aluminum cat project...

Discussion in 'Multihulls' started by jaydh, Jun 30, 2009.

  1. jaydh
    Joined: Aug 2007
    Posts: 26
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    Location: down unda

    jaydh Junior Member

    Hi all,

    We're nearly finished with a 48' alloy cat and wanted to share some pics and progress. I remember how much it helped us in the drooling-to-do-it stage and once we got into building. So go to or search youtube for sail palau.

    best to the future builders,
    (and yep it is HARD work, trying at times and more costly then ya think...but worth it!!)
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  2. nero
    Joined: Aug 2003
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    Location: Marseille, France / Illinois, US

    nero Senior Member

    Great picts of the build! Aluminum looks cleaner and more agreeable than wood/glass/epoxy.

    What do you do to keep the boat from becoming an oven in the sun?
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  3. GDFL
    Joined: Mar 2009
    Posts: 14
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    Location: Guntersville, AL

    GDFL Junior Member

    Excellent website. Thanks for sharing. Since you have built the boat so quickly, can I as how many people are working on it and how often they work? It looks great. Hopefully i'm only a handful of years behind you...
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  4. jaydh
    Joined: Aug 2007
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    Location: down unda

    jaydh Junior Member

    Hi guys,

    For insulation we opted for Armacell's Armaflex stick on stuff. Followed Steve Dashew's luck with it on his Wind Horse motor boat. another alloy cat builder down the road uses it too. Our other mates have been using 2-part blow in foam and it works fine. Cost-wise it's a close toss up for Australia. We didn't care to embed the wires into the to be able to take things apart when needed. Also, another builder said it takes a good 10 full days to trim the blow-in down plus time to wrap/mask/tape things off to cut down on the overspray. The trade-off is it takes awhile to hand fit the Armaflex, but not hard. My wife takes about two easy days to do the salon roof as an example. Not sure if we'll wrap the stringers and gussets yet. Armacell sells a 50mm x 3mm x 50m tape roll of the Armaflex for peanuts which makes a clean easy finish and seem seal.

    As far as workers it's just the two of us working almost everyday. All 120 complex curved bottom plates were hand bent on a homemade bender by us. the big stuff - curved forward beam, front beam, seats, transom, etc we cut and marked off us and we helped the guy bend it all on a 4m press at nearby.

    We've never built a boat nor welded before, but the designer has done 9 or so boats already himself with only his immediate family helping now and then. His instructions kept us on the right path and he has a good set of plans to follow. He can turn one out in 12 months...perfectly faired and painted. the interior is a rough fit out, but he goes up to the Philippines for that. I heard around 6+ months for the interior fitout for around 15,000aud. Looks very nice and clean with all fiberglass interior shell, local wood floors, etc.

    I think we made a significant right move up front getting a good welder - Fronius TPS 2700....beautiful machine worth every cent!! Love the damn thing. The Fronius push/pull gun works like a dream and the thing will do more then one will probably ever have time to monkey around with playing.

    For us we did have to call in some outside help as we near the end because our visas are running out. that helped heaps as making the leap of faith on decisions sometimes takes up more daylight then actually doing the work or particular job. A great guy from winning yachts bailed us out on the engine bed install (at this point I didn't want to muck it up from lack of experience) and fixed up lots of mistakes we did or things that just could've of looked better. A couple neighbors have pitched in with basic woodwork and electrical stuff too which took a huge load off. In hindsight all the crap we stressed over was nothing and next time around we expect it to be a breeze. Learned alot along the way. The little **** is what eats up your time and it never seems to end. You'll be working on something and your eye and mind will wander to a hundred other things to consider.....just gotta to stay focused on the job immediately at hand or you'll go koo-koo.

    If anyone out there is looking for a perspective from a newbie who jumped in head first feel free to email. We're decent yachtie-cruiser types but certainly not pro builders! The address is on the site. We'll be outta touch for awhile whilst heading home, but I'll answer sooner or later.

    best - Jay
  5. Mr. Noodle
    Joined: Dec 2005
    Posts: 2
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    Location: Victoria, BC

    Mr. Noodle New Member

    Thank you very much Sir for posting up those photos and youtube clips.

    I've been in the 'drooling-to-do-it stage' since about 6 years ago. Always for an Aluminum welded sailing Cat just like this one. Same size too (45-50 feet). But with everyone it seems building composite, there is very little out there for sites like yours about aluminum sailing Cats.

    I do have many questions about your build. Like hours involved? Type of Aluminum used? Did you wire feed the entire thing, or TIG the corners? Website for the boat-design. etc. I'll try not to ask too many questions when I e-mail you sometime in the next couple days. haha :p

    1 person likes this.
  6. Guest62110524

    Guest62110524 Previous Member

    your tenacity is remarkable Jason
    I tried get the rudder dwg back to you, but got totally lost looking for you
  7. ldrhawke
    Joined: Mar 2008
    Posts: 2
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    Location: Florida

    ldrhawke New Member

    How do I get in contact with design / builder to get a price on having one built?


  8. Guest62110524

    Guest62110524 Previous Member

    can do that, contact via www.*********************
    I know the boat
  9. jaydh
    Joined: Aug 2007
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    Location: down unda

    jaydh Junior Member

    alloy cat, questions, etc

    hey blokes,

    The designer can be emailed at Heard he'll be back in Oz in a week or so after a quick zip around the world in his last cat. It's for sale I hear...nice boat. He's done 9-10????himself?? Another older cat of his was for sale re-named 'the visitor'. I'm guessing he'll pull into Brisbane as family is here.

    Hours?! Too many. Don't keep track. More or less a daily grind. From mid-feb 2008 to last week. Interior not finished yet.

    Alum is 5083 with 5183 1.2mm wire. 5356 fine too. All pulse mig. Extrusions are 6061, etc (round/square hollows, t-bar, solid rod). Hull 4mm, deck 4 & 3mm. 20, 16, 12mm here and there for chainplates, etc. We did go with all alloy rudders using solid stock. Others have been using SS pipe with SS welded tangs bolted then to the alum foils. We'll see if ours work.

    By the floats! With no leaks (yet?!). Transom outta the water, but the rig and sails go up in two days to push her down. McDonald House Movers did a fantastic job and can't say enough good things about Dean and his crew. Might be some pics up at our website soon of the launch when my wife gets time.

    Damn it's cold at night in this thing!

    no worries on the a copy!

  10. jaydh
    Joined: Aug 2007
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    Location: down unda

    jaydh Junior Member


    ...I think? The dang things show up?

    Attached Files:

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  11. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Well, Jay, I must admit I am very pleased to see you've got her in the water!

    She's one nice looking boat- and as much as some people like to make everything look like glossy gelcoat, I have a thing for the bare aluminum look. Durable, low maintenance, very distinctive, and looks seriously cool. Don't be surprised if people mistake you for a military craft, at least until you get the mast up! Of course, if you do paint her topsides, that's fine by me- I just think there's something cool about an alloy boat that's not afraid to show off.

    It's always an inspiring story when something like this hits the water. Especially so to folks like me, who sit here landlocked, dreaming about the next boat, but wondering how we're ever going to find the time, the patience, the building skills, the money, etc. to make it happen. Seeing someone who just said "screw it, I'm starting" and made the dream into reality is always wonderful.
  12. Ad Hoc
    Joined: Oct 2008
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    Location: Japan

    Ad Hoc Naval Architect

    Very nice look boat...well done. Concur with Matt...bare ally in the right application is very "sexy and sleek"....don't forget to salute to those navy boys as they whistle you by ;)
  13. jaydh
    Joined: Aug 2007
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    Location: down unda

    jaydh Junior Member

    for idrhakwe & Noodle

    guys - The designer just pulled in and is anchored around the corner...assume we'll be seeing him in the next day or so. If you pm me or send an email to I'll pass on his mobile number to you.

    best - J

  14. jaydh
    Joined: Aug 2007
    Posts: 26
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    Location: down unda

    jaydh Junior Member

    those looking at Trim/Cyber cat

    guys, Trim sold in two days. If you want self build plans contact cyberyachts The designer is building his 10th/11th(???) one but not sure if he's selling or keeping. Contact Tim at the above email. Again, for nit-wits like us (and in hindsight) it pretty dang easy.

    best - Jay in Beachmere, QLD

    ps - don't know if another Cyber/Mumby sold yet. Called The Visitor (ne Kilo) and had a site up... with details, but will have to look around the comp for the URL if anyone is interested. Lying Brizzy last I heard....
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