The Bourne Method of Boat Building

[la cage]

For those looking for a cost effective method of building a very reliable, (proven over 30 years) method of boat design it is well worth considering Peter Bournes unique method of construction.

Feel free to take tour of the website listed below and for any further questions please post here for further discussion.

[MikeJohns]

Cage

There are numerous novel approaches to building hulls, I am always intrigued by approaches 'outside the square' Bernard Moitessier was considering sheets of newspaper stuck together with paint at one stage, and I am sure he could have made it work particularly if it had been over/around a mesh as you are using.

I was wondering if any boats other than your original have built by your method yet?

When considering your scantlings do you presume a full bond between the steel mesh and the outer solid GRP layer or do you just use a GRP thickness the same as any other boat of the same size? I suppose structurally you will also rely on bulkheads amd interior furniture as stiffening and mast and keel frames?

When the ferro cement vessel Nostrana was dragged into Lloyds A1 for Ice she had layers of stainless mesh added, I was skeptical about the mesh-plaster bond but it has proven very durable, perhaps stainless mesh would add some additional durability to your method?

Very curious
Cheers

[Willallison]

hmmm - interesting, to say the least.....

What's the approximate displacement of your 12m boat - I expect it would be somewhat heavier than an equivalent boat in say FRP or alloy?

Also, how do you access wiring &/or plumbing for maintenance, given that it's embedded in the foam? Or add new things that require wiring or plumbing runs as time goes by?

[la cage]

The prototype was an 8 metre double ender. She had total strength in the mesh skeleton,mesh bulkheads,interior fitout, and foam.Savings can be made on fibreglass. Because the foam is sanded just to incase the mesh, the fibreglass bond to the closed cell foam is complete. The prototype crossed Bass Strait 8 times. You will see by the web site the second boat is a 12metre, weighing 10tons. In this boat two layers of mesh were wired at their intersections and welded. This creats very strong I-Beams. Wiring on the first boat is encased in foam and has not been a problem. Condute could be used. " Plumbing "Because these boats dont have a conventional bilge, I use a sump in the back of the keel. Into this I drain the chain locker, ice box, engine box, via strainers. If the sump is under the engine box, you plumb it for ease of unblocking. When you are outside of the boat and carrying out these tasks putting your hands through the mesh, its like working on an invisible hull. I would come home with timber on the pack rack, and slide it straight through the mesh to where I was working.

[kengrome]

I cannot find a clear explanation of the construction method on your web site, so I have many questions about it. For example, where does the "carpet" come in? Where is the steel grid attached to the interior structure? Is the steel grid attached to the outer fiberglass skin anywhere, or is the glass skin attached only to the foam?

[Pierre R]

I had thought of doing something along these lines a few years ago. I invented a water soluble core binder for the foundry industry. My thoughts were to put the bulkheads in place and fill the spaces with boxes to get the rough shape of the boat. Then I would mix sand and pack that to get a better shape then finish the top layer with a mix of binder and pumice or binder and vermiculite or binder and pearlite. You can easily carve/sand the hull to get what you want.

You carve the stringers and ribs into the pumice then fiberglass the whole works. The fiberglass penetrates the pumice a bit giving you a core. Once done you simply go underneath with the hose and wash everything out. You would have a hull complete with the stringers/ ribs and bulkheads already in place. The superstructure would be done in the same fashsion. The cost of the sand then pumice mixtures run around $90 per ton for the sand mix and $900 for the pumice. Remember the pumice has much less bulk density so a ton goes much further.

When you are done you have a solid hull without a true core. I have done a kayak this way and it was a very fast method.

[la cage]

Hi Kengrome, The web site is an overview. The interior is attatched to the steel with bolts ,screws, nails, whichever is appropriate.
Cheers