Pressurizing the interior to find leaks

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OverEasy
Admiral
Posts: 2012
Joined: Mon Sep 28, 2020 11:16 am
Sailboat: MacGregor 26X
Location: NH & SC

Re: Pressurizing the interior to find leaks

Post by OverEasy »

Hi All!

Looking at this post it is something we can relate to.
What an ingenious way to find leaks!
To be honest this blower pressurization techniques wouldn’t have occurred to me! :D :D
Genius!

For what it’s worth….
We found some minor “annoyance “ leaks last year that we fixed by gently tightening ALL the window bolt/nut sets.
Two person job with one on the inside tightening the nuts and one on the outside holding the Phillips head screw still.
(Lots of those little interior nut cover caps to take off and put back on ….)

Our windows are set with what we assume is the factory original 2001 butyl putty which is great as it tends to last and remain pliable for nearly forever. The thermal cycling over the years along with the twisting/turning/flexing over the decades loosened things up just slightly. After tightening any window leaks disappeared.

The annoyance leaks back in mid aft berth area that we found were related to the pedestal and feedthroughs.
These we fixed by a couple of approaches.
First was the unbolting of the the pedestal from the cockpit sole.

The factory feed throughs were not completely sealed nor were they sufficiently proud above the deck.
So we took them out and replaced them with new PVC pipe sections that are about 6 inches higher than the cockpit deck and after throughly cleaning away any prior goop that the various prior owners had applied to the base material sealed everything top/bottom/in between with 5200. This has eliminated any rain and wave wash leaks from these feedthroughs.

Then for the pedestal base bolts we again throughly cleaned away any prior sealant to base material.
We applied a liberal coating of 5200 to the bolt shanks and added neoprene washers at the top deck interface before tightening up the bolts holding the little angle brackets to the deck. (We wiped the interior bolt threads clean of ant 5200 before tightening so that in the future these pedestal bolts can be removed.)

These steps took care of the annoyance leaks in this area.

In 2020 we had the rub rail replaced as the original had suffered some cuts and abrasions prior to us.
It was time.
While we don’t know if there were any leaks associated with the rub rail it is nice to know that the new rubber and sealant is in place for the future.
We also resealed the chain plates at this time while we were at it.

Now on to the only remaining annoyance leak we have left which is remarkably similar to the interior engine bowl one presented by JP Kewley 97x in his post
Strategy for mystery leak
viewtopic.php?p=364223#p364223
We noticed that after all the pedestal and feedthrough sealing we accomplished that the annoyance leakage there was substantially reduced but not entirely eliminated.
At some point in time one of the poor owners had routered/dremeled out a crack on the interior surface of the bowl inner liner and applied gelcoat to it. We can only assume that the cracking may have been caused by water migrating into the region between the exterior deck shell and the inner liner shell. How the factory seal the shells together is somewhat if a mystery to us but it couldn’t have been anything but a blind assembly with resin goobered on the surfaces and hope for the best technique. Any water getting inbetween would have become trapped expanding when temperatures dropped below freezing and ice formed.

While we haven’t gotten to it as yet (other than to place a small plastic bin under it) I think that our approach is gonna involve injecting a slow cure thin flowing potting type epoxy resin into this interspace area to see if that will eliminate this last annoyance.
If anyone has seen this and gotten it resolved we are all ears and open to suggestions!

Best Regards
Over Easy😎😎🐩🐈
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