Repower on a True north 34

[rescuesailor]

I am at the stage of reworking the engine beds in my True North 34. What type of wood should I use as a base? Also has anyone had any experience building a "sea chest" to contain thru-hulls? I am also curious about building a manifold system to reduce the number of thru-hulls required.

[Tim]

I think that several layers of void-free plywood, laminated together to the thickness you require, work well as engine foundations when fully encapsulated in fiberglass. I did this the last time I built foundations.

White oak is also common, despite the various pros and cons of using white oak with epoxy. White oak is strong, but may not always bond well with epoxy. I think it can be used with care.

Good quality mahogany would also work, as would a wide variety of hardwoods.

The key to using any wood in this application is to fully encapsulate it during installation. Don't just tab it in at the bottom. Run fiberglass all the way over the top and sides. This need not be done in a single operation; you can do the tabbing first, then cover the remaining areas later.

I have been toying with the idea of a sea chest for a future project, but I haven't figured out any details yet. A sea chest can be as simple as a water proof box, which will contain water at all times, built around a large through hull. Smaller fittings through the box, ewach with its own shutoff valve, would lead to each individual system as required. The box needs to be very strong to prevent it from ever being the weak link.

A manifold might also work effectively, though you'd have to size your main through hull very large to ensure that there would always be an adequate flow of water if you happened to be using a few systems at once.

[rescuesailor]

Tim
Thanks for the input. I like the idea of plywood. Would you alternate the orientation of the plywood? I would also like to bore a large hole through the engine bed and then drill the engine mount attachment bolts from the top into the bored holes. In this way I could use machine bolts rather than lag bolts to secure the mounts. I have even toyed with the thought of elongating the holes to slots in order to have more room to align the engine. I am rather concerned about alignment after reading how important it is. I have built a mock up like you did but still do not trust my calculations. any feedback on this?

David

[Tim]

If you build an accurate engine mount template and take your time using it to properly build and align your foundations, you shouldn't have a problem aligning your engine later. Don't forget: flex engine mounts all incorporate slotted holes so that you have some adjustment room. This is usually plenty.

Through bolting the mounts is a good idea if you have the room. This can be tough sometimes, though. I used some threaded sleeves, which I epoxied into holes in the foundations, to accept machine screws rather than lags. Lags work fine too, though.

There's really no need to alternate your plywood when laminating, since alternate layers of each piece of plywood are already alternating. It won't hurt, though, to do it.