an aluminum ply boat

[wardd]

would it be possible to sub alu for ply to build a boat in a modified manner.

tape and epoxy seams, nuts and bolts etc , the idea is a no weld alu boat

[Rick Willoughby]

would it be possible to sub alu for ply to build a boat in a modified manner.

tape and epoxy seams, nuts and bolts etc , the idea is a no weld alu boat

Certainly possible.

I have largely given up on welding thin aluminium and use epoxy to join sections. This is mostly for frames at this stage but I did use it to join some 0.6mm sheet and it worked well.

I have used various glues with aluminium-to-aluminium joints however epoxy and glass work well. Aluminium and glass have similar elastic properties so share stress well. I do not know how these joints fare in the long term when exposed to fatigue conditions through load and temperature variation or weathering from sun and saltwater. My untested view is that it will actually be better than welding because there is no change in structure through heating. Also no distortion when building.

One bit of advice I got from an expert here was that you should do a preliminary mechanical clean of the surface in open air and then use the epoxy as a cleaning paste to do a final prep as you are joining.

I doubt if it is the method of choice for plate above 3 or 4mm because there would be a lot of work in preparing the joints. However for simple butt joints in 1 or 2mm plate for a light boat I believe it would be a good method.

Rick W

[Milan]

Yes, aluminum plates can be epoxy glued instead of welded. It is done sometimes. For example, this 60 ft yacht was professionally built that way couple of years ago:

http://www.yacht-design.nl/bosgraaf/designs/sailingyachts/stern60.html

Only, they didn’t use tapes but overlapped plates.

Interesting boat by the way, built on the budget, for the fast long distance cruising. Money was saved by keeping systems and interiors as simple and basic as possible, investing in the waterline length instead of gadgets.