[TakeFive]

If you're familiar with lateen rigs like on a Sunfish, you'll remember that there are a couple of blocks on the boom to lead the mainsheet from the aft traveler along the boom, then to a cam cleat in front of the cockpit. We had a rare vigorous breeze on Lake Wallenpaupack today, and were beating to windward when there was a loud pop and our boom jerked to lee. One of the blocks on the boom was gone (later found safely on the mainsheet) and its bail was detached.

We immediately turned around and ran DDW back to shore, which minimized the stresses on the remaining block. Upon closer inspection, I discovered that a rivet had broken, causing the bail to open. The biggest casualty was losing a couple hours of prime sailing conditions while I drove to the Honesdale Home Depot to buy a rivet gun and 120 rivet assortment. I now have 119 rivets that I don't need. [] I'll drill out and redo the others over the winter

 

[Classic30]

Yep, that'll get attention alright.. there ought to be rules about people who post like that!!

... I now have 119 rivets that I don't need. [] I'll drill out and redo the others over the winter

Good idea. Rivets in aluminium don't last forever.

Did you get Al, Stainless or Monel rivets? Did you get some insulating paste whilst you were at it? From the photo posted it looks like the original had none and the rivet simply corroded away.

 

[Capt Len]

A good lashing of twine could have done it bristol fashion and no corrosion.

 

[TakeFive]

A good lashing of twine could have done it bristol fashion and no corrosion.

Sorry, a lashing would not work. The force vector on the block has a large component that is parallel to the boom, so a lashing would tend to slide forward on the spar. Also, the block that is shown would be oriented sideways with a lashing - that's why a bail is needed for this non-swiveling block.

The original rivet was aluminum, on an aluminum boom. And the boat has never seen salt water. There was absolutely no corrosion, not even where the SS bail contacts the Al boom. The pattern of the remnants of the broken rivet showed evidence of brittle fracture. It looks like it had work hardened over its 29 year life, and just broke.

The non-marine rivet kit that I bought had aluminum and zinc coated steel rivets. I used an aluminum one for the closest match to the original.

 

[Rhapsody-NS27]

I was looking at those rivet kits. There's a few things on my mast that could use fresh rivets. Good to see it worked out for you.

 

[Jeff_H]

Sorry, a lashing would not work. The force vector on the block has a large component that is parallel to the boom, so a lashing would tend to slide forward on the spar. Also, the block that is shown would be oriented sideways with a lashing - that's why a bail is needed for this non-swiveling block.

You just needed to do the right kind of lashing and the block would be oriented fore and aft, and the combination of friction and the remnants of the bail would have kept it from sliding.

Jeff

 

[ccriders]

You know, this is a network of shared experience. Your subject line elicits a strong immediate emotional response, especially from those who have paid attention to your posts in the past. So, please tease with less drama.
John

 

[TakeFive]

You know, this is a network of shared experience. Your subject line elicits a strong immediate emotional response, especially from those who have paid attention to your posts in the past. So, please tease with less drama.
John

Good point. I apologize. I've asked the admins to change the thread title.