Water proof hatches

[TROUBLEMONSTER]

Hi, I have the TJ Salvirile AHT tug kit and need to make some water tight hatches on the lower deck. They must be flush a piece of wood decking will go over the hatches to hide them They must also be watertight that deck is low to the water. There are 2 1 1/4 " holes over the rudders to acess the tiller arms and a 4" x 5" acess for the drive motors and steering servo. I will probably not need to get into these areas too often. I was thinking of trying to get some screw type flush fittings for the rudder acess and maby a piece of plexi glass for the motor acess. I could attach it from under the deck from under the pilot house acess and silicone it in place removing it only if needed. The battery and other electronics will be accesed from under the cabin which is high up on the focicle deck and has a nice lip to keep water out.

[toesup]

They must be flush a piece of wood decking will go over the hatches to hide them They must also be watertight that deck is low to the water.
I will probably not need to get into these areas too often.
I was thinking of trying to get some screw type flush fittings for the rudder acess and maby a piece of plexi glass for the motor acess.

Try to crate a 'lip' from under the deck that the hatches will sit in.. and be flush with the deck. Fixings can be as simple as some very small brass (or stainless) screws.
Bath sealant (Silicone) works and once it dries you should have a watertight seal.

Be warned though, dont go fixing things down (semi) permanently untill you have tried the boat out... carefully. You may need access inside these hatches to do some alterations.

[Brooks]

The vac-u-tug has a seldom accessed hatch over the rudderpost. The waterproofing is merely a 2" wide piece of clear packing tape over the 1 1/2" hole, then a non-waterproof-sealed plastic hatchcover over the tape. I hold the plastic hatch on with a pair of neodynium magnets stuck to the bottom of the tape and a pair of small steel washers glued to the bottom of the plastic hatchcover. The packing tape is the standard vac-u-tug method of sealing the hatch, the magnets were my idea, but velcro would work also (albeit with more standoff height to the cover). No leakage yet, though for those sending their tugs out into the surf, a stronger waterproofing method might be recommended.

I added another hatch over the U-joint. This has the lip recommended above (styrene square extrusion from hobby shop) glued to the top of the deck. The plastic hatch rides on the lip, held by a small bolt through the hatch going down to a cross piece of lip material that spans the opening below the deck. The crosspiece length was chosen to fit in the diagonal, then be turned 45deg to span the lip. A nut is glued to the bottom of the crosspiece. Watersealing is a thread of silicon RTV that was squished flat by a scrap of hatching separated from the silicon by waxed paper until the silicon cured. There is no waterproofing of the bolt hole, so this method would not be suitable for a continuously submerged hatch.

[TROUBLEMONSTER]

I will try and make a lip and find some really tiny counter sink screws for the big hatch and I can probably do the same with the circular hatches. I really like the magnet Idea. There is a sheet of deckboards that covers the hatches I think I may try magnets to hold it down. I will try to find a thin sheet of magnet to put under the deckboards and put some metal washers in the hull to stick it to. See attached pictures. Thanks