keel blocking

Rzide

Member
Oct 19, 2019
52
Boat Info
1999 400 Sundancer
Engines
Twin 7.4 Horizons
I am about to take delivery of a 1999 400 sundancer, and I have a few questions about storing it on land, as its being delivered via hydraulic trailer.

I have 6 hostar stands, but, I need information on the keel blocking technique.

How many locations should I block the keel on a 400, anything specific to avoid?
how high do you recommend? I assume its somewhat dictated by the transport trailer?

I plan to cut up some 8x8's, 6x6, and some trim pieces, but i'm trying to get a measure for how many locations. I searched the forum, but, I did not find anything specific to this model.


Thanks in advance!
 
A boat that size I would say you need a min of three. I'd use four myself. You'll need it high enough to clear the props and have it on a slight angle front to back.
 
Interesting thread. When I see boats blocked up on land I rarely see a consistent pattern and have asked myself "What's the right/best way". I assume you'd want a stand where the lift straps go, so 2 on each side, 3-4 blocks, every 8-10 feet under the keel and another pair of stands close to the bow for good measure. I see some yards chain the stands together.
 
Where are you taking delivery? If it's a typical boat yard I'm sure they will be well versed in how to block most any boat coming into their yard.
 
Most powerboats have their weight concentrated in the area of the engines and fuel tanks. That is usually in the aft 1/3 of the boat so I would place use three blocks with 1 at the stern, 1 towards the bow and the third in the fuel tank/engine area. A 4th block would be optional and needed if the ground is soft and likely to settle some.
 
Here's a photo of my 400 blocked. It's hard to see but it looks like 3 sets of blocks along the keel and then 3 stands along either side. 9 total points of support.

33462303158_afc0396701_c.jpg
 
Sounds like you’re using wood so probably not important but worth mentioning - cinder blocks should only be used so their openings face vertically. I’ve come across a bunch of places that use them horizontally, they have no strength in that direction and will collapse.
 
On a 400DA or EC you need a minimum of 4 blocks, 2 of which positioned on the sling marks, the other 2 near the transom and the forward most one about 1/2 way between the forward sling mark and where the bow curves upward.

The blocks should be 12" X 12". Avoid stacking a bunch or smaller pieces of lumber. That eliminates a very expensive accident should the boat get bumped while it is in storage. Our boat is a 450Da and we use 5 sets of blocks under the keel and 4 stands on each side.
 
IMG_4230.JPG
Here is a pic of a properly blocked boat that is approximately 40 feet overall. The transom, the lifting strap site on the aft end and then at least one additional blockeing placement forward of the helm are essential for proper support the structural elements is of the boat. Jack stands adjacent to the blocks add balance to prevent tip overs. Height is determined by the clearance required to pull the hydraulic trailer out from beneath the boat. Chains are a best practice if the storage is for long term.

BFFC769F-2A65-4678-8F38-F3AB56B4CD73.JPG
 
Here is another example... In my yard they tap on the side of the boat to find the stingers and put the jack stands under that area

image.jpeg
 
Sounds like you’re using wood so probably not important but worth mentioning - cinder blocks should only be used so their openings face vertically. I’ve come across a bunch of places that use them horizontally, they have no strength in that direction and will collapse.
Cinder blocks and cement blocks are two different things. Cinder blocks should never be used at all.

Cement blocks should have something under them if used on other than a concrete surface and there should be a board on top the stack between it and keel.
 
Here is another example... In my yard they tap on the side of the boat to find the stingers and put the jack stands under that area

View attachment 76107
SR shows cradles in each of the hoist lift points and that is it. The cradles preform the function of blocks and stands. If cradles in two positions are sufficient under the keel why wouldn't it be the same if just using blocks?

I'll qualify that by saying it would have to be on a good firm surface. Storing outdoors on dirt or on blacktop in a hot environment more blocking would be justified by reducing psi and less prone to settling.
 
IMO your trim pieces should be varying thicknesses because the bow should be a little higher than the stern. They adjust the trailer so that the bow is a little higher then choose blocking pieces for each location that is just a touch short of contacting the keel, then slide the blocking stacks backwards toward the stern until it touches the bottom. Every block is then loaded immediately as the trailer is lowered, no gaps, which would deform the bottom shape. Our boats are just big pieces of plastic. Our yard uses Hardwood only and Cinder blocks. The cinder blocks never go bow and transom, only in the middle, and only oriented with the hollow cavities vertical, just like they lie when building a wall.
As someone else said, make sure you put a block set at the sling locations, and at the transom. After that, the more the better IMO, but I would go at least 4 on your 400. My current boat does not have a garboard plug, but when I owned boats that did, I would store with the plug in so the mice couldn't crawl in if they managed to climb up the transom blocking, and do not store it with tarps or electric cord or anything touching the ground.
As far as height off the ground, a few inches under the prop with one of the blades down is fine or have it higher if you want to paint, pull props, shafts, or whatever. I always block it a little high because I'm always doing something under there it seems.
Enjoy your new boat and welcome to CSR.
IMG_2769.JPG
 
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Where are you taking delivery? If it's a typical boat yard I'm sure they will be well versed in how to block most any boat coming into their yard.

I'm storing it on a private lot, no specialist or anything unfortunately. I will be doing it all myself with some friends.
 
Thanks all for the replies, looks like i'll do at least 4 locations, two of which being the sling locations. That coupled with the three side stands on each side should, fingers crossed, be enough it seems. It will be stored on a concrete pad, so hopefully no sinking into the ground issues!!!
 
Great conversation. I've heard the block should be lengthwise along the keel, so you get the full length of the block vs just the 6" side bearing the weight on the boat.

That being said - the previous owner of my boat had a "cradle" for her, where it was just blocked with the short edge of the blocks at the sling locations with 4 stands, one in each corner.

uS7iuSY.jpg


Right now she's out and blocked, one at the transom and another at the forward sling location. Two stands near the transom, one at each side, chained together. She is very solid and well supported.

3Slq416.jpg
 
Lots of good advice....

I use 12 Brownell adjustable stands and 4 chains.
4 keel stands down the center.
These are GREAT because there’s no shimming or “close enough” blocking. Hull is supported equally.
8 side stands, 4 per side all chained together under the boat.
 
On a 400DA or EC you need a minimum of 4 blocks, 2 of which positioned on the sling marks, the other 2 near the transom and the forward most one about 1/2 way between the forward sling mark and where the bow curves upward.

The blocks should be 12" X 12". Avoid stacking a bunch or smaller pieces of lumber. That eliminates a very expensive accident should the boat get bumped while it is in storage. Our boat is a 450Da and we use 5 sets of blocks under the keel and 4 stands on each side.

How do you determine the sling marks?
 
I've heard the block should be lengthwise along the keel, so you get the full length of the block vs just the 6" side bearing the weight on the boat.
It's typically best to make sure the grain of the wood is perpindicular to the keel to avoid possible splitting. It may become less of an issue as the size of the lumber increases, but I still like to do it as a safety precaution.
 

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