National 12

General Boards => General National 12 chat => Topic started by: Chris Troth on 17 Mar 2009, 09:18

Title: Double bottoms and slot gaskets
Post by: Chris Troth on 17 Mar 2009, 09:18
I took 3412 out for a play in the wind today, and when she picks up speed, water gushes in through the centre board slot. Is this normal for double bottom boats or is there something wrong with my slot gasket?
Title: Re: Double bottoms and slot gaskets
Post by: sam293 on 17 Mar 2009, 09:28
you will probably find your slot gasket is damaged or non existant!
Title: Re: Double bottoms and slot gaskets
Post by: Chris Troth on 17 Mar 2009, 09:47
I guess I'll roll her over tomorrow and see whats going on
Title: Re: Double bottoms and slot gaskets
Post by: sam293 on 17 Mar 2009, 11:17
im sure someone with more wisdom than me will be able to tell you exactly how to fix it,
Title: Re: Double bottoms and slot gaskets
Post by: Crusader 3244 on 18 Mar 2009, 12:52
<h2>"I guess I'll roll her over tomorrow and see whats going on"</h2>
Foxi!   - Ooohh, errr , Missus!  
Surely a medical student like yourself could have expressed that with a little more dignity and eloquence!
Is there course content in med school pertaining to bed-side manner?    Really, you must work on yours!

Honestly, your remark reads like smut.........and almost as smutty as the person who said,
"There is nothing better than enthusiastic 12 owners getting the covers off, being seen to be having
a fun time, and infecting others with their enthusiasm"

Well, peeking out through the curtains this morning, I was minded to to return staight back under the covers and kept them on, but I did at least comply with the other two requirements! :)
Title: Re: Double bottoms and slot gaskets
Post by: sticky (Guest) on 18 Mar 2009, 08:16
Search back through this forum.  It’s been covered at length, let us know if you can’t find it and we can type it all in again.
Title: Re: Double bottoms and slot gaskets
Post by: Crusader 3244 on 18 Mar 2009, 08:40
Hi foxi,
Two came up and have 'pinged' them up the posts.
- Chris
Title: Re: Double bottoms and slot gaskets
Post by: lucy horsley on 19 Mar 2009, 10:07
Hiya, just to let you know Dad and I used to own 3412.  The boat was refurbished a few years ago by Dare Barry and ever since then there has been the slight issue of water coming up through the centre board slot when going fast.  Dad informs me that this is due to the back of the centre board not being quite the same after refurb, I'm sure I could get more tecnical details if required. 
Lucy
Title: Re: Double bottoms and slot gaskets
Post by: Chris Troth on 20 Mar 2009, 08:41
Hi. Thanks - I'm going to fit a new gasket and see what happens!
Title: Re: Double bottoms and slot gaskets
Post by: matt (Guest) on 20 Mar 2009, 07:01
for what its worth water gushed out of hte centreboard case on 3486 until I got the slot gasket attached properly. problem disappeared overnight. 
Matt
Title: Re: Double bottoms and slot gaskets
Post by: Chris Troth on 21 Mar 2009, 11:50
When using mylar strips, is it best to use one strip and cut down the centre, or use two strips and overlap them slightly?
Title: Re: Double bottoms and slot gaskets
Post by: Chris Troth on 30 Mar 2009, 03:18
I've had a look underneath and the current slot gasket is a single piece of mylar with a cut down the middle, held onto the hull with brown parcel tape.
Will change it very soon
Title: Re: Double bottoms and slot gaskets
Post by: sam childs (Guest) on 30 Mar 2009, 05:00
ahhh oh dear that would probably explain the problem, but if it was duck tape all would be well!!!!
Title: Re: Double bottoms and slot gaskets
Post by: John Meadowcroft on 30 Mar 2009, 05:40
Hold on!!!!!!!!!!!!
The brown parcel tape can be very useful.
Whether you overlap the gasket or not is a matter of personal choice.  stick the gasket to the hull using a contact adhesive.  you can get this from B&Q.
We finish off the job with parcel tape.  It does not stick the gasket to the hull but what it does do is seal the side of the gasket that is not supposed to open to the hull.  This can get damaged - particularly by the trolly cradle when launching or recovering.  We let the tape get damaged (a small job) rather than the gasket itself (a bigger job).
For the record - our latest gasket is an overlapped style.  I am sure if you search this forum you can find our method of doing it somewhere.
John
Title: Re: Double bottoms and slot gaskets
Post by: tonyelgar on 30 Mar 2009, 06:21
i ve just replaced my slot gasket and used contact glue, tapering the fore and aft ends of the gasket to reduce the risk of it peeling. it isn't overlapped but it is one peice with the centre trimmed along so it meets flush. I have yet to roll the boat back but will probably do the parcel tape thing, is it trimmed to look neat or do you use the whole width of the tape? It is rather large and my boat does still have a keel so wouldn't be as neat a job. Could i use electrical tape or duck tape as it is easier to trim?
Also worth noting is that my contact adheisive suggested not to apply any pressure or force for 24 (or was it 12?) hours, so maybe times when the glue alone has failed this may not have been followed?
My last gasket replacement was on grimalkin and that was put on with rails screwed back on, so this looks neater but is a bit of an experiment for me.
 
tony