Skin fittings

[orcman]

I saw an article in YM within the last year about a type of skin fitting that is a cheap brand name and can disintegrate very quickly; As I want to fit some new ones into my boat I am trying to find the article, but I can't find it. Can anybody tell me which month it was in and/or the type of fitting to avoid?

 

[VicS]

Welcome to the forum.**

There has been loads of discussion on these forums about the alloys used for sea cocks etc largely centred around an alloy known as Tonval.

If you search Reader to reader and Scuttlebutt back for 2 or 3 months for 'tonval' you will find loads to read.

**Ps if you fill in a few details in your profile sometime you will be even more welcome.

 

[aidancoughlan]

I replaced all my seacocks this season, and spent a bit of time researching beforehand. concensus was that ...

- generic seacocks found in average chandlers should be treated with suspicion
- Gate valves should be avoided (round red handles) in favour of proper seacocks (ball valves with handles that swing 90 degrees seem the most readily available alternative)
- ordinary 'Brass' fittings are prone to corrosion in marine environment and should be avoided
- DZR Brass (dezincification resistant brass) or Bronze fittings are acceptable on boats, and not much more expensive than plain Brass ones.
- proper Bronze seacocks are said to be suitable but more expensive (I didnt find ant readily available bronze seacocks on my search)
- Blakes 'traditional' seacocks are made from DZR brass nowadays rather than bronze (they are expensive, and have to be maintained annualy with grease)
- There are modern plastic (& more expensive) alternatives - search for Marlon or Forespar. Advantage is no electrolytic problems, but they may melt in a fire.
-Gunmetal and LG2 are variations of copper alloys which are better than brass, but apparently vary in quality & specification.
-Stainless steel is apparently available & suitable, but very expensive.

as already posted, searching for old threads on PBO forum should throw up some posts. Some of this info above also comes from PBO July 2004 issue which has an article on the subject.

In the end I replaced my Heads seacocks with Blakes like-for-like replacements because of height restrictions. I used DZR brass ball-valve seacocks for all others, and would have used these in preference to Blakes for the heads if I had the space (less maintenance). After going to the trouble of replacing them, my main concern was to find a supply where the quality of the seacocks was known - I choose Aquafax.com because their website gave full information on the materials used in the various products and quoted Llyods certification and mettalurgical standards etc. - the only supplier I found that was completely explicit about this information up front.
DZR seacocks are also available from ecsmith.com.

hope this helps...

 

[Gunfleet]

By the time the fire has got below the waterline on a grp boat 'melting seacocks' is the least of your problems!

 

[VicS]

The hoses will have already melted and flooded the boat so protecting the seacocks!