Lifting boat

[talbot]

We often discuss how to get at the bottom of the hull for repair or maintenance.
We have discussed careening, hoisting with block and tackle, and using a fork lift.
(No, really. One guy has a fork lift.) After several seasons of complicated and dangerous
hoisting systems, I tried this trick yesterday. Seemed to work well. The premise is: You
don't need to get the boat off the trailer. You just need to get enough clearance over
the bunks to get in with a sanding block or paint roller.
1. Starting with the boat more or less level on its trailer, get it close to the mast support.
2. Lower the trailer tongue as low as it will go. Put a sawhourse under the stern.
3. Raise the trailer tongue with its jack until the stern rests on the sawhorse and lifts off the bunks.
4. Lower the tongue, raise the winch to the top of the mast support, and use it to lift the bow off the bunks.

The exact result will depend on the geometry of your trailer, sawhorse, and terrain under the trailer.
I had to get a little extra lift at the stern, and used a scissor jack on a cinder block to get my sawhorse under the transom.
The boat can rock when it is held by just the sawhorse and winch. It turned out a couple of step ladders I had just fit
under the curved lip of the hull port and starboard, and held it steady while I worked.
Here's a diagram of the basic configuration, minus the scissor jack and step ladders:

Lifting boat with trailer jack

BoatLift.jpg (31.61 KiB) Viewed 11802 times

--Talbot
--DSII 6546 Blue Moon

[GreenLake]

Nice diagram.

If your trailer winch is at the height of the bow eye (as in my case) you would need to use some other means of supporting the bow. (A 2x6 across two saw horses, one on each side of the bow, for example).

[talbot]

Yes, this works best if you (1) have a tall front trailer staunchion that supports the mast and (2) have a trailer winch that grabs the staunchion with U-bolts. For purposes if this maneuver, you loosen the bolts and shove the winch up to the top of the staunchion so that it pulls mostly up.

I finished with the bottom paint yesterday, so I lowered the boat back to the trailer bunks this morning. I realized another trick that might avoid having to jack up the stern to fit the sawhorse in. Use a shop jack to take the pressure off the trailer jack, fold the trailer jack away, then lower the tongue all the way to the ground. That puts the stern a few inches higher. After the sawhorse is in place, lift the tongue with the shop jack until you can swing the trailer jack back into position, and carry on as per instructions.

A couple of other assumptions that might be important:
-- I have a really solid SS U-bolt for a bow eye. I wouldn't have tried it with the wimpy chrome eye-bolt the boat came with.
-- It probably isn't good for the boat to hang its full weight from the stem and stern. If I had to leave it for a while, I would shove wood blocks between bunks and hull and/or use jack stands under the keel to take some of the weight.

[GreenLake]

A moveable winch. Nice. I don't have a post that long. I recently built a simple extension that clamps on to the bow roller bracket to allow better support for the forward end of the mast.

About suspending the boat from stem and stern. Both points happen to be designed in a way that distributes loads into the full structure, where it will be shared by hull and decks. And those should be able to resist sag reasonably well, so it's not the worst way to support the boat. Compare it to the other extreme case where people put it on roller bunks which provide point loads in the middle of nearly flat panels.

[Skippa]

Great information on raising the boat. I have some work to complete on the bottom and have been trying to noodle out solutions for rotating it and getting the topside on a couple of supports.
Careening over most of the way and then removing the mast and continue to roll it over to a couple of saw horses is where I am at with the idea so far.
Any one have suggestions or better ideas ? I am all ears.

[talbot]

How do you plan to handle the transition from tilted with the mast to upside down without? Some kind of brace while you remove the mast? And how do you plan to do the lift to reverse the process? A gang of helpers would make it all possible, but I'm curious about your engineering.

Suggestion: Except for actually laying up new glass on the bottom of the hull, all the patching and refinishing I can think of could be done with the boat on its side. But, yeah, that assumes that you can live with a 22' mast sprawled across your property.

[GreenLake]

There are three choices, in principle:

1. A (small) gang of helpers is all it takes to flip a DS (no mast needed). Four people, of which one is mainly needed to position cushioning and supports.
   
2. A raised mast is a great way for a single person to careen a DS in a controlled manner.
   
3. If you have a garage with access to ceiling joists you can rig something to hoist and turn your DS by yourself (or with a partner).

I've done all three, in the opposite order from how I've listed them here. (3) is a lot of effort in preparation. (2) is great for quick repairs. You can pull out the CB and work on it as well, at least for touching up the parts that will be in the water. (1) requires that you can have access to manpower.

The weight of the DS looks daunting, because it's above what most of us can lift, but I found that controlled rolling of the boat is not as hard as I had feared. Just take it slow and use common sense.

[Skippa]

Thanks for the reply's Greenlake and Talbot.
My boat spends 5 months a year at a buoy in fresh water. The boat has never had any bottom paint and until this past year it was never a big problem other than a lake scum that needed to be scrubbed off. This past fall I found a few blisters. I opened them up before putting the boat in the garage for storage. After much reading I have a plan for filling the holes and giving her a couple coats of antifouling paint and would prefer to do it with the boat fairly level and on her back.
I have careened it many times so very familiar with that process. I was thinking I can take it off the trailer, roll her over till the mast touches the ground, Brace the boat so it doesn't roll back and remove the mast. With one taller and one shorter set of "horses" to compensate for difference in deck height from bow to stern, and the help of a couple of screw jacks I could roll it the rest of the way.
I will most likely recruit a couple of brawny guys to just muscle it over but winter gives me too much time to think of alternative ways to do it.
Thanks again and I am always open to listening to what smarter minds come up with.

[talbot]

Yes, blister repair is one procedure where you probably would want the boat inverted.

I did a whole-hull refinishing a few years ago on my badly-blistered gel-coat. I've repressed the memory, but could manage to relive the trauma if you have questions. We had a forum discussion at the time, and there are photos in the archive.

[GreenLake]

The antifouling paint seems not necessary. If all you got is minor scum accumulation. AF paint is aimed more at barnacles, mussels and similar growth, and you'd have to get one targeted at critters in your lake to have an effect other than leaching some poison into your waters. I think even with AF paint you can expect some scum, in which case it would seem unnecessary. However, local experience would rule.

What I believe you do want is a good barrier coat (usually epoxy-based), to reduce water penetration into your hull. That's usually the coat underneath the AF paint. It would be the one that helps you with the blistering problem.

[talbot]

Another problem with AF paint currently is that the main anti-slime component Irgarol, is no longer in production. Apparently the factory that produces it ran afoul (ahem) of the EPA and can't start up again until they have made some changes. Jamestown Distributors claims to have some Irgarol-containing Interlux VC-17 squirreled away to be sold on a first-come, first-serve basis. VC-17 (or comparable product from Petit) is a thin vinyl paint, popular on our lake. Low copper, goes on thin, dries almost instantly, does not need sanding.

I decided to pass. I used VC-17 for several years, and I still got some slime that had to be cleaned off. And that was when the paint contained Irgarol. It is soft enough that some of it rubs off on the trailer bunks during launch. It doesn't keep water out (it has to be wet to work). And if you do need to remove it to do repairs, you are stuck with rags full of toxic sludge. I switched to Interlux Underwater Epoxy. It gets slimy in the warm petri dish of our lake, but the epoxy is hard and contains Teflon, so most of the gunk scrapes off. Mid-season, I'll sail into shallow water, attach a brush to the end of my boathook, and scrub the bottom.

There is some staining from the algae by September, but the way you take care of hard epoxy is wet sanding, which removes the staining. I add a new layer of epoxy every couple of years. Interlux says don't bother waxing the epoxy. You can't get it smoother than you do through fine sanding, and the material is so hard the wax won't adhere.