Oh you guys are great. I volunteer to be the F12 forum moderator so I can lock this thread before my kids see it <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />. I'm happy with the black annodised beams but will probably be a bit tricky like Gato with the paint, the only problem I see is touching the paint up. I like the thought of 1 can of paint for all the boats. Scarecrow or RG had you given any thought to a rubber bow protector as I will be loaning my boats to novices, it may stop us sinking a 420
regards.

Hi all,
short update, all the hull halves for the 4 boats are finished now, a couple of boards have been made and the flanges for joining the hulls are being installed. Billy's wife wrote an article for the next Aussie Multihull mag that will be out in the next issue, with luck that will generate a bit more interest.
Jeff....why wouldn't we want to sink 420's ? <grin>
Other than that I think life has generally intruded significantly on boat building recently, but some progress has been made.
Cheers
RG

Hi all,

Here's a suggestion for bow protector requirements:

a) Simple, inexpensive, effective, etc. - the usual.
b) Universal - all F12s use the same, if possible.
c) Big - for safety.
d) Highly visible color (orange or red) - for visibility.

A standardized universal bow bumper serves to ID the novice fleet when racing.

Luiz, given that we have such different bow shapes and other designs will probably be different yet again, how do you think your going to come up with a standardized design ?
cheers
RG

Sorry Luiz I reckon any bow protector needs to look part of the boat and not mark the skipper as a novice. I'm thinking of putting just a rubber strip on the bow painted the same as the boat to be unobtrusive but if someone has a better idea.
Great to see you've been flushed out and back online again by abuse of your thread RG. Cant wait to see the article and see if it generates some more activity, I don't want to upset the 420's because we may sink them with a below the waterline shot but then I'm the clubs repairer. My biggest concern is kids swimming, with a 420 not a problem, with the F12 the bow is on the waterline and would crack a skull at very low speed.
regards

Not really a fan of bow bumpers. They deteriorate pretty quickly (within a season of regular use) and are only effective for very slow speed collisions.

I've seen Vagabonds (slow speed training dinghies), Pacers (higher speed teams racing dinghies) and model yachts all get holed or get significant damage after a T-bone with the same boat, both to the "T-ee" and "T-er". All had rubber bow bumpers.

Better to reinforce with learners to keep a good lookout and not run into anything. That concept will hold them in good stead for the rest of their lives, as opposed to relying on bow bumpers.

How about "no bow rubbers" and "wear helmets like Kayakers ?"

Seems to be the cheaper and more easily implemented solution for this situation

Wouter

RG,

You are right.

Trying to find a solution, maybe a compulsory sacrifice bow would do the trick.

An (easy to replace) sacrifice bow would be required of at least X mm length. Soft material painted red for novices; any other color / material for all others.

A soft bow could be a problem when beaching, though.

What do you think?

They dont bump much in the current optis, so I see "safety bows" as kind of overdoing it. Hypothermia is a far more likely danger, but I dont think the boat should be designed with that in mind either.

The DS12 has a solid timber stem. While a little more complicated to build this was done to prevent the ply "splitting" in the event of a collision. Its not unbreakable but it is definitely more robust.

Any measures beyond that are up to the owners.

Im with Rolf, most kids are not idiots and hence will do their best to avoid trouble. I think we are worrying too much. I started sailing young and apart from occasionally getting squeezed on a start line or at a mark with a slight bump (gunwhale to gunwhale) I don't think Ive ever hit anyone.
Cheers
RG

Rolf,

It depends on where you sail. Hypotermia is not a problem in tropical waters, where colisions with swimers are a reality.

In Brasil, for example, it is prohibited to sail or row closer then 100m to shore to avoid colisions with swimers (200 m with engine). Crowded beaches usually have small channels marked with buoys through which jet skis, kayaks, beach cats, etc are supposed to leave and approach the shore.

RG

Kids are smart, especially those who sail, but accidents are more probable when learning than later, whether involving kids or adults.

Sacrifice bows are't present in any competing design, so their absence isn't a disadvantage. On the other hand, they could help build a favorable image of a safe boats for kids.

Along the same line I dream of mast top winglets, not necessarily effective as a go-fast resource, but with enough flotation to keep the boat from turtling. I think their look would help sell the boat to kids while their 'secondary' function would work with parents.

Just my points of view, of course. I can be wrong.

Jeff, just for you :-)
enjoy
RG

Update: see attached pics, 2 hulls closed up and ready for external tabbing, primer and paint. As shown with peel ply still on the outside, each hull weighs 7.7 kg. Expect the finished boat to be well below 50kg finished.
Enjoy the pics
Cheers
RG











[img]http://www.catsailor.com/bb_files/149031-DSCF0801.JPG[/img]

RG your vewy vewy naughty but I like you <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />
Is the blade sticking out the side in the other pics to finish off survivors?
Good to see the pics
regards

[/quote]

RG your vewy vewy naughty but I like you <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />
Is the blade sticking out the side in the other pics to finish off survivors?
[/quote]

Gotta love people who think creatively <grin>

Cheers
RG

I think these are going to be stunning boats RG. Good job.

I second that.
RG and Scarecrow being that you've chosen boats from different materials I'm very interested to know what paints, sealers, undercoats you recommend and why.
regards

Jeff,

For sealing timber structures I always recommend multiple coats of Evidure applied as per the product data sheet.

Resins and composites I use and recommend SP systems (Gurit)

Silicone adhesives and sealants Sika-flex

Paints I use Jotun or International.

saw this link to the multihulls article on boatdesign.net
Vudu Article