BananaShark 34' Build thread

[kitten]

Sorry Chewy, that was a bit obtuse, the rails differ on the steps as does the deadrise and the anticipaited running depth of each section we have placed the rails to try and be right for each section to provide stabilaty and reduce drag when running.
As Cookee says the rails in the boat will be sacraficial so we can remove what is not needed but I am sure they are about right.

[chewy]

Cheers for that, so the placement is more dependant on the actual step they are to be fitted rather than the position of the rail on the step in front, if that makes sense?

I have quite a few "obtuse" days on here!

[paul holder]

first of all thank you for shairing your build with us
how have you determined the size & the placement of the rails . did you use a scale model in a tank or calculation .most manufacters seam to have spray rail because they have .it is the same as the hull shape why a deep v why a shallow v . what angle is best & why when you ask these questions at shows no one seams to know with an enginering ansure

[kitten]

OK first off this is all my opinion and as such can be disagreed with if you wish.
Hull design is always a compromise.

Deadrise, or v angle, shallow v makes for a faster hull but harder landing, deeper v makes for slower but softer.

Rails are there to deflect water and energy away from the hull, mostly down if you can.
There is a high(er) pressure area developed at the hull water contact point, anything above that is in the air and as such useless ( unless you are looking at aerodynamics)
Most of the stuff below that is drag and therefore a hindrance. Trouble is the bloody water never stays in the same place, so this area moves around on the hull so you have to balance that to try and make the boat do what you want it to. SIMPLES.

We do have a scale hullform for this boat and if you want you can see some of the video on youtube search kitten268 and see the dart vids.
You can’t get data for a planning hull from a model, basically you are trying to balance the weight of your boat on a small patch of water that is wobbling about, even in a test tank with loads of money to spend the variables are too great. What you can get is a very good feel for how the hull is going to handle and any nasty/nice characteristics it is going to have.

[Cookee]

It's been a while, getting close to getting the hull mould done now - the formica sides are on now and work is progressing on making all of the corners razor sharp and making all of the bits where everything joins up smooth.

Kitten has also removed the extension on the transom so that it will be easier to provide an outboard alternative as well as the inboard - that will be made separately and retro fitted to inboard boats.

[Cookee]

Here are some more updates for you guys and girls .........

The location points on the flange (last photo) are half ping pong balls glued on, start the mould next!

[Downhilldai]

Coming along nicely Cookee

Originally Posted by Cookee

The location points on the flange (last photo) are half ping pong balls glued on, start the mould next!

You didn't buy a load of those mould clamps off lloyde then?

http://www.henleycraft.co.uk/GRP%20M...e%20Method.htm

[kitten]

Originally Posted by Downhilldai

Coming along nicely Cookee



You didn't buy a load of those mould clamps off lloyde then?

http://www.henleycraft.co.uk/GRP%20M...e%20Method.htm

I think I have a freebee comming in the post, but I aint holding my breath

[Downhilldai]

Originally Posted by kitten

I think I have a freebee comming in the post, but I aint holding my breath

Will one be enough?

[kitten]

Originally Posted by Downhilldai

Will one be enough?

Well he says they are really good. Anyway, what you bin doin on the dark side?

[jwalker]

Using the formica has made it crisp hasn't it. You'll be pleased with it I'm sure. Nice work guys.

[Downhilldai]

Originally Posted by kitten

Anyway, what you bin doin on the dark side?

Just checking whether there's any work being done over there. This shananabark job is dragging on a bit.

[kitten]

Originally Posted by Downhilldai

Just checking whether there's any work being done over there. This shananabark job is dragging on a bit.

We like to string things out.


Cheers JW unfortunatly the formica is not as thick or shiney as it used to be when it was formica. if you see what I mean

[Cookee]

Originally Posted by Downhilldai

shananabark

[Cookee]

The first of three layers of gelcoat was applied on Friday, the second went on this morning and the last layer will be done tomorrow morning, that leaves the fibreglass, stiffening, turning frames, then turn it over and repeat for the top half - separate and make the first hull!

[biffer]

you've started something you can't stop now, chasing the air bubbles always make me sweat, safe to say you won't be laying one up in that colour eh!

[kitten]

Originally Posted by biffer

you've started something you can't stop now, chasing the air bubbles always make me sweat, safe to say you won't be laying one up in that colour eh!

That's the idea besides mould is green
Have done a black boat in black moulds though

[Cookee]

A bit overdue for an update - sorry about that! Well we've finished the hull mould now and it was time to turn it over last Friday. We had made a pair of A frames which will also be used to tilt the mould when laying up the boat. We needed to control the whole thing to stop it turning "at it's own speed", so Kitten robbed a set of front brakes of his XJ900 and made a disc, welded the whole thing on and voila! Thanks to the very nice Paul Mcarthy at Wolf Rock (he's our neighbour) for the use of his fork lift truck - again! The Photos are pretty self explanatory I think ............

[Cookee]

The steps are a regular staircase cut in half.

[jwalker]

Very slick... and full marks to Mr Kitten for his disc brake!
A neat line in staircases too I see.