Any easy ways to flip a boat over to work on the hull?

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Any easy ways to flip a boat over to work on the hull?

Postby toby » Sat Jan 11, 2020 3:42 pm

I want to work on the hull of my boat. Does anyone have an easy way to flip a Day Sailer over (on land!)?
toby
 
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Re: Any easy ways to flip a boat over to work on the hull?

Postby GreenLake » Sat Jan 11, 2020 8:21 pm

Toby, this topic has been covered multiple times, but I agree there's probably not a good keyword to search for.

The simplest method (in terms of preparation) involves three people and some old tires, plus whatever supports you want to rest your boat on while working on it.

Proceed as follows:
  1. "Launch" your boat onto the ground. Use some padding (old carpet) to avoid scratches
  2. Manually turn it over and lower it onto the old tires (or other soft supports, like a thick layer of old styrofoam packing). That's a two step process: First you get it vertical and then you reposition and lower it back on the other side.) Boat is easily balanced when on its rubrail (use some padding where it contacts the ground if you have a DS2).
  3. Have two people lift the stern a bit and place the first layer of your support under it.
  4. Repeat same for bow.
  5. Alternate again, until your supports are at the desired height.

We did this for my boat with two adults and a teenager. We used stacks of lumber for building the support. Something like short lengths of 4x6 or 6x8 and we placed them crosswise to build a square "tower". Raising one half of the boat you'll lift something like 250-300lbs. We found that manageable with two guys. Get more helpers, if needed.

Because you will roll the boat sideways, this may not work in a single car garage. There are ways to rig a hoist that allow you to lift the boat off the trailer and turn it while suspended. We can discuss those, if you need that option.
~ green ~ lake ~ ~
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Re: Any easy ways to flip a boat over to work on the hull?

Postby toby » Sat Jan 11, 2020 8:30 pm

Thank you for the tips. We do have a hoist at our club so the "Hoist method" would be a great option to know if you don't mind sharing. Thank you in advanced, Toby
toby
 
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Re: Any easy ways to flip a boat over to work on the hull?

Postby GreenLake » Sat Jan 11, 2020 10:40 pm

A hoist would need to be at a location where you can work on the boat, unless you have movable supports for the boat when it is upside down.

Also, the kind of hoist I was thinking about would be a dual one, separately supporting front and rear of the boat in a sling that allows the boat to be turned. Standard boat hoist for small boats often attach to a single anchor point or some kind of "tripod" made from three lines to fixed points on the boat. Even if they use a frame with slings, those would be fixed (as you usually don't want the boat to turn).

So, my comment implied a special purpose hoisting mechanism -- some people have built those in their garages. Description in older posts here somewhere.
~ green ~ lake ~ ~
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Re: Any easy ways to flip a boat over to work on the hull?

Postby tomodda » Mon Jan 13, 2020 11:55 am

toby:

I flipped my DS last year, using a hoist and some slings (ratchet straps). Some tips, for what they're worth:

-I ran a line around the middle of the boat, as close to the back lip of the cuddy as I could get. The line went thru a single block that I attached to the chain hoist, in a continuous loop.

-Flipping the boat was "simple" ..use the hoist to get her off the trailer, pull the trailer out from underneath, flip it in the air , and then set her down on haybales. I did it with one very strong helper to flip, by my (weak) self to unflip once I knew how easy it was.

-Obviously, I had to preplan where I put the knot in the line, so it wouldn't jam in the block as I rolled the boat. Also, I had to retie the loop a few times, to account for stretch in the line. No way to do it except trial and error. Also - at least on my trailer - the midpoint of the boat is sitting on the trailer bunkers, so I had to have a friend lift the oat a bit on each side, so I could get the line under. No big deal, although I feared for my fingers! IN retrospect, I could have down this with my ratchet straps.

-You need a sling forward and aft on the boat to keep it from tipping and then slipping out of the loop. As I lifted then lowered the boat, I tightened and loosed the ratchets accordingly. But they're just a safety measure, the action is in the loop. You could do the same thing with two helpful friends, one at each end of boat. Would make flipping easier too!

-Flipping it is not as hard as it looks, the trick is to keep it even on it's axis (first try, she started moving diagonally in the loop, no good) and on an even keel. The weight is really not so bad, all of it is held by the slings, you are just overcoming rotational inertia. You can do it alone, lifting at the midpoint of the gunwale. I'd guesstimate that I was exerting about 100-150lbs of force as I flipped her, remember to bend your knees, spread your feet, straighten your back, and lift from your quads - just like lifting any other heavy object. With friends, put them at the bow and stern and have them flip, just like flipping a mattress.

-The "crux" is when the boat is halfway over - you need to run over to the other side while she's balanced on her side and let her down! Use the fore and aft straps as "brakes" - loose enough that the boat will turn but tight enough that there is some friction. This photo is from when I unflipped the boat, you can see my loop and pulley, as well as how the straps are both holding and "braking" the boat. I was turning her from star to port, clockwise, so I'm not actually at the crucial halfway point yet. Just testing to make sure my slings were properly holding her.

IMG_20190323_185551.jpg
Crunchtime
IMG_20190323_185551.jpg (171.15 KiB) Viewed 4291 times


-Again, friends are very helpful, but you can do this alone if you have to.

-Suggestion, if you can't work on her right under the sling and have to move her somewhere else to work - put two or three 2x4's sideways across the bunkers of your trailer and set your boat down on that. Upside down on the trailer. Then move her off to your workspace.

-Lastly, be careful and move slowly. The DS is a 550-lb unwieldy lump, when you're flipping it in the air like this bad things can happen quickly. You need to pre-plan each move, think of what can go wrong and prevent it. Most important part is to keep everything lined up, including how you use your body. Fingers and feet can get crushed, your back can get wrenched. Slow and steady is the way to go, if it feels wrong then STOP! If you are used to heavy physical work (construction, etc), then this is a cinch. Otherwise, especially if you are a desk jockey like me, then be aware of your limitations. Either way, use your brains, not your back! Sorry of belaboring the obvious, but be safe. And wear boots, use gloves.

Good luck and I'm happy to answer any questions. Somebody actually did all this using an engine chain hoist (like the kind from Harbor Freight aka Northern Tools). As long as the arm is rated for 1000lbs or so (plenty of safety margin), why not?

Tom
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