Clean leak in heatblock, heatbreak unscrewed from heatsink
Hello all,
Thanks for checking out the post.
I recently had to change out my heat break, heat block, and nozzle. After doing so and encountering trouble with the 1st layer calibration, I noticed the entire hot end assembly was a bit wiggly. So, I took apart the hotend again to check for a leak. After close inspection, I found a thing layer of plastic on the top outside of the nozzle and the bottom of heat break. There is also a layer of plastic inside the threads of the heat break where the nozzle and heat break failed to meet. See below for photos.
Is this enough of a layer to even worry about? Could I just assemble it nice and tight and be ok? To be safe I plan on heating the heat break and nozzle (separately) to use a wire brush to get the filament off, but what would be the best way to clean the heat block threads? I dont want to use a tap and potentially destroy the heat block, yet a brush wont fit. Perhaps I could use the heated heat break? Any insight is appreciated.
Related question; the heat break keeps unscrewing from the heat sink when I was taking the nozzle out, is this an issue I need to address or is it ok to just screw it back in (last photo)?
Here is a diagram of the hot end as a quick reference as to what the heat break, heat block, and heat sink are / are located.
Best Answer by zealousPrototype:
Update:
There was another leak. I think it may have been causing small print issues for weeks until there was finally enough filament to seep through and be visible from the nozzle and top of the heat block. Round two of cleaning was much more thorough. I picked up an M6-1 x40mm screw to clean out the heat block this time around.
A note on disassembly:
The heat break as not coming out of the heat block but was fine coming out of the heat sink, to fix this I had to reinsert the PTFE tube to stop the heat break from traveling too far up the heat sink, and then used a heat gun to warm up the heat block. After which I was able to get the heat break from the heat block. I kept the heat break in the heat sink.
Cleaning Process:
After disassembly of the hot end, I used clamps and a heat gun to get the nozzle nice and hot before brushing with a brass brush. I went through with a razor and paperclip to try and clean up what was left. (Careful with the razor as you can shave parts of the threat off, which is undesirable). For the heat break I did the same thing, however I had to be gentler to avoid unscrewing the heat break from the heat sink. Once I was satisfied with the cleanliness of the nozzle and heat break, I warmed up the heat block and m6-1 screw. I used clamps, pliers, and a wrench to hold everything as nothing is cool enough to touch. After screwing the screw through the heat block I cleaned the screw of debris and repeated. This eventually got the heat block clean enough. A special note here to how a screw works and is safer than a tap, not sure how it didn't occur to me the first time around.
Reassembly and beyond:
Reassembly is straightforward, just follow the instructions online. I made sure to torque a little more on the nozzle to ensure a tight fit. No problems in the past few weeks with print quality so this seems to have fixed the issue. This is a very time intensive process, if you plan on cleaning up a leak make sure to have a few hours of podcasts in the queue, or perhaps a short audio book, and some water on hand. I think if I get another leak, I will just replace the hot end and view it as a tax on my shotty nozzle installation. If you're reading this because you too have a leak: my heat goes out to you.
Pay particular attention to the diagrams at the bottom of this page:
https://help.prusa3d.com/en/article/changing-or-replacing-the-nozzle-mk2-5s-mk3s-mk3s_2069
Cheerio,
RE: Clean leak in heatblock, heatbreak unscrewed from heatsink
I have this same question. I saw that diagram, and understand the gap between my nozzle and the heatbreak caused the leak. I know I need to have a tight seal between them, with a gap between the nozzle and heatblock. I'm unsure if I can reuse the same nozzle, heatbreak, and heatblock now that they are all covered in plastic, or if that will interfere with being able to get a tight seal.
RE: Clean leak in heatblock, heatbreak unscrewed from heatsink
Hi Fay. Having waste plastic everywhere makes life difficult
If you are at a senior school. You may be able to disassemble the hotend, borrow an M6 tap from the resistant materials department and clean the internal threads with that. Then a wire brush pliers and heatgun can clean the nozzle and heartbreak.
Then you can easily re assemble your hotend
As an insurance policy. You. Might be wise getting a spare heater and thermistor...just in case you have issues...
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Clean leak in heatblock, heatbreak unscrewed from heatsink
Diam thanks for the diagram but I already diagnosed a leak. I am trying to find the best way to clean after a leak.
Regarding cleaning the leak, @fayschool, I was able to clean the nozzle and the heat break by heating each one up with a heat gun and scraping away the plastic with a razor and needle nose pliers. This was difficult and time consuming since the plastic had burned and hardened onto the surface. The burned plastic seems to have a higher melting point as it was never runny, but moveable or not moveable. I used a soldering microscope to be more precise. I caught the leak early enough so there wasn't plastic in the threads of either piece save at the very top.
The heat block still has plastic in its threading as I dont have a proper tap on hand as Joan recommended, and dont see any other effective way of getting in there. So I left it. This worked in my case because there was very little plastic, I wouldn't advise ignoring it if you have a real leak. In that case you would most likely need the aforementioned tap, or a new heat block.
At the end of the day a leak is going to be a pain so good luck
RE: Clean leak in heatblock, heatbreak unscrewed from heatsink
Update:
There was another leak. I think it may have been causing small print issues for weeks until there was finally enough filament to seep through and be visible from the nozzle and top of the heat block. Round two of cleaning was much more thorough. I picked up an M6-1 x40mm screw to clean out the heat block this time around.
A note on disassembly:
The heat break as not coming out of the heat block but was fine coming out of the heat sink, to fix this I had to reinsert the PTFE tube to stop the heat break from traveling too far up the heat sink, and then used a heat gun to warm up the heat block. After which I was able to get the heat break from the heat block. I kept the heat break in the heat sink.
Cleaning Process:
After disassembly of the hot end, I used clamps and a heat gun to get the nozzle nice and hot before brushing with a brass brush. I went through with a razor and paperclip to try and clean up what was left. (Careful with the razor as you can shave parts of the threat off, which is undesirable). For the heat break I did the same thing, however I had to be gentler to avoid unscrewing the heat break from the heat sink. Once I was satisfied with the cleanliness of the nozzle and heat break, I warmed up the heat block and m6-1 screw. I used clamps, pliers, and a wrench to hold everything as nothing is cool enough to touch. After screwing the screw through the heat block I cleaned the screw of debris and repeated. This eventually got the heat block clean enough. A special note here to how a screw works and is safer than a tap, not sure how it didn't occur to me the first time around.
Reassembly and beyond:
Reassembly is straightforward, just follow the instructions online. I made sure to torque a little more on the nozzle to ensure a tight fit. No problems in the past few weeks with print quality so this seems to have fixed the issue. This is a very time intensive process, if you plan on cleaning up a leak make sure to have a few hours of podcasts in the queue, or perhaps a short audio book, and some water on hand. I think if I get another leak, I will just replace the hot end and view it as a tax on my shotty nozzle installation. If you're reading this because you too have a leak: my heat goes out to you.