Cleaning nozzles using a cold pull or similar technique

Hey everyone, so after having two nozzles clog on me I figured I should learn how to properly fix this problem. The only thing though is that every set of instructions says to use an ABS or Nylon filament for this process (I only have PLA) and I don’t want to drop 40+$ on a roll just for cleaning my nozzles using this technique.

So what do you all do? Is there a product out there to help?

Pic here of what came out of my clogged nozzle. I put the nozzle in an old heat block in the vise, but whatever to hold it, vise-grips, etc.
Heat gun to heat it up(or lighter?), short piece of filament fed in until it stuck, let it cool, heat it a bit quicker with tension on it and the whole plug popped out. You can see the shape of the inside of the nozzle even. Black bits are burned filament, crud, etc…

I guess this will become the thread for “cleaning nozzle porn” XD

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I just tried on mine but it didn’t work out so well.

The nozzle wasn’t fully screwed in because the threads are blocked, the heat block had a clump of filament in there (got that cleaned out), but in the end I was able to at least get the nozzle to extrude by hand I just need to fix up the threads. I don’t have anything to heat it up with, so I’ll be looking for a solvent to melt the PLA with.

Also, I found this cleaning filament and I’m wondering if it’s worth the purchase?

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Yes, Correct Cleaning Filament is Nylon based Filament that has been allowed to Absorb Moisture from the Air.

The moisture makes it more flexible and ductile. Also makes it “steam clean” your nozzle, lol

Disconnect Bowden tube, heat nozzle to 210-220.
manually push the cleaning filament through until a clean bit has come out the nozzle.
Turn off heater to nozzle.
Wait for nozzle to drop to 160-170C and pull hard on the Filament to remove.
This will pull the carbon and crusties from inside nozzle and heat break out.

Roll up remaining Cleaning filament and save / store till later use.
A 10 meter long Spool should last you a Very long time if you have only one printer


Awesome! If I can’t get the cold pull to work, what do you suggest I use for dissolving it in?

If it’s:

ABS = Acetone

HIPS = D-Limonene

PET-G = Chemical Resistant Filament, have to use Hot air gun and 1.5mm Allen Key to push Filament through it

PLA = Ethyl Acetate

ASA = Acetone

Nylon (PA) = Very Chemical resistant, Use Fire :stuck_out_tongue: or just replace nozzle :slight_smile:


For Ethyl Acetate, where would you get it? Is it in any particular products I should be looking for?

Hmmm MG Chemicals Discontinued it…

Wow even is Dry on Ethyl Acetate right now!! is dry too…


wow, This is good to know. I have to place an order and will add some of this. really just waiting for the filament to be restocked heh… the pages are all grey. Actually, I wanted to ask about the high-temperature parts Chris was talking about on 3DPC’s B1’s too

Try Alpha Chem in Mississauga. If you are a business they will sell to you. They can tell you why traditional channels are not carrying it anymore too.

JUst wanted to draw your attention to my reply to Keith. I have some MEK in the shop, i’ll see if thats a suitable solvent for PLA and post back.

Part of my real job is safety person. I deal with lots of chemicals, I am going to point out most of these solvents are crazy flammable. Some have other hazards as well. Before you use any solvent, chemical in general, do a quick google search. SDS sheets might be overkill but wikipedia often will have a blurb on hazards in plain language its worth reading over. Chemicals bite ignorance. Some of the chemicals I work with are quite toxic (lethal if inhaled) knowing what the hazard is means you know how to avoid hurting yourself. (don’t breath it!)

Personally I use the 3DPC cleaning filament it works really well usually. If I can’t clear with it, I usually take the hot end apart (heat gun) and clean the heat break and block and just replace the nozzle it isn’t worth fighting with usually.

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MEK isn’t a solvent for PLA or PTEG. on PLA it’ll soften the surface but not enough to make 2 surfaces cement in a reasonable time. Works perfectly with ABS though.

Guess I’m back to brute forcing the PLA off by melting it off!

I have access to a lot of acetone at work. We print using PLA filament and I found if a nozzle is really clogged you can get most of the gunk off by soaking it in acetone. I have a jar with maybe 30 or more old nozzles left by a coworker who would just order new ones instead of cleaning them. Some of them were blocked solid by burnt on PLA.

Whenever I need a clean nozzle I go to a room with good ventilation and take one out of the jar and run a needle through it to get rid of the last of the filament crud. Anything left behind is minimal and passes through as soon as the next print is started.

No issues so far. Any acetone has long evaporated by the time the nozzle is exposed to heat.


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