Outboard making stern flex? Try this.

[Lord Chunderguts]

Before attaching an external propulsion unit to my regal and elegant gentleman's vessel, I duly checked the TH website to see what horrors lay in wait. Some chaps said their sterns were flexing slightly, causing minor cracks. No chap wants a crack in his rear, so I pondered the problem and hit upon a solution so miraculous, I urinated in delight.
My boat had a half-rotten boarding platform, with a pair of 3mm wire cables going from its outer edges to the thingywots where the two backstay cables attach. Crikey, thought I, a chap could simply attach them there cables to the outboard bracket, so they support a good deal of the weight. This makes my outboard bracket a strong point that I can use a step on occasion, and as an added bonus, it fractionally reduces the strain of the backstay cables on the deck fittings, as these cables will be pulling backwards and down.
Some of you may have brackets that you raise and lower, just add another attachment point for when the blighter's raised long term. As for the flexing caused by the first thrust of the outboard, a full width plank across the transom will distribute the thrust against the strong edges of your boat, and you can add a small step on each side of the outboard (or a ladder) to assist boarding.
I hope this helps some chap somewhere. Now I'm off to buy a meerschaum pipe and a captain's cap in order to look more nautical. Cheerio!

This cable thing will be attached to that bracket thing in a few minutes.

IMG_20210120_210935.jpg (620.94 KiB) Viewed 1570 times

[Miker]

The reason for internal bracing is because when you're under way, the outboard puts uneven pressure on the stern. They're not that thick in their behinds. I watched mine not long after we bought her, and I was surprised to see a movement akin to a wobble board in a choppy harbour. Having the cables is good to prevent the outboard and the bracket disappearing into the blue, but it won't stop the flex when you're beating into a chop.

I have a full 22mm thick piece of marine ply, that is twice as wide as the outboard bracket, inside the hull. No flex, no flex at all not even when motoring from the Entrance to Pittwater in a south swell and no wind.....

[Phillip]

Mark 1 sterns are 10 mm thick, 2’s & 3’s are thinner!

So Michael‘a example of reinforcing the stern is essential.

[Lord Chunderguts]

Thank you chaps, I bought a wooden chopping board from Coles and used it to reinforce the stern, I'm also adding a few wooden steps up beside the outboard as part of the stern bracing. I'm consumed with guilt whenever I drill a hole in my vessel, it's virtually untouched since new, very basic. Two winches, two cleats, nothing on the roof, just a bunch of cleats on the mast. If anyone wants pics of any part of an unmolested Mk1, let me know. Cheerio!