Rebuilding the Compression Post Part One

10 Jan

Below is how I removed and rebuilt the compression post on Satori, the most comical part of this project was cutting expensive and important parts of the boat apart with a sawsall…


I looked at the compression post, wondering how I was going to grind out and remove something that was almost exactly the height of the cabin top. I figured if I cut the post in the middle I could easily remove the top half and have some leverage on the bottom half when I’m grinding out the epoxy encapsulated plate holding the post to the keel.

compression post top plateNext, I cut the post off with a grinder about 1/2″ down from the plate. I will be reusing the plate as it is already polished and matches the mast step bolts perfectly.
cutting new post
I choose 3.5″OD schedule 40 Stainless steel pipe. 96″ of it was about $300 shipped. Its pretty heavy duty stuff and weights about 40 pounds. The old post weighted about 20. In order to cut it we used a metal band saw and some cutting oil. Since the post is so long I needed a way to support it and accurately square it to the blade. A roll around car jack worked extremely well and the cut came out beautifully.
new bottom plate on mast
I ordered a new 7X7″ 14″ plate for the bottom of the post. Apparently, 1/4″ stainless is a pain to drill. I took it over to my Dads shop and used his Bridge Port mill to drill 4, 3/8″ holes that will be lagged into a 1 1/2″ GRP plate that I’ll use as a shim once I place the completed post back in the cabin.




This article was syndicated from Cruising – Beautiful Crazy Happiness


  1. Brian Street

    Robert is exactly right low speed and cutting oil heat is your enemy when drilling stainless. I don’t know how many drill bits I ruined before finding this out.

  2. Robert Lightbourn

    In order to drill SS you need a LOT of pressure and a Very slow drill, the slower (>500 RPM) the better. That usually has worked for me .If you do not have one pull the trigger on and off momentarily, use cutting oil, or a product designed for that . Keep in mind the larger the drill bit the slower the drill. Good luck.

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