Cleaning ABS out of your Nozzle with Acetone (no residue)

I just discovered a cheap and extremely effective way to clean burned ABS out of the inside of your brass nozzle while leaving zero residue. First off you should have soaked your nozzle in acetone overnight especially if it's caked. The outsides of your nozzle can easily be cleaned up. However, inside remains a bunch of residue consisting of burned and new ABS that seems almost impossible to clean up without a blowtorch. Well, I have the solution. Buy coffee filters. twist the filter up until you get a nice pipecleaner. Soak it in acetone. Force it as far as you can inside your nozzle and twist it around as much as your fingers can handle. When you pull it out, you will see everything. Just rinse and repeat about 2 times and it will look brand-new inside with no residue. This works with the j-head and should work with any other nozzle.

You do not want to use anything other than a coffee filter because other materials may create particles like fibers that may clog your nozzle.

Edited 1 time(s). Last edit at 07/21/2012 07:56PM by Zimtower.

Excellent tip, Zimtower. Interior nozzle residue is very easy to overlook (though you might smell it in operation) and can amount to much frustration from repeatedly disassembling a poorly performing extruder to correct only those mechanical glitches symptomatic of the real problem. After a number of different household chemical washes, a boiling vinegar and baking soda bath, and cramming all number of miniature (crumbly) things into the nozzle rear, I then thought that some kind of Waterpik® treatment might best resolve my issue, but your idea was spot on, and neater. Paper tea bags make a fine substitute for us French press folk.

After I clean my tips using acetone I soak them in hot lemon juice to get off any carbon that acetone won't touch. Makes them nice and bright.

CdnReprap Wrote:
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> After I clean my tips using acetone I soak them in
> hot lemon juice to get off any carbon that acetone
> won't touch. Makes them nice and bright.

RealLemon type brand or a Real Lemon? RealLemon has lemon oil in it as well.

Well I didn't have a blow torch and used a zippo, and also boiled my j-head brass nozzle in some lemon juice, all this after an overnight soak in acetone.

Result of overkill operation: shrunk/loose thread and opening is much smaller, no longer possible to insert the PTFE liner in the nozzle. (Actually I threaded it hot and couldn't remove it afterwards without totally messing up the liner.)

On the plus side it's really clean now.

I'll try reaming the opening and using lots of teflon tape on the thread, but doubtfull it will ever work properly again. Anyone have EU links for the PTFE liner, don't really want to wait 3 weeks for delivery from the US.

Did you boil the whole thing or did you remove the brass head and just boil/soak that?

If you soaked the whole thing, plastic parts and all, in acetone I'm totally unsurprised it's ruined.

No of course I only handled the brass nozzle, I completely the disassembled the hot end first.

As far as I know, the liner should have been all but immune to whatever you subjected it to, short of mechanical deformation by blunt trauma or very high temperatures (afaik, in excess of those the hot-end should normally experience)

PEEK, however, is not immune to acids, at least certain acids, and although I don't know what effects hot citric acid has upon PEEK, the hotter an acid gets the more active it is, so at some temperature.

I guess I didn't make myself clear: it's the brass nozzle that got deformed from the cleaning job, the PTFE liner only got mangled because I managed to jam it into the (now smaller) nozzle opening.

My bad. I re-read and it is a bit clearer what you were saying now.

drop the brass nozzles in cokecola (genuine stuff) after a good soaking in acetone

I think I'll stick to simply cleaning them periodically with acetone and perhaps a toothbrush, ensuring that the outlet is clean by using an appropriately sized drill bit in a pin vise, and leave it at that. lemon juice, coke, etc are imo a waste of time, since the nozzle won't really benefit from going OCD on it, and coke, lemon juice, etc will leave contaminating residues on the brass surface, far worse than the film coat of abs the acetone might leave behind.

if you really want it clean get some xylene, it'll break down the abs very very quickly and strip everything away, just a work of warning though keep the container seals that stuff evaporates very quickly

Coke does a bang up job on cleaning up parts. Use it on your car battery and do the science experiment from school and drop a cleaned chicken bone in Coke and come back in the morning. Drop a tooth and watch what it does to it by morning.

It really is a cleaning product.

I can confirm that this method also works with PLA. Pure acetone is strong enough to soften PLA so it can be picked up by the coffee filter, you just have to do twice the work, no lemon juice needed unless you went the blowtorch route.

Edited 1 time(s). Last edit at 09/22/2012 12:49AM by Zimtower.