Compression Post Repair Project
This project was a long one, and the report is comprised of several different sections that cover its progress. The compression post project actually started several years ago, I just did not realize it at the time! The doors that go from the main salon to the storeroom and the mid-cabin were not fitting properly. They were out of alignment. The door that goes from the mid-cabin to the storeroom was also not fitting properly. It, too, was out of alignment. The small doors that go to the air conditioning compressor and the ice maker compressor were also out of alignment. I kept looking around, trying to find the source of the problem. After much thinking, and consulting with friends, I concluded that the problem was that the compression posts under the main mast were sinking, most probably because of rotten wood.
So, the first part of the project (identification of problem) was done. I had figured out what the problem was, now I had to decide how to attack it. I had asked several vendors if they would undertake the project, but no one wanted to take on the project. I decided that I would do the project myself. I was able to get some initial help from a good friend and fellow boater, Oscar.
I think I should put in a few words here about what compressions post actually are, specifically those on sailing yachts, and even more specifically, some information about the type of compression posts used on DREAM AWAY. In all types of sailing craft, the effect of the wind on the sails drives the craft forward, but also, the effect of the wind on the sails attempts to drive the mast through the bottom of the boat. Because of this pressure, the bottom of the mast must be situated, or 'stepped', on a very strong surface. Many sailing craft have the mast stepped on the keel, which typically is the strongest member on the craft. Some sailing craft have their masts stepped on the deck, which typically is not very strong.
On a sailing craft with a
deck stepped mast, the load on the deck, directly under the
deck-stepped mast, is transmitted to the keel via a
compression post. A compression post can be made out of a
metal pipe or a large piece of wood. Each needs a fitting at
one end that attaches it to the deck, and a fitting at the
other end that attaches it to the keel. Usually, if
the compression post is metal, it is made of polished
stainless steel. If is is made of wood, it is often hewn
of teak. In the specific case of DREAM AWAY, there are
actually
two teak compression posts supporting the main mast. In the
line drawings in
About DREAM AWAY, you
can see that there is a door directly under the main mast.
The design called for teak compression posts to be installed
on each side of the door, and two large 3/8" X 2" pieces of
angle
bar installed across the top of the compression posts
in order to transfer
the load from the mast to the compression posts, and then on
to the keel. That is the
way it should have been implemented, but, as it turns out on
DREAM AWAY, the load on the
compression posts was not really being transferred directly
to the keel.
REMOVE FLOOR: The first group
of pictures show the overhead angle bar that spans the
compression posts, and you can see that the doors are
out of alignment. There are also pictures of
Oscar and me cutting out the floor in the compression
post
area, and some of what we found. A couple of the
pictures show the flooring, which is parquet. I
numbered and labeled each of these pieces in order to
save a lot of problems later (had been there and done
that). It was a good
news/bad news exploration effort.
We found the
rotten wood. What was very disappointing was that we
discovered cement had
been poured between the stringers that supported the
floor. Let me
explain a bit how the floors (decks) in DREAM AWAY are
constructed. Stringers (longitudinal framework) are
laid at the bottom, fore and aft, and athwart the
ship. These
stringers are made of mahogany, and, where they abut
the hull,
they are fiberglassed to the hull. A layer
of
mahogany plywood approximately 3/4" thick is laid onto
of the stringers, and on top of that is the teak parquet floor. In almost all
cases, the teak did not
rot. With all of
the leaks we used to have on the DREAM AWAY, plus the
condensation accumulated over the
years, the cement stayed damp, which in turn caused
the stringers and the plywood sheet to rot. What was
even more astonishing, was that the compression
posts were not only on the plywood that rotted, but
the stringers below them were laid out in such
a way that the compression posts were not directly
over the stringers. To my way of
thinking, this was a very weak way in which to
transmit the mast load to the keel. Even the cement
was not of a uniform nature. Some of the
cement had been prepared and poured in such a way that
it was going to be a real effort
to get it out. Other of the cement had been poured
over rocks, making it very easy to break loose and
remove. This contradiction in methodology seemed to
support our long suspicion that the boat was actually
built by two different families, and that they didn't
consult with one another. We have labeled them as the
'Sing' family (for the starboard side) and the 'Ping'
family (for the port side) as the boat was built in
Taiwan.
REMOVE CEMENT: The next group of pictures shows my first pass at removing the cement between the stringers. It also shows some better views of the rot under the port and starboard compression posts. I took a small section of cement out using a hammer and hand chisel, and that was pretty hard going. And, as you may experienced yourself, a chisel often seems to act as an aiming point for smacking the hammer onto your hand. When I completed this small section of cement removal, I decided that the next cement removal would be done with an air chisel.
The next phase of the project was to get all of the cement out from between the stringers so I could get a very good idea of what I would be facing in doing repairs. As I said previously, I decided to remove the remainder of the cement with an air chisel. To accomplish this task, good friend Jim came to Clear Lake on my week off and helped me with the cement removal. During that particular week off, the Admiral was away in Atlanta visiting our children, so we could really "get into it". We also had removing the mizzen mast while DREAM AWAY was in her slip on our list of projects to accomplish and also planned to remove the main mast at South Texas Yacht Services.
Jim brought along a supply of air chisels, and I borrowed an air compressor. We decided that the Thursday of my week off was the day to remove the cement. When we got set up and everything was in place, and we started removing the cement, it became apparent that, because of all of the cement dust we were generating, we would have to build a tent around the work area. Off we went to the local hardware store to get a large, thick drop cloth, and back to the boat to build the tent and start into the cement removal again. We removed all of the cement around the stringers, and the cement that was under the ice maker compressor. That was the biggest disappointment of this whole project. Because of its location, the ice maker compressor it had to be removed during this project! The silver lining to this cloud was that I was planning to replace the control electronics on the ice maker so it would make ice with 12 VDC or 120 VAC. Before removing the compressor for this project, I could make ice only with 120 VAC. I was also going to relocate the ice maker control switches to the main electrical panel.
Jim did most of the chiseling of the cement, and I did most of the hauling cement to the dumpster. By the end of Thursday, we had all of the cement removed, the whole area cleaned up, and the boat livable again. Cold adult beverages were consumed with gusto! The next day, Friday, we spent getting the mizzen mast ready to come down. On Saturday we removed the mizzen mast (no pictures of that) from the boat, and hauled it to the storage yard. On Sunday and Monday we got the main mast ready to come off of the boat. On Tuesday, the main mast was removed from DREAM AWAY South Texas Yacht Services (again, there are no pictures), and, after stripping the rigging, shrouds, and all other heavy items from the mast, we moved the main mast to the storage yard. DREAM AWAY was now officially a trawler. Jim was an incredible help, and we enjoyed the time together. The pictures below are all of the cement removal portion of the project. They start showing all of the cement in place, and the end with all of the cement gone.
REMOVE STRINGERS: I am lucky because I seem to get a lot of help from my friends. Two weeks after friend Jim was on DREAM AWAY to help, I had other friends arrive. Our friends from England, Nicola and Noel, with whom we had sailed with in Texas, Florida, Mexico, Belize, and Guatemala, had just left Guatemala for their return trip home having done the 'around the world' route. While they were aboard, Noel helped me remove all of the stringers in the mid-cabin area, some more cement we found, and most of the fiberglass that had to be removed. The pictures show some of the progress as it was being made. We did not get as much done as I had hoped as my refrigeration compressor picked that time to go south, so I had to replace the compressor. That was an adventure, but not to be told here. The last picture below shows the main mast step on the topside deck. On my next week off, I planned to do a lot of work in this area, and took lots of pictures, so you will be able to get a true picture of what I was facing.
August 15, 2008 Update
The next group of pictures shows the removal of the last of the cement, removal of the last of the stringers, and removal of the last of the support under the port compression post. I also show the removal of the cable and hose tunnel that was under the cement, and there are some pictures of the rotten piece of plywood that was directly under the port compression post. You can see how much the port compression post had sunk, and the port compression post was the good one! I figure the port compression post sunk about 1/4", and the starboard compression post sunk about 3/8" or more. There is also a picture of the temporary floor that I installed so we could walk over the area after it had been cleaned out for the compression post repair.
NEW SUPPORT: Now that I finally had the whole area cleaned out, I was able to start planning how I was going to make a new support for the two compression posts. My first approach was to make the support from stainless steel, so I made a drawing of the new support, and how big it needed to be. But I determined that, by the time I bought the materials and had the post built, the cost would be prohibitive. My next approach was to build one out of laminated wood. Here again, I made a drawing of the proposed support. My good friend Jimmy gave me some really nice pieces of air dried Texas Cypress to use for the support. I took all the pieces I was going to use of the wood Jimmy had given me, and soaked them in Smith's Epoxy. Smith's Clear Penetrating Epoxy Sealer (CPES) is a very thin epoxy. For the last several years, all wood that has gone on DREAM AWAY has been soaked in it. After a few days of soaking the wood for the support, I put the three pieces together using West System Epoxy, and laminated them. Then I fastened them together with 3/8" stainless steel bolts and nuts. The result was a strong support that measured 4" X 5" X 50". The design of this support was actually a cross between the two original drawings. As usual, this was another overkill situation, but I was determined that this was going to be my last compression post project on DREAM AWAY.
Now that I had this really impressive, well-built compression post support, what did I do with it? I had to install the compression post supports such that the compression posts could be installed at the appropriate levels. The port side needed to be raised approximately 1/4", and the starboard side needed to be raised about 3/8". The good news was that, during all the work and checking and verifying, I had found a couple of places in the area of the compression posts that showed where the posts used to be. In my research on this type of project, I had been warned that I should not raise the compression posts all at one time. It had taken many years for the compression posts to sink, so wisdom had it that I should take it easy getting them back where they belonged to avoid damaging other aspects of the boat such as the adjacent decks, bulkheads, flooring, etc. This made for a slow process. I went to my shop and cut several wedges out of wood, and several 4" X 4" blocks of approximately the correct shape. Unlike the original arrangement of the compression posts, my plan was to have support directly under each compression post to direct the load to the keel.
I had borrowed a hydraulic body repair kit from a friend. So, I used it to start the raising process on the compression posts. I placed the support I had fabricated under the compression posts, then drove the 4" X 4" blocks in, directly under the compression posts. Then I drove wedges in at each end of the support. Before putting too much pressure on the support below the compression posts, I verified that the separation between the compression posts was the same at the top, and at the bottom. This was important, because a door went between the two compression posts, and that had to align properly. Next, I took the spreader from the hydraulic body repair kit and attached it to the hydraulic pump. I pumped on the hand pump to move the arms of the spreader apart, which in turn put lift on the support. When I heard the wood creaking, I stopped pumping. Then I drove in the wedges and the 4" X 4" blocks. When I completed that, I released the pressure on the spreader, and did the exact same thing at the other end of the support. When I released the pressure on the spreader the second time, I put it all away, and waited a couple of weeks before doing the process again. I do not know how many times I did the slow process of raising the compression posts using the support, but, after approximately four months, the compression posts were at the proper level.
I purposely raised the compression posts an extra 1/8" because all of the new parts used in supporting the compression posts were made of wood. I thought it likely that there would be some settling involved, especially when the main mast was put back on the boat, and the standing rigging was tightened. I again used the spreader and the hydraulic pump to raise the support just enough to remove the wooden wedges and the 4" X 4" blocks. I then drove in new hardwood wedges and 4" X 4" blocks to be sure that I had good wedges and blocks under the support. When I finished both sides of the support, I mixed up some polyester putty filler. I put this all around the wedges and blocks to form a gentle angle from the hull to the wedges and blocks. When all of the filler had kicked off, I sanded it all down, and got it very smooth. I cleaned up the whole area, and wiped it down with acetone. Then, using fiberglass mat, I fiberglassed all of the wedges and blocks to the hull. When these were set, I sanded it all smooth, and painted it a beautiful white.
NEW DECK: Putting in the new deck was much easier than I had anticipated it would be. My friend Rick, who owns a Hardin 44 Voyager, VISTA CRUISER, was just down the dock from DREAM AWAY, wanted to do some trading. He wanted me to do some welding on his engine mounts, and on a couple of other items he needed for his new engine installation. I was something of a welder. I wanted a new deck put in, and he was something of a carpenter. Basically, the deck went back in from exactly where it was removed, but there was some rotten teak in it that had to be replaced. I also wanted a new hatch installed in the deck. When I took all of the cement out from under the deck, I decided to utilize the open area for storage, which is why I needed an access hatch. Once Rick and I decided where the new hatch was going to be placed, I cut and ran the stringers to support the deck, and I verified that I had all of the teak pieces for reinstalling the deck. As you can see from the pictures below, all of the teak pieces were sanded, on all six sides! I also decided to replace the sub-floor with marine plywood.
When all of the parts were cut and dry fitted, I took them all over to the shop to apply Smith's Epoxy on all of the wood. That operation took a couple of days. When all of that was done, I took all the pieces back to DREAM AWAY, and, after I got all of the stringers screwed, glued, and glassed into where they needed to go, I turned the project over to Rick. It took him only a couple of days to get the deck put back in as well as the one original hatch and the new hatch. While Rick was doing the floor, Shannon, another friend whom I had hired, was working on the exterior teak, and I was working over at the shop. Rick finished the new deck in April of 2009, but I have yet to put the first coat of varnish on it!!
Note: In the following pictures, 'CP' is used to designate 'Compression Post'.
