Hey this is pthayn again, I recently posted on making a new mast tube. I now have another question. I am looking at several diagrams of sunfish and comparing them to my viking wanna-be sunfish. There is no eye strap or swivel block on the deck in front of the foot well on my boat, and there is no reference to one in the rigging instructions that came with the boat. My question is how necessary is a swivel block and can I install one from the outside of the hull, or will it need some support from the inside so that it doesn't tear out under the strain.
Having a small ratchet block mounted to the deck is a big plus sailing in heavy air and aids in pulling the boom down toward the deck, a good thing. You can mount an eye strap with two round head stainless steel machine screws in the space between the forward edge of the cockpit and the aft end of the centerboard trunk opening. If the Viking deck lay out is the same as the Sunfish, the holes will exit just forward of the cockpit lip and you can attach the nuts without having to get into the interior of the hull. I would recommend a back-up plate, either aluminum or hardwood to distribute the load of the block a little. All this should be a 20 minute job if you have the tools and the materials.
I just completed putting a swivel block in myself. It's really pretty simple. I removed the hook, and replaced it with a cam cleat, then drilled two holes in the deck to attach the ratchet block. I used the original hook holes to attach the cam cleat. The whole operations took me about 30 minutes.
You'll need to get a ratchet block (I used the same one that Sunfish supplies on their race model), a stand up spring or boot and a padeye to attach them to the deck.
A regular block is a simple pulley that spins freely in both directions. “Swivel” referes the block’s attachment point to the deck. It can turn 360º to keep the mainsheet always running smoothly toward the boom block.
A ratchet block has a ratchet incorporated with the pulley. When the ratchet is engaged (ON) the block spins freely when the mainsheet is trimmed in, but is locked from turning when the mainsheet is let out. The extra friction created by the locked pulley reduces the level of sail pull the sailor is subject to. That action makes holding the mainsheet less demanding as the wind speed increases.
I don't know about that..., it's more a matter of my lack of self-dicipline. With that arrangement you can't cleat-in when you're hiked out.
Fred makes a good point. The washers you have are ok for preventing the nuts from chewing into the fiberglass, but something twice the diameter or better would aid in distributing the load.