Compression post repair and other amenities
Recently I started to feel the itch to go sailing. Since we docked Tranquility in Frederica River we haven’t been out sailing. We were too busy organizing the new life on land and too lazy to start few little jobs. We said it a couple of times, let’s take her out, but for one reason or the other it didn’t happen.
When we were still living on board but working on shore the cabin became unsuitable for sailing. We dismissed the cruisers clothes and wore the landlubber ones, using the boat as we were using an apartment, and apartments are not made for moving around. It’s enough to have a regular job and a life on land to mess up with your routine.
With this new land identity we acquired also a new social life made of friends, colleagues, events, fast internet, movie theatres and gym memberships. We move around with a car. Instead of walking for miles carrying provisions we run on treadmill and lift weights.
Now Tranquility is once again undergoing a major refit project. We had the opportunity to step out our home to house-sit for somebody else’s house and so we decided to empty the boat and destroy everything again.
This time we faced the compression post problem. The compression post is a solid post of hardwood that sustains the compression force of the mast over the deck. Columbia 29 were built with deck stepped mast and with a structural beam glassed on deck to sustain the forces generated by the weight of the boat moving in heavy seas. The compression post was then installed between the overhead (aka ceiling) and a structural beam resting over the bilge, which supported the cabin sole (aka floor) as well.
A proper designed and installed compression post would rest the top of the keel/bilge, which is the strongest part of the Hull. For reasons that exceed my understanding it is not the case of Tranquility. When the boat was built they lowered 3120 lbs (1414 kg) of lead inside the keel before sealing everything with fiberglass. That happened 49 years ago. Meanwhile, age and human lack of care made the rest.
Talking with one of the previous owners of Tranquility I discovered that there was a persistent rainwater leak from the mast that had rotten. Luckily I was able to prevent any when I stepped the mast in the boatyard. The water leak was fixed but the damaged was inherited. After the first longer sailing passages we realized that the compression post was not properly sustained by the rotten cabin sole. Kate’s alert eyes were the first to spot little signs of the compressin forces, where the paint was cracking and the rotten floor getting bending a little more every time. We couldn’t address the problem while underway and so we kept sailing south in search of warm weather.
This type of repair was not possible while living onboard. The dust and mess of ripping off the floor (plus no place to step but the bilge) discouraged us to proceed. But as soon as we had the opportunity to leave the boat this and several other interior projects begun.
As first thing I ripped out the old rotten floor and all the damaged wood in the area. The more I dug the more I realized that the compression post was resting on a rotten transversal beam suspended few inches from the bilge. The beam was still holding the compression post but it doesn’t take a structural engineer to understand that this was not for long. Better late than never.
At first we imagined we should try to jack the compression post back up but we soon realized that this could not happen without removing the mast itself. The best and only possible thing we could do was to avoid any further downward movement and give the post a solid foot to rest on.
Searching in the teak scrapyard (a collection of odd shaped salvaged pieces of teak from different boat projects I found a solid 3″ thick block of teak that I had to reshape to dry fit it under the compression post and sealed in 2 coats of Epoxy resin. Altough teak is very rot resistant to salt water it will rot in fresh water and you never know what is going to go in your bilge.
After all the rotten wood was gone I started to seal the exposed wood of the beam and the bulkheads with West System Epoxy and fiberglass cloth. I built some support for the beam and made sure to create a solid bedding with the hull of the boat through some fiberglass tabbing.
When everything was sealed I fitted the block under the compression post with the help of some serious hammering. I then added some Epoxy mixed with 404 High-Density filler, a thickening additive developed for maximum physical properties in hardware bonding. In this way the block is “glued” to the compression post and to the bilge with a bonding stronger than the wood itself. Another layer of fiberglass is soon to be added to the block as further shield against water penetration.
Getting rid of portion of rotten floor was like an invitation to go further and so we decided to proceed and rip off the rest of the 49yrs old floor that had been covered with a nasty sticky non-skid surface. I had to grind it off with a angle grinder and a sanding disk, a terrible job that covered all the surfaces of the boat with a black dust. I kept the good parts of the floor with the idea of fairing and painting them. With all this modification we may want to change the boat’s name at a certain point…
Next step is to rebuild the floor over the bilge a major project that will take at least one week. So after the floor will be replaced we hope to go for a sail test, because even if it’s exciting to do boat repairs, the itch is still there and I’ve been scratching for too long.
5 Replies to “Compression post repair and other amenities”
Tranquility is turning you into a master boat builder. She is a good teacher.
She is indeed. Thanks John.
Wondering, could this also work on a Columbia 8.3?
Hi Karen, If the Columbia 8.3 has a compression post between the cabin sole and the bilge it is possible to reinforced it. I am not familiar with the design of the compression post of a Columbia 8.3, but if the compression post rests on a beam it is possible to install a wedge the same way I did.