Freedom mast wedge material hardness

Freedom mast wedge material hardness

Postby Jesse » Sun Sep 11, 2016 5:11 pm

Hello all. First let me say that I am new to this group and this is my first post. I have spent a lot of time reading previous posts about mast wedge replacements and would like to string a few of them together to come up with some conclusion about what hardness of urethane to use for molding a mast wedge.

To set the stage, I have a freedom 21 that I have been fixing up. She has a hinged mast (or tabernacle) and we had to pull the bottom part of the mast out of the deck hole to repair the hinge. In the process, like several other people that have posted to this forum, I had to drill and cut-out the existing urethane mast wedge. So now I need to make a new one.

Having read several other posts, I have noticed various viewpoints about what hardness is best for the wedge replacement.

This says use PMC-790 which is shore hardness 90A viewtopic.php?f=9&t=10&p=93&hilit=mast+wedge#p93

This says a mast wedge of hardness 75A was special manufactured to be the same hardness as the original viewtopic.php?f=9&t=10562&p=42204&hilit=mast+wedge#p42206

This says both PMC-790 (90A) and spartite (55-60D) are softer than the original wedges viewtopic.php?f=9&t=10757&start=20#p49017

A few posts also mentioned that spartite has a hardness of 55-60A, but spartite’s website says it is 55-60D.

I was thinking of ordering a Urethane compounds from McMaster, either the Extra Hard 95A or Extra Hard 60D (see the listings here http://www.mcmaster.com/#urethane-casti ... s/=144hv94)

(Note, if anyone is confused about the hardness ratings A vs D just to a quick google search. I wanted to post a link to comparison chart, but I already reached the maximum number of URLs that can be included in a post. For a rough comparison, 90A is about 40D, 95A is about 45D, 55-60D is harder than anything on the A scale.)

I am planning on going with the harder 60D compound, but wanted to know if anyone had advice about harder vs softer compounds before I go forward.

Thank you and best wishes
Jesse
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Re: Freedom mast wedge material hardness

Postby bad » Mon Sep 12, 2016 10:27 am

I know several WylieCats that have used the Spartight and have many miles on it. No issues. I used the Smooth On of the same hardness to replace the fiberglass wedges on my Freedom 40. I can not see any movement.

Erik
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Re: Freedom mast wedge material hardness

Postby Jesse » Mon Sep 12, 2016 7:36 pm

Thank you for your reply Erik. What Smooth On product did you use?
Jesse
 
Posts: 8
Joined: Sun Sep 11, 2016 3:56 pm
Location: Buzzards Bay, MA & Montreal, QC

Re: Freedom mast wedge material hardness

Postby bad » Tue Sep 13, 2016 3:29 pm

I think you could go with the PMC or Econ series. Highest hardness Shore A80'or above.

I took a 1/16" thick plastic plate with a hole that matched my mast diameter as a seal for the bottom. I cut a slit into it to get it around the mast and used some modeling clay to create a seal. My deck is at an angle so I had to build a clay dam on the deck to make the top level with the deck. I cast two halves, used mold release to get them out, then trimmed to size. Wasn't really all that hard.

Good luck!
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