July 9,
Not too much going on with the boat the last few months. There have been holidays, yard work and very little money. I have done a lot of cleaning of the shop which is always nice. I've started cleaning and inspecting the Isuzu C240 auxiliary diesel. My current plan is to start rebuilding that engine starting with the head. I had some notion of doing a lot of the head work myself, but I think I'm going with a professional shop for surfacing, seats and valve guides. I'll probably get a shop to put new liners in the block as well. I don't expect anymore block work except some surfacing of the top. It should all be bearings and gaskets.
I've given some thought to the rigging as well. There is a case for going with drawn galvanized 7x19 wire rope.
Advantages:
-The wire rope is 1/5th the cost.
-Stronger (than 316 SS but comparable to 304 SS).
-Turnbuckles are much cheaper.
-7x19 wire rope can be spliced with the splice exceeding the tensile strength of the rope.
-This means that I will save considerable money in swages.
-The rigging will be field serviceable.
-This wire rope is also much more widely available.
-Better abrasion resistance and resists work hardening (something people forget about SS).
-Tolerates contact with other metals better (Copper is the exception).
Disadvantages:
-Corrosion.
-Corrosion.
-Corrosion.
-7x16 is stretchier than 1x19.
We can mitigate corrosion issue by applying zinc phosphate etching solution to places that start to show rust over time. These will likely be the lower shrouds, etc. A product like
https://www.eastwood.com/rust-remover-eastwood-fast-etch.html works very well and seeps into hard to reach places. It dissolves the rust and seals the surface with zinc (galvanize). I've use this product before on auto body restoration. I have a bare chassis that I treated with this stuff 15 years ago and it has been sitting bare in my garage with no sign of rust ever since. Did I mention I live in the South of the United States and we have very high humidity.
The stretchiness is not so much a problem given how cheap the turnbuckles are. Just buy them a bit longer to achieve the same compression.
Although 316 SS is considerably more corrosion resistant than galvanized rope, its mode of corrosion is almost invisible and often from the inside out. Galvanized wire rope rusts the ugly red rust of iron. It is easily diagnosed and cheaply repaired (either by replacing or treating). Still, the American Galvanizers Association claims that galvanized wire will last 8 to 10 years in a marine environment. 316 stainless steel is typically replaced every 15-20 years. Twice the life for > 5 times (very conservative estimate) the cost. Plus I really like the idea of field serviceability. Of course, this is contingent on me becoming a competent rigger in the next few years. To that end, I have a very good book and I am making a rigger's vise. I also bought some cheap 7x19 wire rope and thimbles from the local hardware store.
 |
| The photo in the rigging book (reference to come) showing the thimble in the middle with the three jaws holding the wire rope around the thimble. |
 |
| My current progress. I've already threaded the steel block for a 3/8" bolt. The jaws are made from some left over white oak. That is a 3/8" thimble in the jaws for size comparison. It's designed to handle the range of wire rope that I'll be using on the Wren's Reward. |
