Picking up on what Doc Prof opined, sensibly as ever, on the topic of Prop rotation- later ultra-beefy propeller-powered aircraft, often had contra-rotating propellers fitted to reduce the effects of torque on the plane's horizontal stability.
I guess, the same principle applies here. It also explains why there was a specific engine starting procedure for WW2 four-engined bombers.
Never mind the solder, Jim. Ugly or not, they'll be concealed in the water and so long as they do the job, without becoming detached, you'll be onto a winner.
Besides, we'll all be looking at the (undoubtedly) magnificent upper hull to come.
"Get your facts first, and then you can distort them as much as you please"- Mark Twain.
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My Dad always said it looked like "bird droppings"! You should see my welding beads! 
I used to love baseball, now if you throw one at me I duck every time! 
