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question Mark 2 Mast (pennywhistle)
Posted: 7:01:12 pm on 2/5/2006 Modified: Never
 
The five pop rivets at the spreader that hold the bracket to which the lower shrouds are attached have all broken and there is a 1/8" gap between the top of the bracket and the mast. Has anybody experienced this problem?  I assume the spreader bracket goes through the mast. Is anybody familiar with the construction around this area. I can rotate the bracket so I presume my mast wont come down.

In addition the rivets on the front of the mast that I assume holds an extrusion that houses either the electrics or haliards have come loose and occasionally the main haliard, in rough seas, gets caught on one or more   of these rivets. Anyone had this experience. Any idea how long these rivets are?
Carl Armstrong  - Pennywhistle
  Re: Mark 2 Mast (wrapper)
Posted: 1:38:42 pm on 9/18/2012 Modified: Never
 
I just inspected my spreaders and on one spreader base does not seem to have any rivets on the diamond shaped base to the mast.

There is a gap.  I am not sure what is happening here.  I will probably be taking the mast down to inspect and repair.

Has anyone seen anything like this?

Allan
Cygnus
C&C 27 Hull 518

  Re: Mark 2 Mast (clanning)
Posted: 9:18:02 pm on 9/19/2012 Modified: 9:18:51 pm on 9/19/2012
 
The stability of the spreaders is critical.  Frankly you should be thinking about dropping the mast immediately to inspect and repair.

You should also inspect the spreader bracket carefully for a crack in the weld between the tube portion and the flat-ish piece that rests against the mast.  I found cracks in mine after another boat had the same fitting fail (resulting in a broken mast).

I used SS "pop" rivets to reattach the spreader bracket to my mast (after it was repaired and reinforced).  In hindsight MONEL rivets are what you want, as they strong enough and resist corrosion better (also the SS can promote corrosion of the aluminum where it contacts it).  They are also more readily available!

When you reattach the spreader bracket to the mast, I spread some 5200 (or 4200 or equivalent) between the two before refastening, to give some isolation and protection to the aluminum against corrosion.

Just remember, if you lose the bracket, you can quickly lose the mast!
Chuck Lanning
NSC, Ottawa
  Re: Mark 2 Mast (carriden)
Posted: 10:55:20 pm on 9/19/2012 Modified: 11:03:35 pm on 9/19/2012
 
When I bought Carriden in 2005 I found a similar issue with the tang for the lower shrouds on one side of the mast.  However, on my mast the rivets are there essentially as a backup, since the tang and spreader cup assemblies are primarily held in place by a 3/8-inch or larger stainless steel bolt which goes right through the mast.  The bolt is hidden inside the spreader cups and is not visible when the spreaders are in place.  My conjecture is that the rivets are in place to help distribute the downward pull on the tang and thereby prevent the hole for the stainless bolt from elongating under load and wear.  The original rivets appeared to be of stainless steel.  I drilled out all of the rivets and replaced them with new stainless steel ones.  Had to buy a whopping big commercial-grade pop riveter in order to fasten them in place.  After eight seasons, there has been no visible fatigue or degradation, albeit in a fresh-water environment.

I have no idea about your rivets on the front of the mast.  Where exactly are they located?  My mast has no inner extrusions whatsoever.  I had to install vinyl tubes and anchor them to the inside of the mast in order to protect my wiring from halyard chafe.  I did use pop rivets when anchoring the tubes, but only in a few spots and they are all hidden under other fixtures.  Between the anchoring method and the way in which the halyards have been led, it is virtually impossible for the lines to chafe on the rivets.

Marcus from Carriden

Mk III, Hull #847
Oakville, Ontario

  Re: Mark 2 Mast (wrapper)
Posted: 8:33:52 pm on 10/18/2012 Modified: Never
 
Update:

Took the mast down yesterday.

There is a 3/8 in bolt going through the tang/spreader assembly.

The port lower shrouds seemed to have been "pulled" down which sheared the rivets and the bolt wore down the port bolt hole on the mast.  

Right now the plan is to drill out the tang and mast to the next larger size and replace the bolt with a larger bolt.

Sorry this was the only photo that came out okay.

http://i1273.photobucket.com/albums/y407/cygnus27/IMG_20181_zpscd3a6de6.jpg

Allan
Cygnus
C&C 27 Hull 518