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The polyurethane mast wedge in Nova Vita has become pretty dog-eared, more so since I've had the mast unstepped each of the past few seasons. My search for an off-the-shelf replacement was not successful. None of the polyurethane suppliers I contacted could supply a piece to the necessary tapered dimensions without the expense of a custom mold, they could only supply bar stock that would need to be cut on one side to provide the taper. They cautioned against my idea of using a band saw to cut the material, recommending instead that I take it to a machine shop with a water jet cutter.

The shop I was working with asked me to buy an oversized piece as they were unfamiliar with working with polyurethane and might need some practice to dial in their water jet settings. I ended up getting a length of polyurethane bar stock from Polyurethane Products (www.polyprod.com) to the final 2" height of the wedge on my Mull 28, but both wider than the necessary maximum 1-1/8" and a few inches longer. In addition to the dimensions, it's necessary to specify the hardness or the "Durometer Shore" number. From what I could find online I think this should be a 70A to match the original specs; I was a little reassured to learn that the different hardness specs for polyurethane have standard colors, and the color of the bar stock I received matched that of the original. It also passes the very unscientific "squeeze test".

Old and new mast wedges. The water jet cutter did a great job with a nice finish, in fact I ended up with 2 wedges since I bought it oversized and there was so little waste.

Great post and information! This is a very useful approach to a common problem.

Good to know the material can be water jet cut. I am trying to remember how I cut the wedges that I cast, may have been a table saw or a jigsaw, or just a carpet knife. I also think I wet sanded it. Given the shape you are trying to achieve, I think a DIY option is to tape together an acrylic mold, wax it, and cast the polyurethane.

Erik

Hey folks I am dealing with a LOT of noise coming from the mast/partners area since restepping my mast. It was silent before we pulled the mast. Now it sounds like the boat is coming apart. It has a urethane wedge like this but it is a little shy of the full circumference. Completing the circle is a wedge that appears to be a hard rubber.

I am wondering what steps you (anyone?!) went through when re-stepping the mast.

Did you lubricate the ring? If so with what?
Did you drive the wedge down to increase tightness? If so, how?
Did you remove aluminum ring from deck during the process or just leave it in place?

Thanks!

I can only speak for my own experience of having had my mast un-stepped/re-stepped annually for the last dozen years or so:

Did you lubricate the ring? If so with what?
- No
Did you drive the wedge down to increase tightness? If so, how?
- Yes, I use a small 2x3 (approximately 18 inches in length, cut and sanded to place a largely horizontal surface to the wedge at deck level), which I then strike with a small sledge hammer starting at one end of the wedge and moving along the wedge to the other end. The end result is the wedge nearly level with the aluminum ring attached to the deck.
Did you remove aluminum ring from deck during the process or just leave it in place?
- No, and if your ring is attached anything like mine was (suspect 5200), that will prove to be nearly impossible. The bolts on my ring were starting to rotate when tightening the nuts and also started to show signs of cracking (probably causing the bolts to rotate -- and no doubt caused by putting too much torque on them in an attempt to get the wedge more firmly embedded). Took a number of hours to finally extricate along with the use of some machine leveling wedges, and it came out in 3 pieces . Regardless, my guess is that it was cast aluminum and not machined and that the bolts were only stopped from rotating by the 5200 (i.e. the ring holes for the bolts were not threaded). Opted to have it replicated in a much stronger aluminum alloy, machined to the same dimensions, anodized, and I also had the bolt holes threaded, which I then used thread locker on to prevent them from loosening in the future. Regardless -- removing this ring for normal maintenance would not be recommended (if yours was fabricated/installed as mine was).

Thanks for the reply James. But without removing the ring, there is no way to "seat" the urethane ring correct? I think that is what happened to me. We pulled the mast and left the aluminum collar and urethane ring (underneath it) in place. But then when we stepped the mast we didn't take a step to drive the wedge down because it was already "in place". My guess is it is too loose.

On my boat at least (Mull 32), there is a ring and a collar, in addition to the polyurethane wedge (which is only "ring shaped" when it is inserted and in place). The collar stays with the mast when the mast is un-stepped and the ring stays attached to the deck. When the mast is re-stepped, the wedge is re-inserted and when snug and (and close to level with the top of the ring), the collar is then lowered onto the ring/wedge and the nuts are applied to bolts coming up from the ring. At deck level, the interior diameter of the collar is very close to the exterior diameter of the mast, whereas the ring's diameter is larger to accommodate the insertion of the wedge.

I'll be honest, if using the OEM wedge, it could not have been "left in place", as when properly inserted, it, the mast really becomes "un-removable" even with the mast collar unbolted and raised. The first boatyard where we kept out boat thought it would just "pop-out" when they started raising the mast -- which caused the boat to start coming out of the water... The best technique I have seen used is to use a very large screw driver or small pry bar to insert in the wedge gap as the wedge does not completely go all the way around the mast and pry up one end. Once enough is pried up, the wedge will come out easily.

Yeah my mast has the wedge and a metal collar or ring. Not two pieces. That is the the way it was designed so sounds like a different system than yours.

Yeah my mast has the wedge and a metal collar or ring. Not two pieces. That is the the way it was designed so sounds like a different system than yours.

I have a 28' Mull and stepped my mask this past May. I would not really call it two pieces because the plate which has the bolts is part of the boat. Though a previous poster said it would be impossible to unstep without removing the collar, that is what it sounds like happened, perhaps because the wedge was too loose or the previous poster had wedges that were extra tight. I came to this conclusion when you described not being able to seat the wedge with the collar on.
It sounds to me that when you unstep next make sure to remove the collar, and do as the originator of this post did, get some new wedges made up.