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Current Replies for Mast base blocks
  Mast base blocks (windyday)
Posted: 6:10:46 pm on 7/27/2009 Modified: Never

Finally got to that point in this major refit where I can concentrate on rigging. Mast is up, new deck organizers and rope clutches are in. It is now apparent that I need to rethink the mast base blocks for the halyards. I found the few archived posts but not a full discussion. Presently, the blocks for the main and two foresail halyards are simply blocks shackled to a bale. The point of turn of the halyards is too high, creating too much of an angle where they enter the organizers. I could remove the bale and shackle the blocks to the horizontal bolt in the base but my first incliincation is to change to Harken blocks that I can bolt to the deck at the base of the mast. However, I see the comment to use the mast base instead and not deck-mount base blocks. Any thoughts?

1974 Mark II C&C 27

  Re: Mast base blocks (davidww1)
Posted: 3:24:42 pm on 7/28/2009 Modified: Never

I wouldn't bolt blocks to the deck; the loading from halyards is likely to be more than it's really built for. Plus your headliner is going to look like Swiss cheese. The mast base channel, on the other hand, is essentially part of the mast and well able to handle anything you throw at it. I would either look for blocks with a lower distance bail-to-sheave (which would lower the point of turn) or, as you suggest, use the bolts at the front and back of the channel as mounting points, as I have.

David Weatherston
Towser, Toronto
C&C 27 Mk IV

  Re: Mast base blocks (windyday)
Posted: 5:31:04 pm on 7/29/2009 Modified: Never

I'm also thinking of making SS rails for each side of the mast base and bolting them onto the base, then shackling the blocks to those.  Any thoughts?

1974 Mark II C&C 27

  Re: Mast base blocks (Martin Jubenvile)
Posted: 9:13:02 pm on 7/29/2009 Modified: Never

Hey David,

Do you by chance have any pictures of your mast base as you describe?


C&C 27 Mark III 1976

"Shifts and Giggles"

  Re: Mast base blocks (davidww1)
Posted: 9:16:55 pm on 7/29/2009 Modified: 9:29:23 pm on 7/29/2009

For a time, someone around here was making a version of the mast base that included a length of alloy welded on at an angle of 45 degrees from the bottom edge. Large holes accommodated the turning blocks' shackles. A very nice do-it-yourself variation involved bolting a length of alloy L to either side of the base. This had the virtue of providing a flat surface that made stand-up springs more effective.

Originally I thought such an arrangement was essential, but I've managed without (but Towser has only one genoa halyard and one spinnaker halyard). The linked photo shows the mast base before the addition of a Boomkicker (a complication which makes it impossible to see anything). Clockwise from 3 o'clock are: 1. spinnaker and pole lift (shackled to a hole and to the cross-rod on the front of the base); 2. genoa halyard ( aft cross-rod); 3. vang fiddlebock and cunningham small triple (aft cross-rod); 4. outhaul; 5. main halyard (shackled to a hole). One useful addition is to run a line of shock cord around the mast and two forward blocks to hold them together against the mast when they're unloaded; this keeps them from falling over and getting into a bad angle. Similarly, another piece around the base of the small triple keeps the lower cunningham block upright; this keeps the cunningham line from fouling the main halyard block.

These blocks all lead fair to deck organizers just in front of the spray hood (a position chosen to minimize the angle of turn), then aft to clutches and cam cleats.

David Weatherston
Towser, Toronto
C&C 27 Mk IV

  Re: Mast base blocks (oasis)
Posted: 12:50:24 pm on 7/29/2009 Modified: Never

David's first paragraph closely describes the mast base of a Mk V from the factory.  Stainless steel plate about 1/8 or 5/32nds with lip pointing up at about 30 degrees on sides and back.  There are lots of holes through which you can shackle blocks.  Works great.  If you need, let me know and I can send a photo of the system the Mk V uses - photo shows the sides, but not the back - but it is pretty well the same.

Barry, 1987 Mk V, Oasis

  Re: Mast base blocks (Nepenthe)
Posted: 1:24:37 pm on 7/29/2009 Modified: Never

I have considered purchasing a stanless steel mast base that I have seen at some marine suppliers.  It is as described above.  Basically, it is a flat SS plate with a lip on each side with holes to attach the blocks.  I now can't find a supplier that has one on their website.  It is close to the one shown here although the one on this site is designed with a hole for a a keel stepped mast. For a cabin stepped mast, it would not need the hole.The problem on the 27 is that such a plate would have  to be mounted under the existing aluminum mast base - I don't think it would fiit inside the aluminum base and still have room for the mast.  I am not sure if how this would be done or if it is advisable.

Greg Tokarz, Nepenthe, C&C 27 Mk1, Hull #73

  Re: Mast base blocks (davidww1)
Posted: 4:04:26 pm on 7/29/2009 Modified: Never

I wouldn't put anything under my mast base. The shrouds would still fit, but the backstay is a titanic struggle every spring as it is.

The mast base with attachment points, described above, often was the owner's own base, to which the weldments were added. There are any number of marine metal outfitters near any sailing/boating town who'd be happy to do the job over the off-season. Removing the base involves pulling a few screws (4 or 6 - can't remember). Hardly a major undertaking. Or you could add a mounting base yourself, through-bolting a length of alloy L to the sides (which could be done without pulling the stick). You'd have to make sure you're getting a strong, hard alloy, though - not soft screen-door grade aluminum.

David Weatherston
Towser, Toronto
C&C 27 Mk IV

  Re: Mast base blocks (windyday)
Posted: 12:06:04 pm on 8/3/2009 Modified: 12:07:14 pm on 8/3/2009

Another option some use around here is to make two stainless steel plates, one bolted to each side of the base plate. Each plate is bent outward lengthwise about 45 degrees. The lower vertical half is drilled to accomodate the horizontal bolts in the mast base (which will need longer bolts) plus perhaps a couple of extra small bolts for security, and the upper half that sticks out 45 degrees is drilled for 3-4 blocks on each side. Insert anticorrosion between the base and stainless.

1974 Mark II C&C 27

  Re: Mast base blocks (Martin Jubenvile)
Posted: 9:26:16 pm on 8/3/2009 Modified: Never

This is  what I'm going to do except I'm going in front of the mast base also with a 3x1 1/2" for the vang and reefing system. So three down each side and three in the front.

C&C 27 Mark III 1978

"Shifts and Giggles"

  Re: Mast base blocks (Martin Jubenvile)
Posted: 12:41:47 pm on 8/3/2009 Modified: Never

Actually, I plan on using angled stainless steel in an L configuration bolted to the mast base. Instead of blocks on upright spring bases I want to use mast exit blocks at the base monted on an angle towards the deck organisers and then on to clutches for all.

C&C 27 Mark III 1978

"Shifts and Giggles"

  Re: Mast base blocks (ALAN FORD)
Posted: 4:42:27 pm on 2/17/2013 Modified: Never
Has anyone seen or used Garhaur blocks or organizers please? There was a fine display of them at the Toronto Boat Show last month, hence the question.

Alan of SMOKE 1984 Mk V 002

  Re: Mast base blocks (Kilroy)
Posted: 10:13:44 pm on 2/17/2013 Modified: Never
Garhauer Marine has mast plates that you can purchase. I myself went to a shop and bought a stainless steel plate and had them bend the two sides on a 45deg angle. Then I did the drilling and cleanup work. If you can find the right size from them or any other supplier, it would be cheaper and a lot less frustrating.
Tim ,Windsor On.
"Oui R One"
C&C 27 MK III  511
  Re: Mast base blocks (ALAN FORD)
Posted: 10:25:31 pm on 2/18/2013 Modified: Never
Thanks Tim but SMOKE is a Mk V so has her original mast plate with built-in mounts for 8 blocks. It is the Garhauer blocks that I'm curious about.  I wanted to see if anyone had used, or seen someone else use, them. They are different from the more usual blocks we use,  Garhauer is based in Upland, California. I have their latest catalogue and price list which I picked up at the Toronto Boat Show, and it shows several sizes of mast  plates ready to go.

Alan of SMOKE 1984 Mk V 002

  Re: Mast base blocks (diva27)
Posted: 12:13:14 pm on 2/20/2013 Modified: Never
I've sailed on John Daniells' custom Killing 50, To Life, which was built to race, period. There's a lot of Garhauer on that boat and I don't recall any complaints.

Doug Hunter
C&C 27 Mk1
Midland Bay Sailing Club

  Re: Mast base blocks (clanning)
Posted: 9:40:00 pm on 2/21/2013 Modified: Never
Are you asking for an endorsement for Garhauer stuff?

1) It's art.

2) It's inexpensive.

3) It's strong.

Never heard a bad word about Garhauer.

Chuck Lanning
NSC, Ottawa
  Re: Mast base blocks (Steve Reid)
Posted: 10:34:04 am on 2/21/2013 Modified: Never
I got two (bad words that is) massive and heavy.

Steve Reid
  Re: Mast base blocks (ALAN FORD)
Posted: 10:16:28 am on 2/22/2013 Modified: Never
Many thanks for your thoughts on Garhauer.  Discovering that 'To Life' is equipped with them is praise indeed. I met one of the two founders (the -hauer part of the name) at the Boat Show, both were machinists by training, and sailors. It is now run by the next generation of the founding families, who sail, providing test beds for their ideas.
I liked the look and feel of their blocks. They differ from the more standard units we use, but when the need arises I will certainly try one.

Alan of SMOKE 1984 Mk V 002

  Re: Mast base blocks (dmartis)
Posted: 2:06:21 pm on 2/22/2013 Modified: Never
A fellow 27 owner at our club did the following with the mast base on his boat, something I'm hoping to copy.  Not sure if I can attach photos, but he basically used aluminum angle bolted to either side of the Mark 1-4 mast base (the simple channel).  This required replacing the two long studs that hold the mast in place.  The angles had holes drilled in them to accept turning block shackles. I've got photos if anyone wants them.  

Looks like a very simple and elegant solution thanks to Marcus Opitz on Carriden!Dan Martis
Dream Catcher
Oakville, Ontario
Mark 3, Hull #636
  Re: Mast base blocks (admin)
Posted: 3:50:41 pm on 2/22/2013 Modified: 6:44:22 pm on 2/22/2013
If you'll send the photos to the address in The Fleet, they will be posted in Various Projects in Black Arts.

- Admin


  Re: Mast base blocks (ALAN FORD)
Posted: 10:13:52 pm on 2/22/2013 Modified: Never
Some mast plates and parts for them are here:-

Alan of SMOKE 1984 Mk V 002