Generic rubber wedges for mast support?

Nov 6, 2020
272
Mariner 36 California
Can anyone think of any reason why something like these inexpensive rubber wedges would not work as mast wedges at the deck opening? I would have to order a sample, but assuming the rubber is not too squishy i cant see a problem with them. or a similar type of wedge. Spar-Tite has a pourable rubber which i'm assuming is just a particular durometer cheapo urethane rubber but is $300. CR Marine also has rubber wedges that are not cheap either at $100. I like the CR Marine wedge, but i would have to hack it to pieces as my mast opening is not even gap. Something like these are already cut to perfect size.

 

LloydB

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Jan 15, 2006
901
Macgregor 22 Silverton
No experience with a keel stepped mast but I would think a wrap around would work better than a few door stops for moisture protection because of the segmented nature of the stops. If the position of the mast is not in perfect alignment with the opening in the deck than individual wedges may be faster to set up but more prone to leak.
 
Nov 6, 2020
272
Mariner 36 California
No experience with a keel stepped mast but I would think a wrap around would work better than a few door stops for moisture protection because of the segmented nature of the stops. If the position of the mast is not in perfect alignment with the opening in the deck than individual wedges may be faster to set up but more prone to leak.
Thanks, yeah i agree and that thought crossed my mind, however I plan to follow the instructions on this page and have bought an SSI mast boot. The aluminum deck ring is already in place and bedded with Sikaflex. It has a 1.25" height flange that sticks up for clamping a mast boot. I plan to use Sikaflex under the boot/clamps and then tape over it. I'm hoping this would do the trick to seal out the water. I was going to use black locust for the wedges but this would be more expensive, time consuming and i'm not convinced any better than a dozen or so med/hard rubber wedges.

 
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Apr 8, 2010
2,054
Ericson Yachts Olson 34 28400 Portland OR
Something like these are already cut to perfect size.
Looking at the door stops in the link, they are not suitable. The part that holds the spar between the spar and the deck "hole" needs very closely spaced vertical pieces like hard rubber or wood. Our boat has a set of L shaped pieces of wood, each about 3/4" wide. The top of the "L" keeps the pieces from falling thru.
The steep wedge of the door stop would slowly work its way up and out.
Here is a link with our mast partner visible and the wood pieces, and the cover over it to shed rain.

I machined these out of some scrap pieces of teak, about 25 years ago. Most any medium or hard wood will do. No $ cost... just a little time.
 
Jan 11, 2014
12,338
Sabre 362 113 Fair Haven, NY
I don't think the door stops will work well. The wedges are subjected to a lot of compressive force. On a keel stepped mast the mast is a lever arm and the wedges are the pivot points. Thus as the masthead bends to leeward the mast butt is forced to windward, the leeward wedge is compressed between the mast and the partners. A water resistant hardwood or rubber are the best materials.


No experience with a keel stepped mast but I would think a wrap around would work better than a few door stops for moisture protection because of the segmented nature of the stops. If the position of the mast is not in perfect alignment with the opening in the deck than individual wedges may be faster to set up but more prone to leak.
The wedges are not there to stop water, that is what the Mast Boot is for. There are a number of different solutions of varying effectiveness for keeping water from coming through the partners. I've been quite happy with the Waterboot.
 
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cjm1

.
Jul 10, 2013
41
custom Herreshoff 33 sloop Lake Charlevoix
I have a 55 ft keel step mast and use 3/8 inch x 4 inch conveyer belt with oak wedges made on a table saw.
 
Nov 6, 2020
272
Mariner 36 California
I don't think the door stops will work well. The wedges are subjected to a lot of compressive force. On a keel stepped mast the mast is a lever arm and the wedges are the pivot points. Thus as the masthead bends to leeward the mast butt is forced to windward, the leeward wedge is compressed between the mast and the partners. A water resistant hardwood or rubber are the best materials.

The wedges are not there to stop water, that is what the Mast Boot is for. There are a number of different solutions of varying effectiveness for keeping water from coming through the partners. I've been quite happy with the Waterboot.
So something like the CR Marine wedge or Spartite? They say its 'rubber' (CRM) in the description but i have never used one or knows anyone who has. Its marketed as a mast wedge so must be the appropriate durometer. If i used the CRM wedge, I dont think it would fall through. According to their specs, the dimensions at the top are a lot thicker than the gap i need to fill. I would probably cut it into narrower pieces so i could get it to fill in around the mast nice and snug like FastOlsens pic of his wood wedges. I could then trim them at the top evenly once they are all in if they are rubber and try to figure out a way to keep them from slipping upward.


Making wood wedges will be a real PITA. I would have to hand cut and shape every single wedge at the boat with hand tools. Not impossible but would be a chore.
 
Last edited:
Nov 6, 2020
272
Mariner 36 California
Looking at the door stops in the link, they are not suitable. The part that holds the spar between the spar and the deck "hole" needs very closely spaced vertical pieces like hard rubber or wood. Our boat has a set of L shaped pieces of wood, each about 3/4" wide. The top of the "L" keeps the pieces from falling thru.
The steep wedge of the door stop would slowly work its way up and out.
Here is a link with our mast partner visible and the wood pieces, and the cover over it to shed rain.

I machined these out of some scrap pieces of teak, about 25 years ago. Most any medium or hard wood will do. No $ cost... just a little time.
I like the idea of the Sunbrella cover. Do you think it actually helped, or has the vinyl degraded anyways?