Deck Leak by a Stanchion

We found a leak at the base of a deck Stanchion

Peggy noticed that one of the Port Side Stanchions on our Catalina 34 was 'wobbly', I checked and it was beyond 'wobbly' it was being held in place by the lifelines, the deck screws were loose! 

Checking out the cabinet above the Nav Table, I found signs of a leak from beneath the stanchion. I'm not surprised as I'm pretty sure the PO had done some deck repairs in that area.

Step 1. Seal the area to stop further leakage. That involved just simply covering the rim of the stanchion base and the screws with Butyl Tape while I figured out a plan on fixing this.

Checking the deck surface, there was no sign of any soft deck in the area.

Of course, any boat owner has nightmares about the 'soft deck' issue especially on a 38 year old boat, but we have taken care of Eximius and regularly look for issues before they become nightmares.

The plan:

Regular readers of my blog know that I always start with a plan, I kinda obsess about it for a while until I have the plan written down ( the source of most of my blog posts. )

• Remove the stanchion 
• Remove the screws and the backing plate
• Clean up the underside of the deck and determine the extend of the damage.

Well this was a surprise!

The area around that stanchion has a very thin layer of plywood undercovered with a single layer of fiberglass matting. That's it.

To say it was originally a nasty piece of work is an understatement! There's pieces of glue from the original sealing of the top deck to the hull.

In this picture, the camera is looking up, the nut shown in the top right is actually one of the hull to deck bolts.

Accessing this area is not easy when the Nav Table and the cabinets are installed, it would not be easy even then, but Grrrr!

I was able to clean up the entire area using sand paper, scrapers and Acetone. It's still not pretty but I should be able to reinforce the area.

With the threat of rains, we are in SoFla so that's always a threat, I needed to protect the area from on the deck.

I sanded down the area on top of the deck and prepared to repair the hairline cracks around the edge of the toe rail and deck. I also applied some gelcoat to the surface of the scupper which is just a few inches aft of the stanchion base, I'll have to apply at least three coats of gelcoat ( Thanks for a quick delivery Jamestown Distributors ).

After a first coat of Gel Coat a I used Butyl tape to cover the 5 holes in the deck. The larger hole is for the Air Vent in the base of the stanchion which is used to vent the holding tank.

Note those little dings in the lower left of this picture. That's signs of the previous repair by the PO.

Now the chance of rain getting in was pretty well eliminated for the short term.

Continue with the plan

• Make a fiberglass backing plate larger than the stainless steel backing plate, 
• Glue with resin to the underside of the deck and let it cure
• Redrill the holes
• Apply Butyl tape all around the top of the deck where the stanchion mounts
• Re-mount the stanchion with shorter bolts ( so that I can use a socket to tighten them ).
• Secure the SS backing plate in place and torque down the stanchion. All done.

• With the Fiberglass panel in place, next was Drill through from the topside
• 
  
  
   I marked the location of the new holes which would put the base plate of the stanchion about 1/8" from the corner of the toe rail and deck. I'm hoping that this will allow deck water to run behind the plate rather than build up until it's the height / depth of the plate.

Did my best to drill the new holes vertical but didn't quite make it. The SS backing plate would not align with the bolts in the holes, just couldn't get all four bolts to ling up.

Ended up oversize drilling of the holes by 1/16" and that worked.

Had to cover the area with additional Butyl tape in order to keep it all water tight while I drilled out the backing plate.

Back the next morning and it took another hour to get everything aligned and all of the nuts and spring washers in place

Finally tightened down on the nuts while keeping the heads of the bolts stationary, between Peggy & I, we managed to get all of the bolts tight. Lots of the Butyl tape squeezed out from under the Stanchion plate and the Stanchion was now really firm.

I'll go back to the boat on Saturday to re-tighten the nuts and trim off the rest of the Butyl tape. Moving the Stanchion base that 1/8" off the toe rail has left a groove of close to an 1/8' inch.

Also reconnected the holding tank vent pipe to the underside of the Stanchion base vent connection.

Result so far, very pleased! That area should not suffer any leaks for a good while or two.

While at the boat, I replaced the Water Separator Fuel Filter, cleaned out the Raw Water Strainer and checked the Raw Water supply thru hull. All's clear.

Updated the Service history spread sheet.

Brought my repair tools home.

See you on the water this weekend.

Paul