Blanking plate for 2" hole.. idea's??

[Fantasie 19]

Guys - at some point a previous owner has had the idea of improving cockpit drainage by cutting two holes and putting a piece of plastic pipe in between them - sikaflexed at each end. The idea is good, but I'm not sure the execution is... there is nothing securing pipe to boat other than the sikaflex, I'm on a mud mooriing, and sure as eggs at some point the transom end will be under the water and I'll spring a leak... so I'm looking for idea's to fill a 2" hole (above the waterline) on the transom, and in the cockpit... idea's.....

• glass it over - time/temperature constrained, but I'm kind of thinking that at some time I might make use of the hole on the transom (bilge pump outlet)..
• some kind of blanking plate? someone on another thread mentioned tap blanking pieces (for sinks), they're a little too small unfortunately...
• s/s washer with rubber grommet/sealant??

I've discounted the idea of an actual skin fitting due to cost... ideally what I'm looking for is a 60mm dia plastic/metal plate with a threaded bolt on the reverse...

This is the cockpit end...

 

[Searush]

Glassing over is pretty simple & quick, & easy enough to recut IF you ever wanted it back. Anything else would look like a patch.

 

[lw395]

Make a 3 inch disc of thick Perspex/similar.
Route a groove around it to suit a foam neoprene o ring.
Make the necessary bit of the transom smooth.
hold it in place with a tight string.
You might need a locating feature or three on the inside face of the disc?
I've seen foam neoprene o ring cord online, somewhere....

In the long run, glassing the pipes in properly might be nice, maybe with dinghy style non return flap on the outside?

 

[Lakesailor]

This is near in size. Some Sikaflex and a bit of the existing pipe as a spacer would make it fit. http://www.ebay.co.uk/itm/SKIN-FITT...tEquipment_Accessories_SM&hash=item231c23d9a8

Time needn't be a problem. I did this quick grp repair on a quad bike in 20 minutes and he was off around the farm again. It's lasted 4 years so far.

 

[rob2]

I assume these drains are pretty much horizontal? I used to sail on a T24, which has similar drains through the transom. We had hard sorbo rubber balls (dog toys) drilled through and mounted on bungee cord, threaded through the hole. To close the drains, they were pulled up to a small cleat, pulling the ball into the mouth of the drain. A small bullseye below the cleat kept the bungee in position and stopped the eye from disappearing through the drain.

Rob.

 

[DinghyMan]

A set of http://www.ebay.co.uk/itm/4-x-1-5mm..._Metalworking_Supplies_ET&hash=item3389931aa4 some neoprene sheet for seals and a couple of bolts

If you get stuck drop me a PM and I can turn some 60mm white nylon discs for you

 

[William_H]

As said a fibreglass patch can be done but is most successful where you have access to the inside of the transom. The cheapest plastic board is the cutting boards sold in supermarkets etc. This is about 8mm thick of softish plastic. You could cut out a circle (easily cut with a flycutter or hole saw) You might have a router to cut a step in the circumference so that it sits in the hole but covers the hole. You could put a bar or oval shaped piece of plastic or stainless steel across behind with a thread tapped in it to take a bolt in the middle or several around the outside. Seal it with sikaflex or similar. Paint the plastic board to match the transom.

If you want to use fibrglass. If you can't get access to inside the transom. You clean and abrade the inside of the hole as best you can. Cut a chamfer on the outside edge of the hole. Lay up on cling film on a flat surface a piece of f/g about 6mm thick. Make it oval shaped longer than the hole diameter but narrower than the hole diameter. When this has hardened but hopefully not really cured. Drill 2 holes near the middle to take a piece of string or wire. The f/g piece is passed through to the inside of the transom. Use resin to glue it to the inside of the cleaned up transom.
The wire or string is attached to a U shaped piece of wood or similar such that you can pull the inside patch firmly into place on the inside of the transom. But leaving room to attach a patch on the outside. Lay up layers of cloth in the hole and over the inside patch. Getting larger near the surface to fit into the chamfered area. The patch is then bigger on the outside so can't be pushed through. If the internal patch is still not fully cured you will get a good chemical bond between it and the outside patch so locking the whole thing in. Thus with mechanical attachment polyester resin is OK for the patches. The string or wire is pulled out at some point where the patch is going to stay in place as resin hardens and the small holes filled. Pigment in the final resin layers might make it look like the rest of the transom or paint it all.
Do something similar for the floor of the cockpit. or just beef up the existing pipe with fibreglass in a way that gives you confidence. good luck olewill

 

[coopec]

I'd do what William_H says but I have an unlimited supply of clear/opaque plastic, nylon, polycarbonate etc from the scrap bin at a Plastics Fabrication firm. I always go to the front counter and tell them what I am doing and they are only too happy to help. I think I'd would cut two discs (one for each side of the skin) and bolt them through the center of each disc

 

[chewi]

If you like the idea of the drain but not the execution, why not use a similar or slightly smaller piece of pipe as a mould and glass up a replacement that has a flange end. Then you can insert the new one and epoxy it to the hull.

 

[Fantasie 19]

Cheers guys - some idea's there....

Searush - agreed - but I don't mind patches, the boat is 47 years old and no beauty queen

lw395/chewi - I'm not sure you could glass the existing pipe in as it's PVC???

Dinghyman has got closest I think, but I think I'm going to go the GRP route - we may as well do this properly....

Thanks all...

 

[lw395]

Cheers guys - some idea's there....

Searush - agreed - but I don't mind patches, the boat is 47 years old and no beauty queen

lw395/chewi - I'm not sure you could glass the existing pipe in as it's PVC???

Dinghyman has got closest I think, but I think I'm going to go the GRP route - we may as well do this properly....

Thanks all...

I don't have any data on polyester resin sticking to PVC.
But if you glassed some way along each end of the pipe, it would be strong and probably seal very effectively.
Or of course you could glass the whole length, it would only need to be light as the pipe would give strength against crushing.

Big cockpit drains that actually work can be a good thing, OTOH mobile phones are drawn to them.....

 

[Fantasie 19]

Big cockpit drains that actually work can be a good thing...

...no argument - the idea is valid, I'm just unconvinced about the execution....

OTOH mobile phones are drawn to them.....

...and outboard wells.....

 

[rob2]

Revisiting the problem, I wonder if you could follow dinghy practice and mount a perspex sheet on a nylon hinge for a flap and a bungee to pull it closed. To reinforce the leakproofing, you could rout out a groove for an o-ring near the edge. I've cleared an Enterprise 's flooded cockpit with these simply by easing the bow up the beach a little - very quick.

Rob.

 

[chewi]

lw395/chewi - I'm not sure you could glass the existing pipe in as it's PVC???


...

I wasn't suggesting to GRP the PVC pipe, but to make a GRP pipe with a flange on the end and replace the PVC pipe with that then bond it to the hull.

 

[symondo]

what about a blanking plate from a pumbing centre? they must do such things. and then ill the tube with expanding foam?

 

[Lakesailor]

I tried Googling plumbing fittings, blanking plate.
Not as suitable as you may think.

 

[Fantasie 19]

I tried Googling plumbing fittings, blanking plate.
Not as suitable as you may think.

Indeed - and part of the problem is that the existing pipe is cut almost flush to the surface.....

Keep them coming but your advice to date has been most useful... I'm going to go the GRP route - as Searush says, if I want to fit a bilge outlet at a later date I can drill a new hole and fit a (slightly) smaller skin fitting.......

 

[fisherman]

I would simply screw a S/S or plastic or even wood blank on the outside, Sikaflex behind it. Self tappers.