How to check compression post?
- Thread starter Jared1048
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This isn't common with Hunters which have compression posts. The compression post is the support under the mast and inside the boat (so-called deck stepped mast) to the keel. The easiest way to tell if you have a problem is to critically look at the deck surrounding the mast step (base) to see if it has suck in. It should be level or slightly raised from the rest of the deck.
Some Catalinas had a wooden cross member under the mast step which, because of it's location in the bilge and subject to constant water intrusion, rotted allowing the mast step to sink.
Some Catalinas had a wooden cross member under the mast step which, because of it's location in the bilge and subject to constant water intrusion, rotted allowing the mast step to sink.
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Compression post
The 83-87 model 31's and 34's are the ones that have this problem the most.. Many of those boats have this problem because of poor sealing in the wire tube that goes thru-deck inside the mast. The cross beam wood usually rots first, then the post itself.. On mine, there was no depression in the deck at all but the interior beam was deformed .. Search the site under Compression Post and you'll see the work .. Not an eas joby, but not terrible either.. In these two pictures of the top of the post , you can see the depression in the underside of the cross beam and you can see the crunch in the forward part of the beam behind the wood trim..
The 83-87 model 31's and 34's are the ones that have this problem the most.. Many of those boats have this problem because of poor sealing in the wire tube that goes thru-deck inside the mast. The cross beam wood usually rots first, then the post itself.. On mine, there was no depression in the deck at all but the interior beam was deformed .. Search the site under Compression Post and you'll see the work .. Not an eas joby, but not terrible either.. In these two pictures of the top of the post , you can see the depression in the underside of the cross beam and you can see the crunch in the forward part of the beam behind the wood trim..
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It's more common...
on the '84 and later H34's on the boats without the large black casting that is the mast base on the '83's. See pic. Don't know if the same mast base was used on the H31's. Reason for the problem appears to be insufficient height of the wiring tube and the caulking failure around it where it enters the cabin top inside the mast.
on the '84 and later H34's on the boats without the large black casting that is the mast base on the '83's. See pic. Don't know if the same mast base was used on the H31's. Reason for the problem appears to be insufficient height of the wiring tube and the caulking failure around it where it enters the cabin top inside the mast.
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We replaced ours with 4 x 4 oak post. When the teak was taken off it looked like termites had been in there, there were tunnels eaten out of the wood. Previous owner failed to mention any problems thank heavens our surveyor discovered it. It was one of the easier jobs on our 85 31' Hunter. Stained the post to match the teak. I brought the teak home and sanded and scraped all the old inner wood off and am going to make screen doors for the companion way with it.
Checked that region and there is something going on
How serious is this do you think? What can I do to minimize whatever is causing this?
Thanks!
-Jared
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Definitely beginning.. Looks like the stuff in the beam is collapsing a little..transferring some of the load to the bulkhead The front vertical wall of the beam will eventually crack and you will lose rig tension.. Not a catastrophic thing! you can take up the slack with the rigging turnbuckles.. On mine, when that happened, the tube that the wires go through tried to support a lot of the load and it deformed, making the leak worse .. If yours progresses as mine did, I would think you have at least one more season of sailing and maybe two before the work should be done.. I don't see a lot of water damage arouind the top, so your post is probably OK.. Is there evidence of water coming out at the bottom of the post?? Has water come out at the outboard edges of the cross beam?? If you take the mast off for the winter, try to seal the wire tube around the perifery as well as where the wires go through.. If you don't pull the mast, run a bead of sealant carefully around the mast step to stop water from wicking into the tube .. Best way to fix it is to pull the mast then work the beam internals.. I didn't pull my mast and the job ws a lot worse because I didn't.. Another thing to be careful of is that when the rig gets a bit slack, the headstay will sag off and if you are using a roller furler, that willl put a lot of stress on the foil joints and eventually fail a few..
Good Luck with it !
Good Luck with it !
Jared:
The problem is in one of two places. Either the pine inside the post is rotting or the cross member may be rotting. I think you can drill some holes in the cross member and see if you are having problems in there (be careful of the wires).
You can remove the teak covering on the post to inspect it (probably the easiest).
When we did ours we had the original pine member replaced with stainless steel. This is not a cheap fix if you need to have someone do it. The mast should be removed. There is also the chance that the bulkhead between the salon and the head will need to be replaced too.
I would estimate $2,000-3,000 if you have it done.
The problem is in one of two places. Either the pine inside the post is rotting or the cross member may be rotting. I think you can drill some holes in the cross member and see if you are having problems in there (be careful of the wires).
You can remove the teak covering on the post to inspect it (probably the easiest).
When we did ours we had the original pine member replaced with stainless steel. This is not a cheap fix if you need to have someone do it. The mast should be removed. There is also the chance that the bulkhead between the salon and the head will need to be replaced too.
I would estimate $2,000-3,000 if you have it done.
Another easy way to check is to take the head door off the jamb. That door jamb is screwed to the front of the post. Pop the plugs out that cover the screws and after removing them just lift it off. No prying or destruction required. This exposes the actual post and you can see if it is rotted or by looking up into the hole you can get an idea if the tranverse chunk of fir is compressing. Lots of people have done this fix themselves very elegantly and simpler than my original over-engineered solution. Keep us up to date.
Allan
Allan
Thanks for all the info guys!
The worst part is I asked the surveyor (i just bought this boat 2 months ago) to check the compression post because it was reported to have issues. I didnt know what that was at the time and just assumed he would check it out. Nothing in the pictures was pointed out.
Looks like the next step is to remove the door jam and see what it looks like behind.
-Jared
The worst part is I asked the surveyor (i just bought this boat 2 months ago) to check the compression post because it was reported to have issues. I didnt know what that was at the time and just assumed he would check it out. Nothing in the pictures was pointed out.
Looks like the next step is to remove the door jam and see what it looks like behind.
-Jared
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