diameter of served 3/8" wire

[redbopeep]

I'm in search of bronze thimbles for my rig. It is now 3/8" 1x19 ss but will be 3/8" 7x19 or 7x7 galvanized depending on what I can find for wire. I just got off the phone with Pete at Port Towsend Foundry who says "what diameter do ya want--how will you be serving the wire?" hummm... I've read Brion's book and a few others on traditional rigging, practiced a bit of serving while helping a friend with his boat and am getting ready to purchase or build a rigging vise to practice some splicing of the 7x7/7x19, but haven't a clue about what the final diameter of the parceled and served wire will be.

Pray tell, can someone here give me some numbers on the thickness of parceled and served wire? I haven't purchased the materials for this yet, but want to start comparing apples to apples on the thimbles I can find and use...thus should know how much over 3/8" I should be buying the thimbles.

I'm hopeful to keep them fitting inside the #20 (5/8") bronze rigging screws/turnbuckles which is why we're trying to be pretty close on the size. Taking a measurement, the jaws can take a toggle or thimble of thickness 5/8" and it appears the working depth of the fork end is a tad over an inch. When I look up the numbers in Nicolson's "Boat Data Book" it states the working depth to be 30 mm and thickness of eye min= 17 mm max=19 mm.

Thanks, so much for your assistance. Hopefully someone has a bit of parceled and served wire around a thimble and you can take a measurement?

[benz]

I'm in the middle of a similar mental wrestling match but which involves leathering instead of serving. Here's my seat-of-the-pants method: multiply the diameter of the serving twine by 2. (example, 1/16" marline X2 = 1/8"), Multiply the thickness of the parcelling material by 2, or by four if you plan to overlap it as you wind--( say, 1/32 X 4= 1/8). Now add those two eigths (of the marline and the parcelling) together to get a 1/4" more than the 3/8" of the wire. So, 1/4 + 3/8 equals 7/8". Now find out whether a 7/8 thimble will fit into your turnbuckles and Presto! you're either out sailing next month or back to the drawing board.
Hope this helps.
Ben

[redbopeep]

Originally Posted by benz

I'm in the middle of a similar mental wrestling match but which involves leathering instead of serving. Here's my seat-of-the-pants method: multiply the diameter of the serving twine by 2. (example, 1/16" marline X2 = 1/8"), Multiply the thickness of the parcelling material by 2, or by four if you plan to overlap it as you wind--( say, 1/32 X 4= 1/8). Now add those two eigths (of the marline and the parcelling) together to get a 1/4" more than the 3/8" of the wire. So, 1/4 + 3/8 equals 7/8". Now find out whether a 7/8 thimble will fit into your turnbuckles and Presto! you're either out sailing next month or back to the drawing board.
Hope this helps.
Ben

Well, actually part of my problem is that I don't know what the "proper" size serving twine would be. Also, had a friend tell me NOT to count the parcelling because it gets squeezed down to basically nothing with the serving. Hearing that from him is what made me post here since I didn't know that about the parceling (nor do I have good knowledge about proper size serving twine).

Thanks for your reply. Leather sounds a bit harder to figure out. Good luck with it.

[benz]

Welcome to the "design spiral," where the size and location of everything is predicated by the size and location of everything else. Whenever possible I buy a small sample of everything I'm thinking of using (one block, one turnbuckle, one shackle, ten feet of shroud material) and see if it all fits. For my leather-eyed shrouds I'll just buy the biggest thimble that will squeeze between the turnbuckle jaws and hope the leathering fits. Crude, I know, but sufficient for those of us who are mathematically challenged.
Good luck!
Ben

[Joe Henderson]

Dear Redbopeep,

Benz is right, you will just have to suck it and see!

This is why professional rigging lofts have an advantage. They all made thier mistakes years ago and have the right materials laying around to hand so it is easy to make up a test peice to make sure everthing fits.

For 3/8 wire I would use 2.5 or 3 mm diameter black plaited polyester cord. ( V.B. or venetian blind cord we call it in Australia.) I would not worry about the parcelling thickness, just use athletic strapping tape, White Linen, non-elastic, commonly called Leuko tape around here. This is pretty thin and will squeeze down fairly well.

Best of luck.

Joe Henderson.