Many thanks

Chris Cobb

235/48 "Tarakihi"

The 2 seacocks (ball valves)on my boat (No 59) are in hull in the forward locker just thro' the heads bulk head door. This is also the location for depth and speed transducers.

Unfortunately I do not have any photos.

Brian Banham 235/59

Thanks for your response - I had almost decided that ball valves would be my choice, particularly as the Blakes valves cost "an arm and a leg" probably more than the toilet and pump. Could you tell me how they are located i.e. is the inlet forward of the outlet and are they near the log and sounder so as the valve tails are more vertical? At what height do the pipes coming from the toilet pass through the bulkhead - do you think this compromises the water-tightness of the locker?

Many thanks

Chris Cobb

235/48 "Tarakihi"

As soon as I can get to my boat I will measure locations you require.

Brian Banham 235/59

That's great - many thanks

Chris Cobb

235/48 "Tarakihi"

If you could send me your email address I have some photos that I may be able to send you.

Brian Banham 235/59

Many thanks for the offer of pics - I have sent an email directly to your address from the handbook - hope it's the right one.

Regards

Chris

235/48 "Tarakihi"

My attempt to email you direct resulted in a "failure notice" so I assume that your mail address, as in the 2009 handbook, is incorrect. I have sent you another mail via the system on this site but if you don't get that you can always find my email in the handbook - I haven't changed it for some time.

Chris Cobb

235/48

I am not an expert on the P235 but I do have professional expertise in marine sea toilets.

Three points:

Firstly, ball valves per se are fine, but you should make sure that you only use marine grade brass DZR CW602N (CZ132). This is easier said than done, as many chandlers just stock the cheaper, ordinary domestic grade ones which look outwardly identical.

Every volume production boatbuilder uses brass Ball Valves, screwed to Through Hull fittings installed from outside the hull rather than traditional seacocks which are installed from inside the hull. The sole reason that they do so is cost, and the reason for the cost difference is almost entirely in the raw material. You may well be able to source marine grade bronze or gunmetal Through Hull fittings, but not so Ball Valves. Do not economise by buying anything less than DZR [DeZincification Resistant] ball Valves & Skin Fittings - for a succinct explanation and the correct standard to use, follow this link:

http://www.aquafax.co.uk...s/aceimages/TechData.pdf 

Secondly, whatever you do, don't even think of using brass screw down gate valves, even on the inlet - sooner or later dezincification will occur and the spindle will break off inside the valve.

Thirdly, to minimise the risk of sucking in what you have just pumped out, the intake should always be well forward of, and higher than, the outlet; ideally each should be on opposite sides of the boat. If you want to be able to use the toilet whilst sailing, ensure that the intake is below the heeled waterline.

sincerely

Geoff Sheddick

Parker 27/146 "Stroller'

Thanks for your comments and info - I knew there was an issue with using the "right" material ball valves and fittings but you have helped to clarify it. The 235 is only small compared with the 27 and it's not so easy to find optimum placements for the inlet and outlets - they will be located in a "watertight" well that also houses the sounder and log transducers. The well is relatively small and is only on one side of the boat. I will place the valves as far apart as possible to try avoid the problems you talk about.

Regards

Chris Cobb

235/48

I have sent photos of my seacock installation to your email address, did they arrive?

Brian Banham 235/59

I haven't received any mails from you today. Perhaps it bounced because the pictures (files) were too large?

Chris

235/48

The possible reported life of 5 years has been at least tripled, but then she spends most of the time on dry land!

I will just point out that although today's "Blakes" Seacocks are of the same "proper" design as the original, these days they are just made of de-zincified brass [DZR], so the material from which they are manufactured is no better than that used in DZR skin fittings and ball valves. This is not obvious from their promotional literature.

So when you buy Blakes , you get a better functional design, but not necessarily a better material of construction.

Seven or eight years ago we fitted Marelon seacocks to P235 Little Grebe and they continue to function perfectly.

I have decided to go for 'plastic' as I refit this winter. I have had a look at the TruDesign seacocks which look promising on the web but on closer inspection of the real thing I found that they don't appear to be full bore, with significant narrowing through the ball valve, and on the ones I looked at the ball valve didn't open fully, creating a further potential for blockages! I'd be interested if anyone has used them successfully.

So over the winter I will fit new Marelon seacocks and report back any issues.

Phill

I have no direct personal experience of Forespar/Marelon seacocks, but I did have personal experience of dealing with, and supplying other Forespar/Marelon products to mass production boatbuilders more than a decade ago, and can only comment that I formed a high opinion of their product quality and suitability for function.

I think that a combination of ill-informed prejudice against what many boat owners and buyers wrongly denigrate as “plastic” products and the fact that they occupy more physical space are the two main reasons why this type of seacock has not been more widely adopted in the Northern hemisphere.

As some one whose job necessitated monitoring global boatbuilder and end user complaints relating to toilet installations throughout the ‘80’s, 90’s and 00’s, I never had any cause for concern if these types of synthetic seacock were used in conjunction with the products for which I was responsible.