Drain sock

Delta 15 · 11 January 2011, 14:21

I'd like to add a couple of drain socks to my Avon but the scuppers are only about 25mm ID. The commercially available socks start at 680mm. Is there a way to DIY or adapt drain socks to fit my boat short of drilling the transom?

Cheers,

Jon

PeterM · 11 January 2011, 16:16

I guess buy a bit of matching (or not) colour hypalon + glue and make your own ?

Or am I missing the point ?

Delta 15 · 11 January 2011, 16:49

That's what I was wondering. Rib-shop told me the scuppers in the boat are too narrow to allow use of a sock.

I guess I'm not quite clear on how they work. I assumed that they drain water when the boat is underway but close up when the boat stops due to external water pressure?

Does it have to be hypalon or would a piece of PVC? If it's a question of water flowing back in when the boat stops, I can just put the plugs back in when the water has drained.

Cheers

chewy · 11 January 2011, 16:58

Trunk down = water drain when underway, leave it down when you've stopped and it'll slowly fill back up.
Trunk up = water won't drain but then the trunk won't let water in either, simples.

A 25mm trunk will work but not very well, I'd just bite the bullet and buy the biggest one!

PeterM · 11 January 2011, 16:59

PVC will work I am sure & any size will drain if given enough time- just be slower for obvious reasons....

I always used to put bungs in if not 'actively' using mine - just stops the small trickle that will eventually fill the boat if left down.

martini · 11 January 2011, 17:36

Quote:

Originally Posted by Delta 15

The commercially available socks start at 680mm.

I'm guessing you mean 68mm

It would be dead easy to get a core bit and drill your transom out to take a bigger trunk, 25mm is properly small and you'd benefit greatly from a bigger one.

Find a trunk that has an I/D that matches the O/D of a pvc drain pipe, drill transom to suit pipe, sikaflex it in then glue the trunk to the pipe. Seemples

Delta 15 · 11 January 2011, 18:18

Ah, yes -- 68mm indeed!

Thanks for all the feedback - very helpful.

Poly · 11 January 2011, 18:26

Quote:

Originally Posted by Delta 15

Does it have to be hypalon or would a piece of PVC? If it's a question of water flowing back in when the boat stops, I can just put the plugs back in when the water has drained.

if you're going to put bungs back in when drained then why bother with trunks? the advantages of trunks are: (a) you can leave them down for shortish periods without worrying about the boat filling up significantly (whereas with bungs the boat will fill as soon as you come off the plane) (b) you can (if you wish) operate them remotely using a long cord. This is especially useful if you are single handed as with bungs you'd probably have to leave the helm to either fit or remove them.

PeterM · 11 January 2011, 18:35

Quote:

Originally Posted by Polwart

if you're going to put bungs back in when drained then why bother with trunks? the advantages of trunks are: (a) you can leave them down for shortish periods without worrying about the boat filling up significantly (whereas with bungs the boat will fill as soon as you come off the plane) (b) you can (if you wish) operate them remotely using a long cord. This is especially useful if you are single handed as with bungs you'd probably have to leave the helm to either fit or remove them.

I'm thinking he is thinking for periods of more than say 20 mins+ ........ the best trunks in the world will let water in which will be noticed after that time...

Poly · 11 January 2011, 18:48

Quote:

Originally Posted by PeterM

I'm thinking he is thinking for periods of more than say 20 mins+ ........ the best trunks in the world will let water in which will be noticed after that time...

Aye but normal practice (IME) is simply to raise a trunk when sitting still for a while - the only time I can imagine adding a bung as a backup would be if leaving it afloat overnight and worried about the trunks failing (e.g. through wear and tare). Moreover with a 1" tube I suspect (unless its made from some very flimsy/vulnerable material) that it will leak more than a 3" trunk - as it won't collapse as flat? Personally I have a 40mm (?) bung which is central (so can't take a trunk as the engine is there) and manage OK. Trunks aren't really an option due to the transom design - so I've added a bilge pump so I have an alternative when alone and unable to leave the helm when the boat is on the plane. I have wondered about the "duckbill" drainers - which might be an option for the OP?

SPR · 11 January 2011, 19:48

I was told by Zodiac that my self drainers were designed to be left open if on a mooring although they leak very badly!

Idea was the water equalises and boat will never fill up fully....after a week of going to water logged boat, i fitted auto-bilge pump and leave bungs in, unless going out in large seas...

So worse a failed trunk is a water covered boat...but should not reach the battery height....

S.

prairie tuber · 12 January 2011, 17:03

Quote:

Originally Posted by SPR

I was told by Zodiac that my self drainers were designed to be left open if on a mooring although they leak very badly!

Idea was the water equalises and boat will never fill up fully....after a week of going to water logged boat, i fitted auto-bilge pump and leave bungs in, unless going out in large seas...

So worse a failed trunk is a water covered boat...but should not reach the battery height....

S.

Did Zodiac (France) themselves tell you that or did your Zodiac dealer tell you that? If your local Zodiac dealer is as knowledgeable as my local dealer then I'd recheck any advice they provide through other sources

That does seem like very strange advice. Those little rubber flapper diaphragms that zodiac uses for their valves will allow some water to slowly leak back into the boat when the boat is not moving. Definitely put the plugs in when moored.

SPR · 12 January 2011, 17:25

it was both the dealer and zodiac UK...I leave bung in on mooring and use auto pump now...I liked dry feet at least at start if day!

S.

jonnyhas · 12 January 2011, 21:43

Hi Delta, i have installed duck bill drainer in my avon these appear to work pretty good and have an option for plugging them when required, although they are just pulled through the existing hole so if it sits below the water line and sits for some time they may well pass water.

see my thread: http://www.rib.net/forum/showthread.php?t=38148

cheers Jonny

Delta 15 · 13 January 2011, 15:16

Thanks Jonny -- that might be the easiest solution.

Cheers,

Jon

Quote:

Originally Posted by jonnyhas

Hi Delta, i have installed duck bill drainer in my avon these appear to work pretty good and have an option for plugging them when required, although they are just pulled through the existing hole so if it sits below the water line and sits for some time they may well pass water.

see my thread: http://www.rib.net/forum/showthread.php?t=38148

cheers Jonny