Mast rake

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  • 25 Jan 2013 01:25
    Reply # 1188280 on 1178976
    Deleted user
    Gary King wrote:Just to let you know Peter, I plan on using a Spartite substitute like PMC790 (1/3 of the price of spartite but having a higher hardness, more suitable for free standing masts).
    Now I believe PCM790 is similar hardness to Spartite--Someone (Paul Thompson, I think) pointed out that one was rated with Shore A hardness, the other with Shore B hardness. The number is larger for the PCM790 product, but that doesn't make it harder.

    But it still is tough stuff and a heck of a lot cheaper. The folks I bought it from recommended it for making molds for concrete pavers.

    Thus far, it seems to be working great on Flutterby.
  • 23 Jan 2013 18:29
    Reply # 1187034 on 1178627
    Again thanks, Arne. As I wrote elsewhere, we don't need to call these 'sub albums'. They're just your albums, ie you can have more than one personal photo album.
    Last modified: 23 Jan 2013 18:31 | Anonymous member
  • 23 Jan 2013 14:50
    Reply # 1186774 on 1178627
    Anonymous member (Administrator)

                                                             Stavanger, Wednesday

                    Problem  with photo album solved

    When I recently tried to upload more photos, two days ago, I seemed to hit some size limit. It turned out that each album can only contain 50 photos - that is, each sub-album. All I had to do was to make a new album and add the two photos of Johanna’s new mast coat, on the floor here and on the boat here.

    Cheers, Arne

    PS: Corection, I thought we had only one  member album so called the others sub-albums. The fact is that we can create a number of albums, so forget this SUB-

    Last modified: 23 Jan 2013 18:47 | Anonymous member (Administrator)
  • 23 Jan 2013 11:27
    Reply # 1186664 on 1178627
    Deleted user
    Thanks again for the further constructive comments.

    I have a confession to make. I am guilty of not reading your comments thoroughly and giving wrong information myself. I am blaming a senior moment or two for this!

    Firstly the depth of my partners is only 160 mm. 100 mm from the bottom of the partners to the recess where the mast coat is secured.

    I have decided to remove the mast which will make it easier to carry out the alterations which are required at the masthead. I shall also be cutting the aerial wires and reconnecting them using 'N' type connectors as advised by Shakespeare aerials.

    With the mast out I can reshape the partners and move the footplate back so that when the mast is put back in it will have a 2 deg. rake as designed. It still may not fit concentrically in the partners but will be much better than at present.

    I shall then use a hard polyurethane compound to secure the mast having first well greased the partners. The footplate will be secured in its new position and a wedge fitted under it if required. The existing mast coat should keep the water out.

    After that and assuming the launch on 2nd Feb has been successful I shall fit the sail and go sailing. Worry free I hope and with a big smile on my face..


    Last modified: 23 Jan 2013 11:36 | Deleted user
  • 21 Jan 2013 21:14
    Reply # 1185155 on 1184640
    Peter Manning wrote:Thanks to everyone who has posted helpful comments on this subject.

    David, I have been studying your drawing of the partners which as I said earlier is a little feint. It appears to me that the taper of the cone only goes as far up as the point at which the recess is created to secure the mast coat. The wedges however, have be sufficiently long for the hold down ring to be effective. This seems to suggest that the wedges do not touch the partners from the recess upwards. Is this correct? I ask this because I am thinking of using a urethane compound rather than wedges and would like to know how far up the partners to take it. I was thinking of taking the urethane right to the top of the partners and using the existing hold down ring to prevent any upward movement of the compound even though, as ketil has suggested, the mast should not be greased. If I do this then it seems to me that any sideways pressure exerted by the mast will press on that part of the partners which is weakest i.e. from the mast coat tie off recess upwards. If I finish the urethane just below the recess will I need to have some means of preventing the compound riding up even though it should stick to the mast which is held down by a substantial pin through the foot plate.

    Ketil, any observations you may have on this point would be much appreciated.
    Peter,
    I think that it's really as simple as this:
    1. make a floor right at the bottom of the partners with modelling clay.
    2. protect the mast with plastic sheet.
    3. grease the conical hole.
    4. take off the mast protection.
    5. pour in a minimum of 100mm depth of hard polyurethane.
    6. add a waterproof mast coat.
    7. go sailing.
    8. don't worry, be happy.
  • 21 Jan 2013 18:16
    Reply # 1184948 on 1178627
    Anonymous member (Administrator)

                                                                        Stavanger, Monday

    I have used spruce wedges to hold the mast at the steel partners on both Malena and Johanna, and have not have problems with that. I use quite finetaper at the wedges and also add a square of plywood at their top end. This makes fitting the wedges much easier and lets me play around with the mast rake a bit without the wedges suddenly starting to disappear below deck. The soft spruce wedges get a bit dented by the steel flange, so require a couple of "re-tappings" the next weeks until they have settled. For offshore work I would then recommend adding a second set of plywood squares to the edges below deck. For my use I have never had problems with the wedges working themselves out (up).

    Cheers, Arne

    PS: I was to show you the mast coat as well. That is not a closed skirt but just wraps 1.5 times around the mast. Easier to fit and to lift for inspection.

    Unfortunately, now I got the message from Apricot that I had hit the ceiling in my members album, so this is it.

    Last modified: 26 Nov 2021 15:02 | Anonymous member (Administrator)
  • 21 Jan 2013 16:31
    Reply # 1184850 on 1178627

    Hi Peter,

    The forces for heeling the boat are more gentle than the pitching forces when sailing against the wind and seas. When I used wedges, I still had to use some sealing/ gluing agent to prevent the mast from moving upwards. I tried to use a bolt, a long 6mm stainless steel, but that bent(!), so sealing agent was the right remedy. On Marie G I have used Spartite, both in the mast step and at the partners, smearing both parts with gear oil SAE 80. The mast show no sign of moving or turning, so it seems to be well mounted to the boat. I hope that lifting it will be not too much of a pantomime, but I am prepared to use compressed air in the mast step to get the mast moving. (Venting hole is drilled and ready). Refitting the mast and sealing/ gluing it in place, I plan to cut a step in the Spartite at the upper outer edge and fill that with a sealing agent. When pulling out the mast of Edmond Dantes, I had to cut away the sealing agent and knock out the wedges, pull out the wedges at the step and that was it, no drama. My thinking is that you sail at lot, and needs to have the mast firmly in place. Lifting it every 2nd or 3rd year could be a lot of work, but it goes on a few hours at worst.

    My favorite saying is: Be happy you are born, not everybody are. In this forum it will be: Stop worrying, go sailing.

    Good luck and enjoy Malliemack.

  • 21 Jan 2013 09:00
    Reply # 1184640 on 1178627
    Deleted user
    Thanks to everyone who has posted helpful comments on this subject.

    David, I have been studying your drawing of the partners which as I said earlier is a little feint. It appears to me that the taper of the cone only goes as far up as the point at which the recess is created to secure the mast coat. The wedges however, have be sufficiently long for the hold down ring to be effective. This seems to suggest that the wedges do not touch the partners from the recess upwards. Is this correct? I ask this because I am thinking of using a urethane compound rather than wedges and would like to know how far up the partners to take it. I was thinking of taking the urethane right to the top of the partners and using the existing hold down ring to prevent any upward movement of the compound even though, as ketil has suggested, the mast should not be greased. If I do this then it seems to me that any sideways pressure exerted by the mast will press on that part of the partners which is weakest i.e. from the mast coat tie off recess upwards. If I finish the urethane just below the recess will I need to have some means of preventing the compound riding up even though it should stick to the mast which is held down by a substantial pin through the foot plate.

    Ketil, any observations you may have on this point would be much appreciated.
  • 14 Jan 2013 16:59
    Reply # 1179480 on 1179214
    Peter Manning wrote:
    David, the hole is conical and smooth. The main problem is how to grease the mast and hole without taking the mast out which would require me to remove wires back to the switch panel or cut them near the mast and refix using junction boxes. I always thought you should avoid cutting the vhf cable to reduce potential losses.
    Slide a piece of plastic sheeting down around the mast, to keep the grease off it, then use an aerosol spray. I have one which is meant for protection of metal against corrosion, and deposits a soft brown film on a surface. That would do. 
  • 14 Jan 2013 16:13
    Reply # 1179428 on 1178627
    Yes but ... that's Peter Hill.  Some of us are mere mortals.  jds
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