home-made hoisting sling for cb repairs

[mark mirkov]

If you want to do work on your centerboard, like I am, or otherwise get at the boat bottom freely, you can trailer it out somewhere, launch it, beach it, and tip it on its side, as described in this forum. But what if it's raining, or snowing? How much fun would that be? Forgot a necessary tool at home? Oh, well, maybe next weekend we'll try it again. Wait for a nice day? I'd rather be sailing! So here's a great sling I made which allows me to lift the boat up in the air and pull the trailer out from under it to work on it right in my garage. The materials cost about $90, took a few hours to contstruct, and can be dismantled or reassembled in about 20 minutes whenever you need it. Here's what you need to make the sling:

8 2x4's --eight feet or ten feet depending on your garage height
4 2x6's --ten feet
1 2x12 --6 or 8 feet
2 heavy-duty ratchetting tiedowns- 30 ft., 10,000 lb breaking strength
a few shims, like some old cedar roof shakes
a dozen 16 penny nails, about the same number of 8 penny nails
2 llight-duty floor jacks--the kind on wheels, not bottle jacks.
2 1/2" bolts abut 2 1/2" long depending, and 2 nuts to to on them


I go all this at home depot--rounded it up in about 15 minutes. It's not all that much stuff, really.

So here's the idea: you can hang your boat from the ceiling joists in you garage, and pull the trailer out from under it to work. It's really that simple and works beautifully. I only have to jack the boat up about 3 inches to clear the trailer. I know it sounds crazy, but if you do like I did, you won't be in any danger of pulling your garage roof down onto your boat and then all of that onto you who are laying under the boat.

I'll give the simple picture first, then go into detail. If your garage is like mine, the joists run from front to back of the garage (parallel to the direction you park your car ). Those joists are on 4-foot centers. So, just forward of the stern a foot or two, throw a couple 5-foot 2x6's across the two joists that are directly over the boat (you have to center the trailer and boat between the two joists). Spread those 2x6's apart up there about 20 inches. Now throw a 3-foot piece of 2x12 across those two 2x6's. Next haul a floor jack up there and plop it onto the 2x12. You have just completed the aft portion of the sling. Next do the same thing forward, figuring the forward sling should be a few inches aft of the mast.

Now all you have to do is throw the ratcheting tie downs over the jacks and down under the hull. Jack each end up only 3 inches or so, and the jacks are in no danger of tipping over. There's more danger of them rolling off the 2x12s, so tack some scrap wood stops around the jacks using the 8 penny nails. The trailer can come straight out the garage door opening, and your ready to work.

Now for the not-pulling-the-garage-roof-down-on-top-of-you part:

You want to stand legs up under the floor joists in the areas of the floor jacks so that the joists don't sag and snap. That's what the 2x4's are for. You will leg up the joists in four corners--each side of the boat fore and aft. Its a simple matter to stand each 2x4 up where its going to go, mark it for length, and then cut it about 1/8" to 1/4" longer so they're under preload when they go up. Now the joists are supported, and you will not be getting a shingle shampoo when you do hoist the boat up.

Here's the elaboration on the 2x4 legs: the boat is some 6 foot wide and the legs have to be a few inches away from the boat. But the floor joists are on 4 foot centers, so how can you brace them up with the darn boat in the way? Here's what I did: instead of legging directly on the two joists that are over the boat, in each corner I put a 5-foot 2x6 spreader under the TWO ADJACENT joists on that side of the boat--the joist inboard of the boat's side, and the joist next to it outboard of the boat's side. Then I cut two 2x4 legs to length and braced up the spreader, which is holding up a PAIR of joists on that side of the boat. So you are really using two pairs of joists--one pair on each side of the boat. This way, you get the legs away from the boat and still support the joist running over the boat. So each corner is legged up with a pair of 2x4's that hold up a 2x6 spreader that supports two joists--an inboard joist and an outboard joist. Each corner is supported by a letter PI, if you will. I drove a 16 penny nail down through the spreader into the top end of each 2x4 for security.

As for each floor jack up there, I bolted a 6" chunk of 2x4 to the lifting arm and tapered the wood a bit so that the nylon would not encounter sharp corners.

When you do the math: 600lbs divide by eight legs = 75 lbs of load on each vertical leg (assuming the load is spread evenly, which it isn't). A healthy 2x4 handles this load easily. If you are worried about the legs in each PI bowing apart, you can tack a plywood strip across them to hold them together. I didn't do this. The legs of each PI are about 20-24 inches apart--enough to get a ladder between them during assembly.

Two items concerning clearance: 1) The two forward PI's have to be far enough aft so you don't knock them over with the garage door when you open it, and 2) the aft jack has to be far enough forward that it doesn't bump the ceiling when you raise it. My garage is 22 foot deep. I rolled the trailer back to within 15-20 inches of the rear wall--just enough room to get a stepladder in. The rear sling is forward of the rear jib cleats by 4-6 inches, and the forward sling is aft of the mast by 6-10 inches.
I centered all the planking and the jacks on the centerline between joists, and I centered the trailer, too, so that the boat would not swing sideways when it cleared the trailer. I marked the axel centers and the trailer tongue's postition on the floor with masking tape so the boat would land in the same place when lowered. For safety, I only pulled the trailer out far enough so that the centerboard could drop out of the trunk. I cut the pivot bolt loose after supporting the cb with a couple light tie-downs, and then I raised the boat up after I was out of it.

I know this all sounds complicated, but take a look in you garage and picture what you have to do to sling the boat and support the joists. Then read all this again. If I weren't such a throwback, I'd have a digital camera which would tell the whole story for you.

If your joists don't run the depth of your garage but from side to side instead, you'll have too figure something else that will work. Also, if your joists are not at least 2x8's or are not each one continuous piece from wall to wall (sometimes they are made up of two short lengths scabbed together), I would have second thoughts about making this rig. Also, if the joists are old and twisted, you could possibly pull them loose from their anchoring in the rafters --that is, they could tear loose from the rafters and tip over.

More cautions about the jacks: make sure you lock them down so they don't leak down while you'e under the boat. Also, make sure the sling is BETWEEN those two 2x6's holding the 2x12, otherwise the 2x12 will tip up and the jack will roll right off the end of it when you hoist the boat. Set the jacks so their handles are both pointing in the same direction (toward the garage door for cleareance of the roof on the rear one). That way as the jack arms go up, they also travel fore-aft at the same rate so that the slings remain a constant distance apart.

[Roger]

and if you don't have a couple of jacks handy, a set of blocks and some 3/8" line and webbing straps will also do the trick. Similar set up except you use two sets (fore and aft) of 3:1 blocks. the working load on the the person end of the line is 96 pounds. The price might not be any cheaper, but if you have blocks on hand instead of jacks...

[mark mirkov]

Thanks, Roger, good idea! I was also thinking about the set-up for joists running side-to side rather than fore and aft as in my situation. Each jack platforms would simplly be a 5-foot 2x12 tossed over 2 joists near the stern, and similar for the jack up front. I think I'd use two 2x12's laminated with 16p nails for added strength on that 4-foot run.

The legging would also be simplified, since (hopefully) a cross-running joist would be in the right areas fore and aft to postion the legs directly to them, rather than the spreader-PI configuration I have. (Maybe I'll hoist my roof up and spin it 90 degrees so as to simplify the hoist system!) I think I would still like to share the load out with two joists fore and two aft, though, so I'd probably stick with the 2x6 spreaders underneath anyways.

The PI-shaped legs help insure that the load is down-bearing on the outboard joists in my situation--Just imagine if you used only the inboard leg on each corner. Then you would have the 2x6 spreader actually levering UP on the outboard joist. This is what would happen if the outboard leg were positioned all the way outboard on the spreader---it would probably float up off the floor and just hang there uselessly. With that leg positioned inboard from the spreader end, it behaves more like the inboard leg, carrying downward pressure to the floor, tho not as much as the inboard leg does.

I probably would have discoverd this the hard way, had I positioned the outboard legs all the way outboard, but since my 50 pontiac is parked along side the boat, I was forced to set the outboard legs in from the spreader end. Happy chance, not forethought provided this feature.