Page 2 of 2 FirstFirst 12
Results 11 to 18 of 18
  1. #11
    Join Date
    Nov 2001
    Location
    Me: Johannesburg South Africa Yacht: Richards Bay East Coast Africa
    Posts
    7,257

    Default Re: Speedseal Life Discs - metallurgy issues

    Quote Originally Posted by lw395 View Post
    ISTM that a thicker PTFE disc to replace both brass and PTFE disc in one might work OK?
    People do manage to get fumes from PTFE while machining it, best to take moderate care.
    Any one considered making the metal disc from 316 stainless rather than brass.
    Life is too short not to have a sea view
    Distantshaws tinyurl.com/yclt6l68

  2. #12
    Join Date
    May 2007
    Posts
    38,915

    Default Re: Speedseal Life Discs - metallurgy issues

    Quote Originally Posted by Rogershaw View Post
    Any one considered making the metal disc from 316 stainless rather than brass.
    Electrolysis issues?
    I can get pure zinc sheet on ebay, cheap, easy to cut and it's an anode?

    Seems to me I have less issues with pumps without speadseals?

    Ask yourself why the pump doesn't need a ptfe disc and a brass disc on the other side of the impeller?

  3. #13
    Join Date
    Mar 2005
    Location
    Hants/Lozère
    Posts
    4,836

    Default Re: Speedseal Life Discs - metallurgy issues

    I don't have any problems without a Speedseal either. There's a grill on the inlet and a Vetus filter before anything gets to the raw water pump and even through the weedy French canals never had a problem with the impeller. The cover plate on the pump is a bit worn, as you might expect after 30 years, but I still have the option of removing the paint and turning it over ...

  4. #14
    Join Date
    Oct 2018
    Location
    A Member State of the European Union
    Posts
    7,250

    Default Re: Speedseal Life Discs - metallurgy issues

    Quote Originally Posted by DinghyMan View Post
    PTFE is interesting to machine as its soft and wont get hot during machining as its a fantastic bearing material.

    I've machined seals from it for high pressure pumps - max pressure 5000 psi - used for breathing gases so I wouldn't worry about machining it.
    .
    What rake and clearance angles would you recommend?
    "Brexit: like watching a library being burned down by people who can't read"

  5. #15
    Join Date
    Jan 2006
    Location
    West Yorkshire
    Posts
    1,411

    Default Re: Speedseal Life Discs - metallurgy issues

    Quote Originally Posted by Poignard View Post
    What rake and clearance angles would you recommend?
    We use CCGT Alu AK10 inserts, a mixture of 02/04/08's, designed for aluminium but brilliant for plastics, also really good for stainless finishing cuts.

    HSS will work if you want to spend the time grinding but apart from custom tools we rarely use it these days.
    Custom engineering for marine & dive use; http://ffsystems.co.uk

  6. #16
    Join Date
    Oct 2018
    Location
    A Member State of the European Union
    Posts
    7,250

    Default Re: Speedseal Life Discs - metallurgy issues

    Quote Originally Posted by DinghyMan View Post
    We use CCGT Alu AK10 inserts, a mixture of 02/04/08's, designed for aluminium but brilliant for plastics, also really good for stainless finishing cuts.

    HSS will work if you want to spend the time grinding but apart from custom tools we rarely use it these days.
    Thanks for that info.

    They seem readily available at a reasonable price https://www.shop-apt.co.uk/carbide-i...CABEgIW5_D_BwE

    At that price I also wouldn't bother grinding up a tool
    "Brexit: like watching a library being burned down by people who can't read"

  7. #17
    Join Date
    Sep 2001
    Location
    Home - Sothampton, Boat - Gosport
    Posts
    10,566

    Default Re: Speedseal Life Discs - metallurgy issues

    Quote Originally Posted by Plum View Post
    For wear resistance against the PTFE I would not expect it to be any different from the brass and it would not corrode in contact with the seawater, unlike the brass which may last 4 years.

    Www.solocoastalsailing.co.uk
    I wish someone had told the rudder tube on my Snapdragon that. Admittedly it took 35 years, but I had to remove the rudder to fix the bottom bearing and when I put it back, the tube broke at the waterline. It was like lace, and I can't imagine that it would have survived another season without having a good try at sinking the boat.
    Steve
    Never believe anything until it has been officially denied.

  8. #18
    Join Date
    Jan 2006
    Location
    West Yorkshire
    Posts
    1,411

    Default Re: Speedseal Life Discs - metallurgy issues

    Quote Originally Posted by Poignard View Post
    Thanks for that info.

    They seem readily available at a reasonable price https://www.shop-apt.co.uk/carbide-i...CABEgIW5_D_BwE

    At that price I also wouldn't bother grinding up a tool
    Either from apt or from cncpoorboy on eBay: https://www.ebay.co.uk/sch/m.html?_s...=CCGT&_sacat=0

    You can use them on all metals but they dont last too long on titanium or hard steels but for finish cuts they are brilliant, cutting ally with them gives an almost polished finish - go for some 08 radius ones for final cut.
    Custom engineering for marine & dive use; http://ffsystems.co.uk

Page 2 of 2 FirstFirst 12

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Latest YBW News

Find Boats For Sale

to
to