sagging standing rigging

[Dziadeczek]

Is there a way to fix sagging standing rigging on my model? I made those from cotton threads which I twisted on my ropewalk. They looked good and when I mounted them on the model, they were fairly tight, just right, not too tight and not too loose.

But, when we got wet this winter and cold weather came in here, those lines (mosty stays) became loose. At first I thought, I would pretend that "I did it deliberately to show natural way of slightly loose lines", but with each bout of rains and cold and subsequent warm/dry temps, sagging became too pronounced, I am afraid.

If I tighten them some more, when the temps again drop down and we get more rains, they might became too tight and break, I fear.

I don't want to replace them with synthetics - at this stage it would be way too laborious and probably impossible, maneuvering in the midst of this spiderweb of other ropes all over. 

Is there a way to gently coat them with something that would insulate them from the elements and excessive temp/humidity spikes? If so, what should I use?

Thanks,

Regards,

Thomas

 

Edited April 10, 2023 by Dziadeczek

[druxey]

Perhaps, when the atmosphere is right and things tighten up, a little shellac. If you use matte medium, the water content will sag the lines. Test one line first before committing!

[hornet]

Perhaps you could experiment with Model Aircraft Dope which is used to seal and tighten the ‘skin’ on model aircraft. I’ve not tried it but it may be worth a try. 

[Bob Cleek]

1 hour ago, druxey said:

Perhaps, when the atmosphere is right and things tighten up, a little shellac. If you use matte medium, the water content will sag the lines. Test one line first before committing!

I second Druxey's suggestion. There's never any certainty with any of this, so experiments off the model are recommended, as always. Natural cordage shrinks when it gets wet because the moisture causes the natural fibers to swell which tightens the lay. The line becomes slack after being wet because the moisture causes the rope to tighten and stretch. Afterwards, it stays stretched until re-wetted.

 

You should test a section of your laid up rigging line to see if simply applying the shellac before trying to first soak the line in hot water will alone shrink it sufficiently. The shellac soaking into the twisted line may be tighten the line sufficiently on its own and, if so, when the alcohol evaporates, whether the shellac will have sealed your rigging from further moisture and will have cemented the twisted fibers tightly together and sealed out further moisture being absorbed.

 

If that doesn't cause the line to shrink sufficiently, I'd test it with an application of boiling hot water and see if that shrinks the cordage tighter. If so, I'd put the model somewhere the humidity was low for a day or three and then apply a generous amount of boiling hot water and let it soak into the rigging. Cotton should shrink in hot water, even if the cotton has been "pre-shrunk." Your twisting up the rope should cause it to tighten in any event because as the cotton fibers soak up the water, they will expand and your twist will tighten as the fibers become larger. Let the water dry (a hair dryer should speed things up if you are careful) and then apply thinned clear ("white") shellac (most canned shellac can be applied right out of the can.) The shellac should soak into the rigging and "set" the cordage, also sealing it so it will not absorb moisture in the future. The shellac should not change the color any nor should it be visible when dry. 

 

When attempting to shrink rigging, and particularly standing rigging, work on each side alternately rather than both sides simultaneously. This will permit one side's taking up before the other and should prevent a sudden over-shortening on both sides that could cause the rigging to over-tighten and pull loose or break if too tight.

 

And again, experiment with these techniques before you attack the model's finished work with any of them. We're just making it up as we go and free advice on the internet is often worth less than what you pay for it. Let us know how it works!

Edited April 10, 2023 by Bob Cleek

[Dziadeczek]

Many thanks, Druxey and Bob Cleek, for your advice! I too was thinking about clear shellac, since white PVC glue, when dry, would still absorb moisture, soften up and allow it to penetrate into the ropes, and thus the situation would continue...

Shellac should seal the ropes and stop the expansion/shrinkage phases, in relation to changing humidity. At least, in theory.

I certainly will try it on a length of rope stretched outside of the model, and let you know the results.

If it doesn't work, the model aircraft dope will be next.

Thanks again!   🙂
Thomas

[Dr PR]

Be sure to let us know how it works! I have a couple of old models that could use a bit of line handling.

[Auger]

The rigging on my Constructo Enterprise sags in the winter when there’s high humidity. During the summer it tightens back up. I watch the triatic stay, it sags, it goes taught…

 

I did the bees wax melt on all of my lines when building. Maybe that’s helping a little.

Edited April 10, 2023 by Auger

[Dziadeczek]

Actually, in my case, the cotton ropes get tighter when the humidity goes up (~70%) and the temps get down (~60 F).

When the humidity goes down (~40%) and ambient temps go up (~75 F). the lines get loose and are sagging.

 

As I promised, I did a little experiment out of the model. I stretched three pieces of rope (each ~ 18 inches long) and treated them with three different substances: Shellac, Wipe Poly satin and Testors Dullcote - these are what I had handy around the house.  (I avoided any substance which is water based, since I thought it would not insulate the ropes well enough from moisture).

 

 After the first coat (brushed on), I noticed that the treatment has helped somewhat, but not enough. The ropes were still stretching and shrinking, albeit not so much. So, I repeated the same applications. Right now, I am waiting for the results, when the weather gets dryer/warmer (which is more normal for this area).

I also noticed that shellac gave some shine to the rope - a bit undesirable...   😬  Wipe poly looks shiny and whitish.  No...  😬

But after two coats of Dullcote (petroleum-based product), the third rope looks virtually indistinguishable - no shine and no color change!!!   😀

So, i think I will opt for this Dullcote for my rigging.

I attach three pics of each rope treated with the above (in the same sequence).

Notice that these pics are large enlargements of the original ropes, so the effects are somewhat exaggerated, when compared with the original lines.

 

Edited May 2, 2023 by Dziadeczek

[Bob Cleek]

2 hours ago, Dziadeczek said:

I also noticed that shellac gave some shine to the rope - a bit undesirable... 

If you are getting a gloss finish from the shellac, you are putting too much shellac on. Just apply a single coat of thinned shellac (out of the can if premixed, 2 pound cut if not) and let the line soak it up. If that is allowed to dry without excessive shellac build-up, the clear shellac should be invisible. If you put another coat on top of the thinned shellac, you will start seeing a gloss effect. You should be able to remove most, if not all of the gloss shine by wiping the shellacked line down with an alcohol-soaked piece of cloth or a cotton ball. 

[Snug Harbor Johnny]

  I'm betting that polyester thread is a good bet for making scale rope - don't forget that 'stretching-out'  the rope is an important part of the process, just as it is for making full-size rope (which I've done for demos at historic sites).  Cotton and silk can be subject to deterioration over time, as I've seen with a model ship my father made 70 years ago and now needs re-gigging (he used cotton).  Flax is approved in the 'rules' for museum quality models, but flax thread fine enough is hard to find and costly.  Although high quality polyester (Mettler or Guterman) has not passed the 'test of time' yet, I'm betting it will.

[Dziadeczek]

On 4/27/2023 at 6:24 AM, Snug Harbor Johnny said:

  I'm betting that polyester thread is a good bet for making scale rope - don't forget that 'stretching-out'  the rope is an important part of the process, just as it is for making full-size rope (which I've done for demos at historic sites).  Cotton and silk can be subject to deterioration over time, as I've seen with a model ship my father made 70 years ago and now needs re-gigging (he used cotton).  Flax is approved in the 'rules' for museum quality models, but flax thread fine enough is hard to find and costly.  Although high quality polyester (Mettler or Guterman) has not passed the 'test of time' yet, I'm betting it will.

I always pre stretch my ropes right after I remove them from the ropewalk.

Some time ago I got a large spool of linen thread from Barbour, if I remember. The thread is snow white and too stiff to make ropes from. I don't think one can get appropriate linen thread anymore. Who knows, maybe polyester instead of cotton, after all. But I found that polyester is even more "springy" and has this undesirable tendency to suddenly unravel once you cut it...  😕

Spoiler

 

 

[Bob Cleek]

1 hour ago, Dziadeczek said:

But I found that polyester is even more "springy" and has this undesirable tendency to suddenly unravel once you cut it...  😕

 

Indeed it does!

 

Read the below threads (from the "articles - more" drop-down menu at the forum masthead) which address the problem of rope unraveling generally and polyester rope unraveling particularly. Note Chuck Passaro's method of "heat treating" polyester rope to eliminate unraveling. The information in these threads will probably solve your problems with unraveling.

 

 

 

[Snug Harbor Johnny]

  Ah-ha ... I'd forgot about the heat-treat step Chuck uses.  That is, wind the poly mini-rope around a metal pulley and put in a toaster (or other) over at 350 degrees F for no longer than 5 minutes - then allow to cool on a rack.  I will try that.

 

  As for linen, many 'old time' ship modelers used a generic type of fly fishing line known as "Old Cuttyhunk", which was mass produced (many different labels and brands, ergo they're now in collections) through the 1940s and available for quite some time afterwards from stock.  It's a collector's item now and very expensive, and the thinnest version (something like .015" diameter) is the rarest.  It was often white, so for standing rigging it would have been dyed.  I've seen some here and there in antique shops still on a reel (for a rod and reel) as a collector's item ... and very $$$.  But I handled some of the line, and indeed it was true miniature rope that was very flexible ... as it had to be for fly fishing.  I think my old friend used to fish with it back in the day.