Silicone Grease And Stress Cracking

[talkinghead]

I'm gonna just start using spit.....

 

 

 

Rick

[Pen Nut]

I'm gonna just start using spit.....

 

 

 

Rick

 

Ah but what have you been eating eh !!! Always remember doing the 'bulling' of parade shoes at RAF Dishforth and the clever ones in the dorm used tap water in the up turned lid of their Kiwi polish whilst us new faces spat our curry impregnated spit on to our shoes which, apparentley, contain fat thus slowing down the required finish process....... The more you find out the less you know eh.

[niksch]

So we are all concened about the MB resin, but one issue remains...which lubricant "may" or "may not" cause damage to the elastomer seal. The vaseline or the silicone??

 

The seal is the critical component of the MB piston mechanism.

[SamCapote]

So we are all concened about the MB resin, but one issue remains...which lubricant "may" or "may not" cause damage to the elastomer seal. The vaseline or the silicone??

 

The seal is the critical component of the MB piston mechanism.

 

If I was betting, I would think the silicone would be safer for the elastomer....but there is a huge variety and industry body of research that determines the best lubricants for mission critical materials. You would need a chemical lubrication engineer to first know what the elastomer and resin are made from, and then be able to come up with the best solution for both.

 

If I was testing the elastomer, for safety with vaseline, I would just stick one in a jar of it, and pull it out for weekly/monthly inspection. You could probably do the same thing with a spare resin barrel. Put one end in silicone grease, and the other end in vaseline. The seal sliding back and forth is not adding significant force to bring on the microcracks. If it is a chemical interaction you will see it develop over time. Someone has to have some spare parts to do these tests.

Edited April 4, 2011 by SamCapote

[caoquocdat]

 

how about lip gloss, is it safe for pelikan barrel? it's difficult to find silicone grease in vietnam

Edited June 23, 2015 by caoquocdat

[meiers]

You can buy it on amazon. TRIDENT PURE SILICONE GREASE

 

I have never tried lip gloss.

Edited June 23, 2015 by meiers

[Feathers]

 

how about lip gloss, is it safe for pelikan barrel? it's difficult to find silicone grease in vietnam

Please do not use lip gloss or other cosmetics in your pens. They are filled with other ingredients that are not safe for your pens.

[scratchofapen]

I can only give my experiance... I lubricated all my MB resin pens, some 40 years old, with silicone and never experienced any problems. Neither on the resin nor on the seals.

 

Same or vintage plastic an even some celluloid pens-no problem.

 

It might make a difference what kind of silicone you use, some types contain various additives special to the intended use-simmilar to vaseline.

 

If you want pure silicone without adds in small quanitities try the high temperature resistant type used in the food industrie. Namely those used for coffee machines are without any additives, as they would separate under the high temperatures and the pressure, and so contaminate the coffe/food.

 

 

IIRC my chemistry lessons either silicone or vaseline should be sutable for lubricating a pen if it's pure.

Edited June 23, 2015 by scratchofapen

[macball]

I was unaware of this thread and the debate because it started several years ago. I have recently acquired the skill of removing the 146 and 149 piston for cleaning and lubrication. Using the advice on this forum I searched for a supplier of Trident Silicon Grease. It is not difficult to find because every scuba dive shop stocks it. It seems reasonable that the product would be inert. That is why it is used to lubricate diving regulators. It seems that a petroleum product like Vaseline would be damaging to another petroleum product like rubber and plastic. The caution described in the recommended reading product sheet (above) is derived from a test that may not be realistic to its use in a pen. The test plastic was put under stress and heated for 16 hours at 80C or 176F for 16 hrs. That is a lot of heat for a long time. Scuba divers have also been using the same silicone grease to lubricate the gasket seals of their underwater camera cases and some have reported leakage after some time. It has been suggested that some gaskets are made of rubber and others are made of silicone. The silicone grease may penetrate the silicone gasket causing it to weaken and swell. But the evidence on this is weak as well because the divers reporting the problem do not know what their gaskets are made of.

 

An interesting article in Environmental Stress Cracking of Plastics By D. C. Wright (Google) describes the failure of plastic caps used to seal solvent containers. The failure of the caps had been attributed to quality control in the cap manufacture, exposure to the solvents, variable torque used to close the cap, etc. But it turned out that the manufacturer of the cap supplied silicone grease to allow the user to lubricate the O ring seal. The author discovered that the culprit was not the expected causes of cap failure, but the use of silicone grease. The author points out that just because it doesn't happen in every case or that there are obvious signs of corrosion that silicone is safe on plastics.

 

The proposed experiments proposed above in which a spare barrel is exposed to silicone grease on one end and vaseline on the other end would be inconclusive. Stresses induced in the manufacturing process and in daily use may affect only 1 in 5 pens. Without exposure to silicone grease none of these would fail. Just because someone has been lubricating the pistons and barrels of their 20 pen collection for the past 50 years does not mean that silicone is safe for MB pens.

 

All of this might be true for vaseline as well. I am concerned and don't really know what to do. Should I remove as much silicone residue as I can from my barrel, or leave things alone and hope for the best?

 

Now I am stressed!

Edited June 25, 2015 by macball

[Feathers]

Interesting info, @macball - thank you for that input. This is a bit adult, but I do know that personal lubricants that are silicone based must not be used with any adult toy or feminine hygiene products that are made from silicone. Therein lies the problem, we don't know what the materials in the pen are made from, and if there is any portion that has silicone in it, well, adding silicone grease would be a complete no-no, but I also do wonder about the safety of using of a petroleum product such as vaseline. I guess MB would say, 'don't touch it, let us use our patented MB lube on it, and all will be well' LOL. Seriously though, what DO the MB techs use?

 

@Scratchofapen makes a valid point about using food-grade silicone, though.

[Ron Z]

Those of us who repair pens professionally have been using silicone grease for years - some for decades. Not only do we repair pens for clients, we repair our own so see the effects of the materials used over time. We frequently have a pen that we've worked on come back years later for service of one kind or another. Word about problems circulate within the trade rather quickly. I have not heard of, or seen any, problems related to the use of high grade silicone grease in fountain pens aside from the anecdotal reports about cracks in Montblancs.

[Feathers]

Those of us who repair pens professionally have been using silicone grease for years - some for decades. Not only do we repair pens for clients, we repair our own so see the effects of the materials used over time. We frequently have a pen that we've worked on come back years later for service of one kind or another. Word about problems circulate within the trade rather quickly. I have not heard of, or seen any, problems related to the use of high grade silicone grease in fountain pens aside from the anecdotal reports about cracks in Montblancs.

That is reassuring, thank you. So, do you think the reports of MBs cracking is more hype than anything?

[Ron Z]

 

 

So, do you think the reports of MBs cracking is more hype than anything?

 

I don't have a good answer for you. I have heard random reports, not from pen people, but I can not prove the negative either.

[Feathers]

 

I don't have a good answer for you. I have heard random reports, not from pen people, but I can not prove the negative either.

Fair enough. Thanks though, for weighing in with your professional opinion. I really appreciate it.

[macball]

In addition to not knowing what the components are in the resin it is also not known what stresses the barrel or other parts were exposed to that could predispose them to cracking at a later time. Is there photo documentation of silicone-induced stress fractures of the barrel (silicone grease used as piston lube) or section (silicone grease used as feed/barrel sealant)?

 

I am not sure what people mean when they say it would be important to use pure vaseline. Vaseline is a proprietary formula petroleum jelly. When you open a jar of Vaseline that is it... pure Vaseline. The Unilever MSDS sheet says that the components of Vaseline are:

This product is not manufactured to contain a reportable component as defined in 29 CFR § 1910.1200:

 

So, the components of Vaseline are a secret in the same way that MB precious resin is. Perhaps it is safe to use a secret lubricant on a secret plastic.

 

On the other hand, the MSDS for Trident Silicone Grease says that the components are:

100% DIMETHYLPOLYSILOXANE (NON HAZARDOUS FOOD GRADE SILICONE GREASE)

 

So, it is known that scuba diving Trident Silicone Grease is pure and safe for human consumption (in this case exposure to lung tissue). It remains to be determined what plastics are used in barrels, sections and feeds, and pistons to determine if they are compatible with 100% food grade silicone grease (Trident).

 

​Surely there must be a forum member who is a mass spectroscopy hobbyist as well as pen collector who can answer this question.

[Pen Nut]

" Perhaps it is safe to use a secret lubricant on a secret plastic. " Genius !

 

 

Anyway mass spectroscopy hobbyist ...... do we have any ? If so what it is that you do ?

[macball]

I am not a chemist so I am not exactly sure. There seems to be a different battery of tests depending on the class of plastic. Most of these tests are meant for quality control in the industry, but a few companies specialize in reverse engineering of a plastic composition. A plastic expert would likely know where to start by identifying the class based on its appearance. Samples from the barrels of a couple of pens of various vintages would determine if the formula has changed over time. As I understand it, the plastic sample would be dissolved in various solvents (we know alcohol would be one) and the liquified sample injected into a liquid and gas chromotography setup to separate its components. The components would then be analyzed and identified by mass or infrared spectroscopy.

 

1) a forum member who has access to this equipment and expertise could do it for free.

2) a forum member who has the disposable income (which must be most... How many fountain pens, if any, do you actually need?) could contract out to one of the various companies who do this analysis for a fee.

3) a forum member could arrange a date with the chief chemist at MB, loosen them up with liquor and "entertainment", and get them to reveal the secret (see any 1960's cold war spy movie for details).

[luckduck369]

So we are all concened about the MB resin, but one issue remains...which lubricant "may" or "may not" cause damage to the elastomer seal. The vaseline or the silicone??

 

The seal is the critical component of the MB piston mechanism.

Tom from penboard suggests using Vaseline instead of Silicone. Please see the thread.

 

https://www.fountainpennetwork.com/forum/topic/27104-stuck-piston-and-lubrication-question/

Edited June 29, 2015 by luckduck369

[Feathers]

I am not a chemist so I am not exactly sure. There seems to be a different battery of tests depending on the class of plastic. Most of these tests are meant for quality control in the industry, but a few companies specialize in reverse engineering of a plastic composition. A plastic expert would likely know where to start by identifying the class based on its appearance. Samples from the barrels of a couple of pens of various vintages would determine if the formula has changed over time. As I understand it, the plastic sample would be dissolved in various solvents (we know alcohol would be one) and the liquified sample injected into a liquid and gas chromotography setup to separate its components. The components would then be analyzed and identified by mass or infrared spectroscopy.

 

1) a forum member who has access to this equipment and expertise could do it for free.

2) a forum member who has the disposable income (which must be most... How many fountain pens, if any, do you actually need?) could contract out to one of the various companies who do this analysis for a fee.

3) a forum member could arrange a date with the chief chemist at MB, loosen them up with liquor and "entertainment", and get them to reveal the secret (see any 1960's cold war spy movie for details).

For the sake of all current and future MB owners, I am willing to step up and volunteer for #3 LOL

[macball]

I have read the thread

http://www.fountainp...ation-question/

But I do not see a definitive answer. There are opinions by experts who have used both lubricants, each for a long time. The original comment was that silicon weakened the resin barrel and caused stress fractures. But there are few cases and the fractures could be due to other causes. It has also been suggested that silicon lubricant might damage the piston elastomer, which has been also suggested to be made of silicon. Again, I am not a chemist so I hope that someone with a scientific background could address some of these anecdotal comments. I don't think that the piston is an elastomer, even though it has been described as such (even by me). An elastomer is a polymer with the characteristic of viscosity and elasticity of two groups: unsaturated (natural and synthetic rubber) and saturated (silicone and plastic). I doubt that an elastomer has either the durability to serve as a piston seal in a pen or the resistance to some of the chemicals used in inks. I think the piston is made of polyethylene based on its color and texture. It would have good chemical resistance to vaseline and very good resistance to silicon. Does anyone ACTUALLY know what the piston is made of, or should this be on the list for reverse engineering with the barrel plastic?