I have had two Marelon through hulls fittings fail on Exit Only.
I was working in my starboard bilge
, and my hand bumped into the 1/2 inch Marelon thru hull
fitting that serves as the water
intake for the head
. The Marelon skin fitting snapped off flush with the hull
, and I watched a small 1/2 inch geyser of water
arch up into the air and then descend into the bilge
. This definitely was not good.
I quickly put my finger in the hole and stopped the leak. Then I grabbed an emergency
wood through hull
bung/plug, and pushed it into the hole. I called my wife to get a hammer, and then I drove the wooden bung securely into the hole. Once again I was glad that I was on an unsinkable catamaran
I called my friend Ted from yacht Tyche to come over and have a look. He surveyed the carnage, and we decided to change the thru hull
fitting while the boat was still in the water.
I went over the side with my wet suit, a bronze thru hull fitting, a wood bung, and some 5200 underwater caulk.
When Ted pulled the wood bung out of the hole, I instantly jammed a new bronze fitting (caulked with 5200) through the hole in the hull. I plugged the hole in the new bronze fitting with a wood bung so that it would not leak while Ted tightened the nut on the thru hull from the inside and attached the new ball valve.
The bronze skin fitting transplant turned out easier than expected and courage rose in our hearts. Tyche and Exit Only were set to sail together across the Coral Sea
to New Caledonia
, and we decided it would be a good idea to change out the remaining eight Marelon thru hull fittings on board Exit Only.
The next day, Ted and I took the boat up the Mooloolaba River and attempted to beach the cat with only moderate success. We had an unfavorable tide, and all eight remaining thru hulls remained underwater during the thru hull transplants. By late afternoon, the dastardly deed was done, and Exit Only now had eleven bronze thru hulls. We motored back to Lawries marina in the dark hoping that it was OK to replace thru hull fittings while they were under water. (In the six years since doing the underwater skin fitting replacements
, there have been no problems or leaks)
1. We broke off 1/2 inch Marelon thru hull fittings on two separate occasions. One was the cooling
water intake in the engine
room, and the other was the water intake for the starboard head
. It was only the small 1/2 inch Marelon skin fittings that broke. The 3/4 inch and larger Marelon fittings did fine, but we changed them out anyway.
I recommend that people change out their 1/2 inch Marelon thru hull fittings because they will eventually break off, possibly at an inopportune time. The small size Marelon skin fittings have a wall section that is simply too thin, and over time they will fail.
2. It's not that big of a deal to change out a through hull in an emergency
while your multihull
is still in the water. If a skin fitting ever breaks off, don't despair. You can easily fix it if you have the spare parts
3. Be sure to have a wood bung tied to every skin fitting so that you can quickly plug
the hole when a skin fitting fails. The wood bung quickly absorbs water causing it to swell up creating an extremely tight seal. You may find that it's hard to remove the bung when you change out the skin fitting. You might have to knock it out with a hammer from the outside.