Boat Stand Adjustment

Once the trailer that 113 sits on was parked and blocked, adjusting the pads her hull rests against was easy. I just backed off the pressure until the pads could "wiggled" about their axis while maintaining contact with the hull. Given the stable platform the need to re-adjust only arrises when we move the trailer to another site.

This January we brought another boat to MN and set her in the back yard. Instead of sitting on a trailer or cradle, this one is sitting on timbers and boat stands. Well the difference between January and Aprit in MN can be big. As the ground begins to thaw the hull is settling necessitating re-adjusting the boat stands. I kept them pretty snug throughout the frozen months checking them every week or so, more for peace of mind that she wasn't shifting around (falling over) in the gale force winds that blew for days at a time. But how much pressure is enough? Is there a foot pounds measure to apply here? I have been backing them off as she settles but thought I should ask those who have experience with sort of thing before continuing on blindly based on a hunch.

Thanks a bunch!

I have a Commander 26 and I need to know where to put the boat stands. There are soft spots on the hull that I avoid. I am tapping lightly with a rubber mallet to find a solid spot. I would like to see where the structural inside "beams" are so that I can measure down from the deck and back from the bow to get the exact spot to put the boat stand.

Any suggestions?

If you are going to work on the boat on the hard, what is level is important. You
want to set up 2 or 3 dead straight sticks across (athwart) and lengthwise with
torpedo and carpenter levels. When your waterline's level, your whole boat's level.
But you can't trust the WL on an old boat.
If you are doing it by yourself in a back yard, say, you have to build some sort of
frame that supports the boat on its keel with built in jacks below the waterline.
https://www.scaffoldmart.com/marinemart/boat-stands
The best place to find the waterline is in the Manual.

Best jacks for moving weight around are bottle jacks.

Jack stands do no lifting -- they are props.
Minimum are four jack stands on hard immovable surface hold the boat in balance
with just enough equal pressure, firm enough but not jamming the boat or creating
a dent. 6 would be better. You want to place the stands where they cannot skid
up. Three legs equally firm on a hard surface.
Keel should be supported at two places furthest apart on its 6' flat bottom, which is
rounded (on Ariel) and not a level waterline itself. The stern of the hull when sitting
on its keel is slightly higher than its bow, and therefor unreliable for waterlines.

If you are going to work on the rudder, remove it before the boat is locked down.. Or
put it where you can dig a 3' deep hole to drop it to remove it -- and also put it back
in your own good time before launch. Maybe dicey because maybe you don't want a
hole under the rudder where you also have the keel support. Close to the whole
weight of the A/C. You do know how to remove the rudder?

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In the marina where I am, the tarmat is not exactly level anywhere. Initial leveling is
done with the boat in straps hanging from a crane. It uses a massive 4' tall horse
with 4x10 legs and a 6x10 cross beam to support the boat's stem. This horse is
fractionally moved forward and aft while the crane drops and lifts to get the length
WL level. Skipper is in the boat shouting instructions to marina personel.
"Up a little more! That's good!" ..stuff like that.

A short large block of timber is placed under the keel near the rudder, slightly forward
of the keel post. A second similar 14x14"x1.5' baulk is placed 6' forward... And the
boat is lowered onto the blocks with the stem resting on the horse. The rearmost
block is 8" inward to allow removal of the rudder shoe that the rudder shaft engages.

The 2nd block is under the flattest run of the keel, All in all these two load bearers are
quite close. Fine tuning is done with the crane. A piece of 2x4 is stacked on the
blocks which are then wedged flat against the keel with wood wedges, shims, scrap
plywood. With stem on crossbeam, the boat is now immovable, resting on the hard
at three places, the four jackstands positioned under the bilges enforce an absolute
level waterline by screwing the plates in and out. Plywood stand tops have thick
carpet squares glued on with threshold cement.

The yard has done it a thousand times before. It was my job to check vial bubbles in
a bunch of borrowed carpenter's levels blue taped wherever I thought level, not
that many places. Jacks are set up two to a side, set under our slack bilge. While
the boat is still hanging, but on the blocks, the jacks are fitted, two-legs-in-one-leg
-out. Those legs are always in way of a ladder or a foot. The stands are chained
together across port to starboard. Chain taut, touching under the keel. Once you
get the fore-n-aft level, use the screws in the jacks to fine tune the best level. With
the three load bearing places established.
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When you get to grinding and painting you need a couple more jacks to temporarily
set up and swap so all surfaces are accessed. Jack stands are set up inward of the
horse. the rear chained pair of jacks likewise inward of the keel post.
Maybe easy to inadvertently knock a jack stand outward, that's why they get chained
together.

Draw a line across the exact middle of the boat, 12'8" in from each end. That line will
be at the back of the closed slide hatch on the Ariel, about 3 1/2 feet aft the mast.
It is also the point where the keel begins its climb to the bow and becomes the stem..
The boat when sitting on its 6 foot long, fairly flat, but slightly nose down bottom,
has all of the front volume of the boat, 12'8" feet and nearly all of the 2500lbs
ballast, totally unsupported. That's why the yard put that burrito grande at the stem.
Really to support the front half of the boat. This may be a place for a couple extra
jackstands. But, I believe there is reason enough to think the boat could trip forward.
So I won't depend on stands that might have to go up on the topsides.

Believe the keel/stem, about 10.5 feet forward of the rudder post, can be solidly
blocked up (say: a 14x14 on top of a 14x14, or a heavy duty short keel stand) into
the convenient reverse curve of the underwater stem, as solidly as the keel blocking,
will not only support the forward half, but the front end of the encapsulated ballast.
The blocking (looking at a lines drawing) would be 1 foot forward of the mast on
deck. It's inconvenient for prepping the bottom and rolling paint. BUT keep the
stem supported tight when you move the blocking. Maybe a jackstand at the very
front. (referring to the Ariel here -- some fool has stolen my Manual.)
By measure forward from the rudder shaft bearing fitting: 8" -> 5' -> 10",
where a special built up load bearing stack is constructed to support the forward half
of the A/C.
Boat jacks can be positioned under the turn of the bilge, visually just inside
rear load bearer (visually one foot in or less from the end of rudder shoe).
-- 2nd set, port & stbd, visually just inside the front load bearer (actual
measure: about 10 1/2 feet forward from the edge of the rudder shoe).
Three load bearing blocks measured from the end of the keel forward: 8"> 5' > 10'.
Blocks are 14x14"x18" or less, placed short or long, approx. 4' space between. Lines
drawing by Alberg (pg144 Assoc Manual) are accurate but not exact. Many anomalies.
WHAT'S LEVEL
Don't know Commander, seats in the cockpit and below should be level fore-n-aft.
Quite likely across. Companionway hatch logs should be level athwart ship. Up in the
cockpit you can actually see the bubble here. Possibily toerails exactly opposite on
each side are level, certainly should be.. Molded seats in and out could be level
lengthwise. And also across. This means WL level, which can be found on a lines
drawing of the Commander in the Assoc. Manual. You will be able to locate the
original Waterline. Cockpit floors not level, tilted to drain. While one drawing shows
the drains aft, in reality drains usually empty into drains forward cockpit corners.

Have also found that finding and marking the centerline of the deck, cabin, cockpit
and the center line of the cabin sole, makes it much easier, later on, to find locations
for things, because measuring out from the absolute center is the easiest way to get
accurate parallel lines and check right angles. Useful when removing things.
Surfaces change. Tiny V chisel chips out of centered edges will still be there after
sanding or painting to snap, trace, or tape a straight line.

Folks have done this with six jack stands. But you'll be constantly improvising and
possibly the boat could take over, even if you always think you have 5 on.

Bulkheads are sometimes not vertical 90degrees.

Much luck!! Hope reading thru this has made sense.
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Many-words-Ebb has said this elsewhere. Take a lines plan or two out of the Manual
to a copy shop, and have them enlarge the boat image to 9 1/4" WATERLINE.
Do another with the total deck length of the hull: 25'6" = 12 3/4" ruler inches.
Bring a stainless ruller with you! Now you have a 'scale' lines drawing. Get it exact!!
You can find a 1x12 doll's house scale ruller to download that has 12 spaces to the
inch. You may have to use copyshop to get an accurate scale. But I stumbled into
one that downloaded perfectly. Had two or three laminated, Used them often for
years. Have to remember you are 1/2 scale...www.printmini.com/printables/rulers/
Tend towards images signed by Alberg. Some images are very inaccurate. Some OK.
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In case you missed it! Jack stands are placed at the keel post, in a port
& strbrd pair, visually just inside keel end. They are positioned just inside
the turn of the bilge. Second pair of jacks are positioned just inside the
front end of the keel where it becomes the stem. Or foot or so forward
but also under the turn of the bilge.
Each pair must be chained together crosswise, so that they cannot be
moved outward. Light, real chain crosses under keel.
You can always add a third pair.
You must also support the stem where it bends slightly inward in profile.
This can be located on a lines drawing of Ariel or Commander. Which is
quite low down on the hull. Hull must be supported at these 3 positions
for it to be secure.
Those three keel support positions can be achieved with a single 12' - 16'
timber under the keel and forward under the stem..
And some stacking improvisation under the stem.

The appendix to the manual includes plans for a shipping cradle that can guide your efforts.