recommendations for Omas repair
I have a demi-sized Omas, that has decided that the piston isn't in the mood to move anymore... it's a modern (1990s?) pen and has had very little use, since the feed is a single channel version and it starves for ink after a paragraph or two, as well as being unable to sustain feed for flexed writing of more than a character or three.
I know that John Mottishaw could fix this in his sleep, but he isn't taking work on anything that wasn't purchased from Nibs.com :( Suggestions for an experienced Omas repairer within the US would be greatly appreciated!
Thanks!
Re: recommendations for Omas repair
I have sent my omas to be repaired by fountainbel before if that is any help.
Re: recommendations for Omas repair
I have two full sized Omas Paragon style pens, both modern. On both of them I've been able to unscrew the section from the barrel at the threads after soaking them upright in the USC. On one of them I can unscrew the nib unit with the collar and on the other one I can't. That nib and feed had to be knocked out and the collar was left in place. However, once you can unscrew the section, you can lubricate the barrel for the piston.
In the past I've had both pistons out but that's a bit scary, so I prefer to just lubricate them from the nib end when necessary.
I don't know whether your Omas Demi could be unscrewed at the section, but if it was mine I would certainly give it a go for the sake of lubricating the piston. If you don't feel you can attempt this or you never attempt anything like this then I recommend you send it to a repairer.
There was information somewhere about dismantling an Omas but I can't find it at the moment. Maybe it was over at the other place.
The liquid in my USC isn't a straight water and ammonia mix, although it contains some ammonia. It's a jewellery cleaner, and gives some sort of lubrication while cleaning. It always tends to make things easier to unscrew and take apart. I dip everything in there before putting them back together again too.
Re: recommendations for Omas repair
Hi Chrissy,
The little Omas is already apart, it's one of the models with the threaded feed collar and section like you described, the hitch is that I have no idea what lubricant might be safe on the Omas plastics. Do you know what is recommended for modern piston fillers? This one has a clear polymer piston head and it's an opaque blue-green plastic barrel, made in 2003. I also need to find some of the adhesive that holds the knob on to the filling mechanism, as that seems to have given up the ghost as well...
Re: recommendations for Omas repair
When I lubricate a piston I use pure silicone on a cocktail stick.
Re: recommendations for Omas repair
Pure food-grade silicone grease is the thing. I use an almost microscopic amount on a q-tip. You can buy a lifetime supply at SCUBA shops relatively cheaply.
Re: recommendations for Omas repair
I believe this video could be useful:
https://youtu.be/5q-z_GAQVfo
Re: recommendations for Omas repair
Quote:
Originally Posted by
carlos.q
Whoa, that guy needs less coffee!! But a very informative video.
Do you happen to know what the original black putty-like sealant on the section is? Also what adhesive is used to hold the filler knob on to the outer helicoid sleeve?
As far as trying to free a stuck piston, the thicker consistency *grease* that gets used on o-rings in dive gear doesn't seem like it could penetrate to loosen a stuck piston seal, is there a liquid version that is available to consumers? (I know that there are different thickness grades of silicone available for instrument or precision mechanical industry use, but those are often only available through commercial or scientific supply houses that require an account, or large minimum orders...)
Re: recommendations for Omas repair
I bought my silicone grease from Ron Zorn (Main Street Pens) but most pen/inks sellers also sell it in small pots.
You don't need to worry about replacing the black putty-like sealant on the section. Just use some silicone grease on the threads. You may need to unscrew it again the next time you wish to lubricate your piston.
Not sure how the piston cone is attached to the outer helicoid sleeve.
Re: recommendations for Omas repair
You can get silicone grease at your local dive shop.
Re: recommendations for Omas repair
Quote:
Originally Posted by
carlos.q
You can get silicone grease at your local dive shop.
the dive shop/plumbers' silicone is a thick grease (and I already have a tub of it), if I'm going to free up my piston I'll need a liquid variety :(
Re: recommendations for Omas repair
I don't believe that dive shop silicone and plumber's silicone are the same thing. On the other hand do not use liquid silicone. What you will use is just a very little bit, less than a grain of rice, and apply it with a toothpick. A tiny tub, less than an inch in diameter, will last for years.
Re: recommendations for Omas repair
Be very careful with that video. Follow the steps carefully. There is a small notch in the body that you shear off which is what happened to me and hence the repair trip to fountainbel.
Re: recommendations for Omas repair
I have, or have used dive grease, plumbing gasket grease and dielectric insulation grease, as well as ridiculously overpriced silicone grease branded for use on wristwatch gaskets... the exact consistency differs slightly between the variants, but theses products are seemingly all the same base formulation, with emphasis on either food grade safety, temperature and water resistance or low interaction with rubber or plastics.
I'm interested to know why liquid silicone wouldn't be ok to use in getting a seized piston to free up, or just as importantly, how can a thick grease be insinuated into the gap between seal and barrel enough to free the stuck piston?
Thanks for all the suggestions so far!
Re: recommendations for Omas repair
Quote:
Originally Posted by
awa54
I have, or have used dive grease, plumbing gasket grease and dielectric insulation grease, as well as ridiculously overpriced silicone grease branded for use on wristwatch gaskets... the exact consistency differs slightly between the variants, but theses products are seemingly all the same base formulation, with emphasis on either food grade safety, temperature and water resistance or low interaction with rubber or plastics.
I'm interested to know why liquid silicone wouldn't be ok to use in getting a seized piston to free up, or just as importantly, how can a thick grease be insinuated into the gap between seal and barrel enough to free the stuck piston?
Thanks for all the suggestions so far!
Thick silicone grease on a cocktail stick or toothpick wipes onto the inside surface of the barrel and stays there, coating the surface, for long enough to have the piston move up and down over it several times. Easily enough to unstick stuck pistons. Liquid grease won't stay there. It will just run off onto the surface of your feed.
All of the best restorers I know have always recommended and/or sold thick silicone grease, and I've never seen any other type. However, it's your pen, you should use whatever you want and see if it works for you where it didn't work for them.
Re: recommendations for Omas repair
Quote:
Originally Posted by
Chrissy
Quote:
Originally Posted by
awa54
I have, or have used dive grease, plumbing gasket grease and dielectric insulation grease, as well as ridiculously overpriced silicone grease branded for use on wristwatch gaskets... the exact consistency differs slightly between the variants, but theses products are seemingly all the same base formulation, with emphasis on either food grade safety, temperature and water resistance or low interaction with rubber or plastics.
I'm interested to know why liquid silicone wouldn't be ok to use in getting a seized piston to free up, or just as importantly, how can a thick grease be insinuated into the gap between seal and barrel enough to free the stuck piston?
Thanks for all the suggestions so far!
Thick silicone grease on a cocktail stick or toothpick wipes onto the inside surface of the barrel and stays there, coating the surface, for long enough to have the piston move up and down over it several times. Easily enough to unstick stuck pistons. Liquid grease won't stay there. It will just run off onto the surface of your feed.
All of the best restorers I know have always recommended and/or sold thick silicone grease, and I've never seen any other type. However, it's your pen, you should use whatever you want and see if it works for you where it didn't work for them.
The hitch is that the piston *doesn't move*... not trying to imply that I know more than anyone, just that *grease* doesn't seem like a viable solution to a completely frozen piston.
Re: recommendations for Omas repair
Please can I just recap? You have unscrewed the section from the barrel and the top cone is no longer attached to the helicoid sleeve. So you can see inside the barrel from at least one end.
However, what you are saying is that the piston won't push down and out of the barrel from the top. Nor can you get the piston end to move by trying to push it a little from the bottom. Your piston is completely jammed inside the barrel and won't move up or down even if you could insert a cocktail stick with a bit of silicone grease on it from either direction.
If you can't move the piston even fractionally in either direction after introducing a little silicone grease into the barrel then I think you need to send it to be repaired.
Re: recommendations for Omas repair
Quote:
Originally Posted by
Chrissy
Please can I just recap? You have unscrewed the section from the barrel and the top cone is no longer attached to the helicoid sleeve. So you can see inside the barrel from at least one end.
However, what you are saying is that the piston won't push down and out of the barrel from the top. Nor can you get the piston end to move by trying to push it a little from the bottom. Your piston is completely jammed inside the barrel and won't move up or down even if you could insert a cocktail stick with a bit of silicone grease on it from either direction.
If you can't move the piston even fractionally in either direction after introducing a little silicone grease into the barrel then I think you need to send it to be repaired.
You've summed up pretty well, the piston is frozen in the fully retracted position and the mechanics are such that without getting the piston assembly to move a bit, it's unlikely that grease will find its way between the piston and the bore of the barrel. This is why I was considering a lighter silicone product as a possible way to free the piston... but it seems that's a big no-no :(
It also seems like there is no go-to Omas repair that anyone has experience with in the USA, except for Nibs/Mottishaw, who aren't accepting repairs right now :( :(
Re: recommendations for Omas repair
I might get shouted down by many members for saying this, but I'm going to say it anyway. :dirol: If you have a USC have you tried giving it a spin in there? My 1990's Omas has been in my USC several times, but that was only the section when I needed to knock-out the nib. Generally speaking it's sometimes a "no-no" to stick pistons and barrels in a USC. However, when needs must, I don't think it will make it any worse.
It might free up the piston just enough to get some silicone grease in that will help it even more.
Re: recommendations for Omas repair
I do, and had rejected the idea, due to the fact that fluid could become trapped in the helicoid area with full immersion... though just filling the ink chamber and hold in g the barrel upright in the tank could work. The only solution I have access to is an all purpose jewelers' soap that smells like it's mostly ammonia and a metal specific soap that has some more "slip" to it, but makes no claim of safety with plastics.
I think it'll have to be either silicone from the ink chamber end, or a trip to someone who has more tricks up their sleeve than I do. While I have serviced dozens of snorkel pens, over 100 conventional sac pens and many gummed up cartridge fillers, I'll freely admit that piston fillers are not an area of expertise for me. Not that they're so terribly complicated in concept, but I just don't have much experience with them.