[Ajax_MD]

Short story:

Over 42 years and being sailed in heavy weather with the standing rigging improperly tensioned, the top of my compression post has shifted one half inch to starboard. As a result, the head door is out of alignment and barely closes. Everywhere I measure, (door latch, top of door, bottom of door) it seems *at most* one half inch at the top of the compression post is all that is required.

The post is not rotting at the bottom. The post is not sagging downward and there is no sign of deformity in the cabin top. The top of the post has simply slipped a bit and needs realignment.

Yesterday, I slacked way, way off on all the standing rigging to relieve the compressive forces on the post, and attempted to use a 4-ton hydraulic ram braced in the top of the doorway, to push the compression post (which is also attached to the port bulkhead) over. No luck.

Next, I placed the hydraulic ram vertically on the keel, and attempted to jack up the cabin top to relieve even more compressive forces, and tried to knock the post over. Again, no luck.

The problem is, I am unsure of how much force I can *safely* apply before blowing something apart. I was being pretty conservative with the ram.

I could use some advice. I know that Jeff H. and Rich H. are usually pretty good at this stuff.

 

[aeventyr60]

Take the door off and get a planer and make it fit. The boat has been sailing for 40 years just fine, NO? Properly tension the rigging and see if it will come back into alignment, with, natural forces....

 

[Ajax_MD]

I have properly tensioned the rigging with a Loos gauge.
While this did not bring the post back into alignment, it did stop it from moving further.

Yeah, I could plane the door and more the striker plate but I was wondering about a more complete repair.

 

[Jeff_H]

I guess I would start by asking a couple questions such as:

What makes you think that the compression post has moved? The clues as to why it moved may also hold the clues as to why it won't move back.

Do you have any pictures that you can post?

Are there signs that anything else has shifted?

Could the boat have been constructed that way?
Pearson was not always all that great at precision building. I helped a guy replace a rotted bulkhead on a P-26. When the old bulkhead and some of the bunk parts were removed there were a series of paired marks in two lines on the hull that were labeled 'blkhd'. The bulkhead sat against a fiberglass bunk base and was aligned with the far side of the marks and completely outside of the pair of marks which appeared to be where it was supposed to be located. What we did not know was whether the bulkhead was in the wrong position or the marks were in the wrong position, or perhaps we were misinterpreting the marks but either of the first two suggested a questionable layout procedure.

In any event, I would be careful about applying too much force until you figure out what had caused the post to move. The fact that you could not move it suggests that it may actually be structurally okay in its current position.

Jeff

 

[aeventyr60]

Maybe 40 more years of hard sailing will bring it back? Did you notice any difference in speed or performance on one tack or the other? Possible that the hull has been deformed as well? Any difference now that you've got the rig better tensioned sailing performance wise?

 

[aa3jy]

Bulkhead tangs cracked or broken?

 

[Faster]

Is the door issue the only evidence that things have moved, or can you see the original location of the post against the overhead or liner?

Is the bulkhead 'dadoed' into the post? or is the post attached to the face? Is there any evidence of the post and the bulkhead itself having moved relative to each other? or together as one?

Could be the boat has 'racked' over time and the entire bulkhead post assembly been somehow 'displaced'.....?

 

[Ajax_MD]

Bulkhead tabbing doesn't *appear* to be broken.
Boat sails evenly on each tack. The entire boat isn't warped.

Jeff:

I agree that Pearson wasn't very precise, especially on the early boats.

Why I think the post shifted:
When I bought the boat, the head door closed without too much fuss, but the latch still didn't line up.

Before I had a better understanding of rig tuning, I sailed the boat with sloppy rigging in some pretty snotty weather. The post seemed to shift 1/8th to 1/4 of an inch more, and then door refused to close at all.

I think the shock loading of the rigging while sailing, caused the mast to "float" at times, allowing the compression post to slip. I have since replaced ALL of the standing rigging, and put it under proper tension. Since the mast can't "float" anymore, the post has stopped moving.

Sorry, I can't post photos from work, but I can email them to you.

What else may have shifted:
On the port bulkhead, there is a pencil mark from the factory, traced along the cabin liner. It is now 1/2 of an inch or so, away from the cabin liner. I'm betting that this pencil mark was not quite visible when the bulkhead (and compression post) were in their proper location.

 

[bblument]

I don't know how your 30 is set up, but I, like Jeff, have also replaced the compression posts and mast support crossbeam on my P26. I don't know if any of this will be of any use, but here goes anyway..

On the 26, there's a big crossbeam supported by two compression posts, with the one to port being much closer to the mast/center of the boat and therefore supporting most of the weight. On my boat, the crossbeam had almost completely rotted and, while the compression posts were still in fairly solid condition, the main one had shifted downward, bending all of the screws that attached the bulkhead to it and it to the interior of of the foremost dinette locker. The PO's solution was to remove the door because, obviously, it no longer shut, and replace it with a curtain. Solved! sheeeeeesh.... of course, the mast wasn't really supported by anything other than the deck at this point, but hey, what did he care, right?

Because the screws were so bent and damaged, it was a nightmare to remove; required a lot of grinding. I know... too much info, and may or not have any bearing on your issue...

I learned that the MAIN reason that post shifted downward was not a deformation of the deck or crossbeam, but the fact that the wedge that was supposed to support the BOTTOM of that compression post against the keel was missing. On the P26, the compression post rests on a fiberglass tang built into the sole, but there's supposed to be a wedge under that tang to couple the load to the keel. There wasnt' one on mine, so the whole thing shifted down about 1/2". I replaced both compression posts, the crossbeam, built an apppropriately-sized wedge (white oak in several coats of epoxy), dug out and filled all of the mast step mounting holes with epoxy, redrilled, and put it all back together. It's been perfectly solid and immovable for two years.

You mentioned that your compression post had shifted 1/2" sideways. Are you sure? Is it possible it shifted downward and that's what's causing your door binding issue? Is the base of your post solidly resting on a support?

Just thinking out loud.. I really have no idea what I'm talking about.

Barry

 

[Ajax_MD]

No problem, Barry.

Unfortunately, our boats have a different system.
There is no crossbeam, only the port/stbd bulkheads and an overhead cabin liner.
The compression post fits into sort of a socket in the cabin liner. The socket is larger than need be, and allows the top of the post some movement to be in proper alignment.

The foot of the post simply sits in the forward bilge, on a built-up hump of fiberglass.
If the bilge is allowed to remain full all the time, the foot of the post can rot.
Symptoms are: a "dish" in the deck around the mast, and visible sinking of the post.

My post is exhibiting a more lateral move to starboard, and ONLY the top of the post.

 

[RichH]

On a P30 its not the compression post per se is what moves and which causes subsequent misalignment of the doorway into the head !!!!!!!!!!!!!!!!!!!!!!!!!

On the P30, that 2X4 'post' does NOT connect to the coachroof nor the area under the mast; there is NO portion of the compression post at the very top of the bulkhead!!!!!. The 'compression post' only connects (pins itself') to a FRG 'socket' in the bilge and it 'stiffens' the main bulkhead while providing force to keep the bulkhead in firm contact with the overhead FRG flange. The prestressed force of the bulkhead against the overhead (flanges) is what supports the base of the mast in a P30 !!!!!!!!

How (most probably) Bill Shaw designed and Pearson put all this together during assembly: the bulkhead with its 'post' attached was loosely placed into the hull, the cabin top was put in place and joined; after the 'gluing' of the top and hull fully cured they: took a WOODEN WEDGE and drove it 'under' the post (causing the post and the bulkhead to come into FIRM upwards contact with the flanged overhead); THEN, the base section of the post was overlaid with a flanged FRG overlay which 'set' the base of the 'post' firmly and permanently in the bilge.

What has probably happened: since the butt end of the post is IN the bilge, over time that driven-in wooden wedge, and probably the butt end of the post, has softened/rotted ... and there no longer is any 'compression' in that bulkhead/post 'system' .... the bulkhead is now no longer in firm contact with the flanged overhead and was able to 'shift'.
If the hardware (striker place and bolt) of the doorknob on the entryway into the head no longer 'lines up' MOST PROBABLY the butt of the post has rotted/softened and sunk down inside that 'tabbing' in the bilge. The signal symptom is that the doorway to the head is now out of alignment, because the bulkhead is no longer supported by the butt of the post in the bilge (under that FRG tabbing) and the bulkhead has shifted.

The Fix:
1. cut-away/remove the FRG tabbing from the butt end of the post in the bilge.
2. assay how far rot has progressed inside of the butt of the post .... use a small drill bit and do test drillings to see how far 'up' you now have to cut off the post butt. Examine the drilling fragments for rot/wetness to see how high you have to cut off the post. You may see NO external rot on the post. You dont have to remove the tabbing on the butt end of the post in the bilge to do this, just drill through the tabbing and into the post.
3. Cut OFF the butt end of the post to the level of NO rot. Bulkhead is left in place when cutting the post butt.
4. Make a pedestal (approx. 3"X4"X 'length' cut off in #3) of Epoxy filled with chopped strand glass and a 'strength' filler to replace what was cut away from the post butt. Best is to make a mold into which you pour the filled epoxy --- use SLOW curing epoxy .... or 'foamout' due to uncontrolled exothermic reaction. Put 'mold' in ice if needed to keep the thick epoxy layup/'pour' 'cooled' ..... monitor the temperature of the 'pour' carefully.
5. Remove the mast ..... OR remove the sails, the boom and unload the rigging (to about 3% tension)
6. chisel or cut away any FRG tabbing at bottom sides of the bulkhead.
7. Pry the bulkhead back into alignment (if possible; wont be 'easy') ... use the alignment of the head door as your guide.
6. Attach hardwood blocks firmly screwed to the sides of the post. Use bottle-screw type, small 'railroad' jacks against the added blocks to raise and tighten the bulkhead against its overhead FRG flanges.
7. Insert the FRG 'replacement post butt' and drive-in a pre-prepared set of FRG wedges (12:1 taper) under the replacement FRG 'pedestal' ..... just 'good and tight', no gorillas needed. ... use the alignment of the head door as your guide.
8. Re-tab the bottom sides of the bulkhead if needed. Fill in any voids under the pedestal with thickened epoxy ... including new FRG wedges. Tab-in the base of the pedestal AND the new butt end of the remaining to the 'pedestal' to the wooden post.
9. When epoxy 'repair' is fully cured remove jacks, etc., fill any bore-holes or screw-holes in the post with strength thickened epoxy.
10. etc. etc. etc.
11. trim off minor door misalignment with a block plane.
12. By now the striker plate and bolt on the head door should now be back to alignment.

Two day job, once you have all the materials, etc. in place and have already constructed the new FRG 'pedestal'.

If you have a 'dish shaped' depression on the top of the coach roof under the mast .... Sorry, you probably also have rot in the core of the coach roof.

hope this helps.

 

[Ajax_MD]

Rich H.-

I don't have the dish depression on deck. I've seen a P30 with that problem, so I'm familiar with it.

Later this morning, I found this blog: https://pearson30olvido.wordpress.com/restoration-and-updates/compression-post-replacement/

This guy definitely had compression post rot. He did say the rot was *inside* the post, so I'll take a core sample and see what I find. However, you can see that his post had "sunk" where the top of mine has simply slipped 1/2 inch to stbd.

I've heard several times of P30 posts rotting or slipping off of the FRG base, but I've checked this carefully and it just doesn't seem to be the case here. The base of the compression post was one of the first things I checked prior to buying the boat.

Precisely because of the horror stories I've heard about rot at the base, I'm meticulous about keeping that bilge pocket dry. I don't let the base of the post sit in water. Water doesn't really seem to collect there anyway. It runs downhill, to the main bilge sump.

I will still take a core sample and re-fill it with epoxy when done.

 

[RichH]

Also the problem with the old P30 hull is it is 'floppy' or dimensionally unstable as it constantly flexes when underway.
If you havent added longitudinal stringers parallel with the centerline, across the flat bottom sections of the hull, between the turn of the bilge and about 1-2ft. inboard of the waterline ... such also would be a good idea to stop the hull 'squirming' (and which also lessen the constant 'squeeking' of the flanged bulkhead. All is needed are two 1x1 wood 'kerfed strips and glassed-over and tabbed to the hull insides per side.

;-)

 

[hellosailor]

Bubblehead-
If all the tension is off a compression post, it shouldn't need a hydraulic ram to move it over a titch. I'd doublecheck to make sure nothing else is holding it, and run a tape measure to make sure the deck-to-sole height really IS increasing as you jack it up, so in theory the post should be free unless some clever soul added some glue under/over it, perhaps?
But when all the tension is off, and nothing is holding it in place, you should be able to move it without any assistance devices.
Unless they've done something clever like the I28, where it ties into a 4x4 that's part of the head compartment, and other things you'd never suspect some clever "we can make it work, honest!" engineer schemed up.

It could be out of vertical because it is resting on or tied into some subflooring that has rotted over time, if the deck hasn't compressed unevenly.

I say you're right: It is a sign of Something being wrong, structurally. But you'll need to peek and poke and measure laterally and vertically all around, to try to find out what.

 

[VallelyJ]

Sounds like the change in your post's location followed changes in your rigging tension.
I hope I'm not duplicating someone else's comments--haven't read all the detailed responses, but here's what's occured to me:
If you have increased your rigging tension, tension on the shrouds pulls the gunwales inward and this pushes the cabin top upward.
Pulling the gunwales inward will push the port and sbd bulkheads together at the top. It may be that what you can see is the movement of the post, but if the post is structurally one with the bulkhead, the movement of the bulkhead would move the post, and more at the top than at the bottom.
Forcing the cabin top upward, while downward pressure from the mast keeps that area from moving, could be what's dishing your cabin top at that point. The mast step isn't sinking; the rest of the cabintop is rising.
I know you loosened your shrouds and things didn't return to normal, even with jacks. Intuitively, that should have worked to push things back to normal. Is your boat on jackstands now, or in the water? The jackstands could be holding the hull into its deformed shape. Or, the hull/deck/doghouse structure may need more time to return to it's habitual shape. Or, something you don't see has moved and is stopping the rest from returning to normal. Or, my theory could be wrong. But I'd consider whether your change more recent in rigging tension, rather than your earlier use of the boat, may be the cause of this recent problem.
JV

 

[SVAuspicious]

I'm in your neighborhood pretty regularly. I'll be happy to stop by and poke around with you a bit if you would like.

 

[Ajax_MD]

Valley-

I appreciate your help, but I'm afraid there's a miscommunication.

1. There is no dish depression at the top or on the deck.
2. The bulkhead/compression post isn't changing when I adjust the shrouds.
--------------------------------

Rich H.

Core sample results:

I drilled 3 very small holes at the bottom of the post-

1.5 inches from the bottom
1 inch from the bottom
and *at* the bottom (maybe 1/4 to 1/8th inch from the very bottom)

It turns out the post *has* been turning sour, but for now, it's only at that very bottom. The other holes brought out dry wood shavings.

It turns out that the builder was unable to wrap any tabbing cloth around the front/bottom of the post because it's hidden under the cabin sole liner. There is a scupper in the head and any water that drains there, runs right to the base of the compression post. (plus any bilgewater running downhill to the main sump)

Even so, the post hasn't started collapsing yet. That's not what is going on.
I will be dealing with this at the end of the season, around November.
I'll pull the mast, jack up the cabin top and remove the post. I'll cut off the bad section and make a G10 butt plate for it, and put it all back together.

The wet section of wood is so small, that I've actually be able to dry it out completely. When I plunge a drill bit into the bottom drill hole, it comes out dry. I'll pump it full of epoxy to hold me until the end of the year.

I'm going to take one more crack at jacking up the cabin top and bumping the top of the compression post back over.

 

[RichH]

You really wont be able to see the extent of the rot and the dimensional deformation until you physically cut from the bottom and progress upwards as necessary.
If you see that the OEM tabbing in now broken loose from the three sides of where it attaches to the post butt, youll know or can then expect that the post has slipped/compressed; OR, that the infamous wedge-under-the post has been affected.

If you can restore the head passageway alignment, are quite sure that the butt isnt rotted to any significant degree ..... consider to just 'mouse out' that wedge, replace with one of FRG, and *whack* the new one into place to tighten that 'bulkhead'.

Good luck.

 

[Ajax_MD]

Rich H-

The bottom tabbing definitely hasn't broken. I do feel that the softness has progressed beyond any wood wedge beneath the post, and the post will need repair or replacement within a year or two.

Within that timeframe, I'm going to drop the mast, remove the post, trim it, and fabricate a G10 buttplate and re-install.

For this year, I'm going to do what everyone hates: Dry it out, and pump it full of epoxy to try to arrest the rot. I do this knowing full well that it is a temporary fix.

 

[rbyham]

The new to me Bombay pilothouse came with misaligned post. On mine the post was too far forward and overlapped the front of the art by only about 1/2".PO told me he could never get rig tight enough. Snug it down and door to head would not open. I took 1" galvanized thick wall pipe and 3 ton bottle jack below. Was kinda scary because it had to put a slight bow in the pipe before I could wiggle the post. Heard the boat pop a couple times. Lifted maybe 3/4".but post came loose. Unscrewed top and bottom plates and slid aft 2.5".dropped deck back down and reconnected. Rig tightened up well-lit I have not tested with sails. I am thinking you need to lift deck til post wiggles... Not for feign of heart. At one point I am helper just walked away to let things settle and to see if pipe/jack was going to stay in place...