Old mounting holes in the bilge, should I care?

[wyb2]

Hi all. Just purchased a catalina 36 and I have my first of many questions. Been searching but I just end up drowning in bilge pump threads that have nothing to do with my specific question.

1st day on the boat I had to replace the float switch, luckily the previous owner had left a spare on board. The new switch was a different brand than the existing one and didn't fit in the same location, but no big deal, I found a good spot a not far away.

The old switch was mounted with 3/4" ss phillips head screws directly into the bilge floor, which now leaves empty holes that are constantly soaking in bilge water. There are also a few other old mounting holes, I'm assuming for past float switches. So the question is, should I care? My first instinct is that the solid layup could care less as long as the holes don't extend clear through the hull. On the other hand, I hear a lot of folklore about mysterious blisters, and I do know fiberglass can create a wicking effect even when embedded in solid materials. Following that logic, the fact that these holes are exposing glass strands could cause an issue down the line.

Is this paranoia? The way I see it my options are 1. Do nothing 2. Dry the area and fill with 4200/5200 or 3. Dry the area and fill with resin. 3 seems like overkill, even for the paranoid.

Going forward I like an idea I got here on CF - use 5200 to bond a small plate of something (frp, pvc, hdpe, etc.) to the hull, then screw into that.

[pumpcity]

my suggestion is to dry completely, then scrape out any debris or contamination from the holes, then fill with West system epoxy with 404 high density filler to bond to the hole sides. I don't like bare fiberglass fibers either.

Everyone with a fiberglass boat needs epoxy resin with slow hardener in the warm climates, and 404 high density filler for bonding and filling, but not fairing.

[HopCar]

Go to your friendly neighborhood marine store and buy an epoxy stick. Mix some up and shove it in the holes. It will bond and set up under water.
Star Brite Epoxy Putty Stick Mfg# 087104

[roverhi]

Leave it alone unless you've got the time to do the above 'fixes'. Way better ways to use your time.

[GordMay]

Greetings and welcome aboard the CF, wyb.

[a64pilot]

Why not fill with 5200?


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[wyb2]

I actually appreciate the variety of answers, makes me feel less crazy for being perplexed in the first place.

I like the epoxy putty stick, even if I don't use it here, looks like a good thing to keep on board.

Also, I'm sure everyone got this from context, but I'm talking about 3/4" long screws, my original wording could be read as 3/4" dia. It's a float switch, not new keel bolts. Screws are #8 or #10, so the holes are less than 1/4" dia.

Originally Posted by GordMay

Greetings and welcome aboard the CF, wyb.

Thanks!

[Cadence]

I would do something to seal them. Just insurance that the layup wasn't dry in one of these areas and allowing wicking of the water.

[svgypsyqueen]

Fill fill fill!

My preference would be the west epoxy as already described.

I have 20 years in aviation maintaining helicopters and composite structures as well as twelve years of working with off shore race boats and installations of fancy engines and such.

Dry those holes out. Clean them out and fill with the epoxy.

They will collect moisture and crud and anything left wet long enough suffers. Plus it just offends my sense of a clean bilge.

The "leave it spend your time on other things" makes me cringe. I envision a vessel that has old wire runs still installed leading no where from old equipment and most everything in disarray. I am likely very wrong in that... But that's what that brings up in my mind for the aaahhhhhhh just leave it.

But then.... Maybe I'm a little over the top when it comes to maintenance and a ship shape ship.

[Sailorbob8599]

Originally Posted by pumpcity

my suggestion is to dry completely, then scrape out any debris or contamination from the holes, then fill with West system epoxy with 404 high density filler to bond to the hole sides. I don't like bare fiberglass fibers either.

Everyone with a fiberglass boat needs epoxy resin with slow hardener in the warm climates, and 404 high density filler for bonding and filling, but not fairing.

My thoughts re "scraping out" old debris would be: First, thoroughly dry the bilge of all moisture (use a heat gun if necessary). Next, using an over-size drill, clean the holes of "dead" material, followed by blowing out all loose debris with compressed air (rent or borrow a portable air tank if you don't have a compressor). Finally, apply a waterproof epoxy type fix as recommended by other respondents ... I personally favor 5200 ... be very careful of explosive fumes when working in enclosed bilge area.

[wyb2]

Thanks all. Sounds like the consensus is definitely to do something about it, with a split between west systems and 5200 or similar. Not having any experience using epoxy resins, and currently being in possession of some 5200, I'm going to try that first and see if I'm happy with the results.

[artisanmach]

I would take a drill bit slightly larger maybe 1/16 and drill to existing depth... this will give you a clean surface to bond to with no oil present. and follow pumpcity's method of filling holes.

[cjsfsm]

The "epoxy stick" is a quick and easy way to seal the holes. However, you don't need to get this stuff at a marine store for $19.95; you can get the same stuff at any hardware store for about $4.99. Don't be fooled by the term "marine." I have used this stuff for years under all conditions and it works!

[Jim Cate]

The problem with 5200 or other thixotropic materials is actually filling the hole to the bottom... kinda hard to do IME. Better to use a flowing epoxy, injected to the bottom of the hole with a syringe and needle, filling to overflowing. then you can be reasonably sure that it is completely sealed... and it ain't hard to do.

Jim

[CSY Man]

Clean and fill for sure, epoxy would be my choice.
Use an L shaped aluminum foot for mounting pump and switch, no holes in the bottom of the bilge and easy to pull out for service and or replacement.