Acetone Finishing on PLA

[geert_2 557]

This is the gypsum shaker I use, two speed. Small but heavy. Occasionally, it is capable of bringing a whole wall into resonation, like a pneumatic concrete drill.

There is no way to get a *thick* gypsum paste flowing into fine teeth details without a good shaker. That is why I think it might be beneficial here too, if you have flowing problems.

For dental models to be strong enough, the gypsum needs to be a very thick paste like cement or choco (it feels like somewhat inbetween). It is way thicker than honey or syrup, but less stiff than most natural clays. So they can not use a "creamy" liquid gypsum: that is too weak and brittle when cured.

Normally, the mixing volume of (dental) gypsum is about 30g water per 100g gypsum, although it differs from brand to brand. Also, keep in mind that gypsum at this ratio slightly expands when curing (ca. 0.2%). And it may get warm to hot. If mixed in the correct volume, it is dry after curing, since all water is chemically bonded.

But for use as filler like here, it does not need to be so strong, so it can be made more liquid, thus containing excess water.

To slow down curing, you could try using very cold water from the fridge. If the gypsum is very dry (desiccant!!!), you could put it in the freezer or fridge too. But don't do this if it is moist: if you get condensation, that might already start curing it in the fridge.

Edited November 17, 2017 by Guest

[cloakfiend 995]

Nice! I have a slight neighbour concerns though regarding hey vibrations. I assume you don't need to leave it on for long though?

Also another worry I forgot to mention or haven't mentioned it enough is that priming the model may split it also, but that may be just bringing out the splits that you eyes couldn't see before? Some paints do contain solvents especially in spray cans, but Im not sure on this 100% so I'll just throw it out there, I'll be doing some new prints soon so ill give the dishwasher fluid/detergent thing a test. hope it works! as if you are plating after acetone you NEED to wait for the effects to finish otherwise your model will alter inside and you will get rippling on the plate if it is very thin...!!

Edited November 17, 2017 by Guest

[kmanstudios 1,120]

Nice! I have a slight neighbour concerns though regarding hey vibrations. I assume you don't need to leave it on for long though?

Also another worry I forgot to mention or haven't mentioned it enough is that priming the model may split it also, but that may be just bringing out the splits that you eyes couldn't see before? Some paints do contain solvents especially in spray cans, but Im not sure on this 100% so I'll just throw it out there, I'll be doing some new prints soon so ill give the dishwasher fluid/detergent thing a test. hope it works! as if you are plating after acetone you NEED to wait for the effects to finish otherwise your model will alter inside and you will get rippling on the plate if it is very thin...!!

Some paints do contain solvents so that it will bind a bit into the plastic. Krylon has some. But it is not enough to cause damage. Otherwise a lot of my models would be disintegrating at this time.

[nzo 16]

I have a slight neighbour concerns though regarding hey vibrations. I assume you don't need to leave it on for long though?

Nikola Tesla has a famous story to do with resonance. On one of the steel upright beams of his workshop they mounted a small compressed air vibrator hooked up to a very big air compressor. They started the compressor and as the pressure/vibration increased, so did the resonant frequency. They noticed different parts of their workshop began to vibrate until the building itself began to shake. Fearing imminent collapse they destroyed the vibrator with a sledgehammer since there was enough remaining air capacity in the compressor to structurally damage the workshop building.

[nzo 16]

You guys might appreciate these pics of gypsum crystals that grew in a huge underground cavity in Mexico. The cavity would have been filled with superheated mineralized liquid from which the crystals gradually grew over thousands of years.

[kmanstudios 1,120]

You guys might appreciate these pics of gypsum crystals that grew in a huge underground cavity in Mexico. The cavity would have been filled with superheated mineralized liquid from which the crystals gradually grew over thousands of years.

I am thinking the gaps between crystals is because there was not a sufficiently large vibrator to shake all the air bubbles out?

Edited November 17, 2017 by Guest

[nzo 16]

A long slow mild earthquake would do the job

[Edel 5]

Im doing a very descriptive acetone infomercial (lol), and showing the various effects over the years (seeing as no one else seems to be as active in this method as I am) and showing what filaments i think are better and what cracks more and how and why and how to avoid it at best. Its gonna be a talky one though but i will be showing a lot of models i have done even from 3/4 years ago. And yes I still only use colour fabb now but still have a roll of original UM brand filament I only bring out for special prints! It rarer than hens teeth now that stuff!

BTW Colofabb cracks as well if you leave it too long. Thats why the original UM brand filament was the best! ( no cracking EVER!) on a side note cracking is also a sign that your not printing hot enough or the coupler is on its way out!

 

hey i also work witht hat methode you introduce to me!

original UM brand was innofill, i told you

[Edel 5]

So i read no all your new post, show all new video... and i shocked that you dont sand anymore before aceton brushing...

i sand alot with 80grid, then aceton, and then i good the bad problem of getting white parts... this white new areas are not flat, no you build up and raise too! no millimeters, but you would see it... so i sand again with 200grid...

and then its smooth.... then filler, sanding 1000grid. and voila.... all ok!

but this takes also time.... but i learnt all form youside!

and now i you dont sand?!?!? and why are your white areas so flat?

[cloakfiend 995]

I do sand but If I need to use sandpaper, I now only use 240 grit sand paper EVER. nothing else. and I don't use a lot, just to get rid of weird lines or the top were it finishes. But again...

I keep stressing this and many if not everyone seems to ignore it or just say they have a better system or a more powerful feeder or smoother bearings or whetever.

Print OFF the roll, and print in 0.06 layer height. and make sure your centre screw is clean and free from particles of filament dust. Im sure there are other things I check for like 1.2 wall thickness due to me always printing hollow, .8 will simply produce inferior results. and manual supports and as little retractions as possible and blah blah....basically a lot of trial and error.....

and don't upgrade your software if it works. Its another variable you are messing with. I have found what works for me and have suck to it. I have messed with my printer upgrading and such, but now it is back to factory settings apart from a more powerful heater which i think actually makes the prints worse so I will most likely go back to the 25W heater.

You don't need to agree with me about anything I've said, but unless you show me hundreds of different kinds of prints close up that look better than mine all using the same filament and printer setup I won't listen.

I'll try to make a video about my print routine, but its difficult because talking to complete noobs is totally different to talking to people who know what they are doing and like me people have their own opinions of what is best and changing someones opinion is a HARD TASK. Its like trying to convince Flat Earthers that the world is not flat. Sounds simple, but believe me its not. I'm know and hated by that entire community and after much rational arguing and irrational debate I don't thing my logical thinking has gotten me anywhere!

So to confuse you and answer your sanding question, Yes I ALWAYS sand but only for a minute or so because the top of your print will ALWAYS need sanding. I don't spent time sanding and don't consider it as sanding like other assume. Its all in the process of finishing. like a glued model of parts will NEED filler or putty and then what i call 'proper sanding to make it perfect. My models tend to be too detailed to sand. I could never sand eyes for example or in gaps that I simply can't reach into.

How much time you want to spent on your models is your decision but I find that life is too short to spend it sanding!!! I guess I should say my sanding is only a minute rather than none at all. but again I could explain why in an essay and I've already written enough!

If your going to do something, I say do it right or not at all. But the amount of time you want to spend getting it right is what I'm trying to help you with....on an old UM2 that is.

Edited November 19, 2017 by Guest

[cloakfiend 995]

I was just reading through my thread and It looks as if my copper solution is about 2 years old now....time to get some new stuff me thinks!!! then tutorials for my methods of plating will follow! but learn how to acetone stuff first because layer lines and plating don't mix well!

Edited November 19, 2017 by Guest

[kmanstudios 1,120]

I will respectfully disagree on two points you make.

One does not put out information to convince people. One shares opinions and techniques, but not to convince, just to show it can work. It is up to the individual to adapt or not.

Noobs can be a pain too as some of them forget how difficult something can be and wonder why things just do not magically work right off the bat.

I prefer the approach of attraction, not recruitment....changing minds cannot be done by anybody but the person themselves. And, not all things work in all environments.

And, I for one am looking forward to your instructionals on how you do this. Plating such as you are doing is alchemy to me and would love to learn more. And, your experiments with the Acetone cut many, many hours of printing and ruined prints testing.

[cloakfiend 995]

Agreed!!

I keep forgetting my roots, I remember the days when I was begging people for print settings because I didn't have a clue what I was doing and was not happy with my results.

Besides, attraction leads to a more willing audience. I also hate hard sells!

Edited November 19, 2017 by Guest

[SandervG 1,521]

Re washing your prints with dishwasher soap or alcohol, after you dipped your prints in the acetone, will there not be acetone in your print as well? Which is not getting removed by washing just the outside. Maybe it will continue to affect your print from the inside and you want to wash it more thoroughly. Or perhaps it is not in the acetone long enough to really get in there and you're fine. Just a thought

[geert_2 557]

Nice! I have a slight neighbour concerns though regarding hey vibrations. I assume you don't need to leave it on for long though?

...

I only use it in our university laboratory, and only for a minutes or so, until the model is filled and the gypsum is distributed nicely. (Although, since 3D-printing, I haven't used it anymore.) This sort of noise is more acceptable in a lab. But in an appartment, people would notice it a couple of floors away, just like drilling into concrete walls. Unless it would be placed on thick antivibration mats.

The gypsum first looks like dry clumps of cement, but when you switch on the shaker, it starts flowing smoothly, very similar to silicone for mould making or lava, into all corners of the mould.

[cloakfiend 995]

Regarding the dishwasher liquid.

.Ill do a few tests but it will take some time as bad couplers and other variables also cause splitting. And splitting generally can take days or even weeks to occur depending on the climate the model is left in. Luckily my coupler is good though and I will have some exciting new models to print with an experimental faster method so I will do some test prints soon. Just a bit busy with work at the mo!

...and a side note is that i did so much unprotected airbrushing experimenting with funky chemicals and poor breathing equipment that i feel really unwell and have mad stomach cramps. I need to take a break till my proper respirator masks arrive! Just gonna do some modelling and printer settings refining till then!

Edited November 21, 2017 by Guest

[cloakfiend 995]

original UM brand was innofill, i told you

But you also told me it took longer and left more residue?

The UM filament I used before could smooth even 0.1 not only 0.06, and took much LESS time! And never cracked. So i doubt it was the same formuka as your inifil. I read somewhere a batch went wrong and they altered the formula. So i doubt youll see that one around again.....

[SandervG 1,521]

...and a side note is that i did so much unprotected airbrushing experimenting with funky chemicals and poor breathing equipment that i feel really unwell and have mad stomach cramps. I need to take a break till my proper respirator masks arrive! Just gonna do some modelling and printer settings refining till then!

Ouch..! Hope it's nothing serious and you'll get back on your feet soon. Take care!

[geert_2 557]

...

...and a side note is that i did so much unprotected airbrushing experimenting with funky chemicals and poor breathing equipment that i feel really unwell and have mad stomach cramps. I need to take a break till my proper respirator masks arrive! Just gonna do some modelling and printer settings refining till then!

Keep in mind that standard breathing masks (fine dust filters, usually white) do *not* eliminate any chemicals from the air. They only filter out dust particles and paint particles. Which is good of course. But toxic gasses go straight through. To filter out toxic gasses too, you need a real gass mask like those used in hazardous environments in chemical plants, plus an appropriate filter for the type of chemicals you are going to use, and for dust. Filters don't filter all: the active chemicals in the filter are designed to trap specific pollutants only. These filters need to be changed whenever you start using the mask in the morning (thus one per day), and after a specific amount of hours of use during that day. And they need to fit airtight around your head, so: no glasses, no beard; or a special gass mask accomodated for these. Google for: gass mask. The sort of masks that make you look like an alien. We had those when I worked in a chemical plant long ago.

[cloakfiend 995]

I don't mind about my eyes they seem ok, and I have a proper respirator mask with lots of filters and spares so I should be good as I only use it in short amounts. the fine wire wool dust is the worst!!

and thanks @SanderVG I'm sure ill live for a couple more years! lol.

Edited November 28, 2017 by Guest

[cloakfiend 995]

Here are two more vids playing with chemicals...

[geert_2 557]

Thanks for the very informative videos. Also, the clock is a good idea.

I guess the reason why airbrushing did not work very well, might be that the product just evaporates as soon as it comes out of the nozzle, instead of being deposited on the model. To me, an airbrush looks very similar to an injector in a car engine, and the injectors are there to evaporate the fuel as quickly as possible, without depositing it on the cylinder walls...

It is not easy to see on the videos, but it appears that the acetone works better in fine details, and the methylene chloride works better on big surfaces? If so, depending on the model, it might be worth doing both? But that might also increase the risk of later splitting due to the chemicals?

[cloakfiend 995]

I also think the model will not split with methylene chloride. So thats a plus. Whilst it 'can' split with the acetone or ethyl acetate. The methyl on pla is like a fine version of acetone on abs but not as destructive so similar to effects of acetone on PLA but more destructive and only really affecting the surface.

Acetone changes the entire state of  your pla

Methly chloride affects more of the surface than actual structure.

....that is what i have observed. But both go soft and rubbery for a short period directly after. Acetone goes harder quicker after which is why its prone to crack if youve been too aggressive with it. I have not experimented enough with methyl to see what happens later in time...say weeks or months later.

Edited December 4, 2017 by Guest

[geert_2 557]

A thought that just occured to me: most plastics do contain additives. For example: plasticizers, pigments, UV-stabilisers, flame-retardants, water-repellants,... I don't know if PLA or PLA/PHA contains any such additives (apart from pigments of course), but it is not unlikely.

Could it be that each of your solvents dissolves different parts of this mix?

For example, imagine that a plastic blend would consist of a mix of 50% hard plastic, and 50% plasticizer: if one solvent would remove the plasticizer, then the result would be brittle and hard plastic. If another solvent would remove the hard molecules, then the result would be soft and flexible plastic.

Maybe this might be worth trying? For example, if you print 4 small test plates (let's say: 50mm x 10mm x 0.5mm: this prints in a few minutes) and then thoroughly brush each with one of your solvents. Keep one untreated. And then see if there is a difference in flexibility and brittleness, now immediately, and in a few weeks/months?

[cloakfiend 995]

I will check the methyl chloride out as that one seems to be soft. But seeing as pure pla does not react to acetone like the pla/pha from colorfabb then there must be something else in it.

And as for using it to smooth large flatter areas, I maging it would be better as i dont think it will warp either, but again I have not tested this....yet.