Rubber cement

[Crobe]

what product is meant by rubber cement. I think remember rubber cement being for cementing paper together.

 

I am wanting to use it on in a Touchdown blind cap for a good seal.

 

Mike

[AJP]

Hi Mike:

 

Rubber cement is an adhesive made from polymers (typically latex) mixed in a solvent such as acetone, hexane, heptane or benzene. I always think of "model glue" when I think of rubber cement.

 

I know Frank Dubiel refers to it's use often in da book. However, I have seen many posts from the experts cautioning against it's use now days in repair because it can damage pens when used in certain ways (e.g., do not use for attaching sacs or as a section sealent). Now days there are many replacements for rubber cement, such as section sealent, shellac for sacs, etc.

 

Do a search on rubber cement in the repair section Im sure you will come across some of those threads.

 

Im not sure about using on a TD might work but you might want to research it first. Check Richard Binders site too: richardspens.com he has a lot of information on repair

 

Good luck!

Alex

[I am not a number]

I used some silicone sealant on a repair to a Sheaffer Crest recently and it seems to be holding rather well. I went through all manner of things trying to repair a leak on my TD Slim including section seal from Tryphon but all with miserable failure. It's currently sealed with quite a lot of shellac but if that fails I will be reaching for the slicone sealant again.

[Crobe]

thanks. I was getting my information from Da Book. I was considering silicone sealant but wasn't sure. I am going to give it a try.

 

Mike

[jmkeuning]

IIRC, Ron Z says to never use rubber cement on a pen.

[captnemo]

Yes, classic rubber cement is latex dissolved in toluene. Extremely flammable. It's intended for gluing paper. It holds firmly but also allows clean removal. It works well for gluing paper labels to glass containers.

 

Model cement is solvent based (toluene or MEK) and works by softening plastics like polystyrene and "welding" parts together.

 

Neither is much use around pens I don't think.

[Ernst Bitterman]

I have used the rubber cement trick on the blind cap of a couple of Snorkels, and through sparing use seem to have avoided any damage while still making the necessary seal. That being said, Section Sealant from Tryphon works as well, is less likely to damage pen and brain, and is marginally more controllable. You can probably get away with the rubber cement, but having tried it I recommend against it.

[Crobe]

On this Shaeffer Touchdown, after getting everything back together, I was leaking air around where the section screws in. I folded a length of Teflon tape and wrapped the threads. It worked great. I am not sure the Teflon tape should be a permanent fix, though. Da Book again says use rubber cement on the section threads. Would the silicone be proper on the section threads for a good seal?

 

Mike

[captnemo]

I'm no expert on your question but it seems clear that you want a sealant that will release when you want it to. Rubber cement and silicone (RTV) both remain pliable. I would assume that silicone has a far longer stable lifetime (50 years or more) than latex since it doesn't oxidize.

 

Maybe an expert can chime in here. I'm curious too.

[I am not a number]

Was it like this leak?

 

http://i122.photobucket.com/albums/o254/photoboris/LeakySheaffer2.jpg

[GBM]

I would like to second CaptNemo's comments ( not that he needs that)... Rubber cement and modelers cement are very different glues... the only thing I would use rubber cement on is paper which I wanted to move around without messing up the other paper.. it was made for newspaper people...adjusting the copy and pictures without any ill effect... it would not be good to use for long term placement of labels on jars... modelers cement dissolves the plastics enough to weld them together... permanently... So both are on ends of the spectrum which I do not think will serve fountain pen people well...

Greg

[captnemo]

I would like to second CaptNemo's comments ( not that he needs that)... Rubber cement and modelers cement are very different glues... the only thing I would use rubber cement on is paper which I wanted to move around without messing up the other paper.. it was made for newspaper people...adjusting the copy and pictures without any ill effect... it would not be good to use for long term placement of labels on jars... modelers cement dissolves the plastics enough to weld them together... permanently... So both are on ends of the spectrum which I do not think will serve fountain pen people well...

Greg

 

Well I'm no expert on pen repair so I'm all ears and very curious. I'm an engineer and have been involved in construction of many real world projects so I'm not clueless about this stuff but I'm also very conscious of the fact that in a highly specialized field like pens, especially old pens made from "unusual" materials like hard rubber and celluloid, I defer to people who know what they're talking about. My comments are more observations than advice cuz I'm not qualified to give advice on esoteric pen repair questions. :roflmho:

[Ernst Bitterman]

On this Shaeffer Touchdown, after getting everything back together, I was leaking air around where the section screws in. I folded a length of Teflon tape and wrapped the threads.

 

I can't say I've ever had an air leak at the joint like that-- I've found that the section screws in well enough to seal without extra goop being applied. Having said that, I think the teflon tape is probably a brilliant cure; non-invasive, reversible, and if it's doing what needs be done, splendid. You don't want a permanent fix, as some day that sac will need replacing again, and the more permanent a seal at the section, the bigger a nightmare that simple repair will become.

 

Hey, look at me speaking with assumed authority! Correction, if required, will be welcomed by no one more than by me.

[Crobe]

My thinking was if Teflon tape can stand up to 100 PSI of water pressure, the small amount of air pressure building up in a Touchdown would be a breeze.

 

Mike

[Crobe]

Was it like this leak?

 

http://i122.photobucket.com/albums/o254/photoboris/LeakySheaffer2.jpg

IANAN,

The leak was on the barrell side of the threaded silver band.

 

Mike

[I am not a number]

OK, so much for that idea...

 

Hope you get it sorted and let us know how!

[Gerry]

The only problem with teflon tape has been suggested that it tends to add a lot of stress to the joint as it represents a thickness that has to be accommodated. In plumbing joints like steel pipes or copper joints, the stress is quite manageable. In plastics, it can cause cracks.

 

Antonios posted a good analysis showing that there was room for some tape in the thread joints, but others disagreed, so - choose it if you will.

 

A safer solution is section sealant from Tryphon, or a cheaper one - plumbers wax, either will seal threads without stressing the barrel unduly. I don't see a need for a permanent solution like silicon seal or plastic glue or CA. Rubber cement contains solvents that might harm the plastics. Depends on the plastic.

 

I'd go with the sealant or wax myself.

 

Regards,

 

Gerry

[Tom Pike]

Was it like this leak?

 

http://i122.photobucket.com/albums/o254/photoboris/LeakySheaffer2.jpg

IANAN,

The leak was on the barrell side of the threaded silver band.

 

Mike

 

Mike,

 

If you've got an INK leak at that joint (the original post sounded like you just had an air leak), there's a leak in the sac. There shouldn't be any ink at that point to leak out. Ink outside of the sac at that point means rust in the future of this pen's innards. If it was just an AIR leak, then, um, nevermind...

 

BTW, I'd suggest silicone grease as the way to go for sealing TD and Snorkels. Don't forget to put a little dab on the end of the TD tube, where it fits into the blind cap too.

 

 

Cheers,

Tom

[Deirdre]

Rubber cement is an adhesive made from polymers (typically latex) mixed in a solvent such as acetone, hexane, heptane or benzene. I always think of "model glue" when I think of rubber cement.

Wasn't it traditionally toluene? That's the smell I associate with rubber cement ("MS in a bottle").

 

Edited to add: oops, answered above but missed that post the first time.

Edited January 29, 2008 by Deirdre

[Ron Z]

Jumping in late here because I had to deal with car issues after the Philly show.....

 

 

Comments:

 

1] Teflon tape. Good for plumbing, bad for pens. I'm tempted to start charging extra for the time that I have to invest picking teflon tape out of threads on pens. Gerry has it nailed - the threads have to accomodate the extra space taken up by the teflon tape, and so can crack the pen. Not only that, but it cold flows, so will have to be applied again (after removing the first round) when you take the pen apart. Best left in the shop.

 

2] Rubber cement - it doesn't work. Tried it, many times. OK, it "works" but it will fail sooner rather than later, so in fits my definition of "doesn't work." There are better, more reliable alternatives to rubber cement that are readily available. The solvents used can be an issue as well, but the main flaw is that it simply can not and does not give a reliable seal.

 

3] RTV - designed to be more or less permanent, which is why it's so great as a caulk or sealant for tubs, showers, cars. It's a royal pain to remove, which means that it's doing what it's supposed to do. You don't want to use anything that is not easily reversable. RTV/silicone sealant is not. Not only that, but it would tend to ball up as you unscrew the section, which would put outward pressure on the barrel, which can cause it to crack.

 

4] Silicone grease has it's uses. But you have to be careful. Silicone grease migrates, which means that it can get into places where you don't want it go go. Like a feed, where it can be very difficult to remove. The milder solvents won't remove it, and you can't put xylene on a plastic feed, or barrel because it will melt them.

 

Let me encourage you to resist the urge to use a material just because it's easily available. Buy the right sealant for the job. A can of shellac is about $5 USD. A container of section sealant isn't that much, and it won't go bad sitting in your tool box.