Post Print Cleaning for production?

#1

Hey all,

So been experimenting with various cleaning techniques in an attempt to find the most effective and I was wondering what others have been using.

At present, I am printing Wargaming models (scale miniatures 30mm), so typically they are well detailed and I am struggling with getting rid of that final tackiness and the uncured resin from the small details. I have read through the wiki’s on cleaning and in general follow a process similar to that.

  1. soak and vigorous shake within soapy water - to remove as much of the initial resin as possible
  2. 1 minute scrub within IPA (have also tried, white spirits and other cleaning fluids), tyically used a toothbrush, but next time will be using a paint brush, am considering using an electric toothbrush at this stage.
  3. final wash within ultrasonic cleaner, have tried soapy water, and mixtures of IPA and water.
  4. Curing within water using UV LEDs for ~10 minutes.

My ultrasonic cleaner is an old one ive had a few years, typically used to clean up my airbrushes. My intention is to utilise the Moai for printing items to be sold to the public and I am a little concerned with how clean I am able to get the prints (considering the safety precautions of the resins themselves). I am looking at buying a larger scale ultrasonic bath (as I would need a larger one to make production effective).

Fellow Peopolypeople does anyone have any suggestions? I would love to hear how your prints feel after your process. Mine tend to look fine, but have a slight tackiness on contact that when shone under the UV LEDs can be seen to be uncured resin. I haven’t had issues with scrubbing damaging prints, no issues with brittleness post UV cure. Just this final bit of tack driving me barmy.

Ghostpants

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#2

I use the Form Wash machine and it gives super clean models ready for the curing chamber. Before I also did the ”IPA/soap wishwash thing” but lets face it - that is a messy and not so sufficient way to clean the prints. I highly recommend the Form Wash.

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#3

On that front I am wondering if the Prusa CW1 which is a combined wash/cure device would be interesting for Moai users. Also fairly expensive but would end up less than the Form Wash / Cure combination. Not sure what its capacity is.

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#4

Hi! I have my DIY curing chamber that is big enough for Moai printed objects. I only have the Form Wash from the Formlabs product line.

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#5

I also have a cure chamber, however if I were now looking to get a washing station I’d wonder whether to go for the CW1 since I don’t already have a Form Wash. Will be interesting to see if anyone here tries one.

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#6

Try ethanol instead of IPA. I’ve had much better results since I switched. In the US you can get it in big box stores (home depot, lowes, walmart etc) under the brand “kleen strip” for a reasonable price. It’s 95% ethanol. You can order it from Amazon: https://www.amazon.com/Klean-Strip-GSL26-Denatured-Alcohol-1-Gallon/dp/B001EMB2A0/

I was surprised to learn that ethanol is the same thing as “drinking” alcohol. Except the “denatured” part is some chemical that will make you permanently blind and other nasty side effects. You can buy ethanol without the denaturing chemicals in most countries other than the US. In the US you can buy it too, but you have to pay a liquor tax and so it’s very expensive (close to $100/gal with shipping).

That form wash machine does look pretty nice. I’d like to get one sooner or later.

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#7

Unfortunately not readily available in Australia. Aside from IPA the other two options here are methylated spirits or denatured alcohol.

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#8

The thing that makes you blind is methanol, and it’s a by-product of alcohol distillation which is why one should not buy home-made moonshine unless you make sure the guy who distilled it got rid of the first few % of the distillate :wink: Most of the time ethanol that isn’t sold for consumption has additives that not only make it taste real bad but also stuff that make you puke.

@arden denaturated alcohol IS ethanol, and most likely methylated spirits is just the same thing as well. You should go ahead and buy these if they are cheaper than IPA for you.

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#9

Thanks for the replies guys.

I have experimented with White spirit (im UK based), which is not a methylated spirit, i didnt try it in my ultrasonic bath, just scrubbing by hand and the results weren’t great. I may try it in my ultrasonic bath, hopefully it doesnt turn into a pot of fire, but we will see!

So far the bath with IPA has been most effective, but I will also try ethanol. My ultrasonic bath is a cheapo one, and its timer setting maxes out at 8 minutes. Which does a decent job, usually i run it twice for a total of 16 minutes and the parts typically end up getting about a half an hour soak.

What settings do you use on your baths?

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#10

I usually only put parts in the ultrasonic for about 15-30 seconds. Then I put the part in my uv curing bucket, which contains tap water.

I started out using IPA with this same method but switched to ethanol aka denatured alcohol aka ethyl alcohol aka booze + poison. I got far better results with the ethanol.

Actually for parts that don’t have a lot of detail, i don’t even turn on the ultrasonic. I just swish the part around in the alcohol and maybe brush it with a small paintbrush a little.

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#11

I use this method with ApplyLabWork Grey resin but this processing technique works with other resins as well including formlabs and the Peopoly grey resin:

Bradley Systems’ Yellow Magic 7, undiluted full strength, in a Harbor Freight 2.5L ultrasonic cleaner heated to 50C. Clean the parts in this for 480 seconds. After cleaning, while the parts are still warm, pull off supports (the heat from the ultrasonic cleaner makes them peel off very smoothly and easily).

Cold water rinse.

Form Wash for 10 minutes in 91% IPA.

Quick rinse in a dunk tank filled with clean IPA.

Air dry using airbrush compressor.

Form Cure for 1 hr at 40C.

No tackiness.

Major upside to using the Yellow Magic 7 is that it is a surfactant, and the washed-off resin does not go into solution with it as it does with IPA. Every few days pour the “dirty” Yellow Magic 7 into a clear glass container and set in full sun for a few hours. This cures the resin residue out of the liquid. Then filter the clean Yellow Magic 7 back into the ultrasonic cleaner and top off with fresh Yellow Magic 7 as needed. Discard the cured resin residue as usual. By doing this you preserve the life of the IPA in the form wash. Saves money in the long run.

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