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Mark Drew
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Post by Mark Drew »

I'm getting ready to retire soon. I would like to build an aluminum center boat for fishing the great lakes. I'm wondering if anyone can recommend a good design and what is a good size for the great lakes. I would like to trailer the boat as well. I saw a you tube video from bar crusher boats. I think they are in New Zealand. They have a pretty cool ballast system that empties when the boat gets up on plane. No need for pumps. I thought that was a great idea. I figure it's going to take me a few months to figure what I want to build and start getting tools ready. Any help would be appreciated. 
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Joined: Mon Aug 18, 2008 1:37 am
Location: Kenai, Alaska

Re: new to the forum


Post by kmorin »

Mark, congratulations on getting close to retirement and we're glad you're considering building your own welded aluminum boat, welcome to the Forum.

I can't speak to a "good size for the Great Lakes", but 20 to 26' LOA have proven to very successful boats in many different waters.  This size also tows pretty easily unless you're driving a small format p/u. 

Design wise, there aren't a lot of welded aluminum boat plans in the market place, but considering a kit boat (pre-cut parts) may be a good path to help you avoid the longer learning curve of laying out and cutting from blank sheet-  your own boat's hull panels and framing elements.  If you search for pre-cut boat kits or just 'cut files' you'd find at least a few firms and design offices that offer these products to help you concentrate on learning to weld (if you don't already have that skill?) and spend your time assembling and welding and skip the layout learning time.

If the New Zealand company offers their boats in design files, cut files or just plans on paper (?) you may be able to build that design?  The reason to have the ballast pipes that fill while off plan/off step; is to allow the hull's displacement to shift when the boat isn't planing- that way you don't have to push or carry any extra wt./greater displacement while running.  This particular design also increases the V you can have- without radically increasing the roll that would come with a deeper V by filling part of that deeper deadrise shape with water to reduce roll moment at 'rest'. This allows a 'variable draft/draught' to provide a sharper entry (softer ride) while running but not suffer the accompanying increased roll that would come from that deeper V shape when at rest or slow speeds.

This is a pretty sophisticated design element, IMO, so I'd say if the firm doesn't offer cut files, plans for sale of that design?  it could be pretty expensive to hire a designer to do a 'one-off' version.  Not that this isn't possible- just likely to be expensive for a single build.

If you plan to weld the boat yourself (?) I'd make those tools and the needed skills 100% of your prep until you can run decent beads in both MIG & Tig.  Learning to weld is more time consuming that all the other skills needed to build in welded aluminum so getting started on research and practice as soon as realistic is the best course of action.  Welding marine aluminum (5000 & 6000 series aluminum sheet, plate and extrusions) is the usual hard step to accomplish for new builders.  Also the equipment needed to do a reliable job is not cheap- so these tools are usually the most expensive items in the boat shop unless you plan to build full time and decide to 'tool up' with shears, brakes, or sheet handling equipment.

If you'll hire the welding (?) then all you'd need to learn to do is tack- many of the current generation of MIG welding power supplies (often called welding 'machines' even though they're simply power supplies) have 'tack timers'.  These are modes of on/off control that are offered to create very small, extremely short duration welds that are used to assemble the frame and hull panels before the longer continuous welds are added after the final shape of the hull is established by 'tacking up' the shapes that will become the final hull shape.

Hope this helps you as you explore the many options open to you to accomplish your build? Let us know if you have more questions as your plans begin to gel and become focused on one single design?  I'd suggest that you tour the various harbors, or boat ramps in the area you'll be cruising to see what others' have decided are appropriate designs for those waters?

Kevin Morin
Kenai, AK

Posts: 486
Joined: Wed Jan 09, 2008 12:59 am
Location: Brisbane, Australia

Re: new to the forum


Post by peterbo3 »

This is Drumbeat. Built in Brisbane, Australia. Ballast tubes flood at rest & empty in a second as you throttle up.
DSC_0195.JPG (45.64 KiB) Viewed 604 times

Pete in Brisbane
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