Mast beam crushing

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  • August 09, 2019 8:41 PM
    Message # 7821436

    Hello all,

    I want to say that I had a great time at the PNW rendezvous this year. Many great boats t see and more great people to meet.  

    One of my goals was to get a bit of feedback about the crushing that I have under my mast.  It looks like it is stabilized but it is there.  My first question is, does what my photo shows cause a need for repair?

     I saw a few boats that had fixed their issues in different ways.  One person scarfed in what looked to be white oak to replaced the damaged wood and added wood to the compression post making it wider and likely better at distributing the force under the mast. 

    Another boat oat had placed a metal strap and again wider post.

    i even noticed on Dave Kings boat what looked like a build up of material on the cabin top under the mast, presumably to again add support.  Though that probably doesn’t help with the crushing issue if you have it.  

    Anyhow, since I did not get the chance to have my particular issue looked at I was hoping that I could get opinions on what if anything I should consider doing.

    thank you,


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  • August 13, 2019 4:32 PM
    Reply # 7826842 on 7821436
    Anonymous member (Administrator)


    Looking at the pictures - I'm thinking that the wood in the beam is crushed/being crushed - possibly because the beam wood has/is damp or rotting? 

    Maybe use a small screwdriver and probe the area for soft wood. 

    I'll also assume that you have checked that the verticle post is supported down to the hull - ie no soft wood blocks under the cabin sole... 

    If you find the wood in the beam is soft/rotting etc - then the question is where the water came from? 

    Also is the deck plywood that is sandwiched between the fiberglass top and bottom skins also wet?  

    Let's see what you find before talking about a repair... 



  • August 13, 2019 9:13 PM
    Reply # 7827156 on 7821436


    the block under the the post is solid. I have tried to stick it with a knife and it’s hard.  The plywood around the mast is also good.  Here is a photo from before I re stepped the mast (2.5 years ago).  The drill shavings were solid.

    The crushing that is shown in the first post is about how the boat was when I bought the boat. It might have been wet, but it looks like most of the cracking is limited to where the brass plate is.

    thanks for the reply and any advice that you have.


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    Last modified: August 13, 2019 9:19 PM | Anonymous
  • August 14, 2019 9:26 AM
    Reply # 7827923 on 7821436

    Hello Bryon,

    I saw your original post and the pictures of your mast compression problem.  It's difficult to tell exactly what's going on from the pictures, but I agree with Jay's comments about possible water penetration. Based on your latest comments, it sounds like the area is dry (so maybe there was a leak at one time but it was fixed?) but that portion of the deck beam directly above mast post does look like it could be soft "punky" and even some level of delamination in the deck beam?

    If you haven't already reviewed it, the Westsail Service Manual section A-19 discusses this issue and makes recommendations for a fix. Based on your pictures and the brass plate already inserted, it could be that a prior owner already attempted or completed the repair suggested in the manual? If the repair has been completed and you feel comfortable with the aesthetics and structural integrity, then perhaps no additional repair is necessary.

    I'm certain others here will have additional thoughts and recommendations.  If, after further evaluation you question structural integrity, the fix may be more complex including scarfing in an entire new center section of the beam or full beam and post replacement.

    Best of luck and I hope you find a solution that works well for you. 


  • August 14, 2019 10:56 AM
    Reply # 7828101 on 7821436
    Hello Bryon,  The best word to describe that crushed beam is “ugly “.  This is what I would do, and have done on a different W-32.  Bite the bullet and unstep the mast.  Use a jack and jack up the ceiling just a bit.  Remove the compression post and then the entire support beam.  It is made up of multiple parts and is through bolted from the top of the cabin.  Use the parts as a pattern for a whole new support system.  Important note:  use Oak, not mahogany, in the area of the compression post.  The oak will not crush. Mahogany can.  The oak piece, in the lowest lamination should be about 10” long.  (Like on Solstice).   Reinstall everything and insure there are no leaks in the area from the mast wiring that could again cause a problem.  Also modify the compression post or replace it so that the contact area is as large as practical.  (Like on Saraband).  The whole repair only took about 5 days, although I do have a shop for making things.   Good luck on everything.  Send pictures in a couple of weeks of the completed repair.    Dave
  • August 14, 2019 4:04 PM
    Reply # 7828495 on 7821436
    Anonymous member (Administrator)


    Adding to Dave - comments - "replace the Oak" - I'd recommend White Oak as Red oak is very porous.

    I also found a picture of Saraband mast support and my fix on Pygmalion in 2012... 



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  • August 14, 2019 7:17 PM
    Reply # 7828727 on 7821436

    Dave, Don, and Jay,

    thanks for the responses.

    Dave, I am certain that your suggestion is the best course of action. I looked for some diagram in the factory build manual on the beam.  Specifically, to see how it it through bolted to the cabin top like you said. I could not find anything. Can I expect bolts along the length of the beam (port to starboard) on the cabin top?

    I am guessing that loosening the rig and trying to jack up the top with mast would be too much weight on the keel.  So, after taking the mast down again, I would like to do anything and everything that should be done.  Dave I noticed that Saraband had what looked like an extra layer of plywood glassed in directly under your mast. Was I correct in what I saw? If so, could you talk me through what and the why of that?

    thank you,


  • August 15, 2019 1:15 PM
    Reply # 7830127 on 7821436

    Hello Bryon.  Give me some contact info at   Thanks.   Dave

  • August 16, 2019 6:01 AM
    Reply # 7831073 on 7821436

    Just curious. Why doesn't the main bulkhead prevent crushing. Seems to me that in addition to the main beam it would provide support as well.

    2ndly, when jacking the main beam/cabin roof to add a support plate and/or wedge under the mast support post surely the bottom of the jack is not on the cabin sole, right? Where would the bottom of the jack be placed?

  • August 16, 2019 2:43 PM
    Reply # 7832866 on 7821436
    Anonymous member (Administrator)


    If you have to replace the crushed wood - please take photos of the project as I'd like to make them available for others on this site.


    One of the fixes that Bud suggests and that I've installed - are 4-5 bronze nuts/bolts installed through the deck beam.  Two of which can be seen in the attached image. 

    My understanding is that the bolts are supposed to tie the beam and the bulkhead together ie spread the load from the deck beam to the bulkhead. 

    This suggests that the bulkhead isn't secured originally to the bottom of the cabin nor the beam.  There may be an air gap between the top of the bulkhead and the bottom of the cabin top hidden inside the deck beam. 

    On Pygmalion the deck beam is made out of multi pieces of mahogany and ash? that surround the bulkhead but were not actually secured to the bulkhead before I added the bolts. 

    In Bryon's case, the mahogany has been crushed - I think we will know the cause later assuming he works on the area. 

    A disclaimer is that I have NOT actually disassembled the desk beam and so I can only guess from what I see on Pygmalion. 

    Also I would not be surprised if other boats are different in this area as construction did change over time. 

    Jacking up the deck/beam - Yes the jack will need to be supported carefully to spread the load on the cabin floor and desk beam or there will be issues...  also the standing rigging will need to loosened to allow movement. 

    I'm told that the bottom of the beams are supposed to be on the same plain... sight along the bottom or use a tight string to see if the beam under the mast has moved. 



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    Last modified: August 16, 2019 2:46 PM | Anonymous member (Administrator)
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