I recently bought a Pilot Custom pen with inlaid nib that was heavily clogged. No ink flow whatsoever. A long ultrasonic bath in warm water helped, but not enough. So, I went ahead and tried a 50/50 ammonia/water solution. THAT ended up doing the trick.

However, after the bath I was "toweling off" the section and rubbed the nib with a little firm pressure to clean off a smudge, when the nib SLID OFF. Yep, the ammonia semi-dissolved the glue that holds the inlaid nib into the section. Yikes! I managed to reset the nib quickly and then let it air dry overnight, which seems to have done the trick (although I have a slight trace of 'contact' ink leakage that wasn't there before).

Anyway, there had been a number of threads talking about using an ammonia/water solution to clean out ink feeds (removing any manufacturing residue, etc.) for better flow. If people employ this, definitely be careful. Know your pen. If you suspect it uses any adhesives to hold things together, take care not to melt that adhesive with the ammonia!

The generally accepted "strength" to use is 10% ammonia. This is a volume percent so 1 part ammonia solution diluted with water to make 10 parts.

I have always assumed that the stock solution used to make the cleaning solution is household ammonia and not reagent grade or saturated ammonia.

Household ammonia is between 5-10% by weight ammonia. Saturated ammonia (the stuff we have in the lab) is around 58% by weight ammonia. So there is a big difference in the dilution factor.

I guess we could express the solution to use in a more chemical or scientific manner but that just makes things complicated.

Chemical Todd

I think normally a 1:9 solution of household ammonia: water is recommended. Yours was probably a bit too concentrated. But still, even a 10% solution might cause problems, and your warning is good to keep in mind!

Ah, so that's what holds those Pilot Custom nibs on. I could tell they had to slide on from the slots and tabs underneath. I've thought about this kind of thing because I have one that could tweaking. I once read on the PT yellow board that Pilot has a special tool, but now that makes less sense, unless it's just something safe but strong enough to crack the glue.

Thanks for warning us. Which pen, more striped steel? Tell us how it works later.

This was household ammonia, so it is already diluted, but I can see how I should have used a lower concentration first. Thanks for the 1:10 recommendation--will abide by that going forward.

About the Pilot Custom nib, the glue reminds me of silicone. It is blackened, but I suspect from ink exposure. And it looks like I may need to strip this one down and start over, as the reset has stemmed back the ink flow a little. Some of the silicone may have gotten onto the feed. In any case, it's an interesting design--almost half the nib is used to secure it to the section. Combined with the slots, the nib is anchored in place very well. That is, until exposed to a strong ammonia solution.

In the original post you mention that first you tried warm water. Was the ammonia solution warm as well? Heat itself could have melted the glue as well. Also, IIRC many people recommend against putting inlaid nibs in the US cleaner. It is also known to remove Parker 61 arrows.
Anyway, If you have a safe method to remove these nibs, putting them beck in place (with the same adhesive or something else, ask the repair gurus) should not be a huge problem.

Hi rlucks, yes the ammonia solution was with lukewarm water. I've run these nibs through the ultrasonic with very warm water and they hold up quite well against it. But there could be a chance that the warmth might encourage loosening. I'll try using cold water next time to help guard against that. Thanks.
As for adhesive, I expect that seam sealers (waterproof, slight flex) would work best in absence of using a special custom pen glue, but it might be worth running a query by the experts.

Richard Binder's soaking solution for the routine cleaning of pens uses 1T of ammonia per 2/3C water. When you make it much stronger (50/50) you will remove petrified adhesives of most kind including shellac/resin compounds, so don't use it in that strength on anything with gaskets UNLESS you really want to take apart EVERYTHING. The only time I use ammonia in that strength is on really difficult to clean Sheaffer Triumph nibs with lots of fins or some of their 1930's feeds that are clogged. In any case, it is a last resort for me.
Gerry

On the same line, I had soaked an Esterbrook inner cap once that turned into some form of jelly! 1-10 solution here as well. I now try not to soak things for a long time if it is not needed.

Hi all, and MYU in particular,

I have just bought a Pilot FP in an auction in Japan, and it happened to be seriously clogged. By ultrasonic bath I could dissolve a lot of material --dry black ink-- from the nib. Although it did not seem enough, I persevered and suddenly there was some flux. That happened after like 48 h or soaking, and about 2 h of US.

My conclusion is that the US bath does not damage the pen even when the bath temperature reaches --by the mere contact with the US machine-- about 40 C (100 F). And being patient --something I am not-- pays off.

So, I was saved from the risks of using ammonia water in the pen.

Hope this helps!

Iosepus