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New Deck #117768
09/21/07 09:33 AM
09/21/07 09:33 AM
Joined: Jun 2006
Posts: 177
Sydney/Northern Beaches
Bandit Offline OP
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Bandit  Offline OP
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Sydney/Northern Beaches
I have finally seen the light and have procured a mozzie.
Currently sanded back to bare timber the hulls weigh 22kg.
I feel however to reach overall min weight of 55kg,
More weight needs be lost and the centre deck is 6-8mm ply. The rest of the decking is 3mm. I want to replace the centre deck with 3mm ply with one layer of fibreglass with the hope of losing a kg from each hull. I am no expert on this so I am wondering what other methods or suggestions people have in regards to this topic and what weight lose I might expect to realistically gain...?


Sail 1635 Blue Tongue
-- Have You Seen This? --
Re: New Deck [Re: Bandit] #117769
09/21/07 05:08 PM
09/21/07 05:08 PM
Joined: Jul 2006
Posts: 461
Victoria, Oztralia
mattaipan Offline
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Hi Bandit

I think 3mm for the main deck is too thin, make it 4mm with glass, but also check the class rules there might be minimum thickness, good chance you'll lose some weight but I'm not sure how much. Original plans for the Mosquito had two layers of 4mm ply, and back then Gaboon ply wasn't around, so I'm sure theres some savings there if you replace with Gaboon (Okoume)Ply.

Regards


Matt Harper Homebuilt Taipan 4.9 AUS 329 'GOT WOOD' SEEDY PIRATES RACING TEAM
Re: New Deck [Re: mattaipan] #117770
09/21/07 07:17 PM
09/21/07 07:17 PM
Joined: Jun 2006
Posts: 177
Sydney/Northern Beaches
Bandit Offline OP
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Bandit  Offline OP
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Sydney/Northern Beaches
Ok I was thinking the deck is very well fastened down so I might try cutting back the top 4mm sheet and then sanding through the adhesive until I hit the second 4mm sheet. Glass over the top of that with 2 layers of light cloth.
If I can shave a kilo then I might be able to reach min weight. Also I noticed a rule Proposal 6.5 to make the center beam optional. After reading the rules I am confused.
It states

(Accepted at Annual General Meeting, 3rd January 2007:)

Does this mean a proposal has been accepted to be further voted apon? or is the rule officially changed now?

Last edited by Bandit; 09/21/07 07:20 PM.

Sail 1635 Blue Tongue
Re: New Deck [Re: Bandit] #117771
09/21/07 07:35 PM
09/21/07 07:35 PM
Joined: Jul 2006
Posts: 461
Victoria, Oztralia
mattaipan Offline
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Hi Bandit

Without actually looking I not sure that proposal didn't go through, I stand to be corrected, but I think the centre beam stays.

With regards to your deck, I would start again from scratch, I would get a router if you have access to one, get a straight cutter bit, if the deck is say 6mm, set the router to 5mm and go nuts, start off near a hatch hole so you can make sure your not going all the way through.

Regards


Matt Harper Homebuilt Taipan 4.9 AUS 329 'GOT WOOD' SEEDY PIRATES RACING TEAM
Re: New Deck [Re: mattaipan] #117772
09/21/07 09:06 PM
09/21/07 09:06 PM
Joined: Jun 2006
Posts: 177
Sydney/Northern Beaches
Bandit Offline OP
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Bandit  Offline OP
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Sydney/Northern Beaches
I will try grab some 3mm or less gibbon ply.
I'll beef it up with supports like grey matter and fiberglass the deck.
More deatils on the rule change can be found on page 17 by using this link.

http://home.vicnet.net.au/~nmcca/doc/Mosquito_BRR.pdf

If I cant drop the center beam then I don't think I will make min weight. So clariforcation on this rule is important as I intend to order a tramp designed around this factor.


If it isn't a change then old rule has 2 loop holes..
It isn't clear as the center beam as compulsory only that you have to have a rear and main beam.

Also according to the rules they do specify aluminium for the main and rear beam but they do not specify what material the center beam should be made of only dimensions are listed...
has anybody used carbon tube??
Unless someone else had already done this I would be hesitant as I belive its a loop hole that was unintentional..
Anyone care to argue the pros and cons further??
How far could you go. Could a pool noodle constitute as a beam???

Still I need to establish the rule change first before trying to exploit a loop hole...

Last edited by Bandit; 09/21/07 11:18 PM.
Re: New Deck [Re: Bandit] #117773
09/22/07 02:35 AM
09/22/07 02:35 AM
Joined: May 2003
Posts: 4,451
West coast of Norway
Rolf_Nilsen Offline
Carpal Tunnel
Rolf_Nilsen  Offline
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Posts: 4,451
West coast of Norway
Bandit,

as seen from an outside viewpoint, class minimum weight is mostly an psychological issue. The difference between minimum weight and minimum weight+5kg is so minute that not even the olympians would notice. It is nice to have a regatta boat at min. weight, but finishing the race is much more important if you want to win. Marginal structures are known to break from time to time <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Re: New Deck [Re: Bandit] #117774
09/22/07 03:12 AM
09/22/07 03:12 AM
Joined: Jul 2006
Posts: 461
Victoria, Oztralia
mattaipan Offline
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mattaipan  Offline
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Victoria, Oztralia
Well after reading that, I guess it is optional, it does say at the top, accepted at the AGM.

I still say 4mm for the deck, but if you've your heart set on it, not much I can say, accept, that adding extra material to beef it up and having two layers of glass, would probably weigh more than having the 4mm with one layer of 100g/m cloth.

Good Luck though, its all good fun.

Regards


Matt Harper Homebuilt Taipan 4.9 AUS 329 'GOT WOOD' SEEDY PIRATES RACING TEAM
Re: New Deck [Re: mattaipan] #117775
09/22/07 04:32 AM
09/22/07 04:32 AM
Joined: Jun 2006
Posts: 177
Sydney/Northern Beaches
Bandit Offline OP
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Bandit  Offline OP
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Joined: Jun 2006
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Sydney/Northern Beaches
The old deck weighs 4kg.
I am hoping 3mm sandwhiched between fiberglass will weigh 3kg saving 1kg per hull.
I also plan on a new one piece tramp with a rear bolt rope and wire sleaves for cable attachment via the beam bolts at the corners.. The new tramp overlaping half of the hull makes this possible in accordance with the new rules.
Thanks for the help so far Matt..


Sail 1635 Blue Tongue
Re: New Deck [Re: Bandit] #117776
09/22/07 05:29 AM
09/22/07 05:29 AM
Joined: Jul 2006
Posts: 461
Victoria, Oztralia
mattaipan Offline
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Victoria, Oztralia
Normally I could weigh the sheets and let you know difference, perhaps someone can, but all my sheets are in my caravan, which is full to the door with other stuff as we've just moved house.

You would have prebend the decks to the approximate curve if your going to glass both sides I would imagine.

I've just put the decks on, glass over and down the sides a bit, 3mm ply on the foredeck, 4mm ply on the main and rear decks.

My mossie which was an original kit boat from the 1970's, the platform alone weighed 75kg or there abouts. It was built up to the deck stage and twenty years later, and about 12 years ago now, I followed the original plans and put the 2 x 4mm decks on, not knowing what I do now. I'm planning a restoration next year and the decks will be No1 job when it happens.

Regards


Matt Harper Homebuilt Taipan 4.9 AUS 329 'GOT WOOD' SEEDY PIRATES RACING TEAM
Re: New Deck [Re: mattaipan] #117777
09/22/07 05:58 AM
09/22/07 05:58 AM
Joined: Apr 2007
Posts: 134
greymatter Offline
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greymatter  Offline
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Posts: 134
the decks on my boat are 3mm and glassed on the inside. be carfull as the older boats wouldnot have the same amount of foam frames and timber frames as my boat. if you are replacing your decks put as many foam frames in as possible and some timber frames to support the decks.

Re: New Deck [Re: greymatter] #117778
09/22/07 06:05 AM
09/22/07 06:05 AM
Joined: Jun 2006
Posts: 265
Sydney AUST
becjm Offline
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becjm  Offline
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Posts: 265
Sydney AUST
Rodert,
What do you mean by glassed on the inside?
How do you do this?


---Ben Cutmore---
--MOSQUITO 1704--
Re: New Deck [Re: becjm] #117779
09/22/07 06:20 AM
09/22/07 06:20 AM
Joined: Jun 2006
Posts: 265
Sydney AUST
becjm Offline
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becjm  Offline
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Sydney AUST
Hey Cam,
Here are some photos of your hulls. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />
Thaught You might want to see the damage I've done on your behalf <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Attached Files
119141-Cams2.JPG (215 downloads)

---Ben Cutmore---
--MOSQUITO 1704--
Re: New Deck [Re: becjm] #117780
09/22/07 06:23 AM
09/22/07 06:23 AM
Joined: Jun 2006
Posts: 265
Sydney AUST
becjm Offline
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becjm  Offline
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Posts: 265
Sydney AUST
Can anyone tell By the photos who may have built the hulls?

Attached Files
119142-Cams3.JPG (215 downloads)

---Ben Cutmore---
--MOSQUITO 1704--
Re: New Deck [Re: becjm] #117781
09/22/07 06:26 AM
09/22/07 06:26 AM
Joined: Apr 2007
Posts: 134
greymatter Offline
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greymatter  Offline
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Posts: 134
what i mean is to glass the inside of the deck before fitting them.
1)cut the ply out to the deck shape
2) mark a line around the deck 20mm this is so you don't get resin on this line at this stage so when fitting the decks you get a fresh glue line, no old resin.
3) cut glass cloth to size
4) mix rein and paint onto ply keeping the out side 20mm clean.
5) lay glass cloth on deck and roll through the resin.
6) lay deck on bench with a beam under one side (long side)
7) when the resin starts to go off place a large rubbish bag on top of resin and place a small amount of weight on it to put a slight bend in the timber when cured, to help with deck curve, the plastic bag should not stick to the resin.

Re: New Deck [Re: becjm] #117782
09/22/07 06:46 AM
09/22/07 06:46 AM
Joined: Sep 2006
Posts: 393
Camden NSW
wildtoy Offline
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wildtoy  Offline
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Posts: 393
Camden NSW
Quote
Can anyone tell By the photos who may have built the hulls?


The boat was built by someone in Newcastle. I could find out for you if Im bothered going to kurnell tomorrow.


Re: New Deck [Re: Bandit] #117783
10/07/07 06:08 PM
10/07/07 06:08 PM
Joined: Mar 2003
Posts: 943
East Gippsland, Australia
Tim_Mozzie Offline
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Tim_Mozzie  Offline
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East Gippsland, Australia
Sorry I haven't replied to your questions about the centre beam rule earlier but I've been away a couple of weeks.

That proposal you have picked up in the 2007 rules was purely a typo. That heading "Rule6.5" and the three paragraphs that follow simply shouldn't be there. It's a mystery to me how they got there, but I must have done it when I updated the rules so I'm sorry to have caused this confusion.

Mick Floyd has already corrected the online rules on the NMCC website.

The text originated 3-4 years ago when a proposal was made to make the centre beam optional, but the idea received no support at the time and never went any further.

In answer to your questions about rule 6.5:

1) The centre beam is definitely not optional - it's in the Mosquito plans and the BRRs don't say it can be left off.

2) The material is not specified and it could be argued that other materials (like carbon) would be permissible, however the size and wall thickness is very specific and this would limit the kinds of materials that would be possible. It's not much of a loop hole since a carbon beam 50mm x 1.5mm may not actually save much weight - should be stronger though!

3) A beam is a "beam". A piece of string or bungee is not a beam, and neither is a pool noodle.

If you are getting a new tramp and your boat had the aluminium tracks down the sides you can save some weight by replacing the tracks and bolt rope with a piece of spectra between the front and rear beams. You just need an eyelet halfway between the beams to tie the tramp down to the hull.

Matt Kirby has his boat set up like this, and some South African Mozzies too, so they might be able to supply some photos if you're interested.


Tim Shepperd
Mosquito 1775
Karma Cat
Re: New Deck [Re: Tim_Mozzie] #117784
10/07/07 07:14 PM
10/07/07 07:14 PM
Joined: Jun 2006
Posts: 177
Sydney/Northern Beaches
Bandit Offline OP
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Bandit  Offline OP
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Joined: Jun 2006
Posts: 177
Sydney/Northern Beaches
It would be nice for my boat to be within the rules but I like things to be simple and I think the centre beam is an eye sore.
In the interest of assisting change I have gone for a one piece wire mounted tramp via the beams for simplicity and to save stressing my light weight deck.
I will have only 200mm length of centre beam for my traveller cleat to mount from but that’s it.
The tramp will sit under it with a bolt rope mounted to the underside of the rear beam. If people like it they may opt to copy me and the rules may yet be changed.
A beam after all is classified as a support and while mine doesn't span across the tramp to the front beam it still supports my traveller cleat and the rules don't specify the length of the centre beam. Hopefully this is a loop hole.

I think for NSW we need the mossie to be simple and cost effective otherwise the enthusiast who wants to build his own may build another design.

Beam sections are sold in 6.5 mtr lengths and expensive purchase for one beam and until NSW numbers grow we can’t divvy up the left over’s..

I also would like to approach the wooden boat building classes for novices. It’s based here in Sydney and if we offer the mossie plans I hopes they might build up NSW members. The cost will help that factor as a mossie is a good class per dollar value...
Increasing that attribute can only be a good thing or otherwise they may prefer for a little extra, to build a taipan or a new blade...

I also was wondering how the vote system works is it counted by votes received yay or nay then the percentage or is votes not received from members considered a nay vote to affect the percentage?

I hope encourage the KISS Factor of the class and will go ahead with my adopted design (race legal or not) to help promote the changes..

Last edited by Bandit; 10/07/07 09:15 PM.

Sail 1635 Blue Tongue
Re: New Deck [Re: Bandit] #117785
10/07/07 07:32 PM
10/07/07 07:32 PM
Joined: Jun 2004
Posts: 502
Port Noarlunga, SA, Australia
D
Darryn Offline
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Port Noarlunga, SA, Australia
Quote
Beam sections are sold in 6.5 mtr lengths and expensive purchase for one beam and until NSW numbers grow we can’t divvy up the left over’s..



I recently purchased a 6.5 metre length of the correct material for a centre beam and it cost $22. It was cut into 2 pieces for nothing at the aluminium distributor to make it easy to transport home and after making the beam I had enough left over to make an axle for my beach rollers. I dont beleive the cost was excessive and the waste is minimal.

I also dont agree with the majority of the rest of your post, best of luck with your boat that was a Mosquito.

Darryn
1782

Re: New Deck [Re: Bandit] #117786
10/07/07 08:03 PM
10/07/07 08:03 PM
Joined: Mar 2003
Posts: 943
East Gippsland, Australia
Tim_Mozzie Offline
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Tim_Mozzie  Offline
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Posts: 943
East Gippsland, Australia
I guess it depends on the circumstances but you should know a Mosquito was protested out of a regatta a couple of years ago for not having a centre beam.
If you start beating other classes on handicap they may start asking questions about why your boat looks different from the others!

You're not the first to think whether a stub of tube or a bit of string would do instead of a beam, but the rule says its 50mm dia (or square) for the whole length and just plain common sense says a short piece of tube that goes nowhere is not a "central beam". The plans (which are still referenced by the rules) also show the beam. It's not really a loophole.

On a different tack altogether, I wouldn't consider removing the beam from my boat as I think it would just make it very difficult to sail the boat competitively. When sailing downwind with or without spinnaker we spend a lot of time in the centre of the tramp to get the hull to fly. Without the beam this would be a lot harder.

Other reasons to have a centre beam are to provide a mounting for a centre mainsheet cleat, and to stop your front beam breaking if you rig a spinnaker. There are doubts over whether the beams are strong enough to take the side loads without the centre beam on a sloop rigged boat.

As I mentioned this came up a few years ago as a serious proposal to do away with the centre beam, and it received no support at all.

As far as buying the material I know Bob Keeley in Melbourne has it (03 9555 4622). 50mm tube is pretty basic stuff that I would imagine a lot of chandleries could get. That guy in the little shop near the CYC in Rushcutters Bay springs to mind.

To summarize the voting on rule changes, everyone competing at the nationals gets to vote then at the AGM, and each state association also gets a vote for every 5 members. How the state association decides to cast it's vote on behalf of it's members is entirely up to that state association to organise for themselves.


Tim Shepperd
Mosquito 1775
Karma Cat
Re: New Deck [Re: Darryn] #117787
10/07/07 08:09 PM
10/07/07 08:09 PM
Joined: Jun 2006
Posts: 177
Sydney/Northern Beaches
Bandit Offline OP
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Bandit  Offline OP
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Joined: Jun 2006
Posts: 177
Sydney/Northern Beaches
I encourage a difference of opinion as I am relitivly new to the class..
Here is my reasons for the change.
I have found old mossies popping up here and there but they can be too heavy to be competetive especially for myself at 100kgs.
The old rule min of 65kg was changed to 55kg making these older boats slightly disadvataged. I have lost 4 kg from dropping my center beam and 4 kg from my heavy decking giving me half a chance at reaching min weight with an old boat. Cant see why the optional main beam would cause any issue as most boats these days are all under weight with a main beam an unless I am mistaken it has no bearing on a boats performance. Your spinniker sloop rig boat may put more of a thorn in the idea but I intend to race Cat rig.
If I don't like my changes it wont be hard to install the beam...

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