My climbing rope is full of pine pitch. Help!

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I put my ropes in the jaccuzi tub with woolite and turn on the jets every so often for a day and then run them through a wash cycle with very light soap. Seems to work very well for me.
 
Experiment Update

After being away for about 3 days, I returned to find the nail was completely clean. When I shook the test tube, a hazy cloud of emulsified pitch swirled up from the bottom to fill the tube.

That is a nice experiment, Moray, but it really isn't good chemistry...

Bad chemistry? Hmmmm...I don't remember saying anything at all about chemistry when I described my test tube experiment. I drew no conclusions, made no predictions or comparisons, made no mention of washing machines. I simply described exactly what I did and what I saw--the raw ingredients of good experimental science.

But I did intend the experiment to isolate the chemistry from the much more complicated situation of the washing machine. Having completed the chemistry experiment, I am now entitled to offer an opinion about the chemistry: very concentrated laundry detergent is only feebly able to remove pitch from a rope, and it does so by forming an emulsion with the pitch. Acetone and denatured alcohol rapidly dissolve the pitch completely. If you merely want to rub out the pitchy spots, you probably won't have much luck with laundry detergent.

The undisputed testimony of many that the washing machine delivers nice clean ropes, coupled with the evidence from my bad chemistry experiment that even very concentrated laundry detergent is extremely slow in removing pitch, tells us that all that rope flexing and rubbing that goes on in the machine plays a huge role in getting the rope clean in one short wash cycle.
 
Moray! I admire your contributions to this forum too much. Please don't presume that I am offering you any harsh criticism. You seem to have been offended by my comments. I sincerely apologize.

"Not good chemistry" is quite a bit different from calling your work "bad chemistry". I didn't say that it wasn't a good experiment, nor that it didn't show what you wanted it to show. In fact, I seem to recall stating that it was a "nice experiment" I was only trying to say that it didn't qualify as a thorough and complete chemical analysis of the situation. Since this is "arborist" site, and not "chemistry" site, I didn't really go any further with it.

Your test tube experiment does a nice job of showing that pine pitch does dissolve in a soapy solution. What is doesn't really show is whether that is effective at washing ropes, since the concentrations and type of agitation are considerably different. We should also consider that pine pitch may undergo some chemical changes when it dries on a rope.

There is an entire branch of chemistry that is somewhat dedicated to the science of solutions and solubility. It's called "Quantitative Analysis". My simple and only point was that while you were able to determine that soap would cause (wet) pine pitch to go into solution, you were not able to say how much soap was required to do the job, nor how effectively it would remove dry pitch.

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You could have some fun with this by trying the same test a few different ways. With my strong background in chemistry, I quickly came up with these related but unknown tests that could be run for more information

1. Test with NO soap added: this would tell us how much pine sap dissolves in water. Good measurements would be helpful.

2. Using lower concentrations of soap in larger amounts of water. I suspect that wet pine pitch will dissolve better with less soap. 3:1 is pretty strong.

3. Try mixing pine pitch with straight soap, see how that compares to the straight water.

4, Try any of the above tests on dried out pine pitch, which will probably be available running down the side of the tree you have been testing. I would expect very different solubility, since most of the pine sap is composed of volatile elements. If a significant part of the pine sap will not mix with water, but the water immiscible elements evaporate away, how well do the resins that remain mix with water/soap/detergent?

I'm just making some experimental suggestions, since you seem to enjoy the quest for knowledge.
 
I sincerely apologize.
Pdqdl, now I feel bad. The devil made me do it. I knew you meant no insult and none was taken, but somehow my words came out as if I were miffed. I apologize for whiny tone of my post.

We should also consider that pine pitch may undergo some chemical changes when it dries on a rope.

This is a good point and probably helps explain why the pitch problem just goes away even if you don't wash your ropes. Old pitch drops, like those that fell on my car a few months ago, become powdery and somewhat crystalline. The volatile components soon escape, and the double bonds in the terpenes left behind should be readily attacked by UV and atmospheric ozone. Once this process has rendered the pitch non-sticky and somewhat crystalline, the ordinary flexing of the rope in use should simply flake away whatever is left.

At first I was dismayed that our two "authorities" from the rope manufacturers gave contradictory advice about the use of acetone and the like for removing pitch. Then I realized this was a "teachable moment," as they say. We defer to them as authorities because they should be trustworthy and they should know much more than we do. We want to pose our questions to them and take their answers to the bank. End of story.

Now we have to rethink all of that. They aren't both right--maybe neither is. We are back where we started, not having definitive answers to our questions, and not knowing how to recognize or find an expert who knows the answers.

I like your list of proposed experiments, but I have another I want to do first. The individual strands that make up 1/2 inch TreeMaster each have a tensile strength of about 80 lbs. If I pull two strands out of the same piece of rope and soak one in acetone for a few days, I can then separately test them for tensile strength. While I'm at it I'll soak another strand in denatured alcohol, and maybe one in PineSol.
 
I put my ropes in the jaccuzi tub with woolite and turn on the jets every so often for a day and then run them through a wash cycle with very light soap. Seems to work very well for me.

I think this sounds logical. Jump in the jaccuzi after a hard day to loosen up so why shouldn't that relax a dirty rope and get it ready for the next day?
 
...
I like your list of proposed experiments, but I have another I want to do first. The individual strands that make up 1/2 inch TreeMaster each have a tensile strength of about 80 lbs. If I pull two strands out of the same piece of rope and soak one in acetone for a few days, I can then separately test them for tensile strength. While I'm at it I'll soak another strand in denatured alcohol, and maybe one in PineSol.

Is your tensile strength setup sensitive enough for just a couple of strands? I would think that you would need a few more than a couple.

This could get interesting! Your testing of strength reduction is an excellent idea, and is much closer to our interests than some arcane solubility tests. It occurs to me that testing ropes made of of different fibers would be of great interest. Do you recall that the manufacturers all listed bleach as a no-no? Quite frankly, I would start my testing there, and with plain water as a standard, to see if I could establish a range of decline in tensile strength.

Let me know if you need any fibers. I have some used rope sitting around in Stable Braid, Arborplex (I think), some of the cheap rope from Bailey's, a short chunk of Velocity, and I could sacrifice a little bit of my Beeline. I have some other types, but I am not willing to sacrifice any of my good, intact ropes.

P.S.: You didn't sound "whiny" at all. "Miffed" is a more apt description, but it sort of makes sense given the circumstances. You put in the hard work to do all these unsolicited experiments, and some impertinent twit comes along and offers criticism? Let 'em have it with both barrels...
 
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I have the results of my experiments to determine the weakening effect of various treatments on residual fiber strength. All the strands tested came from the same piece of slightly used 1/2-inch Samson Treemaster. These are the smallest strands in the rope--162 of them--all made of filament polyester. The tested strands, about 30 inches long, were subjected to 5 treatments (thanks to pdqdl for suggesting #2 and #3):
1. No treatment (control).
2. Soaked in water for 66 hours.
3. Soaked in full-strength household bleach for 66 hours.
4. Soaked in acetone for 72 hours.
5. Soaked in denatured alcohol for 72 hours.

After removal from their respective baths, the samples were air dried for 24 hours. The bleach sample received special treatment and was rinsed thoroughly in tap water before air drying. Since 3 strands were subjected to each treatment, there were 15 samples to break by pulling between two 1/2-inch stainless steel pins.

Results in lbs for each treatment:

1. 48,50,54
2. 50,50,52
3. 48,52,46
4. 50,48,50
5. 46,48,44

General comments. These results don't show that any of the treatments, compared to the control, are harmless. Nor do they show that any of the treatments are harmful! Well, then, do they show anything at all?

Even though 3 samples is normally a ridiculously small sample size in a statistics experiment, it depends on the question you are trying to answer. If you are looking for a big difference between the control and an experimental group, then a small sample can detect it. And if time is a factor, as it surely must be in the chemical degradation of polyester, then a long exposure time also adds power and resolution to the experiment.

Conclusion: it may well be that ALL of the treatments are damaging to the fibers (likely true), but are any of the treatments highly damaging? Clearly not, not even after 3 days of soaking. For a very short exposure of the sort needed to rub out a patch of pitch, the damage to the rope, if any, must be essentially undetectable and therefore negligible.

The guy from Yale Cordage:
"hand wash in acetone - absolutely not!!

Do not under any circumstances use anything like gas or acetone to clean your ropes. They may look ok when done but they will fail due to the high chemical concentration."

This is nuts. Where is the evidence? Fail at what tension? What high chemical concentration? We wanted sound engineering advice from these guys, but got fearmongering instead.
 
I think you got it down pretty well, Moray. I really didn't think alcohol or acetone would make any difference.

I think that it is interesting that bleach seemed to have no effect, despite it's widely rejected use on ropes. It is a pretty strongly reactive chemical, and I would have expected some red-ox reactions to occur, weakening the rope if exposed long enough. But then again, maybe not? We have been washing our clothes in bleach for a long time, and it is not commonly believed that it makes the fibers in our clothes weaker.

Are you good at statistics? It would be interesting to see a chi-square analysis of the small sample size to find out if the differences observed are "statistically significant". Maybe someone else on line will pick up your numbers and run with it?

I would do it, but I would be digging very deep into my math background to pull that off. It's been about 30 years.
 
...but I would be digging very deep into my math background to pull that off. It's been about 30 years.

Well, I dusted off my statistics book (way more than 30 yrs for me!) and think I have it figured out.

The control group broke at 48, 50 and 54 lbs. for a mean value of 50.67. The ethanol group seemed most degraded by the long soak with a mean breaking strength of 46 lbs. The 3 tensile measurements clustered rather closely at 46, 48 and 44 lbs.

The question is: is there some real degradation going on or could those 3 low tensile values be accounted for by the normal variability in any kind of sampling process? It's like flipping a coin--once in awhile you'll get 3 heads in a row. If you did, you couldn't then conclude that the coin wasn't fair, just that you were unlikely to see such an outcome with a fair coin.

Mathematically we ask: what is the probability that the observed low values could be observed by chance assuming there was no experimental effect of the ethanol soak? The answer (using Student's t test) surprised me. Only about once in 36 times would you expect such a cluster of readings if the alcohol was doing no harm.

This strongly suggests that denatured alcohol (which contains several compounds besides ethanol) is mildly harmful to polyester rope.

I think I may repeat this experiment, this time soaking 6 strands for two weeks. The results should be interesting and maybe conclusive.
 
Flake the rope losely into a tub of lukewarm water with a generous amount of Woolite in it. Let it soak for a few hours. Rinse. Check rope for more pitch. Repeat if necessary.

It removes most of the sap but doesn't harm the ropes.
which Woolite product? dark? there is a few to choose from. what do you mean by "generous amount"? is that like half of bathtub to 100 oz woolite?
 
sunbrella recomends Turpentine (100%), Dishwashing liquid (2 oz.) / 1 gallon water, for tree sap removal, I don't know how safe it is for climbing lines. I am in search for an answer ASAP
 
If you have a low-suds washer without the agitator up the middle of the tub, you can throw your ropes in there and wash them. If you have pine pitch on them, use a rag and WD-40 to clean it off the rope, then throw it in the washing machine. The best thing I've found, that is safe for all non-organic rope fibers, is this stuff... usually available in the organic/environmentally friendly section of grocery stores.

ZumClean.jpg
 
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