Spinnaker retrofit on a Capri 18

[Kayden]

Hello, thanks for reading and having me in your forum. This is my first post.

I welcome all advice, criticism and ridicule related to this venture.

NOTE - Photos to come later.

I purchased a 1998 Catalina Capri 18 this year and have it in Lake City, MN on Lake Pepin.

So far, I am really enjoying the boat and plan to use if for a few seasons, learn all I can and eventually move up to something along the lines of a Cape Dory 25D.

The boat has a fractional rig (CAPRI 18 (CATALINA) sailboat specifications and details on sailboatdata.com) and came with a main and working jib(furling). The jib is great for the boat's displacement in everything but very light winds and broad reaching/running. (Swept back spreaders causing their own downwind issues.)

The point is I would like to add an asymmetrical spinnaker to the arsenal. I know there are more suitable sails, but I own an cheap asym that "fits" the boat. Thank you ebay.

So you ask, what gives?

No crane, bail, or otherwise provided for a spin my Capri 18. I do not want to use the internal jib halyard for the usual reasons. I am reluctant to drill holes in the mast until I know a spin will even work on this boat. What to do?


My attempt will be to use round and shear lashing to attach the relevant hardware to the boat.

Twine I plan to use for lashing: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Line for soft shackles (it's small, but so is my boat): https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

D-Ring - lashed to bow pulpit for the swiveling tack line block - https://www.westmarine.com/buy/west-...03?recordNum=1

Rectangle loop (not this one, but something like it) to be lashed near the masthead for the swiveling halyard block: http://www.92062.com/image/iron/A25-1.jpg

I chose this as, in my head, the closer the attachment point is to the lashing the less leverage it will have for vertical twist vs. a D ring. We'll see how this plays out. The angle of the pulpit should put the D ring at 90 degrees of the tack line pull (again in my head).

2 swivel blocks, 2 more blocks to lash/shackle to stern cleats or the stern pulpit, halyard line, tack line, sheet(s). Appropriate fairleads to be contemplated after initial testing.

Potential issue 1 - lashing interfering with the mainsail track. Upon examining, with the headboard design, position of first slug and cut of the sail I should have over free 12" for the lashing.

Potential issue 2 - steel ring indenting/galvanizing to the aluminum mast. The hope is wrapping the ring in the twine before shear lashing to the mast, plus frapping turns of the shear lashing separate it from the mast should help prevent this....I hope.

Potential issue 3 - Slippage of the masthead lashing- the one that will have more pull against the friction of the lashing vs the "strength."

I have tested the shear lashing with this twine on a painted steel railing on the back stoop and cranked on it with a tow strap. Not worried about strength. But there was some vertical slippage if I pulled down. Lashing was hand tightened (no marline spike hitch) on 1" painted steel tube. I am predicting that somewhat tighter lashing on the significantly larger spar (with an even greater increase to surface area) will make it a non issue for the downward loads that will be put on it.

I welcome any advise or criticism, even if it's to talk me out of the whole thing.

Thank you all in advance.

-Kayden

PS - the spin is barely asymmetric - 18'8" luff, 18' leech, 12' foot.