SV211 boat hoist questions

[homer12]

Hey all, I'm new around here and have tried searching some of this and outside of PN too. Making headway but have some questions for those utilizing a boat hoist with cradles. My parents recently bought a lake house with a Lunmar hoist there set up for a pontoon so I'm converting it for the new SV211. I think capacity is either 3k or 4k so I need to verify and will upgrade cables and pulleys and other parts from Lunmar as necessary.
As for bunks, are most using vertical 2x12's or 2x10's for bunks?
For the boathouse structure itself, I want to make sure it can handle the needed weight. For the joists running perpendicular to the boat that the straps, cables, and cable wrap poles are mounted to Lunmar told me those should be double 2x10's minimum but recommended double 2x12's. That seems excessive so just looking for feedback.
Will post some pics as it changes. Thanks!

[Quinner]

As for bunks, are most using vertical 2x12's or 2x10's for bunks?

What is the span? On most vertical style lifts a 2x6 horizontal works fine, IIRC typically they are about a 9' span and the 2x6 cantilevers a foot or more at each end.
If you use vertical the 2x10 is likely fine, personally I would prefer the hull to be on a larger flat surface, like the 5.5" of a 2x6 vs the 1.5" of the vertical member. Also the horizontal member can bend a bit with the hull contour though that may not be entirely necessary.

For the boathouse structure itself, I want to make sure it can handle the needed weight. For the joists running perpendicular to the boat that the straps, cables, and cable wrap poles are mounted to Lunmar told me those should be double 2x10's minimum but recommended double 2x12's. That seems excessive so just looking for feedback.

Impossible question to answer accurately without knowing the span. Also how does that load carry down, posts, column, steel, wood ???

[homer12]

Quinner - thanks for helping out.

For the structure, the span of the joists the lift straps are hanging from have about a 10' span. The straps and hardware hanging the lift cradles are probably 8" from the ends of where the joists rest on the beams. The beams they rest on double 2x10's that sit on 4" steel posts. Those posts are about 6' spacing.

[shag]

I have built a few boathouses (myself) and always over build... On purpose... Usually, your lumber costs to go from a 2 x 10 to a 2 x 12 is very little, all things considered... I would also use 2 x 6 for the bunks... I have seen on the occasion where a vertically installed board split down the middle and tilted some... I would hate to see a metal bracket into the fiberglass... Just my .02 on the issue. I am not a contractor, but I can tell you my first boathouse made it through 3 hurricanes (Charlie, Frances and Jean) and only lost 1 shingle... winds measured in the area at 130 MPH..

[homer12]

Thanks Shag! When you say 2x6 for bunks are you talking the nominal 6" side for boat support? If so, what do you raise the bunk off the cradle with vertically so hull and tracking fins clear cradle?

[homer12]

Well quick update from being at lake house yesterday. The hoist is actually hanging on 2-2x12's resting on 2-2x12 beams so everything is much better with the structure than I thought! The bad news is the hoist is a 3k so need to order parts and upgrade that. Not a big deal though.
Anyone with a 211 have recommendations or even measurements on their bunk setup whatever the lift?

[nukemustang]

Should be able to use the trailer bunks as a guide, and get the measurements off of it, to "mimic" the support it provides the boat.

[homer12]

So far I've measured the bunks on trailer and compared to if it sat on 2x12 vertical bunks that way. It doesn't look like enough vertical clearance to clear the skegs over the cradles supporting bunks. I'm thinking this means I need to move the bunks in somewhat to raise the height of the boat to clear those. If anyone else has any thoughts on that or their bunks that would help. The cradles I have are straight and not the "v" shaped ones I've seen in some places. thanks!

[homer12]

Ok, some updates and pics here. Finally finished this hoist up this weekend! The quick summary is we got new pulleys to double the cables up to get a 2:1 lifting advantage making the 3K lift a 6K capacity lift. We got longer cables and new brackets for vertical 2x12 bunks. I saw so many boats in the Tampa Bay area while visiting my Aunt and Uncle I felt pretty good about it. I started with the bunks approx. where the trailer bunks are but since these are straight boards and the trailer bunks follow the trailer frame it won't be exact. I have the inside dimensions of the bunks at about 40" in back and about 34" up front. I'm going to move the rear bunks in to 37-38" in back to help get the bunks on the more angled part of the hull. Here are the pics.

[nukemustang]

Looks great!!!

I'm jealous.... I would love to be able to decide its ride time and in less than 5 minutes walk out back, flip a switch and be riding... ahhhhh one day....

[homer12]

Thanks Nukemustang... very blessed indeed! Also happy with the turn out.