Knot to tie to lift rope lifting keel

[roblpm]

I have a Parker 275 and plan to replace the keel wire with dyneema. The keel is 300kg I think.

So which knot should I tie it on with!? Someone on the Parker forum suggests a "Chinese Constrictor Knot" but a quick Google reveals a Constrictor know nut no Chinese one!

Any ideas? And websites so I can copy it?

I don't want to be embarrassed on my first day out in my new boat!!

(Also as a bonus question (I am too embarrassed to post another thread on this!!) why does my diesel take have 2 fillers? I assume it is so that the fuel could be removed out of one of them? I would have expected a breather, but it seems to have 2 deck inlets, one through a larger diameter corrugated pipe, and one through a more hosepipe looking pipe. Any ideas??!!)

 

[prv]

Without a picture to suggest anything different, I would probably go for Selden's halyard knot. Google should find some instructions for it.

Pete

 

[typhoonNige]

As you will only need a fairly small diameter dyneema why not get some fids and splice a thimble into the end? Probably stronger than any knot and less prone to abrasion. Plenty of youtube clips on how to do the splice.

 

[lw395]

As you will only need a fairly small diameter dyneema why not get some fids and splice a thimble into the end? Probably stronger than any knot and less prone to abrasion. Plenty of youtube clips on how to do the splice.

A simple splice, taper the end and feed it into the standing part, then whip it.
Easy to do and very strong.
Hollow needle splicing tool is worth having IMHO.

 

[Bilgediver]

I have a Parker 275 and plan to replace the keel wire with dyneema. The keel is 300kg I think.

So which knot should I tie it on with!? Someone on the Parker forum suggests a "Chinese Constrictor Knot" but a quick Google reveals a Constrictor know nut no Chinese one!

Any ideas? And websites so I can copy it?
)

Something like this maybe!


http://www.youtube.com/watch?v=M9kImggLWUQ

 

[knuterikt]

I have a Parker 275 and plan to replace the keel wire with dyneema. The keel is 300kg I think.

So which knot should I tie it on with!? Someone on the Parker forum suggests a "Chinese Constrictor Knot" but a quick Google reveals a Constrictor know nut no Chinese one!

Any ideas? And websites so I can copy it?

Dyneema is a slippery rope that don't hold knots well.
I would suggest you use a brummel splice, much neater and not difficult to make.

This series show how you can make this splice without using both ends with timble.

Only allowed one video, link to the other two
http://youtu.be/u9pnLY_HHRU

http://youtu.be/eR5qbzQ0q9w

 

[roblpm]

Thanks for all those!!

So a splice it will be!! Bit worrying though!! I have already done some and have the tools, but if they fail, so far the sails fall down! Not too worrying, if the keel falls down its a problem!!

No-one got the bonus for my other question. I may have to man up and post a separate thread for it!! The embarrassment may be too much to bear though!

 

[knuterikt]

Thanks for all those!!

So a splice it will be!! Bit worrying though!! I have already done some and have the tools, but if they fail, so far the sails fall down! Not too worrying, if the keel falls down its a problem!!

Why do think that a knot would work better? The brummel splice in my post is locked by the brummel. A knot i Dyneema has a tendency to slip..
Follow the video and it should work fine.

No-one got the bonus for my other question. I may have to man up and post a separate thread for it!! The embarrassment may be too much to bear though!

It's always better to have one post for one subject
I tried to visualize your tank setup but..

(Also as a bonus question (I am too embarrassed to post another thread on this!!) why does my diesel take have 2 fillers? I assume it is so that the fuel could be removed out of one of them? I would have expected a breather, but it seems to have 2 deck inlets, one through a larger diameter corrugated pipe, and one through a more hosepipe looking pipe. Any ideas??!!)

Take some pictures of the system and make a new thread

 

[Keen_Ed]

There's a very long thread over on SA about knots in Dyneema. Worth working through.
http://forums.sailinganarchy.com/index.php?showtopic=154025

"Estar" who's doing all the testing is Evans Starzinger. http://www.bethandevans.com/index.htm

Knots in single braid dyneema don't really work - splices are much better. Brummels aren't as good as a long bury and good taper, and lock stitch it.

 

[knuterikt]

Brummels aren't as good as a long bury and good taper, and lock stitch it.

Interesting conclusion
Seems other do disagree.


Source: http://www.bethandevans.com/load.htm

5. Tapered straight bury splices are potentially just a little stronger than the Brummel splice. The key to high strength in the straight bury is to finely and carefully taper the buried tail. The splice will usually break at the end of the bury unless it is very carefully tapered. If you do a 'bad' splice, with the end buried but no taper at all in the bury, the strength will be about 86%. If you do an even worse splice, with the end sticking out and not buried at all, it will be 80%.

source: http://www.chicagoyachtrigging.com/news/new-england-ropes/

Well, as you can see it was the bury splice that walked away the winner, besting the brummel which lost at 2958lbs. This is 134% of rated strength for 1/8″ Endura 12, so pretty happy with the result. If you read the semi finals, you’ll get some explanation of why it’s so far above rated, but it’s nice to know CYR splicing is beating the numbers we use for specifying rope.

Based on the result, you might ask why we don’t use the bury splice as standard, instead the brummel is the default for sheets and halyards. The reason is the brummel is faster, and has a locking mechanism which can be verified and can’t possible wear out or be removed. At the numbers seen in this and other tests, it’s always broken above rated for good quality lines, so I can use rated strength when speccing with no concerns about strength.

 

[zambant]

Without a picture to suggest anything different, I would probably go for Selden's halyard knot. Google should find some instructions for it.

Pete

Dynema - splice

 

[Bilgediver]

Thanks for all those!!

So a splice it will be!! Bit worrying though!! I have already done some and have the tools, but if they fail, so far the sails fall down! Not too worrying, if the keel falls down its a problem!!

No-one got the bonus for my other question. I may have to man up and post a separate thread for it!! The embarrassment may be too much to bear though!

I suspect it could be an air release if the boat had filling problems!

 

[rgarside]

Rob,

PM sent

Dick

 

[fitlike]

I own an e-boat so the lifting keel comes in at about 300kg. I replaced my wire with dyneema and selected a double figure of 8 knot, I read at the time that it was one of the strongest knots. Anyway it is still holding after 2 years.

IM

 

[zimp58]

I also replaced my wire with 4mm dyneema, lifting keel of about 200kg. I used Ashley's stopper knot. It is still there after two years.
http://en.wikipedia.org/wiki/Ashley%27s_stopper_knot

 

[Interlude]

Can you just loop the line through the hole in the keel (or whatever you were going to splice through or tie to) and bring both ends up to the winch?

 

[johnphilip]

When in the raised position is the top of the keel close to the first pulley or sheave so that a splice is being pulled into a restricted gap? If so the knot would be preferable as it obviously will fit a smaller length. They seem unseamanlike as they are a pig to undo but the Seldem Halliard knot has been very effective on my main halliard and reefing pennants for eight years.
With a metre or so of spare Dyneema you could cut off the knot and remake it every few years.

 

[roblpm]

When in the raised position is the top of the keel close to the first pulley or sheave so that a splice is being pulled into a restricted gap? If so the knot would be preferable as it obviously will fit a smaller length. They seem unseamanlike as they are a pig to undo but the Seldem Halliard knot has been very effective on my main halliard and reefing pennants for eight years.
With a metre or so of spare Dyneema you could cut off the knot and remake it every few years.

This is the suggestion of another Parker 275 owner.

The issue with the splices is that the spliced bit will have to go on the drum as the gap is so small.

So a knot it will be!!!!

Interlude: I don't think there is a hole in the keel. There is a threaded hole for a bolt. I don't think there is enough room either side of the keel inside the keel box allow a rope either side.

 

[estarzinger]

There are four loop knots that hold well in bare dyneema - two relatively common ones:the figure 8, and the water bowline. These do not slip but are relatively low strength. And two less common ones that are stronger: the polamar and estar. Even stronger than any of these is the multiple brummel without bury (repeated 5 times the brummel is about 80% strength), and without any bury at all it is almost as short as the figure 8.

 

[KenMcCulloch]

(Also as a bonus question (I am too embarrassed to post another thread on this!!) why does my diesel take have 2 fillers? I assume it is so that the fuel could be removed out of one of them? I would have expected a breather, but it seems to have 2 deck inlets, one through a larger diameter corrugated pipe, and one through a more hosepipe looking pipe. Any ideas??!!)

We have two fillers because we have 2 tanks, a main one and a small seperate tank for the heater. See where the pipes lead.