I know this will be a can of worms but, anyway, what are your opinions on drilling holes in the spreaders? I want to attach a micro block on each side for pennant halyards. Around my sailing club I have been getting a lot of ideas. Some say never put holes in spreaders, just creating points of potential stress failures. These people wire tie / wrap blocks to the spreaders to avoid holes. Others say they just drilled the spreaders and pop rivited the eyes to the spreader. I know many of you have all sorts of stuff hanging off the spreaders and mast. Opinions?? Or should I just rivet eyes to side of mast below the spreaders for the blocks and move on?
I've added burgee halyard fittings by drilling holes into the spreaders. I've also seen deck lights added. Neither have caused fatigue cracks, nor would I expect them to do so. The spreaders are either unloaded or subject to relatively low compressive stresses.
If there was a concern about stresses and fatigue, the area to check would be at the pins attaching the spreaders to the through mast bar and in the mast itself where it's perforated for the through mast bar.
Several weeks ago I removed my spreaders for the winter and inspected them for damage that would have occured during the 10 years they have been up there. Other than a bit of galvanic corrosion, causing the paint to lift where the SS eyelets were attached and the hailer mount, there is no damage to the spreaders.
Jim Kane
The spreaders on my C34 mkII came stock from the factory with the arrangement you described. The spreaders are hollow. In this case, the blocks are riveted to the bottom surface. The holes are no more than 3/16".
I think you will be OK as long as you stay near the center of the bottom face.
Good luck.
Whatever you choose to do, remember about dissimilar metals.
When we had our mast down last year, I had to clean up around the rivets.
Suggest you use lanocote on whatver you choose to use for mounting the block.
Don't know if ours came from Catalina that way or if the PO did it, but both port and starboard halyard blocjks are still working after 14 years. ;)
Thanks for the tips, especially the Lanocote tip. I wondered about that. Guess this will be a "small" project shortly, then I can fly the cocktail flag!!!
The tiny holes aren't a worry. Look at all the holes in bridges and their girders.
Just don't put any more downward load (side load on the spreader) than is required to keep the line slightly taught. A side load is a lot more of a concern.
Charlie P.