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baDumbumbum
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Discussion Starter #1
Our Albin Ballad is sitting on the hard for three or four years, undergoing an extensive top-to-bottom refit. Among the tasks are removal and retabbing of the major bulkheads, pulling up & re-bedding the cabin sole, and a bit of structural glassing near the mast step strut and the aft end of the keel/hull transition, where some sloppy repairs indicate a past grounding. (Here I ought to mention the Ballad has an integral fin keel, lead ballast in bottom 30".) All interior furniture is getting rebuilt, too.

Anyhoo, the boat sits on its keel with plenty wooden shoring and some tiedowns to resist Wyoming winds. As commonly happens, boat sitting on keel rather than keel hanging from boat creates a bit of a hump in the cabin sole & some minor distortion in the hull shape versus same boat in watery mode.

Should I take steps to unload the keel before fitting the replacement bulkheads and re-glassing the keel areas? If so, how best to simulate the hull's natural shape? Slings? Cradle? One of our tasks will be adding a couple floor stringers athwart the keel sump, & I'd hate to build distortion into the repair due to the upward thrust of the keel.:(
 

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Had the same issue for my stringer rebuild a while back.. finally determined the only/best way for me to feel 'right' about it was to have the boat afloat.

If the boat is flexible enough to 'hog' over the keel then if the hull is wholly supported on stands the keel may 'sag' the middle portion. It's always tough to know that you've actually got the proper shape when sitting on the hard.

This does raise some caution flags if the water is especially cold and condensation might form to interfere with the bond.. so far it seems I've gotten away with it.
 

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baDumbumbum
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Discussion Starter #3
Good points, Faster. Alas, the nearest likely body of water is 1000 miles from us. I could build a big tank & float the boat in the back yard.:D Girlfriend has been pining for a swimming pool....

There isn't any appreciable hogging, or distortion fore-and-aft, ala the 'Catalina Smile' in reverse. Rather, the cabin sole humps up slightly between the settees, side-to-side. The hull-to-keel transition is 1" of solid glass; I'm not worried about strength. But the bilge turn is seeing roughly a 7300# difference from tension (afloat) to compression (a-hard). I wonder if we could alleviate maybe 2000# of the hull's 3800# via jacks or slings or cradles, whether that would get rid of most of the hump?
 

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I guess I'd try jacking the hull up until the 'hump' in the cabin sole goes away and hope for the best??

My worry would be that you 'lock in' a false form with your repairs/structure, which would immediately be 'stressed' when the boat's lifted and launched - perhaps to point of cracking then and there.. could be an anxious moment.
 

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baDumbumbum
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Discussion Starter #5
That's exactly my worry if we do the repairs with the keel pushing upwards. While it will be hard to reproduce floating form perfectly via slings or cradles, just approximating normal keel dangle has to be better than what we have now, when perhaps half the total boat weight is concentrated on the keel/hull transition zone.

Dunno if jacks between keel sump and deck underside would help any?

One possibility would be to weld up a gantry just aft of the companionway out of some 4" Sched40 and an I-beam across the top. I kinda want to pull the Penta MD6 out of this beast anyhow, and that would be a useful way to lift it in and out. Fat lifting sling and two chain hoists to the corners would unweight most of the keel; a second gantry at forward lifting points could do the whole boat. Would also make it easy to lift it onto a transport trailer when the time comes to move it; unloading that sucker with a 20,000# forklift was not a stress-free day.
 

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Remember you're a womble
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If you were clever you could probably figure out the total weight of the boat in the water, and then raise the hull on land until the boat weighed the same which would in theory be at least pretty close to the force on the hull from the keel.
That makes sense in my mind, but likely not once I hit the Post Quick Reply button :)
 

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██▓▓▒▒░&
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Consider that when the boat was built, the keel was NOT pulling down on the hull. The hull was laid up, finished, and then the keel bolted on or dropped in. Or, the keep was attached at some point during the build, and the boat then sat on it.

So I'd suggest generous jackstands or cribbing, until you feel the whole alignment is "natural" and then expect that yes, it will change when the boat is floated. As it did when built.

It's an imperfect world.
 

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bobmcgov

My suggestion is that you get in touch with Peter Jacobs. He has this blog:
........ Mostly About Boats
that covers a recent complete restoration of a Ballad in his driveway from an abandoned wreck in a field to an as new boat. He not only knows the Ballad very well but is a retired engineer. He previously had a Vega which he did a large amount of exceptional work on. I actually talked to him today in the marine store I work at. He is easygoing and approachable.
There is a link here to his email just below his picture: https://www.blogger.com/profile/06549321574020928322
 

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Bob,

Did the distortion only happen after you pulled out the bulkheads? Any boat oughtta be engineered to sit happily on its keel without bending, but bulkheads and stringers (and settees and other cabinetry) may be a big part of giving the glass "skin" that strength.

If you're using the old bulkheads as templates, can you just adjust the jackstands till it's "right," i.e. the new bulkheads fit? Barring that, I think your theory about unloading some of the weight and seeing if the glass flexes back to natural is the way to go.

My only similar experience is, the trailer bunks put big creases in the (thin and floppy) aft quarter skin of my friend's Siren 17 this summer, after trying to haul her out with a load of water in the bilges (no we didn't know the water was there!). Bad enough to break the tabbing to the bunks that run aft under the cockpit and form the only internal bracing. After I patched the leak that let the water in and splashed her, the glass relaxed back to "true".
 

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Our Albin Ballad is sitting on the hard for three or four years, undergoing an extensive top-to-bottom refit. Among the tasks are removal and retabbing of the major bulkheads, pulling up & re-bedding the cabin sole, and a bit of structural glassing near the mast step strut and the aft end of the keel/hull transition, where some sloppy repairs indicate a past grounding. (Here I ought to mention the Ballad has an integral fin keel, lead ballast in bottom 30".) All interior furniture is getting rebuilt, too.

Anyhoo, the boat sits on its keel with plenty wooden shoring and some tie downs to resist Wyoming winds. As commonly happens, boat sitting on keel rather than keel hanging from boat creates a bit of a hump in the cabin sole & some minor distortion in the hull shape versus same boat in watery mode.

Should I take steps to unload the keel before fitting the replacement bulkheads and re-glassing the keel areas? If so, how best to simulate the hull's natural shape? Slings? Cradle? One of our tasks will be adding a couple floor stringers athwart the keel sump, & I'd hate to build distortion into the repair due to the upward thrust of the keel.:(
I would assume the sagging took 3 or 4 years to get to where it is now. And it will have to be a slow process to undo. If the sag can determine and measured how far it is sagging by measuring the hump inside. Maybe a straight edge across the settees then measure down to the top of the hump. This will get you in the ball park as to how much you need to evenly lift the hull. I would lift the hull in small increments, like 1/4" at a time. You may need to add additional supports, like twice you have now, on the hull to lift so there is no damage or distorting of the hull with the lifting. 1/4" even lift and let it rest for a month or so, then lift it another 1/4" and let sit of a month. Do this until the measurement you took of the hump is gone. 1" hump will take you 4 months. Hot weather will also help, I would not try to lift the hull in cold weather. And hot weather will greatly help.

IMO it will take time to fix this, and by rights just as long as it took to disfigure. But it is hard to say it took 6 months with the boat incorrectly supported or 4 years to disfigure. And at what point was the boat unsupported correctly. Was the boat moved during the 4 years. Was is stored on the soft ground? Are your wind tie down too tight and pulling the hull down? Is the hull dis-formed where the supports are supporting? Are there humps at those locations.

Good luck, hope this helps!

Eric
 

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bummer we just did most of our bulkheads in the water with rigging semi loose that way stuff didnt get too out of sinc

thats one issue I have with leaving boats on the hard too long....stuff can and will distort if you leave it in the same place for ever like jack stands...the more the better and the closer to the waterline the better, you can also change them a few feet at a time so they dont push on the hull all that time

as of now I can only recommend taking measuremnts each side say from cabin sole if possible to deck undersisde, if you can at the same spots...if there is a dufference you will have to either jack up one side internally or press down on one side from the deck to acheive same size and distances....

this is a tough one since naturally the boat will go back to its shape in the water and when your rigging is readjusted...but since your bulkheads are removed or being retabbed stuff gets shifted

op did you completely remove bulkheads or just ground and retabbed in places?
 

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baDumbumbum
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Discussion Starter #12
Consider that when the boat was built, the keel was NOT pulling down on the hull. The hull was laid up, finished, and then the keel bolted on or dropped in. Or, the keep was attached at some point during the build, and the boat then sat on it.

So I'd suggest generous jackstands or cribbing, until you feel the whole alignment is "natural" and then expect that yes, it will change when the boat is floated. As it did when built.

It's an imperfect world.
All true, HS. But we'll be adding MORE support in the form of additional floor stringers -- largely to get rid of squish in the cabin sole. Better limber holes, improved cross bracing in the bilge (table supports are not adequate), and biax where the aft keel joint got crunched a little. Right now, that whole structure has some natural flex to it: hump appears, hump goes away. When we are done adding stiffness in the bilge area, more bulkhead support, and extra glass, maybe hump don't go away.:( (For one thing, we're installing a floor-to-roof grab bar at the end of the nav station bulkhead. I want that length to be right.)

bobmcgov

My suggestion is that you get in touch with Peter Jacobs.
Thanks, mitiempo. Peter is indeed approachable and his recovery of Bennath has to rate as one of the greatest boat makeovers ever. Everything first class. We chat regularly on the Ballad Exchange, a BBS dedicated to the boat. It's a sweet but taciturn bunch over there -- one or two postings a week the norm.;)

Bob,

Did the distortion only happen after you pulled out the bulkheads? Any boat oughtta be engineered to sit happily on its keel without bending, but bulkheads and stringers (and settees and other cabinetry) may be a big part of giving the glass "skin" that strength.

If you're using the old bulkheads as templates, can you just adjust the jackstands till it's "right," i.e. the new bulkheads fit? Barring that, I think your theory about unloading some of the weight and seeing if the glass flexes back to natural is the way to go.
Bulkheads are still in place. All the distortion occurs in the 22" walkway between the bulkheads/settees. Hull shape outboard of the keel area is just fine -- at least, until the bulkheads come out! Point is taken about the furniture supplying some hull shape, although like most Scandinavian boats, the Ballad has no extensive FRP liner. I prefer loose furniture like this, but you don't get the stiffness advantage of a liner. The bulkheads are likewise mostly bolted in place; I'll be moving one a couple inches and tabbing the hell out of all bulkheads, both faces. That may alter the flex profile of the hull versus what came from the factory.

I would disagree that distortion of boats on the hard is unusual: every boat, whatever the material, will change shape to some extent when sitting on 3sqft of fin keel versus same heavy keel hanging below a uniformly buoyed hull afloat. Steel, alloy, wood, or FRP -- the shape will change. I want to be sure the additional structural work I do now won't cause trouble when the boat returns to form in the water.
 

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baDumbumbum
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Discussion Starter #13
Pics would help, wouldn't they?;) Here's a 25" long straightedge laid across the tummy bulge in question, at the point of greatest distortion:

<a href="http://www.flickr.com/photos/[email protected]/11999677646/" title="himp1 by wyooffgrid, on Flickr"><img src="http://farm6.staticflickr.com/5533/11999677646_0e3c70900e_z.jpg" width="640" height="403" alt="himp1"></a>

And another with floorboards out, so you can see the keel sump and factory 'floors':

<a href="http://www.flickr.com/photos/[email protected]/11998875945/" title="himp2 by wyooffgrid, on Flickr"><img src="http://farm4.staticflickr.com/3728/11998875945_c585860fbc_z.jpg" width="633" height="640" alt="himp2"></a>

I want to peel up the sole -- which has foam between it and the hull, foam that has gotten nasty and squishy over 40 years -- glass in a few really stiff stringers to maximum span, add some additional bracing to the keel thwarts & table leg sockets, and then remove, clean up, and properly tab in all bulkheads.

The boat is held upright by extensive props, mostly tied together with diagonal bracing and chained together side to side. Tie downs are also extensive, attached to earth augers, but not very tight -- the few remaining ratchet straps are being swapped out for 1/4" chain, hand-tensioned. All the props and tie downs are for is to keep the boat centered over its keel so it does not tip over. The keel is carrying maybe 90% of the hull's weight, with the remaining 10% spread over perhaps 20 timbers, a bow support, and the rudder skeg firmly blocked beneath. Guess we could transfer more of the weight to the timbers? I'd worry then about localized denting.
 

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The picture with the straight edge...does not look like the keel is humped up. It looks like the floor on either side of that access/keel is drooping down. Assuming the floor was flat at one time. The straight edge looks like it is a straight line from the bottom edge of the baseboard on Port and Starboard and straight edge is sitting on, so called hump. Meaning the floor is sagging. Looks like floor structure issue, not hull settling around the keel. Just IMO.
 

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baDumbumbum
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Discussion Starter #15
The picture with the straight edge...does not look like the keel is humped up. It looks like the floor on either side of that access/keel is drooping down. Assuming the floor was flat at one time. The straight edge looks like it is a straight line from the bottom edge of the baseboard on Port and Starboard and straight edge is sitting on, so called hump. Meaning the floor is sagging. Looks like floor structure issue, not hull settling around the keel. Just IMO.
Could be, Delta. But... the outer edge of the sole, at the line of the settees, is the hull itself. The sole material is glued straight to the roving there, where you see the mahogany baseboard. The keel pushing up on those transverse panels in the bilge, the ones the table socket is screwed to, would cause a flat-topped plateau with gutters to the sides like we see in the photo. Here you can see where the pan has cracked upward at the aft table leg socket:

<a href="http://www.flickr.com/photos/[email protected]/12000999715/" title="himp3 by wyooffgrid, on Flickr"><img src="http://farm3.staticflickr.com/2883/12000999715_9312beeffb_z.jpg" width="640" height="543" alt="himp3"></a>

It is not a new crack, but its edges have pulled away from each other -- that rib was under considerable tension. If the pan or its bedding were breaking down, I might expect that to happen worst in the middle, where it is unsupported nearest the bilge or in front of the engine. The foam areas are bad, tho, and someone tried injecting Great Stuff underneath to firm up the pan. Joy.

The boat has only been on its keel for one year at this point; I doubt any flex is permanent. It was a Great Lakes Boat most of its life, so it spent maybe half the year in dry storage & half on the water.
 

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I would not look at cabin soles to look at distortion like that, I think its safe to say that many many boats can have sagging or mostly uneven soles, and thats not an all or nothing scenario on how the keel is pushing up...

can you take measurments of the hull sides for example, and sole to deck underside?

you can also use lines in diagonals and measure distances like that too

say from mast step down to a fixed point either side of the hull

I think this would be a better measurement as you eliminate the possibilty of misreading a "flat" surface" per se

on my boat...the sole is all uneven or sloped so you cant take a measurement from floor boards to either side for example as its not accurate to do so...

what does the oustide look like?
 
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