SparTalk

SparTalk (http://www.briontoss.com/spartalk/index.php)
-   SparTalk (http://www.briontoss.com/spartalk/forumdisplay.php?f=1)
-   -   Fabricating New Mast Wedges (http://www.briontoss.com/spartalk/showthread.php?t=2486)

s.marcotte 08-29-2014 09:28 AM

Fabricating New Mast Wedges
 
Hello-
We're looking for suggestions on mast wedge materials. We think we want a rubber or plastic type stock that could be shaped similar to traditional wood wedges. Alum stick/glass boat... But not sold on the SparTite solution.
Any comments on materials and sourcing would be appreciated.
Thanks

Steve

knuterikt 08-30-2014 01:44 PM

Quote:

Originally Posted by s.marcotte (Post 7270)
Hello-
We're looking for suggestions on mast wedge materials. We think we want a rubber or plastic type stock that could be shaped similar to traditional wood wedges. Alum stick/glass boat... But not sold on the SparTite solution.
Any comments on materials and sourcing would be appreciated.
Thanks

Steve

I have switched to "rubber pads"
The deck ring was designed for wooden wedges that seemed to want to creep up all the time.
The local rigger suggested I should switch to these rubberpads

They are available in different thicknesses.
The are inserted between the mast ring and mast,
I first insert the aft pad then I use the winches to pull the mast aft at deck level before inserting the forward one - need to use washing up liquid to let it slide into place.

Have never dislodged..

Brion Toss 09-03-2014 07:38 AM

Density
 
Hello,
Any measurement of density of those wedges? Source?
Fair leads,
Brion Toss

knuterikt 09-04-2014 03:11 AM

Quote:

Originally Posted by Brion Toss (Post 7278)
Hello,
Any measurement of density of those wedges? Source?
Fair leads,
Brion Toss

Referring to my post?
I got them from my local rigger here in Norway http://www.southerncross.no/en/
They source parts from vendors like Selden, Sparcraft and others but I don't know who made these.
These pads are made in different thicknesses.
Have not measured the density but they don't compress much.

I have an old keel stepped Isomat mast. the deck ring was designed to use small wooden wedges.
The wedges we had where like this


They worked loose, I discussed solutions to this with my rigger, he suggested switching to these rubber pads. No problems more than 5 years later.

Ian McColgin 09-21-2014 07:51 AM

I've seen plenty of instances of wedges shaking up and out. In all cases this was solved by making more accurate wedges that contacted the partners over almost their whole depth.

Even a steep wedge will lay against the mast flat and provide protection to the mast but if it's only in contact at the upper part of the partners it's just an incline plane that wants to shift the load.

Make a very gentle bevel. As a start, make the wedges way too long so once you get them set you can mark where to cut the bottoms off. Flat bottoms makes getting them out easier as well.

Make the bevels fit. If a round or ovular mast, the inner (female) arc is a bit tighter than the outer. Get these right for good contact. Whether flat or round sided, number or lable the wedges so you can get them in and out without a lot of fooling around.

Personally, I do not like rubbery wedges. They move and they have high friction making them hard to set and harder to extract. Good hardwood wedges properly shaped are the way to go.

Even on glass boats.

I' not against the poured wedges if the parnters are beveled just a little, bottom a sckoch smaller hole than top, so you can set and remove with confidence.

G'luck

Douglas 02-19-2015 07:01 AM

Rubber Mast Wedges
 
Ahoy Brion ,,, do you stock or order those rubber wedges for mast to partner spaces ?

asdf777 02-19-2015 09:23 AM

I have starboard wedges, installed by a professional rigger, but don't like them. They seem too hard for both mast and deck, and I can feel the mast pushing on deck when the boat is heeling. Softer material like rubber seems like a good suggestion.

Ian McColgin 02-19-2015 12:59 PM

Feel mast pushing on the deck?

Properly made partners handle that stress and part of the idea of a keel stepped mast is that it's held in two places and can be a nudge lighter than a deck stepped mast.

In an older boat, the racking strain can be interesting. My old Goblin, an Alden 43' schooner, was almost 70 and when beating in any sort of wind the main mast cranked the hul and coach house so much that the door between the aft stateroom and the main saloon could not be opened if it was closed and not closed if it was open. The rectange of the door frame became a sort of trapazoid. Made her leak some as well.

If the structure is not handling the load at the partners, then you have some interesting problems possibly with the partners, maybe with the stick itself, and certainly with how you tuned it.

Start with a careful analysis which, if you're not up to it, find a qualified rigger who can.

G'luck

asdf777 02-19-2015 02:29 PM

Hi, not sure how else to put it, but I don't have a good feeling about these starboard wedges - they're just relaying the force exerted by the mast to the deck without absorbing the vibrations. Of course, the opposite side argument is that if the wedges are too soft, the mast is subjected to greater pressures.

BTW, not sure if Brion has a preference, but I know some riggers recommend spartite. It's expensive and not easy to install by yourself, but if properly installed, it's deemed by many to be the ultimate solution.

Best regards,
Gleb

asdf777 02-19-2015 02:41 PM

Another thing to keep in mind is that if there is uneven amount of space between the mast and deck, it's going to be difficult to select wedges to keep the pressure distributed equally while keeping the mast straight.

For example, in my case, there is slightly less space on the port side, and even though the starboard wedges have a big O clamp around them to distribute the pressure, the boat is creaking more on the starboard tack, when the boat is heeling to port.

So anything that can fill in the gap uniformly while providing the necessary density will probably be a better solution. Especially if it can keep the water out. Spartite is supposed to do all of the 3...

What would the argument be against spartite besides cost?

Thanks,
Gleb


All times are GMT -7. The time now is 05:37 PM.

Powered by vBulletin® Version 3.6.7
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.