Blakes seacock help

[prv]

I can't find Boatlife Lifecaulk for sale, Arbokol 1000 is available, is that just as good? Dow Corning Marine Sealant is a silicone sealant I can get. If sikaflex, 291?

I wouldn't use silicone. The previous owner of my boat loved the stuff, it's in practically every joint, but most of it has failed.

I would instantly pick Sikaflex 291, which has served me well. Lifecaulk I've heard good things about too but never used. Not heard of Arbokol.

Pete

 

[Tranona]

Lifecaulk is supposed to be back on the market having been absent for a couple of years because of a change in distributor - don't know who the new one is. Not sure it will sell well because the price I have seen is £20 a tube - nearly twice what it was. Arbokol 1000 seems to be the same and that is what I am using now.

 

[lynnrival]

bolts and Boatlife

Suggest silicon bronze bolts from a supplier such as Anglian Fasteners - when we bought some three years ago they were a quarter of the price of Blake's. The main function of the plates, which are available with or without strainers, is to prevent the (cup square headed) bolts from turning when you install them.

The bolts are the weakest link - some recommend pulling a bolt or two to check them every ten years. This is probably a good idea. Ours had been in place for thirty one years and over two thirds of them failed in torsion when we turned the nuts! The old style Blakes seacocks will see you out; the new ones appear to be of a rather less durable alloy.

Boatlife products are now imported by RLM products Ltd. They have a website www.yacht2haveit.co.uk. Almost any bedding compound will do - we used Sika 291, but an old fashioned non hardening compound might be better. If you use Sika or similar just pull the bolts up hand tight, then wait for a few hours before final tightening, otherwise you'll squeeze all the goo ouit of the joint.

And don't forget, the best maintenance is to turn them frequently - we do ours every Sunday.

Paul and Rachel

 

[doug748]

....

So to bed them in, polysulphide, silicone and sikaflex have all been suggested and I'm confused to what I should use. Is it a case of just use any of them as they all do the job, or are there particular advantages / disadvantages to any?

I can't find Boatlife Lifecaulk for sale, Arbokol 1000 is available, is that just as good? Dow Corning Marine Sealant is a silicone sealant I can get. If sikaflex, 291?

All will do the job so, yes, it is just a case of using what you can get hold of.
Folk have reported problems with getting some Sikaflex products apart
later, so bear that in mind. It is also expensive and this tends to impress some mariners a great deal, others not so much.
It is a very basic application, ordinary silicone is fine. Not might be, should be or would be, it is fine for this application.

 

[vyv_cox]

Until recently I used Sikaflex 291 for all sealing jobs, above and below the water. Never had a problem with it. I now use the polyurethane sealant sold by Screwfix, which appears to be exactly the same stuff. It costs £4 per tube.

 

[doug748]

Thanks vyv, that is certainly a better price point. With all these tubes it is the expensive waste that particularly annoys.

 

[maej]

I've given them all another good go with the grinding paste and the 2 x 3/4 size seacocks look like they will seal very well now at both ends of the cone. But I am concerned about the 1 1/2 size seacock as the cone's not so good at the bottom.

The cone has a wide ring at the top that has been worn by the paste so I guess that seal will be good, but at the bottom of the cone it is only about 2 to 3mm wide at best reducing to 1mm near a pit in the surface. Since the area in the middle of the cone isn't ground so well I guess that won't seal much.

Is this good enough to stop water coming back up the waste pipe when it's closed? From the looks of it a new one would only have about 5mm of seal at best on the bottom anyway as that's how much cone protrudes under the opening.

 

[doug748]

......Is this good enough to stop water coming back up the waste pipe when it's closed? From the looks of it a new one would only have about 5mm of seal at best on the bottom anyway as that's how much cone protrudes under the opening.

I would not worry about this too much. The main thing is that it keeps water out of the boat, and, of course, grease completes the seal.

The wisdom is: when you refit the cone do not overtighten, as this will squeeze out much of the grease. You will have to adjust the thing in use and there is always the possibility of the odd dribble, this is nothing to worry about either.
Did anyone suggest making a special spanner for adjustment? If not, get yourself an old spanner from a junk stall and cut it down so it is just a stub. This helps a lot in a confined space.

 

[maej]

I would not worry about this too much. The main thing is that it keeps water out of the boat, and, of course, grease completes the seal.

The wisdom is: when you refit the cone do not overtighten, as this will squeeze out much of the grease. You will have to adjust the thing in use and there is always the possibility of the odd dribble, this is nothing to worry about either.
Did anyone suggest making a special spanner for adjustment? If not, get yourself an old spanner from a junk stall and cut it down so it is just a stub. This helps a lot in a confined space.

That's a brilliant idea! Thank you I notice new ones have a slot for a screwdriver rather than a hex head, but at £14.66 each I'll only be getting the 2 I need to replace the ones a sheared (a costly misunderstanding about the lock nuts).

Thanks for the reasurance as well, much appreciated

 

[vyv_cox]

Did anyone suggest making a special spanner for adjustment? If not, get yourself an old spanner from a junk stall and cut it down so it is just a stub. This helps a lot in a confined space.

I didn't need to do this, but I filed all the Imperial nuts down to a metric size to avoid the necessity of carrying a special spanner.

 

[VicMallows]

My Blakes outlet seacock cone developed quite severe pitting (about 0.5mm) opposite the inboard port opening (when closed in the usual 90deg position). The pitting occurred within the first 10yrs.

After lapping as best as possible, I now close the seacock at extra 30deg which brings a clean section of the cone across the port. (check which direction in your particular case!).

Curiously, since then (15yrs) there has been no further significant pitting.

(I'm sure that regrinding the cone would be a trivial task for a machine shop).

Vic

 

[captainboo]

Which sealant?

Until recently I used Sikaflex 291 for all sealing jobs, above and below the water. Never had a problem with it. I now use the polyurethane sealant sold by Screwfix, which appears to be exactly the same stuff. It costs £4 per tube.

Can I ask which one you have been trying as I have found both of the following to be very good.

http://www.toolstation.com/shop/Adh...e/Stixall+MS+Polymer+White/d180/sd3199/p69243

http://www.toolstation.com/shop/Adh...e+PU40+Sealant+310ml+White/d180/sd2350/p67949

The first is listed under grab type adhesive and the second under sealant.

The technical data sheets can be found here:

http://www.everbuild.co.uk/products/9,Adhesives/10,Grab-Adhesives/2
http://www.everbuild.co.uk/products/1,Sealants/55,Industrial-Sealants/4

 

[vyv_cox]

It's the second one, PU40. Sorry I said Screwfix when I probably meant Toolstation. I use the Chester branches of these two, which are immediately opposite each other, about 10 metres apart. Easy to confuse them!