Head re install

[Sandero]

I am re building the Groco head and re installing it. But the Groco K is replaced an OEM head.

The head is mounted on a fiberglass gel coated insert which forms the shower pan and part of the hull liner behind the head. The area where the head is bolted down had solid wood beneath the liner for a secure attachment of the head.

Cosmetically the Groco did not line up with the former head bolt holes (4) and so when I installed the Groco years ago I screwed in some round head screws to fill in the old holes. Not especially attractive or hygenic, I suppose. I now have 8 holes into the liner and into the wood below

My plan is to install a corian disc which would cover all the old holes (8) which I would file in with epoxy so no moisture can get into them and into the wood below. The Groco will then be mounted on top of the disc.

My quandary concerns how best to mount this new "assembly". The options are:

1. Use 6 flathead countersunk stainless steel screws in a circle, and then tap the corian to receive 4 stainless bolts w/ washers to secure the Groco I can add acorn caps over top of the nuts. No adhesive between the corian and the gel coated liner for easy removal and replacement.

2. Use 4 flathead countersunk stainless steel screws located under the new head so they would unseen, and then tap the corian to receive 4 stainless bolts w/ washers to secure the Groco. I can add acorn caps over top of the nuts. No adhesive between the corian and the gel coated liner for removal and replacement. (4 holes penetrating into the wood)

3. Drill 4 clearance holes through the corain and use ss anchor bolts (screw threads on the end going into the wood and machine threads to accept the nut and washer securing the Groco. The corian acts like a spacer/cover and plays no part in holding the head. Drive the 4 anchor bolts deep enough to accept SS acorn nuts and washers. (4 holes penetrating into the wood)

The above options with a round bead of silicon caulk at the bottom edge of the corian to prevent water from getting under it.

Note the entire head is also the shower so there is water "there" regularly.

I don't like the exposed screw heads because water will collect on them and work it's way down into the wood below, so the fewest penetrations into the wood seems like the best approach. Even bedding the flat heads in caulk seems like something which will leak eventually.

Do you think I should put silicone into the anchoring holes (in the wood) below the liner?

Suggestions please!

[Charlie]

Question: 1) What kind of wood is beneath the head. Would it be good to take it out completely, and 2) Is Corian strong enough to take a thread. I've never heard of this being done.

[svTOTEM]

I also wonder about tapping into Corian, as Charlie does. I'm not sure, but the leverage one may put on a toilet in a seaway, may be to much for the toilet; making the user less fun. What about option #4. 1) Drill the mounting holes though the Corian and wood. 2) At each hole in the wood, drill out a larger diameter and then fill with epoxy. 3) redrill the hole though the epoxy 4) Caulk the bejeezers out of the hole when you put the bolts through.

It's the same idea as a proper thru-deck fitting, to prevent water intrusion into the core material. I'm working on a nearly identical project. I've looked at elimating the wood (FRP, garolite, plastics, etc) but they all seem to expensive. Water water everywhere...

[Sandero]

Can't get at the wood and the liner covers the head for, is the shower pan and lines the hull on one side. up to 3' above the sole. Don't know what the species is. Yet it IS like do a deck fitting.

Corian can be tappped. The material is 1/2" thick so I think there is sufficient thread to hold the head.

I can drill and fill with epoxy and set SS threaded rod into it

Here's the platform which covers the wood.

I don't think the forces on the head are a serious consideration as a deck fitting, but I do want it secure and soundly fastened.

[colemj]

I have several things tapped into 1/2" corian on our boat and some of them have pretty good loads on them (reefer and freezer hinges - large heavy doors). No problems for 10 years so far.

Mark

[Charlie]

On my boat PO or builder cut an access pannel in the platform. They then took one of those round plastic ports and installed it in the hole. This allowed me to thru bolt the toilet in place. Its hard to tell but you may be able to do the same thing. The reason I ask about the species of wood is that if it isn't a noble wood I would replace it sto that you don't have rot in the future.

On an old IOR boat that I raced on there was a story going around about it I don't know if it is true but it shows the forces on a toilet when you have a 200 lb person sitting on it.

"On an ocean race one of the crew went down to use the toilet. On this boat there was a strap -- a seatbelt on the toilet. The boat was running with the chute up. On a particuilarly big wave the boat broached and the toilet was sheared from its fittings. The crewmember ran up on deck with a toilet strapped to his butt."

I would assume that you would feel the toilet move before the bolts were torn from the corian but the leverage and forces on a toilet would be stronger than a door given the weight of someone sitting on the toilet.

[svHyLyte]

We had a similar situation on our old boat and I didn't want the new head secured with screws. Accordingly, as discusssed above, we cut an access port that allowed one to get a box wrench under the platform. I suggest you use the same approach. If you don't like the plastic inspection ports, make a cover out of teak. As for the exisitng screw holes, if the wood is dry (unlikely) use some craft paper held in place with duct tape to make a dam on the underside and fill the holes with thinned epoxy. Then cover the entire top of the base platform with 1/4" white or off-white starboard you'll only need 4-#12 oval headed machine screws-one counter sunk in each corner-for that as the through bolts for the head will also secure the base.

While it may sound silly, for boats that travel off shore it actually is wise to have seat belts on the heads and at the nav table. Replacement automotive seatbelts are pretty inexpensive and I have found them to be pretty useful in rough seas.

FWIW

s/v HyLyte