waterproof sealing strip

[michael howarth 1Participant @michaelhowarth1]

To seal aperture in boat hull

[michael howarth 1Participant @michaelhowarth1]

Assistance required please to locate a sealing strip. The strip is required to seal a thin metal plate which goes over an aperture in the top of a boat's hull. The metal plate is removable for access to a battery and other gubbins inside the hull. The metal plate will not be below the waterline but very close to it and will inevitably get wet when the boat is in motion. I would like the sealing strip to have as low a profile as possible. The metal plate will be screwed down onto the sealing strip to give a bit of squeeze. Does such a sealing strip exist ?

Mick

[OldironParticipant @oldiron]

You could probably use Hylomar or one of the other flexible gasket sealers. That would entail a clean up after every removal but would be really thin. A very thin rubber gasket would work but will need pinch bolts quite close together if the metal cover is very thin.

IHTH. regards

[Jeff DaymanParticipant @jeffdayman43397]

MickH – depending on how thick the deck plating is, the size of the opening, and how high the plate to be sealed can be off the deck, the weatherstrip at the link below may work. The U shaped bit is fitted over the opening edge, and the bulb part compresses under the plate or door. I have used this style on heavy equipment access plates and doors in the day job for years, and it gives a dependable seal. It is made by many firms worldwide. It does need to be cut to be a slight interference where the two ends meet, with a bit of silicone sealant (bathtub caulk type) to seal the ends. Hope this is useful.

[SteviegtrParticipant @steviegtr]

What are the dimensions of the plate. Only asking because if we are talking something small.

Or are you talking about a full size boat.

An O-ring bonded into a groove would make a permanent & re-usable seal. Reshaped to a square if required.

Steve.

[old martParticipant @oldmart]

You can get closed cell foam rubber sheet in various thicknesses which could be bonded to the plate with double sided tape.

[Sam Longley 1Participant @samlongley1]

10 * 3mm rubber type sealing strip, adhesive one side compresses to 1mm thick

[Dave HalfordParticipant @davehalford22513]

If this is a model then a deck hatch should have a 1/2" deep and wide gutter with a pipe glued in to drain it through the transom. The hatch can then have a simple catch to secure it.

Scale can get away with a coaming with the hatch over it instead of in it.

Radio and speed controller all go into a sandwich box with a rubber gaiter to seal the rudder pushrod.

Edited By Dave Halford on 02/10/2020 17:43:19

[michael howarth 1Participant @michaelhowarth1]

Thank you gents for the usual abundance of ideas. I am making a submarine ….outline only, not a diving model….which will be a replica of the Jules Verne Nautilus, 1954 film version. The model is 32" long. The stern and bows are built up from turned oak and the centre section of the hull is a 10" length of 110mm drainage pipe. This centre section has a section 8" x 2" cut out of the top into which the motor, battery and servos etc can be accessed. This is the hatch that I hope to close with a piece of curved 0.5mm brass sheet. I now feel that it would have been easier to give this information at the outset so apologies for the omission.

Mick

[Dave HalfordParticipant @davehalford22513]

Your hatch may only work if you have external sockets for charging it's a bit thin to remain undamaged for more that a few weekends.

You can easily form a glass fibre hatch before you cut out the hole. Just put 5 or 6 coats of car polish over the tube then paint on resin, follow with 3 layers of resin and glass cloth much larger than the hatch you need. Get some of that hard clear plastic sheet that comes as windows in toy boxes etc. Wax one side then cover over the resin waxed side down secure with parcel tape wrapped tightly right round the tube like you would wrap a mummy.

When cured it will ping off with the careful use of a screwdriver.

Use a prop shaft with a grease point otherwise they leak and and the model won't be fast enough for a self bailer to work.

[BazyleParticipant @bazyle]

A few years ago one of our club members made a submerging Nautilus with two cameras that transmitted back to a tv on land if it didn't go too deep (like a foot).

You are using a bit of drain pipe in the middle and have thrown away the prime reason for using it About 50 years ago in Model Boats magazine was the first published design using drainpipe which had a round hatch in the front end with an o-ring seal. It had two prepared plates with the seal sitting in a v-groove formed by the chamfer between them that were pulled together in situ to push the seal out to the inside of the tube. This required a lathe or so I thought at the time so I never was able to make that design.

When you try to compress a rubber seal the area involved means the force goes up rapidly but if you have good clean flat surfaces only a line seal is adequate. To see if it is touching all the way round it is best to make the hatch from perspex. O-ring is available as continuous length to cut to length but it is still a hard rubber. Use vasaline which really helps. Ideally you want the squashy rubbery plastic used to make kids toy octopusses and similar little gimmicks. You will probably find more experienced protagonists on the modelboatmayhem forum.

My first submarine was to the MAP plan Sardine, a truly appauling design of tinplate from the old fashined cube bulk bicsuit tins from which grocers sold loose product. All soldered together with 15w iron and I sealed the hatch with glaziers putty. I had not allowed for the on/off switch in the top letting air out so watter could come up the prop shaft. Its only outing ended at the bottom of a clear but very cold Dartmoor river.

[Nick HughesParticipant @nickhughes97026]

If you can arrange a groove that will accept a standard sized "O" Ring, than you could use a Quad Ring or X-Ring in it's place. The X-ring in particular compress far more easily than O rings.

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