myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website

Welcome to myHanse.com the forum for Hanse Yachts owners throughout the world.

Forum Home Forum Home > Hints and Tips > 320
  New Posts New Posts RSS Feed - SD20 Saildrive
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

SD20 Saildrive

 Post Reply Post Reply Page  <12
Author
Message
alidal View Drop Down
Captain
Captain
Avatar

Joined: 30 September 2010
Location: Norway
Status: Offline
Points: 233
Post Options Post Options   Thanks (0) Thanks(0)   Quote alidal Quote  Post ReplyReply Direct Link To This Post Posted: 01 December 2016 at 12:31
Originally posted by Drumduff Drumduff wrote:

Hi, 
Plastic and any kind of heat aren't a good combination either.

It`s not made of plastic.... 
If you have 90 C around the valve/thruhull you have a serious problem. 
Here is the spec for trudesign:

  • Manufactured from a glass-reinforced nylon composite - High strength and light weight
  • Immune to corrosion and electrolysis - Long life with no concerns over decreased performance due to corrosion
  • Chemical resistant - Impervious to diesel, petrol and antifouling paints
  • UV resistant - Will not degrade or discolour with ultraviolet light from the sun
  • Large operating temperature range (-20 to +90C)
  • High quality surface finish - Will not discolour with green film as similar bronze fittings do
  • Approved by IMCI & Bureau Veritas to ISO standard 9093-2
 
Hanse 400#655
Back to Top
Mark_J1 View Drop Down
Captain
Captain
Avatar

Joined: 12 March 2013
Location: Dover&Medway UK
Status: Offline
Points: 200
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mark_J1 Quote  Post ReplyReply Direct Link To This Post Posted: 01 December 2016 at 16:09
For my 2 cents I note there are a lot of 'plastic' pipes and components in an engine bay. Boats are about a balance of perceived v actual risks and costs v longevity. An individual's choices will vary :-)

Mark
Hanse 400e "Grey Goose" Hull #31
Back to Top
Drumduff View Drop Down
Commander
Commander


Joined: 11 April 2008
Location: Kip Marina Scot
Status: Offline
Points: 149
Post Options Post Options   Thanks (0) Thanks(0)   Quote Drumduff Quote  Post ReplyReply Direct Link To This Post Posted: 01 December 2016 at 19:27
Yes I was simplifying it calling it plastic. The are a couple grades of which one contains something like 33% glass fibre to nylon and the other about 16% the 33% being the stronger. It's quite right that the nylon/glass valves don't corrode but be aware that they do actually degrade by as much as 60% over a short space of time. The material has also a very poor impact rating with instances of snapped handles causing leaks. Yes there are many plastic bits in an engine bay but they have been carefully located to avoid contact with direct heat from the engine but why introduce another one when it's not necessary especially as it could sink the boat if it fails.

Edited by Drumduff - 01 December 2016 at 19:29
Back to Top
D0bbies View Drop Down
Captain
Captain
Avatar

Joined: 05 August 2014
Location: Falmouth, UK
Status: Offline
Points: 167
Post Options Post Options   Thanks (0) Thanks(0)   Quote D0bbies Quote  Post ReplyReply Direct Link To This Post Posted: 24 March 2017 at 14:43

Just changed my seized SD20 water inlet valve.

I purchased all parts from www.asap-supplies.com, and the parts I used:-

1 x 434603 Maestrini DZR Equal Nipple Male Thread 1/2" BSP..... 2.51 + tax
1 x 405703 Maestrini DZR CR Ball Valve, BSP Female Each End 1/2" Ports..... 9.14 + tax
1 x 418338 Maestrini Brass 90 Degree Hose Tail, 1/2" BSP Male to 19mm Hose.....4.26 + tax
CARRIAGE First Class Post 3.45 + tax

No problems encountered in the operation and about 1 1/2 hours.

Hope this helps

Bob



2005 312, Tiller, Engine 2GM20, SD20 Saildrive. Facnor SD 130 Furler.
Back to Top
Mike2145 View Drop Down
Commander
Commander
Avatar

Joined: 18 October 2014
Location: UK Hamble
Status: Offline
Points: 144
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike2145 Quote  Post ReplyReply Direct Link To This Post Posted: 06 April 2017 at 11:53
Just an update.  I removed the SS fittings and there was no visible signs of any corrosion.  This seems to be the same as posters on other forums.  
Also I noticed that the oil drain plug is SS.  I assume that if there was a serious issue with SS and Aluminium in this context then the drain plug would be of a different material?  Although the top of the drain plug is obviously soaked in oil!
If doing the job again I would use  the DZR parts as D0bbies has done
Back to Top
StavrosNZ View Drop Down
Captain
Captain


Joined: 24 October 2014
Status: Offline
Points: 185
Post Options Post Options   Thanks (0) Thanks(0)   Quote StavrosNZ Quote  Post ReplyReply Direct Link To This Post Posted: 06 April 2017 at 22:30
Hi, i admire your intentions but do not think your choice of materials is the best option, i would seriously recommend moving to glass filled nylon ball valve and fittings. No electrolysis and you can guarantee the valve will perform for many years to come with no fear it will not shut off.

On my SD50 sail drive i used ball valve by Trudesign the same as all my through hull valves and a glass filled nylon male to male adapter to fit the valve.


Stephen
2010 H400, Auckland, New Zealand
Back to Top
StavrosNZ View Drop Down
Captain
Captain


Joined: 24 October 2014
Status: Offline
Points: 185
Post Options Post Options   Thanks (0) Thanks(0)   Quote StavrosNZ Quote  Post ReplyReply Direct Link To This Post Posted: 06 April 2017 at 22:50
Not correct to say that glass filled nylon degrades as much as 60% over short period of time, nonsense. 

Degradation in seawater can be measured on some synthetic polymers depending on the composition and type, this is not the case with glass filled nylon used by the major manufacturers. Nylon in a raw material granule form is hydroscopic (absorbs water) the granules are dried before processing and once molded or formed into a shape the material no longer is hydroscopic, it does not absorb moisture any longer. These high quality synthetic fittings will last the life of the hull, bronze will not nor will any other metallic alternative.

Instances of snapped handles is due to design and not material.

If people don't understand the science and mechanics behind polymers i would suggest its worth understanding. You are correct in stating that the impact resistance of glass filled nylon is not as high as bronze but do you actually know what the shear strength of a glass filled nylon ball valve on a glass filled nylon skin fitting is? the magnitude of the impact that would cause the synthetic fitting to break would also do considerably damage to a bronze fitting or any other material for that matter. Most fittings on our Hanse yachts are in cupboards in in voids where it almost impossible for anything of any weight or substance to slide and impact any type of skin fitting. If you have a valve where it is vulnerable it is worth noting that Trudesign make a collar that fits over the skin fitting thread before ball valve is fitted that mean any impact will be taken by the collar onto he hull not by the valve and skin fitting.

You should all be far more concerned about the stainless wire reinforced PVC pipe that Hanse has used on all of your ball valves, these hoses are infact an extension of of your hull integrity and are not fit for purpose below the waterline. PVC unlike Glass filled Nylon will harden and loose strength overtime, Multiwall fiber reinforced pipe is what should be used here.

Old school thinking is that synthetics cannot replace metals, if that were the case race yachts would still have hulls made of timber or aluminium be using aluminium masts with stainless steel rigging wire and hauling their sails with hemp rope............please.






Edited by StavrosNZ - 06 April 2017 at 23:20
Stephen
2010 H400, Auckland, New Zealand
Back to Top
 Post Reply Post Reply Page  <12
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 11.04
Copyright ©2001-2015 Web Wiz Ltd.

This page was generated in 0.063 seconds.

Links : www.hanseyachts.co.uk www.hanseyachts.com www.fjordboats.co.uk www.dehler.co.uk www.varianta.co.uk