Clean burnt UM2 nozzle

[Nicolinux 269]

Hi,

Suspecting a partial clog I have burned out my UM2 nozzle (using a bunsen burner). The nozzle is clear but the inside walls of the filament chamber are dark and I can't get them as shiny as before. What do you use to clean it? So far I tried acetone, cellulose thinner, vinegar (stuff that I had at home...).

Here is a picture of two nozzles - the one on the right, is clean and shiny and the one on the left is the nozzle in question:

By the way. Printing with the nozzle like that (after the burning) produces extremely bad results:

 

[pm_dude 26]

We got that discussion just a few days ago.

http://umforum.ultimaker.com/index.php?/topic/8935-best-way-to-clean-old-nozzle/

 

[Nicolinux 269]

I saw it, but I didn't have metal polish at hand nor did I want to use sandpaper. I had hoped for other ideas.

 

[kvones 5]

As I posted elsewhere, the only thing that would work is very weak sulphuric acid, heated gently in something like a slow cooker but has to have a ceramic pot. I am a jeweller, so work with metals all the time, and I keep a pot in the utility room for cleaning parts after soldering. In the UK it is sold as 'pickle' in granules. Just mix with water (add granules to water NOT other way round) and heat gently. Immerse part for 30 mins or so. Flush well with water. Dont use steel utensils otherwise everything will be copper plated. Afterwards you can brush it gently with a brass brush - all these things you can get from jewellery suppliers such as fischer.de

[Nicolinux 269]

Thanks for the info. I'll try it at some point because I'd like to keep this one as a spare nozzle.

 

[korneel 169]

so i burn out my nozzle regularly. what i do is to make sure it's burned out completely, so i can see through the hole in the nozzle. i do use the end of a matchstick to make sure the inside is nice and smooth but yes, there will be black "stuff" inside.

i then install the nozzle, once it is installed i use a little bit of cleaning filament to get the large junk out and finish off with a cold pull using nylon. my nozzle prints perfectly after that..

 

[Nicolinux 269]

That's what I tried first - but even after excessive atomic cleaning there was under extrusion (check out my second image...).

 

[eldrick 58]

For the brass nozzle, metal polish - Simichrome or Brasso from any hardware store - on a cotton swab (Q-Tip) will clean it bright and shiny once again in a couple of minutes.

BTW, plastic residue won't be touched by sulfuric acid at all.