Idea!!!!

[Tom Hoffman]

I have always wanted a rowing shell, since I started my Glen-L Whitehall, I have gotten the boat building bug much worse than I have ever had it in the past. My son-in-law wants me to help him build a skin on frame kayak.

Now for my Idea;

I have Robert Morris's book and it led me to think about building a skin on frame Rowing Shell. I have Graham King's Plan for the Kingfisher. It is a beautiful long shell. Have any of you built such a thing?

I would be grateful for any help or encouragement.

Tom.....

[Tim B]

I am no expert but the frameworks of a rowing shell (the kingfisher included) are not strong enough to support the stress encountered during rowing. The shell gets most of it's strenght from the skin be it plywood or a single plank per side. In an aritcle about King's shells, he explained that the plywood used has 3 ply's that were so thin that it was easy to sand through a ply by mistake. Doing so would result in the shell folding into a ball on the first stroke.

[JimD]

Have a look at Geodesic Airolite Boats from Platt Monford. Might be something here for you, Tom:
http://gaboats.com/ http://www.imagestation.com/picture/sraid175/pf50da1d7c463e0c67e568e5b3bfd3e3d/f3794bc9.jpg

[ 06-30-2005, 06:21 PM: Message edited by: JimD ]

[indianabob]

my new project is a skin on frame kayak,,, ash and oak,,,gunnels of cypress,,cover heat shrink dacron,,,,i may or maynot use adiagional roving,,,,i am planning on using a bamboo skewer as a dowel on every wood to wood joint,,,,,glue,,, undecided,,,epoxy or the PL premium construction adhesive,,,thaat stuff is unbelievable,,( ive seen a boat made with plywood,, nails and pl adhesive,,,,u break the wood before the glue joint fails.... indianabob,, grower of fine weeds and afew hostas

[nedL]

Tim has it right. There would be no stffness to the hull, built like a 'regular' shell but as SOF it might even fold in half just by sitting on it. If you added enough framing to stiffen it the resulting weight would be rediculous. Remember we're talking a 26 - 30 foot boat that weighs less than 30 LBS.

[DGentry]

This is a 6 year old thread.

IndianaBob - what design of kayak are you building? You might note that diagonal kevlar roving has a purpose in Platt Monfort's boats (because they are so delicately built), but not so much in a kayak. Also, heat shrink Dacron is pretty dainty - there are much tougher alternatives that are commonly used to skin kayaks.
I'm happy to answer questions....

As for reviving this thread, the Kingfisher it is 22' long, spec'd at 42lbs. I doubt you could save any weight if you built it SOF. The only advantage would be cost, speed of construction and availability of materials (fabric v quality ply that thin).

Plenty of double and triple SOF kayaks and baidarkas range into the 20'+ length.

[indianabob]

hey gentry,, thanks for the reply,,,first,, im limited to build anything i want as long as its under 12 feet,,,,, last year i did a striper canoe a wee lassie,,modified , 2 in wider,, came out nice except i had ssomebad epoxy and it all had to come off,, and redoo with west sysyem,,,,this kayak plans i found if fmsome canvas kayak,,,,i shortened it to 11 ft,,30 in wide,,,,using kelvar rovings secured at ends only doesnt do much for me,,,i was thinking of using 100 lb dacron and any time u cross anything u use a clove hitch like u tie coil springs in a chair,,,when that is done it will be rock solid,, this is my first try on a skin craft,,, its been fun fo far,,,if this works i may try a round primative thingy,, nice hobby,,,, indianabob

[Ian McColgin]

You're too far away so it matters not for WBF decorum, but I have a friend with a nice wooden single scull that's too big for her - more suited to a man about 160# or more. And it's a whole lot longer than 12'.

[indianabob]

rowing shell/scull,,,,my daughter suggested i try making a rowing shell,,,ultra light...any free plans available,,i wonder if a modified kayak plan wouldnt work,,,and my othere real important question,,, how short can i make it....indianabob

[Cuyahoga Chuck]

If you are building a rowing shell to be able to go fast you MUST pack on as much waterline length as possible. That's one of the laws of hydrodynamics. Plus shells are very narrow so you must make them long enough to achieve enough displacement to support the weight of boat and occupant.
There are rowboats that are configured to slice thru' the water but still be usable for other activities like sightseeing, birdwatching or fishing. Here's one;
http://www.bateau.com/studyplans/SG15_study.htm?prod=SG15

[Dan McCosh]

FWIW, a rowing shell puts a premium on stiffness more than almost any other boat. That's why they traditionally have been made of thin wood, and more recently of carbon fiber. The flexing of the hull is a major source of drag. Wood, particularly some cedars, has an extremely high stiff to weight ratio, while a skin-on-frame construction would be among the worst.

[upchurchmr]

Gentlemen,

The first rowing shell I ever saw was an Antique (60 yo) Pocock. The deck was Tereline which I think is British for a fabric reinforced plastic. The reason the boat was stiff was the spine down the middle with trusswork shear webs to make the whole thing like a beam. Certainly it was not the deck, which should have been taking the compression, since it was almost not there (about .020 thick plastic).

I suspect you could relatively easily make the boat stiff enough, I just wonder what the weight would be.

The thing I wonder about for a SOF shell is how to make the hull surface in the water smooth - less friction/ wavemaking. This would be a really interesting SOF project, but like everyone points out you need the length and also some beam if you are not a good quality racer. You could put a hogged shape to the boat, when you put it in the water with the person onboard, the boat could flex to the intended shape. That would save some weight. These boats are not meant for waves anyway.

Dave Gentry could talk about the where the stiffness comes from in his 18' boat. Sorry Dave, I can't remember the name right now.

All the stiffness would be in the frame, with the skin just keeping the water out.|:)
Marc

[indianabob]

very interesting reply,,,im not interested in racing,,my dau would like to do some rowing,, and her pappy likes to make things,, i am limited to length,, unless i make all the parts and wait for summer,,,,i cant find plans,,,but ive looked at pictures,,,seems like a slight v bottom,, no rocker,,lotsa thinking ,, keeps me sane,, indianabob grower of fine weeds and a few hostas

[DGentry]

. . . This would be a really interesting SOF project . . . These boats are not meant for waves anyway.
Dave Gentry could talk about the where the stiffness comes from in his 18' boat. Sorry Dave, I can't remember the name right now.
All the stiffness would be in the frame, with the skin just keeping the water out.|:)
Marc

A SOF shell is an interesting project, yes - one that I've been considering for a few years now. Not that it has taken me years to figure out what I want, just that I haven't gotten around to it (and it's still low on the list!).

First, one must realize that most homebuilt rowing shells are never going to be competitive with a modern composite racing shell. I'm not saying it can't be done, but . . . .

So, if you build a SOF (or wood, practically speaking) rowing shell, the reality is that it's going to be a "recreational" or training shell, not a racer. Ergo, you don't have to worry about being as ultra efficient, or as extreme in dimensions - your boat is just for going fast, having fun and getting some exercise.

So, shorter, wider, less rigid, etc - these things are all fine. SOF would allow you to build a light weight boat, quickly and inexpensively. I envision a drop-in rigger (a la the Piantedosi), btw, rather than an integral one.
Could you make a more efficient shell out of wood? Sure! But, it would take considerably longer and cost far more, and might weigh more, too. And, if you're not racing, is that extra knot - or maybe just a half a knot - going to be noticeable? And will it be worth the extra money and time?

One day, I'll build a SOF shell, just for fun. Till then, I have my non-shell: An 18' x 33" SOF wherry, RUTH, which definitely goes plenty fast with just fixed seat rowing, or can go even faster with a sliding seat. She has many advantages over a shell, but she can't keep up with them, of course.
Err, unless there are waves over 8" high.

Here's RUTH with my neighbor, forumite Paul Helbert, giving her a spin:
http://i174.photobucket.com/albums/w117/alias1719/Paddling in VA/Arrowhead6.jpg
RUTH can use a sliding seat, too, if you really want to move. Most significantly, as she is a skinboat, I was able to build her in just a week and a half, for very little money.

Yes, all the stiffness is in the frame. A rec shell 3 feet longer and half as wide would certainly be stiff and fast enough for any rowing that I'll ever do.

IndianaBob, check out Tom Yost's website for some free SOF kayak plans - his Sea Bee is just about the size you are looking at. www.yostwerks.com (http://www.yostwerks.com)

Dave Gentry

[CapnJ2ds]

Gentlemen,

The first rowing shell I ever saw was an Antique (60 yo) Pocock. The deck was Tereline which I think is British for a fabric reinforced plastic.

Tereline - Terylene is the English word for Dacron. Same stuff.

[indianabob]

thanks for the reply,, i went to yost site,,,WOW, i learned more and got more ideas ffm this site than all others combined,,, i have all the tools i need (lol who needs 7 routers),,,,my wheels are turning now,, i do have all the materials for a bent rib ultralite kayak,,,heat shrink dacron skin,,,soon as i clean the shop,, make the strong back,,they kayak wont take a lot of time,, i do have a beautiful old quartersawn buffet to refinish,,that can wait,,,i have about 170 trays of hosta seeds to plant and germinate...i have 7 banks of 4 bulb floresents to grow my seedlings...back to boats,,ill bet i can loftout a very nice rowing shell after seeing his site.. not a racer,just something to row in the evening,,,,i have ssome 3 x 3 dry ash blanks i was saving for baseball bats,,would make some nice oars,, as my uncle jimmy said,"u quit using your brain and stop making things they are gonna plant you",,, thanks again,, nice site... indianabob