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Mast Step and Partners

  • 21 Mar 2011 03:22
    Quote
    Reply # 550034 on 534932
    Anonymous member
    Whether or not I use timber or poured rubber wedges (and I have about a month at the most to decide), I intend to use a mast boot system I found in Cruising World.  First get a car inner tube, lay it flat and cut along the creases to give two flat circular pieces of rubber.  Wrap it around the mast with the narrow side at the top.  The article recommends fitting it upside down, secured with a hose clamp then folding it down over the clamp.  The top edge is then filled with sealant and it is clamped to the partners with another hoseclamp.  You can join hoseclamps together to get the required circumference.  Sealant can aso be worked into the vertical overlap.  This rubber, hopefully watertight boot is then covered with a canvas cover to protect it from UV.  The traditional way of just painting the canvas works too but in my experience the odd drip is inevitable sooner or later.   
  • 20 Mar 2011 21:43
    Quote
    Reply # 549828 on 549072
    Anonymous member
    Annie Hill wrote: I am reading all these comments with more than a little interest, having finally stepped my mast.  (All went well, to my intense astonishment).  My gurus all say Spartite (which we used successfully around Iron Bark's anodised, aluminium gaff mast), but my wallet suggests otherwise.  At present the mast is wedged into place with Kwila - a hardwood, which is not ideal but was available on the day.  I still have some Oregon/Douglas Fir that may also be suitable.  Due to my folly  in going for stainless steel rather than wooden partners, and the expense thereof, I avoided a tapered section.  Nor do I have a tapered mast.  However, I am sure that I can sort out the wedges so that, once I'm happy with the angle of the mast, fore-and-aft and athwartships, I can hold it where I want it to be and stop the wedges from falling out.  But an affordable alternative to Spartite - ie about $50 - would be nice!
    Oh dear, Annie! I drew you the conical tapered deck ring so that you would avoid the silly mistake that I made of having parallel mast, parallel partners - and now you've got yourself into the same corner that I did on my mizzen mast.( the mainmast has wooden wedges, deck and heel, and has been very well-behaved). There wasn't enough room to put in a tapered, wedged system. I tried wooden wedges, and couldn't get them to wedge satisfactorily, or to stay in place. The mast squeaked, groaned and rattled continuously. So I had to turn to Spartite, which has been extremely successful in holding the mast well and silently, but it is going to be very difficult to get the mast out again. That can be rationalised by saying "well, I'm unlikely to want to get the mast out in my lifetime" - but in my case I do have a reason, the wiring conduit has come loose. I'm just going to have to live with it. 
    I have just one wedge suggestion: pairs of thin wedges working together, one driven from above, one from below. Otherwise, I'm afraid that you'll have to do as I did, and pour something in. Do grease up both surfaces well, though, so that you have the ghost of a chance of pulling the mast.
    Last modified: 20 Mar 2011 21:43 | Anonymous member
  • 20 Mar 2011 20:38
    Quote
    Reply # 549794 on 534932
    Anonymous member
    I'm reading everyone's comments about partners and wedges with interest and I'm laughing at myself as I do... 

    We inherited an inadequate version of steps and partners with mehitabel, and I've created three more since then. The present one is the best, I think, but... far too much work for me to recommend to anybody. 

    In retrospect, sturdy partners and softwood wedges seem the best and cheapest choice. Why didn't that system seem good enough to me from the start, I wonder?

    Cheers,
    Kurt
  • 19 Mar 2011 17:14
    Quote
    Reply # 549283 on 534932
    Anonymous member (Administrator)

    Stavanger, Sat

         Mast partners, spruce wedges, mast coats and Sikaflex...

    Annie,

    I can’t see much wrong with using wooden wedges at the mast partners and covering them with a mast coat made from canvas. I suggest you rather look for soft wood for the wedges and shape them with a very slack angle. The edge of the metal partner will crush and shape the wedges a bit and they will have to be tightened a couple of times, but then they will stick well and be easy to keep in place. I nail a little piece of plywood to each wedge above the partners to keep them from ever falling through. Now that I think of it; I could even screw on plywood bits to the wedges below deck to keep them from ever creeping up (..but that has not been a problem....). The soft spruce wedges I have used have held up well even without fancy rounding off to fit the mast or the partners. The mast coat of Johanna is made in PJR fashion (p.143) with one exception: Instead of making it as a cone with a vertical seam to close it, I made it so that it wraps 1½ times around the mast (still as a cone), similar to the way we wrap a towel around our hips. This both let you fit the mast coat after the mast has been stepped and it also makes it easier to lift the low edge of the coat to inspect the wedges.

    On the schooner Samson, Svein Magnus Ueland uses another interesting method which has proven to hold well and stay watertight. After having wedged the masts in place at the partners and all is well and more adjustments are not needed, he cuts off the top of the wedges, flush with the steel partners. Then he smears Sikaflex on the wedge-tops. I guess he squeezes the putty just gently down between the wedge tops and then he covers the whole lot with more putty to keep out the rain. The Sicaflex keeps the wedges from moving, but when he is to lower the masts he is still able to bang the wedges loose from below deck.

    I guess I would opt for the spruce/pine wedges-and-mast-coat method until I saw how it worked, having no experience with metal masts.

    Anyway, good luck!

    Arne

    PS 20110320: Today I took a couple of photos of the mast partners on Samson and uploaded them to my personal album. There you can see how neat they look.

    Last modified: 19 Mar 2011 17:14 | Anonymous member (Administrator)
  • 19 Mar 2011 16:33
    Quote
    Reply # 549257 on 549072
    Deleted user
    Annie Hill wrote:An affordable alternative to Spartite - ie about $50 - would be nice!

    Annie,
    From what Paul Thompson said, my wedges are very similar to spartite (more so than I thought!).  I ordered from my kit from theengineerguy.com.  This "trial kit" was sufficient to do both my main and mizzen masts, but I have no idea how the volume between partners and mast of your rig compares to mine.  I suspect that it was about the same volume as a single spartite kit.

    I have no idea if this company will ship to NZ, or what shipping/duties would be, but I would hope that you can find a more local supplier for it at a similar price.  (They charged US$30 for the kit.) Your geometry is different than mine, so you will have to calculate if you will need more or less.

    I would personally be worried about getting your mast out again without any taper on either the mast or the partners, but I have no experience around that.

    Barry
  • 19 Mar 2011 06:26
    Quote
    Reply # 549072 on 534932
    Anonymous member
    I am reading all these comments with more than a little interest, having finally stepped my mast.  (All went well, to my intense astonishment).  My gurus all say Spartite (which we used successfully around Iron Bark's anodised, aluminium gaff mast), but my wallet suggests otherwise.  At present the mast is wedged into place with Kwila - a hardwood, which is not ideal but was available on the day.  I still have some Oregon/Douglas Fir that may also be suitable.  Due to my folly  in going for stainless steel rather than wooden partners, and the expense thereof, I avoided a tapered section.  Nor do I have a tapered mast.  However, I am sure that I can sort out the wedges so that, once I'm happy with the angle of the mast, fore-and-aft and athwartships, I can hold it where I want it to be and stop the wedges from falling out.  But an affordable alternative to Spartite - ie about $50 - would be nice!
  • 19 Mar 2011 03:03
    Quote
    Reply # 548990 on 534932
    Anonymous member
    My partners are an untapered steel tube but the mast at this point is tapering, so it should be possible to get timber wedges to match the taper for a snug fit.  Robert's comment about corrosion with rubber collars like Spartite on an unanodised spar interests me.  The major attraction of timber wedges for me lies in the ease with which they can be extracted for inspection of the area.  If moisture did get trapped between the mast and the rubber collar it might be hard to detect.  On the other hand it might be easier to keep the area watertight and certainly easier to ensure an even bearing load over the structure.  As for strength, Spartite advise me that their product has a PSI compression strength of 50,000 lbs, which seems adequate to a bush engineer like me.  A friend of mine, a staunch traditionalist who wanted me to fit a gaff rig, points out that timber wedges have been used successfully on boats for centuries.  I may make a set of wedges to start with and see how they go.  If I am not satisfied with them I can switch to rubber.  I plan to wax the mast as well to reduce the oxidisation.  I did that on Arion's current mast with good results.  For the first few years the mast was so shiny peoiple would ask me if it was made out of stainless steel!  I always seem to have something that wakes me at three in the morning to worry about - stepping the mast is just my current issue.  I joke that I must be making progress as the things I worry about are coming along. Thanks to everyone for their advise.
  • 18 Mar 2011 12:33
    Quote
    Reply # 548532 on 534932
    Deleted user
    Over time I have read many opinions about mast wedges. How tight should they be? How long should they be? Wide or narrow?

    On Easy Go we have narrow wedges custom cut of softwood western spruce. They are tapped in but not driven particularly tight, hence the need for some mini blocking to keep them from riding up. They are tapered and that seems to keep them from falling down with a backup of the cinch knot. The wedges are close to 18" long giving support and flexibility at the partners. They show virtually no signs of wear after long and sometimes abusive use.

    I'm not knowledgeable about the spartite and other rubber based products available. A spar builder informed me that they were not compatible with non anodixed masts and would lead to corrosion and eventual mast failure. Enough advise for me.

    In tall ships and some not so big I have seen the wooden masts squared or multi sided at the partners so that larger flat wedges could be installed. Looks like a great ans sturdy installation but I have not had any success in trying to adapt this to the rounded aluminum flagpole masts that we use.

    What good/bad experiences have other had with their partners and wedge installations?
  • 18 Mar 2011 12:22
    Quote
    Reply # 548524 on 548005
    Deleted user
    Paul Thompson wrote: Spartite hardness on the Shore scale  is 55 - 60D ( see Spartite technical info ) which is equal to a shore hardness of 90A. So as far as hardness goes, PMC-790 is a drop in replacement as the hardness is approximately the same The Freedom yachts link is wrong on this.

    I just quoted them...didn't actually research anything myself.  Since I don't know much of anything about Shore hardness scales, I guess I'll take your word for it.  I do see that the "A" and "D" scales are different, although a minute of googling didn't clear up much other than that the D scale is harder than the A scale.

    Now, I hope my poured wedges work OK.  When I finish my rig and start sailing, I shall find out.
  • 17 Mar 2011 19:39
    Quote
    Reply # 548005 on 546807
    Anonymous member
    Barry & Meps / Stellrecht & Schulte wrote:

    We did not use Spartite because it is expensive, and it is also reported to be too soft for a freestanding mast.  Instead we used a harder PU rubber compound called PMC-790.

    You can read more about it on this thread from the Freedom owners forum. http://freedomyachts.org/viewtopic.php?f=9&t=47

    Spartite hardness on the Shore scale  is 55 - 60D ( see Spartite technical info ) which is equal to a shore hardness of 90A. So as far as hardness goes, PMC-790 is a drop in replacement as the hardness is approximately the same The Freedom yachts link is wrong on this.
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