Mess About 12 foot

[Kudzu]

In case you don't read the Announcement forum the Mess About 12 is now available.

Jeff

[woodman]

Nice to have a variety in you're selection Jeff...I think you have designed a beautiful line of kayaks...

You have commented that you like to build each of you're designs before releasing the plans...

I don't know as if you need to personally build everyone you design...

I don't see how Matt over at JEM could keep up with building all his designs..

[Kudzu]

The more do the more confident I become. Some boats I know they will go together and there is no reason to build. Especially one like this that is just a resize of an existing design.

But some boats with new ideas must be built to make sure it can be built. The Rowing boat is a perfect example. I have some new ideas I need to test and I need to document for the manual.

[Global Nomad]

I finished one of these this summer from the plans in More FF Boats & was disappointed with the result. It may be that I just don't understand what 250 lb displacement means. With me or my son-in-law in there (about 190 lbs) sitting on the floor boards, it was low in the water & initial stability was bad. With a 140 lb paddler, it was fine.

 

Having built a screw & glue SOF decades ago, I loved the lashing method -- SO much better! Cost was significantly higher than $300 but I was OK with that & thinking about a Ravenswood for a 2nd boat till I got this one in the water. Now I'm gun shy about investing the time & money in it.

 

Don't know what I'm missing. I had to build a short boat because of limitations in shop space (think Jethro Gibbs, if you're an NCIS fan) but I thought a 250 lb displacement would handle a 190 lb paddler with no problem. Now I've got to decide whether to hang onto it for when the grandkids get older or try to sell it to somebody little.

[Kudzu]

Stability is a personal thing. Most anyone can learn to paddle a skinny boat with a little seat time. What I use to call scary I would now call stable. Other would call it a barge. So you have to take the person in the boat into consideration when they stay it is not stable. That is not a stab at you, it's just a fact that stability is a personal opinion.

 

But, I looked it up and even double checked my calculations. A properly built MA-12 should have a stability factor of 117. I know that means nothing to most people, but anything above 110 is should be comfortable for a first timer. So I find it very surprising your saying it is unstable.  It brings up a lot of questions that can not be answered over the internet.

 

First thought that comes to mind is, is it built to the plans? Since you had to loft it is soooo easy to make a mistake. We all do it. 

If it is built to specs your not going to like Ravenswood, because is it lower in stability.

 

I would ask about seat height. Where are the floors? How did you mount them? Seat height, even a 1/2" can make a HUGE difference in the feel of the boat.

 

Have you ever paddled before and if so what? That goes back to what I was saying about when I started out.

 

It's just next to impossible to see what the problem is over the internet. But you are the first one to say anything about the stability of this boat. So best I can do is just guess.

[Kudzu]

OK, I meant to ask about your cost. I know that some areas materials are higher than others and I have been raising that estimate to $350-400 as prices increase.  Based on my area it would break down something like this.

 

$50 for a sheet of BB plywood

$50 for wood stringers This is pretty variable depending on what wood and where you live.

$85 for Kit with footrest, sinew, backband

$63 for 13 feet of 8 oz fabric

$35 for finish materials.

$25 for misc. items.

 

That comes to $306 plus shipping cost.

 

PS  OK, I just realized I left a seat. That could run from $20 to camping pad to $175 for a custom Redfish seat.

[Bcone1381]

Jeff, How does a kayak's stability react to increasing weight assuming the Center of Gravity (CG) is not raised?  I remember being in a canoe that was half filled with water and recall its decrease in stability.

 

Global Nomad, As an example of how a higher CG effects stability,   A standard Coast Guard Approved boat cushion raises the CG about 3inches off the floor, making my Cast-a-way's (15' Messabout hull) stability a concern and thus slightly uncomfortable.  However,  it is rock solid using A Kayak seat that raises my butt about 1 inch lift above the bottom of the kayak.  At least 10 people (all under 160 pounds) have used these kayaks and have not even mentioned stability concerns. When prompted, they all say it feels stabile.

 

Watching my 190 pound son paddle our Ravenswood last week made me wonder if the increase in weight decreased its stability as compared with my wife (110 lbs).  When questioned, he said it felt good. 

[Kudzu]

I stole this but I like the way he said it.

 

"The higher center-of-gravity factor is important, but so is the amount of weight. Think about it this way. The more weight you add to a boat, the more hull volume is submerged, and the more hull volume that's submerged the less the displacement profile changes when the hull is leaned. An extreme example is a boat that's swamped. A swamped boat has virtually no resistance to tipping, because with most of the hull already underwater, almost nothing about the displacement profile changes when it's tipped."

 

But no two people are alike. So that is why  like the Stability Factor I use. It gives a single number that you can compare boats with. It doesn't tell you everything there is to know about stability but if you now you are not comfortable in a boat with a Stability Factor of 100 and the boat you looking at is 93 you know it is less stable than what you paddle now.

[Global Nomad]

Built to plans? Yup. This is kayak #5 for me. I've paddled each.

 

16' Folboat double (built back in high school from a kit)

15' CLC Cape Charles (stitch & glue lofted from plans)

18' CLC Cape Charles (stitch & glue lofted from plans)

14' Pygmy Kayak Arctic Tern (stitch & glue from kit).

 

The Pygmy performed the best. I built it for my daughter & if I could have afforded to, I would have built another for myself. The 15 foot CLC was a good fit too. I've also done a strip-built Cosine Wherry from full size plans & a couple other small boats.

 

Seat height:

 

I didn't sit on the boat cushion for long! Pulling it out improved the stability. Floors are 5/8" slats lashed on top of the frames.

 

Secondary stability was great.

 

It's true that feel is a personal thing. A canoe is like a second skin to me and it takes the right fit & feel to feel at home in a kayak. I loved the lashing method -- screws on that old folboat were forever pulling out -- and loved the light weight. Looking for the right design will just keep me building, I guess.

 

I'll look up cost & post that.

[Global Nomad]

Cost.

 

Now, this is a matter of debate. There's a difference between the cost of raw materials that are strictly part of the boat (that is, they end up on the water) and the cost of building it (strongback, special tools). The first comes to $470, the second to $395. Shipping is included but that only applies to the $77 & $152 orders below. The rest was bought locally. I'm in the Washington DC area where EVERYTHING is more expensive, so that probably factors in too. The only tools involved were paint brushes, and cheap bungee cords & hot knife from Harbor Freight.

 

$45  plywood

$56  glue, cedar stringers 1x4x8

$42  floor boards & paint

$10  screws for rub strip, Lexel caulk

$13  paint for coaming

$77  tung oil, keepers foot braces, 1 roll of sinew

$152  back band, 14' 11 oz fabric, needles

$38  8 ft 1x6 for strongback

$37  bungee cords for assembly, 6 chip brushes & Harbor Freight hot knife

Total: $470      

 

I had wood for the coaming & rub strips, sandpaper, hardware for strongback assembly, & silcon bronze screws for the coaming so no cost there.

 

Without tools & strongback -- take off the last 2 lines & it comes out to $395. Can't really build one without a strongback though.

 

Not included:

   cost of the book (plans) -- this should be in there, but I'm too lazy to look it up.

   seat

   paddle

 

I could have cut costs by painting it all one color. I used cheap plywood because it was an experiment. I didn't want the expense of shipping BB or driving over to Annapolis for a $130 sheet of marine mahogany ply.

 

So, it cost more than I expected but it was fun to build anyway. I'd love to do another model if I can ever make it to Alabama for a test paddle first!