Stay measurements

[seawolf]

That sounds good. I will give it a try and see what I come up with.
Dividing the difference is good advise.
Just one more question regarding measurements.
Since I will be using the old wire as a template, can I omit any working elasticity value of the new wire and just make sure my new turnbuckles are at mid adjustment when making my final measurement against the old wire?
I believe any constructional stretch for the lengths mentioned above would not be a worry.
7/32" 1x19 SS longest length, backstay at 38' 1 3/4"
Thanks again to all for your kind advse.
Bob

[Brion Toss]

Hello,
Instead of measuring from the masthead, we simply make a pencil mark, as high as we can easily reach, on the front center of the mast. We measure down to the chainplates from there. Essentially we are measuring the hypoteneuse of a very short triangle, instead of a very tall one. At least as accurate. Several advantages: there is no worry about elasticity; we find out where the lower part of the mast is; and it's easier and faster by far.
Centering the bottom of the mast by measuring means we can sight our way up straight.
We also measure out horizontally to the upper shrouds. This will tell us if the mast is situated midway between the chainplates. If it isn't we can compensate accordingly when tuning.
As Ian pointed out, there might also be asymmetries in chainplate height. There are ways to check for this, even when in the water, but I've found that careful sighting from forward of the boat will usually reveal if the chainplates are significantly non-level. Sighting can also reveal if the whole mast is straight, but not coming out of the boat at right angles. I suspect that is what is happening on your boat
As for the measurements, if the tune is good you can indeed use the old wires as templates. The most constructional stretch you'll see is on the longest wires. In your case it will amount to less than an eighth of an inch.
Fair leads,
Brion Toss

[Brian Duff]

I am constantly reminded that this biz is all about the tricks

i never really think about chainplate height except by eye as I come and go, but I suppose it should be measured every time as well.

thanks again Brion, I like the idea of not having to spend time getting a tape aloft and then walking around the lowers and toppinglift with it...

[seawolf]

Thanks to all for the good advise once again.
Brion,
My lady Cheryl and I were in Port Townsend a couple of weekends ago on the 19th and 20th. We love your little town, and try to visit a few times a year.
We sure didn't expect snow in April, leaving the mid 80s temp of SoCal. Our boat is in Dana Point Harbor. Possibly the next time we are in Port Townsend, it will be during the work week and hopefully catch you in, to say hello. Thanks for allowing the layperson to join in and learn.
All the best.
Bob