Cradle for Hunter 240

[nola2172]

In order to facilitate me being able to do bottom work on my 240 (especially the centerboard, which is rather difficult to access), I am thinking about building a cradle for it. To start with, here is a link to some pictures from DJN51 that give a rough idea of what this will look like:
http://forums.hunter.sailboatowners.com/showthread.php?t=117379


What I would want to do, though, is the following:

1. Use 10' of steel tubing as the primary cross member supports. I think a 2"x4" tube with wall thickness of 1/4" should work OK. Could go thicker on the wall, but that gets really heavy. Based on my calculations, over a 10' span with 2000 lbs dead center on the beam, it would sag no more than half an inch at the center. Since the boat does not weigh 4000 lbs this will be less, and the weight will be somewhat more evenly distributed than dead center which will also reduce sag.

2. Build a wood frame around the steel tube to curve to the boat's shape and give it a bit more width on contact with the boat (i.e. like the linked pictures)

3. In order to get it up in the air, use a jack stand on the center of the boat to lift it up, then slide the cross member under the boat.

4. Use jack stands on each side to push the cross member up, lifting the boat off of the trailer.

5. Attach fixed side supports (similar to the picture) under the cross member and attach them with bolts (so they can be removed). Remove the jack stands.

6. After everything is good and secure, pull the trailer out from under the boat (pulling it forward). This is the reason for the 10' span of the steel beams - it allows the trailer to be removed which will make bottom care a lot easier than if the trailer is still there.



So my question is - does this sound like a good idea? Also, is there anything I am missing?

 

[Crazy Dave Condon]

Basically, there is a lid affixed to the bottom of the hull to create the water ballast tank. Since the weight of the boat is resting solely on stands, I would have additional supports because if left sitting too long, the weight of the boat will sag in the center and possibly crack the seal of the ballast tank lid and centerboard housing as well.

In addition regardless of how the supports are under the boat to include the referenced photos, they need to be secured to one another via chain or heavy duty line to prevent them from kicking out. The one referenced photo of the support at the end of the boat could very well kick out and if you are underneath it, I would not want to read about your obituary. Over the years I have experienced much and seen much occur that resulted in injuries and death. So lash the supports together. What many fail to observe, the hull is curved and supports can kick out. Why do you see chains affixed to stands across from one another. Even in my yard when a boat was in the travel lift, I always secured the straps together to insure they would not slip out due to a curved hull.

For the record, I was involved with this boat and as a former dealer the top seller of the 240 which I base a lot due to experience and knowledge only as I have seen a lot in my life time around boats. Just be safe my friend.

crazy dave condon

 

[Indianabob]

I also was going to do the same thing in order to change the centerboard on my H240 and put bottom paint in the centerboard recess. Crazy Dave - if I created 2 cradles like what was shown in the photos, and also added 2 Brownell boat stands on either side of the centerboard, would that provide enough support so I would not harm the water ballast?

The alternative is to have the boat yard raise the boat on a hoist, but that costs between $200-300. It's worth it if I might damage the hull structure in doing things myself. I don't want to try to save a few dollars and do a lot of damage to the boat.

 

[nola2172]

Crazy Dave - Thanks for the feedback. My boat has markers on it for where the slings would go, so if I support it there, should it be OK? I don't see why using slings or using a wide bottom support would be a lot different.

Also, I would not plan on leaving it up there for a long time, just long enough to get the centerboard/bottom worked on and then set back down on the trailer.

 

[Crazy Dave Condon]

Add four additional brownell or similar stands making sure you are chaining them together. What most do not realize the weight of the boat is being supported by those stands vs. traditional keels where the keel takes the weight of the boat and stands more or less keep the boat from leaning over. I would rap the hull to determine the thickness of the hull when figuring placing the stands. If the hull depresses into the stand base, then readjust the stands or move them as the hull thickness is not that great.

Like I said, I know this boat from being involved with the construction, selling 1/4 of the production line and personal working on them from a dealer perspective. It is called knowledge and experience which I answer from only.

crazy dave