Unblocking Nozzles: Manual Unclogging and Solvents

Blocked nozzles are an annoying but common issue with 3D printing and can result in under extrusion or messy prints. In order to fix this, your first step should always be the Atomic Method (aka Cold Pull). If this method has not worked for you, here are a few tips on manual cleaning!

1. Manual Unclogging (with Nozzle in Printer)
Turn up the temperature to your regular printing temperature or 10-20°C higher (note that you don’t have to remove the filament or Bowden tube from the printing core, but feel free to do so if it makes things easier for you). Then use a wire or hypodermic needle whose diameter is smaller than that of your nozzle (usually ≤0.4 mm) and insert it through the nozzle. Try to dislodge the clogging gunk by moving the wire/needle around a bit. The aim is not to extract the clog altogether! Just break it up a little so when you push filament through the printing core as a next step, the clog comes out with the filament.

2. Manual Unclogging (with Nozzle outside Printer)
Remove the nozzle from the hot end altogether. Then carefully heat up the nozzle (e.g. using a hot air gun on a low setting) and completely remove the gunk with a wire, needle or other pointy tools. Be careful not to burn yourself or heating up the nozzle to the point of softening!

3. Chemical Unclogging (for ABS or PLA)
For ABS, place nozzle in a bath of acetone or other aggressive solvents. PLA dissolves somewhat in baths of ethyl acetate. After the nozzles have been sitting in their solvent baths for a few hours, take them out with pliers and use a wire or needle to remove the last remnants of the clog.