Thread Sealant Versus Silicone Grease

[Clyde Suckerpunch]

For the knowledgeable amongst ye, a question :

 

Assume the application is to create a nice water- and air-tight seal on a threaded connection; e.g., the business end of a parker vacumatic. What are the comparative faults and virtues of silicone grease versus a rosin-based sealant such as sheaffer and parker used of old (and currently recreated and sold by fine pen peoples around the interwebs).

 

Thanks in advance for your consideration.

[watch_art]

I think silicone grease is an acceptable substitute. I know others will disagree, but from my experience with an old Sheaffer vac-fil (and Steve Light's with his many MB149s) it's not absolutely necessary. Why did they use this semi-permanent rosin? So you had to take it to a repairman? I dunno. So kids playing with the pens wouldn't get them apart and loose bits and render them useless? Probably closer.

 

I'm sure in some cases the rosin is irreplaceable, but I don't know when it would be b/c I haven't needed to seal too many pens.

[viclip]

My favourite thread sealant is the rubber cement sold at office supply stores for use on paper. It gives a good seal yet can be easily taken apart at any time by hand.

 

The reason that pen manufacturers & professional restorers use shellac is not only to seal but also to make it impossible to take the pen apart by hand. Take the typical office meeting for example ~ the favourite past-time of the participants is to play with their pens including taking them apart. Whereas we know better than to playfully remove the section from an inked Parker Vac that we've restored, most people wouldn't think twice about screwing it off if they could loosen it by hand; after all, it's great sport to disassemble ball points pens. I leave to the imagination how many complaints to the manufacturer/restorer would be generated each time a fountain pen user discovered how many mls. of ink their barrel reservoir pen holds (or used to hold)...

 

However, some pens due to their design call for sealing via shellac or rosin notwithstanding the user's knowledge base. The Parker 51 Aerometric comes to mind, I've had the hood inadvertently loosen while removing the barrel prepatory to filling. Thus I use shellac on P51 aeros to hold the front section tight. And other pens generate pressure/vacuum conditions which may mandate a more robust seal.

 

 

Therefore use silicone, beeswax, rubber cement, rosin or shellac depending upon the end user as well as taking into account the pen's design.

[Goncharov]

I’m far from an expert, but there are two reasons that I prefer the rosin sealant to silicone grease for most applications. First, I don’t want my pens coming loose or open unless I’m taking them apart. The rosin keeps threads tight, but also gives up its grip far more easily than shellac. Second, lubricating threads could lead to over-tightening. You might strain or damage a pen without even realizing it.

 

I used to use silicone grease on threads until I got a jar of the rosin sealant. I now much prefer the rosin. I’d encourage all of my fellow hobbyist restorers to get some - a lifetime supply costs less than a pizza.

[Cicero]

I’m far from an expert, but there are two reasons that I prefer the rosin sealant to silicone grease for most applications. First, I don’t want my pens coming loose or open unless I’m taking them apart. The rosin keeps threads tight, but also gives up its grip far more easily than shellac. Second, lubricating threads could lead to over-tightening. You might strain or damage a pen without even realizing it.

 

I used to use silicone grease on threads until I got a jar of the rosin sealant. I now much prefer the rosin. I’d encourage all of my fellow hobbyist restorers to get some - a lifetime supply costs less than a pizza.

 

Hi, where can I get a jar of this rosin sealant, or a bottle of shellac, and does it work well on Parker 51 aerometrics?

Thanks!

Edited August 8, 2012 by Cicero

[Ray-Vigo]

I like the Sheaffer-type rosin thread sealant for these jobs. When heated it melts and becomes workable, then cools to a sticky semi-solid. My issue with the silicone grease is that while it does help the seal, it also adds a slickness to the threads that makes it somewhat easier for them to unthread inadvertently. The rosin sealant actually helps to lock the threads in place to a degree. I used silicone grease for awhile, but ultimately converted to the rosin sealant. I would not go back.

[Dillo]

Hi,

 

The rosin allows one to take apart the pen easily when repairs are needed while sealing the joint and keeping the pen from coming apart while in use.

 

Dillon