Compression Post Replacement
Tayana 37
Bill McMullen
Email: <bill.mcmullen@mail.dfrc.nasa.gov>
November 16, 2005

Project completed...  (Didn't have a lot of time to write this so please over 
look the spelling and format, if anybody has questions email me at my 
address and I'll send you my phone number. Had to do a few things in 
between so it jumps around a little, sorry..) 

The new compression is in and looks great. Replacing the post wasn't that 
bad but I tend to end up with several things going at once and this was no 
exception. The Mast was removed to replace/change the standing rigging 
and add a Harkin Furler and do the post. I don't see how you can do the 
post without taking the mast down as you have to get to the mast step bolts 
inside the mast, on my boat you do.  

Also I'm re-bedding the Chainplates with Spartite ( 
http://www.spartite.com/testimonials/index.htm ) and included some 
pictures of that. I think the Spartite is the best answer to fixing this 
problem the chain plate leak problem.  If any interest let me know as I 
have the product number to buy it direct form the maker at 32.00 a can and 
tested this with great success.  I also pulled the intermediate uppers (D-2) 
stay chain plate and replaced it with a heavy duty chain plate to take two 
stays, like the aft chain plate for the stays coming from the staysail hounds 
to just aft of the aft lowers. I'm converting the mast to a two spreader rig, 
with no aft intermediate 1/4 inch stays, the tangs for the 1/4 inch stays 
were replaced and they will hold the new 5/16 Jack stays. It's a long story 
but Mr. Perry was nice enough to answer a few questions on this change 
(for a 50.00 dollar bottle of single malt scotch) and he feel things should 
work out fine, will post it once I know for sure. 

Note on the Spartite, it's a two part mix, sets up like a hard rubber and 
really sticks, as it's a liquid when installed it fills every crack and is air 
tight. I simulated a chain plate setup at home with an old chain plate and a 
deck core. Once setup I bent, hit it with a hammer and it still held water 
tight with standing water for over 24 hours. I had to un-bolt the chain plate 
to break the seal, when the plate was removed I still had a water tight seal 
to the deck and core with a nice rubber plug. 

Anyway, back to the compression post, the goal here was to have a tight 
fit between the keel and the cabin top, keep the loading square on the post 
at all times and do the job cheap and somewhat easy.  The post was 8 feet 
304L 3.5 OD and just a hair over 3" ID. with a 1/4 inch wall. The cost was 
126.00 and another 150.00 to polish it at the local shop. I cut off the top of 
the old post 5 inches below the plate at the top and removed another 5 inch 
section of old post after that. The 5 inch section of old post was welded to 
a 1/4 inch 6x6 plate of 304L, the plate was drilled in the four corners to fit 
a 3/8 SS clevis pin and was used as a base for the new post. At the boat 
once the old post was removed, I found a teak block that had rotted out 
under the old post, a welded on 1/4 plate had rusted and bent letting 
everything settle into the rotted wood block about 1/2 inch. I believe this 
will be the problem with most boats, you can see it with a straight edge 
across the cabin (outside) at the base of the mast as the cabin will drop 
down with the post. I ground out area of the old foot on the keel and 
slightly cross grooved the fiberglass on the keel with the grinder. I left 
some of the old solid glass in place to help hold the new base and I cut off 
small wood dowel to place on the downward slope later on to keep the 
new plate foot level once installed. Once ready I mixed up some West 
Systems,  205 or 206 hardener can be used depending on how cold or hot 
it might be inside the boat but only use the high stress 404 filler to get to 
the thickness you need to keep the mix in place once installed. Before you 
mix in the 404 filler, paint the foot area (fiberglass) on the keel with the 
un-thickened West System, I used a 6x8 x1/2 inch SS 304L block for a 
foot and also grooved and painted with West Systems the bottom of that. 
Mix in the 404 filler and dump the stuff on the keel where the old foot 
was, place the dowel on the down side and place the 1/2 plate on the mix. 
Push it in the mix until it's level on the dowel and keel, use a putty knife to 
firm up the West System mix around the plate but make sure none of the 
mix is any higher then the plate or it will be in the way later when the new 
post is installed. Take note, I went over this with the West System people 
and the load factor with the 404 filler is 20,000 lbs per Sq inch, with a 
block of mix around 9x7 by 1 inch thick it's in the 100K range. Also, this 
stuff gets hot, real hot, the SS plate will act as a heat sink and the 404 filler 
also cuts down on the heat but have a fan ready as it will get warm. The 
directions say not to set it in one batch thicker then 1/2 inch but with the 
SS block as a heat sink and the 404 filler you can go up to 1 inch or a little 
over that. Let all that sit and cure with the fan on until it cools down and 
go to work on the post. 

The problems you run into with the post is as follows, the old post can be 
hard to get out and the new post is harder to get back in unless you do the 
following. Forward of the post on the cabin roof (toward the front of the 
boat) you need to remove a section of the teak molding. Insert a putty 
knife between the molding and the roof and cut the molding with a small 
metal cutting wheel on your grinder, the putty knife will protect the roof 
panel. With the mast step bolts removed from the post you can un-screw 
the section of molding and not have to remove the bung. If the post has 
dropped down you may have some space between the roof and the top of 
the plate so it will most likely slide right out through the gap in the 
molding. You may have to jack the cabin roof up a little to get the old post 
out and you will need to jack the roof up and you want to anyway to get 
the new post installed. Set the jacks up on the side as in the pictures, the 
roof should go up just a little over 1/4 inch. On my boat the cabin roof was 
over 2 inches thick and at 1/4 inch it stopped going up and the 2x4 started 
to bend! At this point the old post is out and the new foot is installed on 
the keel. I used a straight 2x4 and fitted it between the top of the cabin at 
the center of where the post will sit and the center of the foot with the roof 
jacked up. I cut this 2x4 for a slight rub as it was pushed into place and it 
became the template or guide for the new post. The major problem to 
avoid here is alignment with the new post. It must be bolted to the cabin 
roof and mast step and line up with the hole in floor boards and the foot on 
the keel. If you use the top of the old post you save the cost of having to 
have a new one built, so you use the old top and as its 3 inch OD it will 
slide right into the new post. The 5 inch section from the old post welded 
to the 6x6 1/4 plate will slide into the bottom of the new post. I didn't weld 
either end top or bottom as the stress of the cabin and the mast is so great 
there is no way other then the boat breaking up that the post will ever lift 
off or pull out of the new post. Also not welding it will allow the load it to 
sit square on the post once installed. I did chamfer the top of the new post 
for a better fit around the weld area of the old post of the top attachment 
point to the plate.  Once assembled, bottom stand, post and top plate and 
held up to the 2x4 guide, I cut the pole on a horz. band saw until 
everything was exactly the same size as the 2x4 guide. Once done it was 
back to the boat, with the jacks in place the bottom stand was placed half 
on the new foot and half on the keel with, the post (about 60 lbs) was 
fitted on the bottom stand and leaned back until the top plate was able to 
be inserted in the top of the post. and the post was then pushed into a 
straight up standing position through the gap in the molding. At that point 
I could work it in to align the mast step bolts, the cabin floor boards and 
position it on the new foot. When in position with the floor boards in place 
the jacks were removed and it was a very tight fit with no shims required. 
Once the jacks were down you couldn't move the post, it felt like it was 
bolted in top and bottom. The last step was to drill into the 1/2 plate with 
the pre-drilled holes in the 1/4 inch bottom stand as a guide. Once done 
the clevis pins were tapped in and it was done. 

Remove mast $150.00 to $200.00 
Store mast in yard 6.00 bucks a day 
Post $126.00 
Polish $150.00 
8x6x1/2 Foot $15.00 
6x6x14 Plate $7.00 
West Systems $80.00 everything 
Pins $12.00 
Replace mast $150.00 to $200.00 
Welding on bottom stand $30.00 
I had all the tools required