Building 23' catamaran. Build updates

[stevemid]

what system are you painting with,cheers chris.

The thing I noticed w the black guide coat is the overspray. I had the motor wells fair but covered one in guide coat working on the adjacent hull panel. that's why I was thinking of using this black powder Swannie1975 mentioned

I am going to use Wattle 2 pack hi- build, and am tossing up roll & tipping with Alexseal or Sterling for the paint.

Cheers
Steve

[timeout]

Hey Steve this is much better than chassis black mate.
http://solutions.3m.com/wps/portal/3...glQX28R3361Cbl

one of these will take a lot of pain out of it and useful before final buffing also.You can get a foam interface pad to use on the curved bits also.
http://solutions.3m.com/wps/portal/3...glXHVZ8N3977bl
any good auto paint suppliers in Aus will have them.

[Swanie1975]

timeouts on the money there but i would call into a local panelshop and ask where they get their supplies from - should be able to get a powder product hopefully at a better price. dont worry about the spray can residue as you need to keep sanding until its all gone anyway and it really helps show your highs and lows.

when you are sanding i take it you are criss-crossing not rubbing in straight back and forth lines. if you experiment with sanding the bog gently just as it goes off with the 40 grit you will find you can shape it quickly and with less effort but it will clog the sandpaper up. it takes practice but saves a lot of hard yakka. once the bog hardens up fully you can finish it off nicely with the finer grits.

whereabouts are you steve? if youre close to the goldie i could show exactly what i mean.

cheers ryan

[stevemid]

Hey Ryan,
Much as I'l like to be on the GC, I'm on the NSW Central Coast midway between Sydney & Newcastle. I've found the 3M stuff on the web. Not cheap, $55 for a smallish pot. I expect it goes a long way though.

On the sanding front, I've gotten the hang of it now criscrossing with a longer board and changing paper often goes faster and does a better job.
Steve

[stevemid]

Great news boys,
I had the boat's designer out yesterday for a look see. He pronounced the boat straight as a die and near professional in the fairing we've done. He helped me re-fair up two spots in the front where 3 chines come together and suggested I now cover the hull in three coats of high build primer then do a final long boarding prior to turning. This was music to my ears as I can now proceed confidently. Whew!
Steve

[Chimo]

Great news Steve.

Cheers
Chimo

[The Woo]

Great stuff Steve, you'd be pumped! Well done.

[stevemid]

IMG_0366.jpgIMG_0374.jpgAfter getting the hulls fair, I put on 3 coats of epoxy, rolled on and tipped off with a brush. This process avoids the orange peel effect. After the epoxy, I re-sanded then rolled on three coats of high-build sand-able primer. This actually acts as a guide coat, giving the hulls an all one colour finish. When you start fine-sanding that you can easily see the high and low spots . I don’t want to go too crazy with the under-water sections as that’s going to get a copper-rich epoxy based paint job and wouldn’t need to be finished for a mirror paint job. In order to paint on 3 coats of primer, I laid boards across the tunnel, laid on the boards and painted 3 coats one after the other without stepping on previous coats. Must have got my inspiration from the olympic acrobats.

[Chimo]

Be a shame to use the boat. Straight into the pool room I reckon. Saves on a trailer and a 4WD!

Cheers
Chimo

[stevemid]

Nah....I gotta at least weigh the thing in case Mister asks. And I'd like to check out top speed WOT just to get even with my mate who built one with 60 Suzuki's who has the better shed. I'm going with Yamaha's. (I didn't say 70HP did I?)


Steve

[stevemid]

I lost 500kg!

The wife of a mate of mine who also built a Spirited 230 catamaran (he passed away recently) was trying to get the boat registered and the need for an Australian Builders Plate came up. All boats being registered now need an ABP. She didn't know what numbers to put on the plate and I was having a conversation with the designer about this. Here is a picture of the ABP.
Aus Builders Plate.jpg Here are the specs of the boat:
230 Specs.jpg
Now I've always thought that you added the payload to the displacement of the boat. No, the designer said the displacement already included the estimated payload! Therefore where I've been thinking about trailers and tow vehicles I've always calculated 1200Kg +500Kg= 1700Kg. No he said. The boat itself, with the motors, batteries and fitout should weigh about 700Kg. To that you have to add fuel, water, equipment and people. So for trailering purposes I'm going to be 500kg lighter than I thought! That's why they say composite boats are strong but light!

[Horse]

Steve, is he sure of those numbers? It seems to low for 7m X 2.5m hull. Even vac bagged would struggle big time

[stevemid]

Hi Horse,
Yahh thats what I was saying to him: "no friggin' way! and him saying, "yes way." We ended it by him saying, "Well I should know, I designed it." To be fair, the Schionning family have been built hundreds of composite cats (mostly sail) for 20+ years so I would say they do know what they are on about.

But I just did some quick calculations:
The boat is made up of 54 10mm duflex panels. Each panel weighs 11kg and let's say we're getting a 60% yield from the panels on average. 54X11X.6 = 356kg. To calculate the weight of the glass and resin: All the glass is 450g/sqm double bias. We'll use a roll of that (60% yield) 90 sq.m X450 X .6= 24Kg plus an equal amount of resin for a total of 48 kg for glassing. Next we have the weight of the fairing the primer and the paint. Looking at what I've put on the hulls so far (and what I've sanded off) I can't imagine there being more than 25kg in that.

So the weight of the shell should be about:
356
48
25
----
429kg. To that we add
2 motors 180
2 SS fuel tanks 20
Steering: 10
2X105AH AGM Batteries: 62
Wiring: 10
Electronics: 10
Carpeting: 10
Lighting: 5
Stove: 10
Fridge: 20
Windows: 30
Total: 796kg

So, by that calculation, we are within 10% of his figure. Fuel, fluids etc all go into the payload figure. So we could be close.

Steve
PS Forgot I haven't added anchor & chain, windlasses and SS railings. Now the weight gain begins....

[Fed]

At this rate you'll be down to a single axle trailer Steve.

[Horse]

They are amazing numbers Steve. If you can hold it under a 1000kg dry weight it will make your towing a breeze