Backstay insulator

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nimbusgb

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Having finally acquired an HF transceiver ( ICOM IC-718 ) after many years of wanting one I am now looking to set up an insulated backstay. Browsing around soon put me off the thought of using the swanky swage type fittings. £165 EACH! Wow!

I have twin backstays, either of which will support the mast adequately so I have decided to use a metre long, spliced, continuous loop of 8mm Dynema fitted inside a jacket of UV protective heatshrink. The loops are being made up by a rigger so I am confident about the quality of the splices.

Can anyone see any problem with this?
 
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nimbusgb said:
Having finally acquired an HF transceiver after many years of wanting one i am now looking to set up an insulated backstay. Browsing around soon put me off the thought of using the swanky swage type fittings. £165 EACH! Wow!

I have twin backstays, either of which will support the mast adequately so I have decided to use a metre long, spliced, continuous loop of 8mm Dynema fitted inside a jacket of UV protective heatshrink. The loops are being made up by a rigger so I am confident about the quality of the splices.

Can anyone see any problem with this?
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I made my own with two swageless terminals and two shackles lashed together with dyneema .It works perfectly.The terminals can be swaged on as it will be much cheaper.
 
Why not just have a length of wire that you can hoist to act as your aerial? thus keeping your existing backstays. What consideration have you given to the ground plane?
 
nimbusgb said:
swanky swage type fittings. £165 EACH! Wow!
Click to expand...

Why not use these?

140.jpg


99p on e-Bay!
 
sarabande said:
does this give any light ?

http://www.toyobo.co.jp/e/seihin/dn/dyneema/kakou/index.htm


From the same site, I note that there is negative expansibility (i.e. it shrinks) between our normal sailing temps of 0C to 30C. The figures are very small - about 0.05% - so not noticeable over a 1m length.

My concern would be the conductivity if the rope were splashed in sea water.
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Yes I also thought of that.Insulating the shackle loops with heatshrink sleeve would work.
 
And after all the buggering around, why not buy two Sta-Lok insulators for 7 mm wire at £116-00 each and do the job properly. These are terminal-terminal so you can save on labour.
 
parsifal said:
I was going to suggest them but I coulnd't remember (or more likely never knew) what they were called!
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As soon as I started reading the thread I was going to suggest those, but I was beaten to it.

they are commonly known as Egg Insulators, because they are shaped a bit like an egg.

The crucial thing is they act in compression so they are immensely strong rather than the other type that are in tension and if they snap you lose your backstay.
 
Thing about the "egg" insulators as pictured, is that they seem to be designed to go into a spliced loop. Now I rather like the idea of handspliced galvanised wire and a regular dosing of stockholm tar, but I'm unusual. Most people will be wanting to fit insulators in 1x19 stainless, which I'm led to believe you can't splice. Talurit fittings to make crimped loops also seem to be frowned upon for standing rigging (although it is what mine uses, my boat is small and gaff-rigged so the loads are lower).

Pete
 
prv said:
Thing about the "egg" insulators as pictured, is that they seem to be designed to go into a spliced loop. Now I rather like the idea of handspliced galvanised wire and a regular dosing of stockholm tar, but I'm unusual. Most people will be wanting to fit insulators in 1x19 stainless, which I'm led to believe you can't splice. Talurit fittings to make crimped loops also seem to be frowned upon for standing rigging (although it is what mine uses, my boat is small and gaff-rigged so the loads are lower).

Pete
Click to expand...

I think that as the OP's boat has twin backstays and that each can take the full load using talurits on one of the stays would be ok.
 
nimbusgb said:
Can anyone see any problem with this?
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Yes. They will absorb salt water however carefully you protect them and become conductors.

I found that I only ever played with the ham radio ( do you have a licence by the way? :) Many ham operators, me included, wont talk to pirates ) when on a mooring or at anchor. So on my last boat I made upo an aerial with egg insulators and I hoisted it up on a halyard making sure that I tied the bottom end down in the same place on the deck each time. Worked OK ,. Bit of a faff but performance wise it cost little.

Same with the ground plane connection. I found that using the anode connecting bolt worked OK as does the keel bolt on this boat

P.S. A pal has a multi band whip aerial which works really well.
 
Seems strange that having spent all that money on an SSB rig you did not budget for a proper installation - its not going to work very well without a correctly set up antenna and ground plane anyway.

Egg insulators could be spliced into flexible ss wire rope (7x7 I think, but its many years since I worked with any), not as strong as 1x19 but still useful as a second back stay.
 
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Atlantic Rigging said:
And after all the buggering around, why not buy two Sta-Lok insulators for 7 mm wire at £116-00 each and do the job properly. These are terminal-terminal so you can save on labour.
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£232 for 7mm wire solution. My backstays are 8mm. Proper? My solution will cost < £50, can be tailored on site in a Greek yard and is stronger than the existing stay. Making the dynema sections 1m long will ensure that even soaking wet they will still offer a good insulation, a layer of damp salt along a 200mm stay-lok has got to be just as much of a leak.

Just a foundation licence.

I only paid £200 for the Icom. The radio is pristine, not a mark on it. It was a snap buy. So I wasn't exactly budgeting when I made the decision to buy the set from a chap clearing out his shack. I'll be fitting a sintered bronze ground shoe and I have my eyes on a nice ATU unit.

Actually I did consider a ceramic egg. The nice thing about them is that they fail safe. If the ceramic does break the two eye splices still maintain the stay integrity if not the tension. It's just that the dynema solution is that much slimmer and tidier, a 2 inch long lump of brown porcelain spliced into the backstay is not exactly a 'pretty' solution on a modern rigged yacht.
 
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HF radio antenna

I used egg insulators a long time ago on a catamaran. It was on a side stay and with huge stay loads the egg insulators failed (crushed). They were fairly small egg insulators. ie about 50X 40mm.
The reason you don't just haul a wire up to the mast top is that all the other nearby stays can suck the RF power. Yes it works but you will lose some power. The same will happen to the op with parallel backstays. For best results the other backstay should have an insulator as well. You want to break the wire length into small portions of 1/2 wavelength at the highest frequency.
Best results in theory would come from dyneema/ spectra used in both backstays with a conducting wire under the heatshrink of one backstay. Or one backstay as antenna with insulators and the other insulated into 2 or 3 sections. Hopefully the mast is sufficiently remote from the antenna to not be so influencial.
In practice of course anything will work OK.
I favour the whip antenna as it will still stand after loss of mast. good luck olewill
 
nimbusgb said:
£232 for 7mm wire solution. My backstays are 8mm. Proper? My solution will cost < £50, can be tailored on site in a Greek yard and is stronger than the existing stay. Making the dynema sections 1m long will ensure that even soaking wet they will still offer a good insulation, a layer of damp salt along a 200mm stay-lok has got to be just as much of a leak.

Just a foundation licence.

I only paid £200 for the Icom. The radio is pristine, not a mark on it. It was a snap buy. So I wasn't exactly budgeting when I made the decision to buy the set from a chap clearing out his shack. I'll be fitting a sintered bronze ground shoe and I have my eyes on a nice ATU unit.

Actually I did consider a ceramic egg. The nice thing about them is that they fail safe. If the ceramic does break the two eye splices still maintain the stay integrity if not the tension. It's just that the dynema solution is that much slimmer and tidier, a 2 inch long lump of brown porcelain spliced into the backstay is not exactly a 'pretty' solution on a modern rigged yacht.
Click to expand...

OK, £121 for a proper job in 8mm then.
 
New Backstay Clamp

New Backstay Clamp.
Yachtfunk.com provide a new backstay clamp for GTO-15 Cable.
waterproof connection for the GTO-15 with good connection for the backstay.

For all backstay also rod-rigg.

the material is V4A
 
>so I have decided to use a metre long, spliced, continuous loop of 8mm Dynema fitted inside a jacket of UV protective heatshrink. The loops are being made up by a rigger so I am confident about the quality of the splices.

I don't understand the question. An aerial must be wire but you don't mention it. I would strongly suggest you us Stalok fittings, there have been many swaged fittings failures but I've never heard of a Stalok failing. The ground was mentioned, bear in mind that it makes up half the aerial and a bad ground will give poor performance. Connect as much metal as you can inside the boat with copper foil to the ATU, which I assume you have.
 
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