Post compression help

May 21, 2009
360
Hunter 30 Smithfield, VA
Ok, please do send more pics and direction, I was already thinking loosen shrouds, jack it up to straighten top of beam, and find a better piece of cheese( lol) than the old plywood look, but where can I find a jack small enough yet strong enough to get in such a tight space
Put another post adjacent to your existing and use a flat piece of plywood on the ceiling to spread the load. Use a scissor jack from your car or bottle jack. It really won't take all that much force to raise things back up. Hard part is spanning your work area under the jack so that you can repair the floor.
 
Sep 20, 2011
135
hunter 30 md
So the post itself is behind the fascia!
Release some tension on shrouds
Jack up a new beam with plywood to support cabin roof load
Then remove or repair sole( cheese on cracker)
Put back together
What is the general concensus to replace the piece of wood( cheese) that always rots away?
Any one please chime in
 
Jun 5, 2010
1,107
Hunter 25 Burlington NJ
The short, the fat and the ugly.

Willie, I would consider having a new 'I-beam' under-sole support made that takes up the whole space (no plywood above it). This part could be easily made from readily-available stock by any welding shop who can do aluminum. Before installing it should be epoxy- and/or powder-coated. Then, it should be inspected and maintained regularly.

If the spacer is necessary, it should be solid fiberglass or G-10. Neither of these will crush.

Any of these materials are available from McMaster-Carr. Go shopping online and take your pick!

The real reason for this godforsaken spacer is to stiffen the structure under that bulkhead. I've long maintained that bulkheads, not sole panels, should be the ones that go straight through. In other words, the loads taken by bulkheads-- between bilges and cabintop, between sides, between chainplates-- are way more important than those taken by cabin soles (people walking about). It's not a house-- you don't have to build a 'floor' first and stand all the 'walls' on it. Let the bulkeads go skin-to-skin, and the bunk fronts too, thus transmitting loads to the skin of the boat, which is the only way to go with a fiberglass (stressed-skin) structure; and provide cleats and dropped-in panels for all the soles. I've been advocating this for our C44s for years, more from an accessibility issue than from a structural one; but done right accessibility to the bilge is easier as well.

The other posters are correct in that you need to get loads off this failed/failing structure before you can do anything on it. Consider having the mast pulled-- no point in rebuilding this with it in place. A new aluminum 'foot', suitably stouter and stronger, elimination of the plywood or mahogany pad above it, and proper epoxy-saturation of the cabin sole and cabintop, and this structure can be rock-solid.

Your other option, as was done at Raider Yacht, is to have a one-piece all-aluminum post made out of a box section, standing on a stoutly-constructed crossmember in the bilge and extending straight up to the underside of the mast step; and this is what I'd do if it were my boat. Keep in mind you can't just stand it on the keel, or on the hull bottom where the keel bolts come through. That would extend the compression load of the spar straight into the tensile load of the keel, in theory (and more than just theory) encouraging the bottom of the hull to fail and the keel to fall off. It is vital that the load be spread to as much of the skin of the boat as possible; which is the original job of the load bulkhead.

In my H25 the one side (starboard) of this bulkhead bore the whole load of the compression post, which was screwed (with no bedding compound or epoxy) to it. The post did not even carry through to the bilge; it just stood on the plywood of the sole. The bulkhead did most or nearly all of the job-- the post only kept its end, towards center, stiff enough and in place. My improvement was to provide a doubled joist of 5/4 mahogany, duly treated in epoxy, and to stand the post on a plate of G-10 before it got screwed to the bulkhead. In this way the bulkhead and 'joist' share the load, which is about as good as you can hope for in a lightweight, mass-produced and cheap-to-begin-with fiberglass boat over 35 years old.

The pic shows Diana's bilges before I installed the sole-- half of it is in place to starboard. The post is standing on the doubled one and the rest are all 5/4 mahogany, cut and fit to the hull and bonded with 5200. Note that none of them are in contact with the actual bottom of the hull. The goal was to spread each one's load to as much surface area as possible. Note the limber holes and spaces, access for keel bolts, and the central joist having cleats to accommodate the leg of the drop-leafed table (looks like a tripled joist). (Under each settee is a water tank and a house battery, so all this weight goes here, not to the ends. The part on top of the can that looks like 2/3 of a joist goes in the head compartment.)
 

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May 21, 2009
360
Hunter 30 Smithfield, VA
Seeing JC's post above reminded me that my installation is a repair - it isn't original to the boat. I don't know what the original construction looked like. The PO told me that he had it repaired, and that this is a common failure in the H30s.
 
Sep 20, 2011
135
hunter 30 md
My new compression post, if there is ANY one that needs help on their sailboats in annap/severna park, Pasadena area, I have found a great, reasonable person , the post pictured is his handy work , I will upload pics as we repair!
 
Sep 20, 2011
135
hunter 30 md
I will take pictures and hopefully give a step by step! The gentleman doing the job says we don't need to remove mast , saying release tension on shrouds and get it done! I will post as it moves along. If you are in area I can pass his info along,,,, after we are done of course.
 
Mar 4, 2013
12
Hunter 30' Sloop Key West Fl
I will take pictures and hopefully give a step by step! The gentleman doing the job says we don't need to remove mast , saying release tension on shrouds and get it done! I will post as it moves along. If you are in area I can pass his info along,,,, after we are done of course.
That would be great thank you. I'm not in the area, i am in TN and my boat is on the hard in FL keys. I'm going down in august to get her ready to put back in the water and stay there for 7+ months. :)
 
Jun 5, 2010
1,107
Hunter 25 Burlington NJ
Looks like the Stonehenge model in 'Spinal Tap'.

If I am seeing it properly, it will still transmit the load to the bottom of the bilge, exactly where you should want it to not go. Hm.