slight_smile:

27

Mark -

I know you are “keen” to experiment, but stop for a moment and consider … “If” you roll the veneer around a flashlight battery or PVC tube, you will come up with perfect underwater semicircle cross sections. Unfortunately, there will be no rocker ( curveature) underneath the centerline of the keel. With a flat like that, tacking will be like pushing a plywood panel flat-ways through the water. The thing will track like the proverbial “freight train”, but changing course will be something else. Kayak builders speak to this at great length - long straight and flat for touring, currved keel for easy turning - now find the happy medium. :stuck_out_tongue:

The ply hulls that are compound bent are cut to allow the sidewall curvature, as well as the ability to go from pointed bow to circular stern and also to have a keel line that has curvature too. As you bend and stitch the panel takes on bending in multiple directions depending on the cut and the seams. It’s difficult to find panel plans for compound bent multihulls as there is more stress than on a hard chine monohull - and those are difficult enough to get to line up and have the right curves along matching seams.

Other than “dust” and static-cling, the foam really shapes easy. Use something like 80 grit to do the fast shaping, then 110 grit fo final shaping. You can cut ( as you are probably aware with a coarse handsaw, a hacksaw, a hot wire, or I use a bandsaw with 1/8 " blade made for plywood.

Go for it.

Dick

28

good point…I never thought about that. kind like turning a car with a solid live axle…or a tandem axle trailer…

if I cut the stations out of balsa and then glue the 3" foam to it, at least that way I can use the basla as a guide…

29

You betcha’ - and if there is one or two sections between the balsa you want hollowed out, a bit of acetone will quickly melt the foam (into a gooey mess, but you will have the hollow) - or melt it out with a soldering gun/woodburing pencil/hotwire etc.

Here is photo of solid foam and hollowing for radio gear in main hull (Water Resist design) I used an old “pistol type” of soldering gun - and made up my own tip with formed stiff wire (see photo below). Kind of rough finish as cut, but will be hidden inside of hull when done.

30

dick

I finally go the mk7 plans in dfx format…so printing and scaling to any size is not a huge problem…

thinking out loud…

maybe building a smaller tri for my first home built(not counting footies) might be a good place to start…Any thoughts/ideas on this…I figure I can hone my building practicies on an rg 65m

also, where are the class rules for the formula48?

31

Ssshhhhh - you didn’t hear it from me … don’t tell anyone! :wink:

I am going to try an RG-65 “Multihull” this summer, given the time. I will probably use my 1Meter templates with some displacement modifications. That’s what is nice about the small classes - rather fast to build and experiement. Would hate to lay up three 48 inch long hulls and find performance issues when it’s too late and they hit the water.

Well - I just went out to AMYA website - as they “Used” to provide links to the rules. Seems our current AMYA webmaster has everything disabled and you can look at photos, but nothing goes anywhere - kind of an endless loop of links! :mad:

I have them in PDF format and they are attached. There are a few, but subtle differences between the F-48 rules, and the Mini40 rules and we felt ours were less restrictive and also eliminated some confusion in certain areas. Those issues were “put to bed” years ago and I won’t return to the argumentative issues from back then. Suffice to say, these were/are “cleaned-up” Mini40 rules that we created when the French threatened copyright infringement when we tried to clean up the original rules. If you do have personal questions, I will detail some differences, but will do so in private email so as to eliminate reopening of that can of worms. Hope you understand?

Regards, Dick

32

thanks Dick… saved a copy to my HD. yeah the amya… don’t even get me started on webskippy…Sigh…Did pay my dues so I can play…

being that I’ve never laid up a glass or carbon hull the smaller size may be a good place to start…

33

For first time builders, a good place to start is with the foam concept. Hollow out a place for a winch and rudder servo, and wrap the hulls with plastic packaging tape. Clear is “cool” and you’ll seee the blue or pink foam. The brown stuff is - well - ugly - but either will et you get a flavor with minimal time spent. The Germans are doing this with the full size 1.2m/48" sized boats.

Shape as desired or per plan.
Hollow out main hull
Try a dual swing-arm winch and let the arm protrude above deck
Let the rudder log/tube extend above deck and use simple single wire to actuate
Hollow a hole and glue in a piece of wood for attaching your cross beams.
Use a solid wood dowel (1/2 inch max) or even a fiberglass tube for beams
Then cover the hull with tape
Grab the complete rig off your Vic (or whatever) and transfer to the multihull - you should size to allow your rig to fit. example - if you use Vic rig, hull lengths should be close to the Vic size.
It will be heavier than a purpose-built boat, and “rough” in appearance, but will give you an idea of possibilities.

This is a quick way to see how well and fast it will sail. Then build in balsa or glass and performance will only get better once you have decent hull weights and a regular sized rig/sail for the boat’s size.

Just an idea. Dick