Shoring for reparis

[Kudzu]

Pretty basic question for some of you. But my old 20' Chris Craft Sea Skiff is in need of some hull work. At a minimum it needs some refastening and possibly a plank or two replaced. I need to take it off the trailer and put it on something while I work. My thought has been something along the lines of the shipping cradle originally used for this boat since I have a set of plans for it.

Once I get the boat in the shop and look closer at what is required I might want to modify that a little. Main concern is just safety since I do work alone. I have seen lots of make shift supports used in local boat yards but I just don't have faith in them. Plus I want the hull properly supported in case this turns into a long term project. So just looking for ideas. I know this is done all the time. But my project boat are usually much smaller and lighter. (kayaks)

[BA.Barcolounger]

You'll need something that you can work around. With a shipping cradle, there will be areas of the hull that will be inaccessible (without major adjustments).

I would suggest a combination of jack stands and (if your shop can hold the weight) cables/chains/straps secured to the ceiling. I do not know what kind of lifting rings your boat has. This way, if you need to get to an area that is covered by a stand, you can jack up it's neighbors to relieve some weight, and shift the interfering jack over a bit (then move it back afterward).

You can never have too many jack stands.

Are you planning on flipping it to work on the hull? A 20 footer might be a little big for flipping.

[5.5 Meter]

I concur with the cradle; it will limit your access. Start with blocks to set the keel on. They can be made to whatever height you desire to provide access under the boat. These blocks should be made to take the weight of the boat and you can place a heavy timber (for and aft) on them to which you then set the boat, this will distribute the weight for the long term. You can make them out of 6 x 6 or larger, cross laying the individual pieces as you stack them. For additional piece of mind you can further secure the blocks with plywood on the sides to keep them secure thus making one 12 x 12 block out of four pieces of 6 x 6. The key is to stack each layer 90-degrees. You might consider a 12 x 12 block and 6 by on top of that. You can even go with two 12 x 12 provided they have a large enough footprint. I find that having several blocks at different heights adds for flexibility.

These “keel” blocks will take 100% of the load; meaning if the boat was perfectly set someone (theoretically) could hold the boat and prevent it from tipping over…again theoretically.


I also concur with regard to the jack-stands outboard because they are very easy to move around to gain access. The jack stands are only needed to keep the boat level. If jack stands are not in your budget you can also use blocks outboard. But remember they should not bear any weight and are only to keep the boat from tipping. If you set them right you can place a piece of ply against the hull and a wedge between the ply and block. This way you can tap the wedge just enough to make it snug (but not to much that it starts to take a weight). Then if you need to move it you can place another block some place else and tap the wedge out on the one you would like to move.

For long term you can let the outer blocks take more weight…pounding in the wedge.

[Kudzu]

This boat has lifting rings. It used to hang in my boathouse by them. My shop is a daylight basement and unless I build a gantry there isn't going to be a way to lift it straight up.

I don't have any (boat) jack stands. Just automotive style. Was hoping not to have to buy any and instead build something from materials I have.

No plans to flip it. It would be nice but I don't have the means to do that nor the space I don't think. So I am stuck working on it upright.

I realize the cradle creates some issues with working around it. That why I was asking about better ideas. I can jack up and shift them around some when I need to work under where they are resting. Of course everything will depend on if I have to replace any planking. If I do that is going to change the situation.

I think most of my issues are just a couple of loose seams from improper storage and refastening some screws that have backed out. There is no obvious rot, just a couple of gouges on the hull that just don't justify replacing the plank.

There are a couple of frames in the bow that need to be sistered. But basically she is pretty solid. Till the paint is striped anyway. ;)

[Kudzu]

Just looked at the diagram for the shipping cradle. Forgot about it having beams running for and aft. What is you did something along that line minus the long beams. Two independent stands for and aft. Propely braced so they didn't tip forward and collapse of course.

From the drawing it looks like the boat was supported under the two lift points. Under the bow and then at the transom. You would still have to work around them some but I could lift the boat and shift them a bit fore and aft when I got to stripping that part of the hull.

[Todd D]

I would put the keel on blocking made from 6x6s as sugested above then use 4 jack stands to keep the boat level. The picture below shows my 32' boat sitting on blocking and 4 jack stands. TAs mentioned above, jack stands are nice because you can move them easily. They cost about $100-$125 each new. If you wanted to save money, you could use two flat top stands at the aft end of the boat and just use pieces of 4x4 wedged in further forward.

My boat is rock solid on its blocking and stands. A plus of using jack stands is that you can use them to get the boat perfectly level from side to side.

http://todddunnmicroyachts.com/tortuga/at_home-2s.jpg

[Peter Malcolm Jardine]

Take the motor out of the boat, then you don't have to worry much about taking it apart. It will hold its shape based on its own weight. The motor with tranny is probably about 30% of the boat's gross weight.

[Excalibur]

Kudzu, please forgive the short detour of your thread, I have a related question. My boat is 38', powered, lapstrake ply planks below the waterline, and carvel above It weighs 9 tons. It needs the worm shoe on the bottom of the keel replaced. How do I block/shore it so that I can work on the keel without deforming the hull?

[Todd D]

Excalibur

You can block your boat with jack stands like mine in the picture above. Replace the worm shoe back to the blocking then move the blocking so the new worm shoe sits on the blocking. To move the blocking you simply use a hydraulic jack to lift the boat off one set of blocking. I jack my boat about 1/8" to 1/4" off the blocking, adjust the jack stands, then move the blocking so it is under the new bit of worm shoe and set the boat back down.