San Juan 21 Class Association

I am excited to share the boat hoist system that i created. When i decided to pull my own keel and paint the boat, i started searching for ways to lift the boat. I have the restriction that it has to fit in my garage since i live in a neighborhood with a fascist home owners association. Lifting from the rafters didn't seem like a good idea, so it had to come from below. I searched and searched the intertubes for designs and only saw variations on the trailer technique. I wanted to be able to lift the whole boat up and down as needed for removing the keel and to get better access to the bottom for sanding/painting. So, to the drawing board i went. here is what i came up with, pictures speak better than words:
The whole system is 4 of these piers. they can be adjusted in 4in increments. basically, walk around the boat and jack up cross beams one at a time, replacing the pins as you go.
Here you can see i need to raise the port side up one notch. the two smaller boards on the cross beam only serve to keep the boat centered and not wobbling; all the weight is on the bow keel. I blocked up the back beam as well. I was able to remove the keel last night with much more ease than i expected. i will do a write up on that as well once i get it back in. my rough estimates are that i will be able to raise the boat high enough to install a keel gasket when the time comes. I am also able to shut the garage door to keep the annoying neighbors happy.

couple of lessons learned:

on the back cross beam, make sure it is very near the transom. even a foot or two forward, the fiberglass is not solid enough to hold the weight. if you go forward even more to where the keel trunk begins, you are back in solid territory.

Don't use 4x4s for the cross beams, they are not strong enough. To get the trailer out, the front cross beam has to be 10ft. In the picture above, the trailer is long gone and i have brought the piers in closer to reduce the leverage on the cross beam. the front beam is two 2"x8"x10' s screwed together. In the back i used two 2"x6"x8's. At my hardware store, 4x4s only come in pressure treated and thus are expensive. it is actually cheaper to use the two untreated boards screwed together and much stronger.

Excluding the two 4x4s that i wasted, it ran me about $120 for lumber and hardware and $50 for the tractor jack. I priced the lift at the marina and it was $80/hour, so i felt this was a great solution that allows me to take my time and lift it off as much as i like. I used screws and intend to partially disassemble and store the piers for the future.

Very interesting... just thinking of some improvements for the next person:)

If you take your "cross members" and have them be more of a "cradle" style, you should be able to move them a bit further away from the transom. That would allow you to move them around to do some bottom painting or sanding as needed.

Using bolts instead of screws might allow you to take things apart easier... Assuming things are "flat" underneath so that the angles don't have to change.

Also note, for "newbies" the widths quote might be different depending on your trailer.

Another thing you could do that might make it easier than jacking up each 4 corners individually... Get some of those "lifting winches", basically the same as our keel winches... Get two of them, throw a pulley on one of the towers, and run a "cradle" from each of the towers, and attach it to those winches, so you just crank up the two winches from one side and it would raise the whole boat up. Might need a picture to show it, but in my head it seems pretty straight forward:)

Later
C

Good ideas cklamp. I agree about the cradles. Time and lack of carpentry skill kept me from doing it. I thought about the winch idea, but needing 4 instead of two, which seemed more expensive. It would be cool to just have 2 cranks.

How did you get the boat off the trailer onto your lift?

The front cross beam has to be wider than your trailer. Roll the trailer in, put your piers in place and the cross beam, then just work the boat up, lifting each corner in turns until the boat is high enough to clear the trailer, then roll it out. Lower quickly and get the keel weight off.

I used the same method to raise my boat in the garage to paint the bottom and it worked great! The stands I built were pretty much identical to those above. The only major difference was that I used some scrap plywood to brace the base of each stand.

I did run into one problem. I had measured everything so that I could slide out the trailer. However, I neglected to account for the thickness of the garage door when open and the fact that the trailer fenders rose slightly when the boat weight was removed from the trailor. Both of those miscalculations resulted in the fenders of the trailor not clearing the 2x10 support and preventing the trailor from fully being removed from the garage. It did move out far enough to allow me to drop the keel enough to paint it and I ended up just working around the trailor to access the rest of the bottom.

The procedure was a great idea! Thanks!

Badgerjuan
Madison WI

Glad to hear it worked for you! Yeah, I had my bow pulpit off or the garage door would have been an issue for me as well. i tended to take off the fenders too just to make the width of the pillars a few inches closer. It isn't hard to pull off the bow pulpit and it is a good idea to drill and seal those deck fittings anyway if you need to raise it again for any reason.