Securing Knots

[bartley]

When rigging our ships we all have a need to secure knots to stop them loosening.  There is a range of products available for this purpose so I thought that I might express my opinions on the subject.

 

 

Here are some of the products available:

 

As with most on this forum, diluted PVA is my “go to” for stiffening rope, attaching rope to blocks etc.  The only comment I would make is that I think on rigging one should use a non-acidic product (pH7).  The pH of Titebond for example is about 2.5 (very acidic) and I would be concerned about the long-term effects of this on natural fibre rope.  However for securing knots (on ratlines for example) I am not sure that it has enough " holding power".  Many use CA for this purpose. I am not a big fan of CA.  I don't like its toxicity (although we are only using small quantities rather compared to industrial use).  However, my main objection is that it forms a rigid, sometimes brittle, bond.  It often discolours the rope and is glossy.  My “go to” for this purpose is Hypo Cement.  For those who do not know this product, it is a fabric cement used primarily by costume designers and appliqué artists and so it forms a flexible almost transparent bond.  

 

 

There is also a range of fly tying cements – some solvent based and some water based.

 

 

Below I show some knots treated with various products.  I know that only a small drop is needed to seal a knot but here I have covered the whole knot in order to try to demonstrate the differences.  Unfortunately the differences are not so obvious in the photographs

 

 

 

 PVA.                                                                                                          CA

 

Hypo Cement.                                                                                       Fly tying Cement

 

 Water based Fly tying.                                                                        UV activated Fly tying

 

Amongst the fly tying cements the water-based version seems to be the best and while the UV version is attractive, it seems to darken the rope and is rather glossy.

 

John

Edited November 29, 2020 by bartley

[Bob Cleek]

And then there's white (clear) shellac. A touch with a loaded paintbrush wicks quickly into the knot or line and dries very fast. It's invisible when dry. Line can be shaped as desired while it is drying. It cleans up easily with denatured alcohol and, most importantly, can be reversed after drying by applying alcohol again to the shellac, which will then dissolve, as before. Oh, and did i mention, it's the cheapest of all options and also serves as a great wood sealer and finish.

 

Your mileage may vary, of course.

[bartley]

Yes indeed, Bob.  I should have mentioned that one as well.

 

John

[VTHokiEE]

21 hours ago, bartley said:

Amongst the fly tying cements the water-based version seems to be the best

Have you used the water based with synthetic (polyester) line at all?

[Bob Cleek]

Clear nail polish thinned with acetone works, as well, and the bottles come with a handy built-in brush. Getting the acetone into the bottle can be a pain, though. I use a hypodermic syringe to fill the bottles through their narrow openings. Nail polish will dry glossy, but if you thin it enough, there's no gloss when it soaks into the line.. It's handy for its quick-drying characteristics and the built-in brush.

[bartley]

5 hours ago, VTHokiEE said:

Have you used the water based with synthetic (polyester) line at all?

No, I haven't tried any of these products on synthetic rope.  The rope I show is Syren rope.  I am sure the effect will be different on polyester rope.  The fly tying cements hold quite well but they are an expensive option and as Bob says, shellac is pretty cheap.

 

John