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Mast Step

The Baba/Panda/Tashiba 40 mast is not truly keel stepped. The load bearing surface was constructed from wood as a bridge and covered with fiberglass mat. This technique was also used on the Mason 43 and 44 and is prone to failure. Over time water seeps into the wood causing it to  rot. The structure eventually collapses.  We noted that Veritas had been repaired on our first look. Bill Reynolds provided a photo of s/v Baidkara showing an example of the original structure. 

 


Swiftsure Yachts of Seattle provided following extract from the 2015 pre sale survey.

There is unbonded FRP tabbing and interior laminate fractures on the hull skin on both sides of the mast step. A previous repair has been conducted to the mast step but appears to have voids beneath the aft face from acoustical sounding. No information on the extent of the repair was available.

 

Recommendation: Pull the mast to gain full access. Open up the mast step to investigate further. Conduct full repairs as determined necessary to make sound. This is an ocean going vessel and is intended to be used for major offshore passage making. Conduct additional FRP repairs to interior hull skin and the loose and unbonded tabbing. Repaint the bilge area repaired and conduct any additional cosmetic repairs as necessary. Reinstall the mast.

 

The recommended work was performed by CSR in Seattle. However the invoice does not provide any details on the work performed. I contacted CSR and Scott Anderson responded via email with some general information:




On Jun 21, 2018, at 5:49 PM, Scott Anderson <scott.anderson@csrmarine.com> wrote:
Hi Myles
I can tell what we do to repair wood core mast steps. We remove all the wood and replace it with 1/4 G-10 fiberglass plates. We will stack them on top of each other until we get to the proper height. G-10 will not crush. Then we glass over the top. The delam in the photo could be injected with epoxy. Let me know if you have any questions. Scott


The 2018 survey findings stated the following.


THE AREA OF THE MAST STEP HAS BEEN REPAIRED AND THE SECONDARY BONDING HAS SEPARATED. REVIEW SERVICE RECORDS FOR DETAILS OF THE REPAIR. RE-TABBING THE SECONDARY BONDING IS RECOMMENDED.

We are finding the delimitation (or bonding separation) has occurred because the initial surface was never prepared properly in both the initial and secondary repairs. The layers glass fiber/resin were applied directly to the inner hull surface without removing the gel coat and/or bilge paint from the inner surface of the hull. 

The wood bridge construction was replaced with solid wood blocks in the initial repair. We believe this work was done by KKMI in Sausalito, CA in 2011. Unfortunately, the previous owner at that time, Kieth Essex, could not locate copies of the work order and KKMI will not provide copies without Kieth's permission. Kieth has not replied to several request. 

Found the following message on the Yahoo Baba-l list server:

To: baba-l@yahoogroups.com
From: keithessex@...
Date: Mon, 2 May 2011 19:51:38 -0800
Subject: Re: [baba-l] Mast step

Has any one had a problem with their mast step?  I found our rigging had loosed after a passage.  After noticing this I checked the Spartite on the mast collar and found it had settled a little over an inch and a quarter!  I had Riggworks in San Diego tune the rig the day we left.  The rigger was an Americas Cup racer, seemed knowledgeable but he didn't use a gauge.  In my opinion he tighten the crap out of the rig like it was a high tech racer.  There my be another underlying problem the caused this but I think the over-tentioning of the rig helped it along.  Our Baba 40 was the last one made, 1996.  It hasn't done a lot of sailing until we purchased it.  I wouldn't expect a problem like this with a relatively young boat.  Have any of you had a similar problem?   
Keith
Nunatak, Tashiba 40



The second repair, by CSR in 2015, was done for Swiftsure Yachts. This work appears is superficial. Several layer of glass roving and epoxy were added on top of the initial repair. The wood was not removed and replaced as intimated by CSR. As noted in the 2015 survey voids exist beneath the aft surface of the repair. We opened this to check inside. We can see the wood inside the aft surface of the mast step and the supporting structure appears to be a solid block of wood. The wood is damp and shows some rot on the outer surface. However, it does not appear to have collapsed.

 

It is difficult to take pictures that clearly show the issues. We are trimming the failed tabbing back only to find that the original surface was not prepared properly. Most areas under the tabbing are still covered with gel coat and/or bilge paint. 

  


While the more ideal solution would be to completely remove the mast step down to the hull skin, it is not practical to do so at this time. As long as the supporting structure appears sound we will repair the tabbing and provide a secure bond to hull. The primary load is vertical and the lateral moments are minimal. By preparing the bonding surface properly and using a flexible epoxy resin the cracks are less likely to reappear. 






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