Boat stands without blocking

[Jmstee]

I have some damage on the bottom of my keel. While it is out of the water for the winter I want to dry it out and reglass it. The only issue is that the blocking is in the way. It is not cost effective to have a boat yard lift it and hang it in slings day after day while i repair, fair, barrier coat and paint. My thought is maybe it is ok for the boat to be in stands alone without blocking for a few days if i use a few extra sets. When it gets trucked out it is lifted by pads on the sides only until out of the water. Also when lifted out its hanging in slings which provides no keel support. I don't think that the hull will deform or have too much pressure if i use a couple extra sets of stands, but I also don't want to die from being crushed under a falling boat.

[Nicholson58]

Boats are not made to be point-supported on the hull. Repair the accessible parts then have the yard move the keel supports and repeat.

The other alternative is to have a sling support made that mimics the travel lift slings.

[Mike OReilly]

I’d think it depends on the boat, but I think Nicholson58 is exactly right. The hull is not intended to support the weight of the boat. I suspect with some heavily built boats, or some that are very light, you may be able to do as you suggest and get away without causing any damage.

Do as Nicholson says. Far safer for your boat, and probably for you as well.

[billknny]

You didn't tell us what kind/size of boat you are talking about, that obviously make a huge difference.

Boats can rest on jackstands, but... it has to be done very carefully. None of the stands can be in the middle of unsupported panels, they all need to be at bulkheads, bow stem, chines, etc. It's not easy and not for the amateur.

In general, is far better to shift the blocking as you work.

This seems is area where you should be talking to your yard for advice. Any yard I would ever put my boat in has VERY hard and fast rules about customers NEVER touching jackstands-EVER. I have seen the domino effect of what happens when a moron tries to move jackstands. It's not pretty.

[sailah]

When boats are hauled on a trailer, the hydraulic trailer they use has 2 I-beams already installed. I know this as I have my boat hauled 2x a year by the same company. The hydraulic arms are for stabilizing the boat only, all the weight of the boat rides on these 2 steel beams. I motor the boat onto the trailer, he aligns me using the front pads until my keel touches the beams. Then he pulls the trailer up to the truck on a winch cable (it is deployed about 15' down the ramp into the water fully submerged, but truck is not in water) until it latches back onto the truck receiver.

When the truck gets to my house, the driver blocks under the keel with 6x6 blocks and then lowers the boat down on the keel only by letting out the air in the trailer airbags. Once the keel has come to rest on the wooden blocking, he removes the arms at the rear of the trailer and replaces with my jackstands. He also inserts the front V block stand. So boat is now upright, resting on keel blocks, with 2 jackstands about 30% from the transom and a single V block stand in front.

Then he drives forward, gently, until the trailer is removed and we place the front 2 jackstands. Since I'm on asphalt pad, we use plywood pads under each jackstand foot.

So, no, you can't suspend a boat using jackstands with nothing under the keel. I'm sure you might be able to if you really engineered it but you'd be putting massive strain on the structure of the bulkheads and core of the boat, not to mention that jackstands aren't designed for the full weight of the boat and keel. Just designed to keep it upright.

When I used to have boat hauled with Travelift the rear sling was always on the aft part of keel taking most of the weight and the front sling had some but seemed more for balance than anything.

[Jmstee]

Ill just have the yard move me around several times to adjust blocking. better to spend an extra buck and be safe and not break anything.

[Mike OReilly]

Originally Posted by Jmstee

Ill just have the yard move me around several times to adjust blocking. better to spend an extra buck and be safe and not break anything.

Good plan.

[Cheechako]

Block only two places fore and aft small length. Do your work in between. Then reblock if necessary.

[Cadence]

Move the keel blocking as needed. It is amazing what a hydraulic jack can do. You only need to lift enough to place another set of blocks prior to removing existing ones. Have a supply of shims handy or if you have jack stands attend to them . Go a pump, of the jack. at a time, if needed.

[deblen]

Alternative boat "stands". vs brownell style yacht stands.
This facility is open year round and is subject to hurricanes & winter winds of up to 100kts,with no damage in it's 30yr life.
If you must work on the bottom of your keel,use spaced blocking. Move blocking ,as required, by using a 20T common piston jack under the keel.
By using timber boat stands as pictured,placed under bulkheads at bilge turn,the boat can't fall off. / Len


https://www.facebook.com/FundyMarineServiceCentre/

[Cadence]

Originally Posted by Cadence

Move the keel blocking as needed. It is amazing what a hydraulic jack can do. You only need to lift enough to place another set of blocks prior to removing existing ones. Have a supply of shims handy or if you have jack stands attend to them . Go a pump, of the jack. at a time, if needed.

PS One caution, insure the hydraulic bottle jack/jacks are not positioned at an angle. They can zipper/split. Ask me how I know. Shim everything, scaring the sh&$t out of you is best case, wearing the boat is worst.

[wsmurdoch]

I have supported my Tanzer22 by its hull only for two months or so several times. I did not use jack stands with their smallish flat plywood pads resting on the curved surfaces of the boat. Instead, I supported the boat with two 10" wide 1/2" plywood strips covered with several layers of carpet set athwartships with one pressed against the hull forward of the keel under the forward bulkhead and with the second just aft of the keel in an area where the hull is supported by the interior fiberglass. The plywood strips were pressed into place by lots and lots of 2x4 wedges and blocks driven between the plywood strips and two sets of four athwartships 2x12s which themselves rested on four concrete block piles outboard of the boat. The waterline was 6' in the air. That let me lower the centerboard which withdraws into a slot in the bottom of the keel for maintenance. Now, this is a 3500 lb boat, and I think the support was as good or better than the slings of a travelift. I saw no evidence of hull distortion or damage.

Bill

[thinwater]

Every time you move a stand you risk changing the tension on others. For example, if you lift the boat to change a keel block, you loosen all of the stands.

This is really not a good thing to learn-by-doing. Unless you really understand rigging... don't. And the yard probably (wisely) forbids DIYs touching stands.

[thruska]

Originally Posted by Jmstee

I have some damage on the bottom of my keel. While it is out of the water for the winter I want to dry it out and reglass it. The only issue is that the blocking is in the way. It is not cost effective to have a boat yard lift it and hang it in slings day after day while i repair, fair, barrier coat and paint. My thought is maybe it is ok for the boat to be in stands alone without blocking for a few days if i use a few extra sets. When it gets trucked out it is lifted by pads on the sides only until out of the water. Also when lifted out its hanging in slings which provides no keel support. I don't think that the hull will deform or have too much pressure if i use a couple extra sets of stands, but I also don't want to die from being crushed under a falling boat.

Depends on the boat , sooo what’s the boat mfg and model?
Personally , I feel if you position stands in strategically on the bulkhead framework positions you will have no problem. Also blocking under the keel will prevent sag. I don’t understand all the oh no you can’t do that! Malarkey.
Ok now go ahead and crucify me , blah blah

[coopec43]

Originally Posted by billknny

You didn't tell us what kind/size of boat you are talking about, that obviously make a huge difference.

.

If his yacht is a catamaran or trimaran I don't think what you are saying would be correct! On the other hand...... (Why don't people provide some clues in their profile? )