Best way to clean very fine hairs/strings on PLA print?  

RE: Best way to clean very fine hairs/strings on PLA print?

I don't know why the image got all distorted, but you can see the strings regardless, I guess.

RE: Best way to clean very fine hairs/strings on PLA print?

A tough toothbrush might help if they're not holding on too well. Or a mild abrasive scotch-brite pad.

Regarding heat - you'll get better results with very hot air, possibly even flame, for a very very short time, just licking it quickly with the hot air, as that'll only be able to heat up the hairs beyond the melting point compared to using lower heat for longer, as that'll soften the model too and it'll deform.

That was the reasonable options. Now the mad science options. Definitely not recommended unless proper equipment and education is applied. 😎 

Dichlormethane or tetrahydrofurane as those dissolve PLA. A quick minute or two exposure to vapors would be all that's needed. Plus it'd make the surface shiny. Exposure of the model, mind you, not yourself, both these substances are rather dangerous and hard to filter even with activated carbon breathing apparatus. The problem with dichlormethane is that it smells rather nice, but makes people lose consciousnes in higher concentrations of vapors in air and since they don't run away while unconscious, they tend to die.

Dunking into a hot solution of sodium or potassium hydroxide, this would hydrolyse the PLA in a matter of hours. Again, thin hair a couple orders of magnitudes faster than solid material. This would make the surface matte. I should mention that hot hydroxides also hydrolyse many other kinds of organic material, not just PLA. People for example.

RE: Best way to clean very fine hairs/strings on PLA print?

My understanding is that PLA is also mildly susceptible to isopropanol. Not to the degree one sees with the "polishable" stuff, but enough that it removes residue from your bed. So it may also work on hairs without doing anything to the main print.

Chlorinated organics are nothing to mess with.  Case study: There used to be glass fire extinguisher "balls" that were filled with DCM's cousin, tetrachloroethane. They would smother the fire by removing all oxygen, but were very rapidly discontinued, because of a) the suffocation hazard, and b) a rather unpleasant side effect of decomposing into something particularly nasty when heated... like, say, in a fire. Obviously, very dangerous for any first responders!

RE: Best way to clean very fine hairs/strings on PLA print?

Posted by: laurel.w

I don't know why the image got all distorted, but you can see the strings regardless, I guess.

If you remove the size numbers from the dialogue, that helps the distortion. It's also good to have the image link to the original size.

RE: Best way to clean very fine hairs/strings on PLA print?

A heat gun will work great if you you are just careful to keep it far enough away and at a low enough temp to not harm the model. It only takes a second or two to clear away the strings. 

RE: Best way to clean very fine hairs/strings on PLA print?

Let's see - let's use a water bomber to put out the fire in Notre Dame.  Sometimes the idiocy is funny - sometimes it isn't.  We can only hope people are smart enough to figure it out before they try to follow bad advice.

+1 to a heat gun. Simple, works really well.  

RE: Best way to clean very fine hairs/strings on PLA print?

Not to worry, tim-m30, I will not be applying dichlormethane or anything else of that ilk. (but maybe someone else would...)

I'll have to see if we have a heat gun in the house - if not, I'll experiment with a hairdryer on high, keeping a sharp eye on the rest of the model.

I'll play with the image settings.

RE: Best way to clean very fine hairs/strings on PLA print?

RE: Best way to clean very fine hairs/strings on PLA print?

Still wrong aspect ratio ...

RE: Best way to clean very fine hairs/strings on PLA print?

Argh. I forgot the allowed time to edit was so short. And there is no preview ...

It seems that it is reversing the width/length, but I don't know why. I can't make the dimensions render correctly. Full size image here.

RE: Best way to clean very fine hairs/strings on PLA print?

I always worry when people mention dangerous things on a forum where kids often post for help. 

A hair dryer may work, the real trick for managing spider webs with hot air is to apply high heat for extremely short periods.  The webs have a low enough mass they shrivel instantly, while larger masses are able to absorb the heat pulse without too much trouble.  Use the hair dryer on high, let it warm up, then pass it across the part just slow enough you see the webs shrink. Let the part recover, make a pass in a different area, repeat on the other side.  

Any small details are at risk, like those clips at the top of your part, but the 2 mm sections should handle the heat pretty well... just don't leave the dryer pointing at one spot.  If you see any deformation of the part before the webs shrink, you need higher temps. The webs melt back to the larger parts, and will leave a rougher surface over all; but a scrub with a stiff brush removes most the beads; sometimes I'll use an Exacto knife to clean up the part. And, sometimes the webs go away well enough they are no longer a problem and don't require extra work.

As for the photos; it's how the new forum handles images: some parts of the forum obey the camera rotation meta data, some parts don't.  Growing pains...

RE: Best way to clean very fine hairs/strings on PLA print?

As Tim and Voj say heat is easiest, I use a jet flame butane torch for fine hairs like that.  You quickly waft it over the problem area and no more fine threads.  Never stop moving the flame and the model is usually fine.

RE: Best way to clean very fine hairs/strings on PLA print?

Posted by: ...

I always worry when people mention dangerous things on a forum where kids often post for help. 

I prefer my kids to know that dangerous things exist and that they are indeed dangerous and how to be safe. Because blissful ignorance will not protect them should they meet one of them in real life. But I digress ...

RE: Best way to clean very fine hairs/strings on PLA print?

I use a butane torch and quickly let it burn away the fine hairs. Just keep the flame moving rapidly and never let it stop on the print and there will be no hairs on the print left. I use something like this for it. Works perfectly.

RE: Best way to clean very fine hairs/strings on PLA print?

Update: I tried the hair dryer and it did not do much - and I worried some areas might be starting to deform. Then I tried simply passing the pieces over a candle flame (as you all suggested) and it worked beautifully without any deformation. It was almost kind of hypnotic how well it worked. So basically, I should have been a better listener the first time. Thank you, everyone!