Audioraven
Well-Known Member
INX RubberKleen works really well.
Rubber rejuvenation
- Thread starter Catmanboo
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Retrovert
Addicted Member
You are completely correct. I actually knew the structure is different. I intended to write functionally similar in the context of solvents and the volatility was lower than toluene.
The inclusion of weight was per volatility of hydrocarbons generally decreasing as molecular weight increases. So the smaller the molecule (toluene, xylene) the more volatile and aggressive the solvent, plus generally the riskier it is for neurological and hepatic effects, while the larger the molecule (kerosene) the less volatile and agressive the solvent, and (more or less) the safer it is.
My brief experiment with trying to use limonene to rejuvenate rubber did not work. I don't think it sufficiently swelled the rubber to allow the plasticizer to migrate in.
Retrovert
Addicted Member
For softening rubber? Huh. The MSDS shows a combination of toluene, unspecified hydrocarbon solvents (including the obligatory Prop 65 warning for benzene), denatured alcohol (ethanol + methanol), and ethyl acetate (common acetone substitute, such as in nail-polish remover). That should remove pretty much anything on the surface, but it's not going to rejuvenate since it doesn't leave behind a plasticizer. I expect it attacks the surface a little bit, roughening it so it better grabs, like on wide belts.
Seems to be for printing plants. I don't think it would be a long-term solution for idler wheels or pinch rollers. A lot of those solvents will pull plasticizers out of the rubber, worsening the hardeness.
Years ago I asked a copier repair tech what was used for the big laserprinters and copiers and the answer was either Fedron or something nearly identical. I took one look at the ingredient list (glycol ethers and other nastiness) and decided to instead purchase new rollers. Which was the right answer. (I don't know what the lifespan of repair techs is, but it surely cannot be that good.) Jams instantly stopped.
I well remember the stink of the volatile solvents used for cleaning the presses and conveyor belts from whenever I went to the printers to verify proofs before the full run began. The sweet smell of cancer and neurological deterioration. I don't think slathering solvents on equipment like that would be today permitted.
Audioraven
Well-Known Member
I'm no chemist, all I know is I used it on 4 hardened R2R pinch rollers 5 years ago and they are still good today. YMMV.
phantomrebel
Serial Tapist
I would think there may be a possibility that the organic solvents help re-distribute the endogenous plasticizers (most are oil-based I believe). This would give a previously dry surface a softening effect. That said, old rollers are probably best replaced.
Retrovert
Addicted Member
That's one possibility, but this would imply some great penetration into the rubber which seems dubious. Shallow penetration and diffusing whatever plasticizer was left would account for the reports that the product only works for a short time.
Yet Audioraven reports it worked for five years. An alternate explanation is therefore needed.
So I conclude the manufacturer has hidden a plasticizer under miscellaneous hydrocarbons. Which the SDS and MSDS tend to bear out.
Both the MSDS and SDS list a "trade secret" ingredient (NJTS = New Jersey Trade Secret registry aka Trade Secret Registry Number = TSRN) for both cyclic hydrocarbon and aliphatic hydrocarbon. Both are other names for an enormous class of molecules which contains, among many others not having any function remotely like this, plasticizers. Since it is relatively non-toxic it need not be specifically listed other than as hydrocarbons.
I'm thinking this trade secret is methyl salicylate, ethyl salicylate, something similar, or a blend. Which explains how and why it works.
In any event, one can purchase or mix up the simpler version (solvent plus methyl salicylate) at little cost and it doesn't have the denatured alcohol or acetone, or acetone substitute.
Retrovert
Addicted Member
PB blaster should be experimented with. I swelled a idler tire to unusable condition once, so it does something.Toluene should be used with caution also. Wiped a turntable belt with it to deglaze, and it instantly grew in length.
Non-crosslinked, such as non-vulcanized, rubber readily dissolves in toluene; this is called "rubber cement" or "surround dopant".
PB Blaster is mostly deodorized kerosone and other solvents but no plasticizer.
Once the solvent evaporates the rubber should return to its normal size and properties.
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Retrovert
Addicted Member
That's a mix of glycol ethers. I suggest you look up the EU findings that such glycol ethers cause reproductive cancers, testicular and ovary atrophy, teratogenic effects, and low sperm count. Other that that, Mrs. Lincoln, how do you like your shiny new rubber?
Besides that, it's really just a cosmetic surface treatment. For years brake fluid was used to make tires shiny. You're old enough to remember whitewalls, I think. Nowadays silicones are used as these are longer lasting.
It didn't.
Are you familiar with PB Blaster? Says right on the can it renews O-rings.
Retrovert
Addicted Member
Maybe so, but consider the ingredients.
Alkyloxy Polyethylene Oxyethanol 0 - 3%
Solvent Naphtha Heavy Aromatic 40 - 50%
Heavy Petroleum Distillate 20 - 30%
Hydrotreated Light Distillate 30 - 40%
Solvent Naphtha Heavy Aromatic 40 - 50%
Heavy Petroleum Distillate 20 - 30%
Hydrotreated Light Distillate 30 - 40%
The Alkyloxy Polyethylene Oxyethanol is a surfactant, which lowers the surface tension and assists in cleaning, much like a detergent. Hydrotreated Light Distillate is the lighter fraction of kerosene aka naptha, which is a mix of petroleum distillates. The approximate boiling point of the hydrocarbon mix is indicated by the terms "light" (C4 to C9), "medium" (C8 to C13), and "heavy" (C8 to C23+). So what the ingredients indicate is a mix of short to long hydrocarbons. Basically the unrefined early evaporating distillates.
This will not be superior to any of the products specifically designed for rubber rejuvenation using methyl salicylate? It's just solvent that swells the o-ring which is not exactly the same as making it more pliable.
Any rejuvenation effect likely works as phantomrebel suggested by pulling plasticizer out of the interior and redistributing.
It likely also breaks certain crosslinked bonds on the surface, which makes the material more pliable.
Any of the non-chlorinated solvent paint removers work this way. The solvent diffuses into the paint, and crosslinked bonds are swelled which breaks them, softening the paint so it can be removed. I've used CitriStrip (on paint) and it works, just takes a while and may require a few applications to break all the bonds. The paint, which was large molecules, is now smaller ones.
Edit: clarified use of CitriStrip and paint strippers.
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maxhifi
Addicted Member
Only the thin ones from the 80s, the big wide ones are before my time. I appreciate the warning, brake fluid can stay in the garage!
Westley's Bleche-Wite (SIC) is the stuff. I have no idea whats in it, and too lazy to look right now. Its been around for a long time as a tire cleaning product.
I'll try the xylene and wintergreen oil next time I have a slightly slippy record changer idler though. Thanks for the tip.
Not to be contentious, but why do you say kerosene "also known as" naphtha?
Gadget, as someone who hangs at the Fisher forum, I'll retouch on this thread just because of you.
Feel free to douse a turntable idler wheel with whatever you want. All it's going to do is ride on an inner turntable platter housing. You won't get anywhere near the vinyl or stylus doing that.
But I would exercise extreme caution over using any of these discussed treatments on a pinch roller in a magnetic tape machine. The primary participants are discussing it in a complete vacuum, without regard to the operational environment. These rollers directly contact the oxide-coated side of the tape media.
Absolutely zero consideration has been given to the subsequent leeching effects of these solvent-based chemicals on the polymer oxide binders used on magnetic tape media. None. Especially with older media of any archival value, you proceed at your risk using any of these solvent-based treatments anywhere near magnetic tape.
And if they seep into the capstan bearing, its permanent lubrication charge could be attacked.
The old-time product we used to use was a water-based highly dilute trisodium phosphate solution that only provided a temporary topical treatment until new parts could be sourced. But more importantly, it could be fully rinsed from the parts without exposing the tape media to potentially destructive chemical residues. I do not believe that these synthetic rubber parts can ever be 'rejuvenated' or restored fully, but I know later users are now resorting to more adventuresome methods due to parts unavailability.
But nevertheless, proceed with caution.
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Retrovert
Addicted Member
That came in two formulations. My earlier explanation of that was removed as off-topic. Since it's resurfaced, here's the explanation.
(1) The older product was TSP (Tri Sodium Phosphate). It is highly alkaline, pH of 12, about the same as a 10% dilute bleach solution. It's not a rejuvenation product, it is a degreaser and cleaner. TSP is very useful because it chews up organic material, and also binds to calcium and magnesium in water, softening hard water, and also prevents the redeposition of removed material. This is why it was added to laundry, dish, and dishwasher detergent, and why I have a box which I blend with laundry detergent and dishwasher detergent. Absolutely amazing results. You're likely old enough to remember when detergent actually worked without added quantities of bleach; this is why. Phosphates were removed from consumer products because farmers were dumping quantities into the rivers, lakes, and oceans, causing algae blooms, and the supplies were running out. The ban did not, however, reduce the algae blooms. The phosphate supplies run out in about twenty-five to fifty years, estimates vary, and then massive famines will ensue as phosphorous feeds the world.
(2) The newer product, which is a mess of alkaline products:
Sodium Alkyl Benzene Sulfonic Acid 1 - 5%
2-Butoxyethanol 1 - 5%
Sodium Metasilicate 1 - 5%
2-Butoxyethanol 1 - 5%
Sodium Metasilicate 1 - 5%
The Sodium Alkyl Benzene Sulfonic Acid is a strong detergent.
The Butoxyethanol is a glycol ether which I above described. The entire family is problematic, and has been banned from certain applications in the EU (cosmetics, etc.) and will soon be banned for most cleaning products. The link to reproductive abnormalities (teratogenic, atrophy, cancer, spontaneous abortion, etc.) plus a variety of other illness are too strong to ignore. I would not use this indoors.
The Sodium Metasilicate is a very strong base; it's pH is 13, the same as sodium hydroxide (lye). Yeah, that.
Products this alkaline are not good for rubber. The main uses for strong bases are chewing up organic residues, particularly in metal vessels. Any benefit would be in deglazing the rubber and removing any surface organic, such as polymerized oil.
Retrovert
Addicted Member
No worries.
Both are a variable mix of petroleum distillates which are not further refined and have vague and sloppy meanings.
Kerosene is sometimes used to refer to the higher weights and Naptha to the the lower weights, but this is not guaranteed. This is why kerosene is often labeled as "light" or "heavy" or the term "fraction" is added. The difference is the molecular weight of the constituents
The other term often seen is "Stoddard Solvent", which was a blend of solvents created in the 1924 by Joseph Stoddard and Lloyd E. Jackson for use as a dry-cleaning product that was less volatile, i.e. lower flash point, than gasoline. That, too, is naptha. White Spirits is another one.
All of these terms have been abused to the point that one can't really tell what the ingredient is. Many companies hide exact formulations through the definitions.
Retrovert
Addicted Member
It's a good point, but the question is: how much solvent remains after treatment. The commercial renewal products contain that exact formulation and have been sold for decades for that purpose. Toluene is highly volatile and will rapidly evaporate. Methyl salicylate was, furthermore, likely used as the original plasticizer as it was ubiquitous for that purpose. Once the solvent has evaporated the plasticizers are largely trapped in the rubber.
I've never seen any comments about problems on the tape forums when using this for roller softening. That doesn't mean it doesn't cause problems, just that nobody wrote about it.
You mean removed. It would not be degraded or the physical structure altered.
That lubricant will polymerize over the years and should be replaced, in any event.
TSP or other alkaline products can only remove organic matter bound to the surface. None will re-plasticize rubber.
When servicing these particular machines, more than the success of any so-called rejuvenation chemistry for a mere piece of rubber needs to be considered. Especially when the media substrate, which is the most important and irreplaceable component of all, is involved. Quite directly in this instance.
You seem to have lost sight of that crucial factor in your purely chemical deliberations to restore rubber. Magnetic tape oxide binder formulae varied from manufacturer to manufacturer (the formula variations for many being a protected trade secret), so the range of chemically compatible interactions is necessarily narrow and complex in any event. What one binder formula may tolerate may attack another. And in the case of archived or older examples, they have already become less stable and more subject to oxide shedding and other binder detachments due to age. In particular, many polymer oxide binder coatings have hydroscopic characteristics to begin with, and are subject to age degradation if not properly stored and handled. In the case of aged and/or archival tapes, that concern is heightened.
As the oxide goes, so goes the data, or audio in this instance. And once it is gone, it is gone forever.
We never sought to re-plasticize rubber or restore a part that could never be reasonably restored when a pinch roller dried out. We looked to temporarily keep the equipment going until a new part arrived, without exposing invaluable tapes to chemical attack. Whether the chemistry used for 30 seconds was unduly alkaline on the surface of an already worn-out rubber part was secondary. The topical treatment we used served that purpose quite admirably without incident for many years. I do not have such confidence in the various chemicals that are being casually tossed about in this conversation, including brake fluid and highly penetrating petrochemical solvents.
I do not agree that your treatment chemicals necessarily remain trapped in the rubber, and you have presented absolutely no proof to support that. Whether they use aromatics or not, these other methods appear to break the molecular composition of the synthetic material to penetrate past the surface and saturate into the body of these parts with more lasting chemicals that can only leech back out again over time. And directly onto the polymer oxide binder layer of the media.
A tape machine that may chemically attack and damage tape media should not be the result of this process. Whether your solvent-based treatment attacks solid and impregnate-lubricated capstan bearings is a separately debatable issue. But that risk is certainly present as well.
There is really nothing further to discuss. I simply take a more holistic approach to these matters than you do.
People can do whatever they want with their machines. But they should be aware of the possible risks to their media in consequence. Having that sole audio recording of someone's dead parents start shedding off the tape six months or a year after being run across this treated roller would not be very nice.
You seem to have lost sight of that crucial factor in your purely chemical deliberations to restore rubber. Magnetic tape oxide binder formulae varied from manufacturer to manufacturer (the formula variations for many being a protected trade secret), so the range of chemically compatible interactions is necessarily narrow and complex in any event. What one binder formula may tolerate may attack another. And in the case of archived or older examples, they have already become less stable and more subject to oxide shedding and other binder detachments due to age. In particular, many polymer oxide binder coatings have hydroscopic characteristics to begin with, and are subject to age degradation if not properly stored and handled. In the case of aged and/or archival tapes, that concern is heightened.
As the oxide goes, so goes the data, or audio in this instance. And once it is gone, it is gone forever.
We never sought to re-plasticize rubber or restore a part that could never be reasonably restored when a pinch roller dried out. We looked to temporarily keep the equipment going until a new part arrived, without exposing invaluable tapes to chemical attack. Whether the chemistry used for 30 seconds was unduly alkaline on the surface of an already worn-out rubber part was secondary. The topical treatment we used served that purpose quite admirably without incident for many years. I do not have such confidence in the various chemicals that are being casually tossed about in this conversation, including brake fluid and highly penetrating petrochemical solvents.
I do not agree that your treatment chemicals necessarily remain trapped in the rubber, and you have presented absolutely no proof to support that. Whether they use aromatics or not, these other methods appear to break the molecular composition of the synthetic material to penetrate past the surface and saturate into the body of these parts with more lasting chemicals that can only leech back out again over time. And directly onto the polymer oxide binder layer of the media.
A tape machine that may chemically attack and damage tape media should not be the result of this process. Whether your solvent-based treatment attacks solid and impregnate-lubricated capstan bearings is a separately debatable issue. But that risk is certainly present as well.
There is really nothing further to discuss. I simply take a more holistic approach to these matters than you do.
People can do whatever they want with their machines. But they should be aware of the possible risks to their media in consequence. Having that sole audio recording of someone's dead parents start shedding off the tape six months or a year after being run across this treated roller would not be very nice.