3D Printed scenery self destructing Thunderchrome/Bad Roll problems

[robh]

Over the past few weeks I have been sorting through all my Post Apoc figures and scenics preparing to sell them and have come across a potential major problem with some of it.

Back in 2017 I bought and painted a lot of 3D FDM printed 28mm scenery from Thunderchrome/Bad Roll which was great. When finished it looked like this:



It has not seen a lot of table time which is why I was considering selling it. A few PA and some Inq28/ITEN games only, the last one being about 3 years ago.
It was stored dry in boxes wrapped in shredded paper which is still clean and dry so this is an "internal" problem.
The scenery was originally cleaned and spray undercoated in Armory Black primer, acrylic painted then gloss varnished and matt coated.

Now the actual FDM material is decaying, sort of crumbling and going "floury" and brittle. The roof of the building above split apart when I picked it up from one end unable to support its own negligible weight
Just touching one of the unpainted pieces (A walkway) is enough to cause it to disintegrate and crumble.







Anyone involved with 3D printing have any idea on how or if this can be stabilised? Or do I have a few hundred euros worth of rubbish now?

[Daeothar]

It hugely depends on the type of filament used.

I've worked with a company that did a lot of prototyping and expendable tool making with FDM printers, and the type of filament used was (what they called) biodegradable.

Meaning it would break down after a couple of years. This was no problem there, because the tools (sorting trays, dividers etc) were printed for specific projects and were useless afterwards, if they even made it all the way through; replacements were being printed daily. Same went for the prototypes.

But using those types on miniatures/terrain would pose a problem considering we generally hold on to those items a lot longer than a year or two.

Looks to me like this is a tragic loss of material; irreversible and inevitable... 

[Mammoth miniatures]

PLA is very susceptible to UV exposure and humidity apparently. It's meant to "biodegrade" although I think that really just means "falls apart into a big pile of microplastic if you leave it outside".

I don't want to make the same point I made in the exploding UV resin print thread a couple of weeks ago, but so many of these materials are untested in any sort of long term sense,  and often they are only tested under short term lab simulation or under local conditions according to their area of manufacture, so they are inherently experimental to a certain extent. the whole market for 3d printed materials is entirely unregulated so it's hard to know if a material is inherently short term, or if you've just been sold a cheap and nasty reel of sub standard stuff.

[anevilgiraffe]

should the filaments still be present? I've no idea how it works, but assume that the filament is melted in some way. I had some terribly printed stuff (market stall awnings) and they literally were like a wicker chair on the underside. all that loose stuff got filled in.

[Elbows]

Mammoth pretty much hit it on the head.

Unknown manufacturing process.
Unknown filament provider.
Unknown printer settings.
Unknown printer speed.
Unknown curing time, heat settings, etc. etc. etc.

I know several years ago, even someone posted here a similar issue with resin 3D prints from 10+ years ago.  They were also becoming brittle.  There's a not-zero chance of full armies of 3D printed miniatures becoming brittle/falling apart in a kind of 3D print apocalypse, so...get them on the table while you can!

[Easy E]

Yikes.  Makes me kinda glad I did not jump on that particular band wagon! 

[robh]

......the type of filament used was (what they called) biodegradable.

PLA is very susceptible to UV exposure and humidity apparently. It's meant to "biodegrade"......

There's a not-zero chance of full armies of 3D printed miniatures becoming brittle/falling apart......

Yes, hunting around the web last night and this morning it seems that a limited lifespan is standard, 7 or 8 years is about all you can expect from prints like this. 
The pieces I painted were completely encased in paints/varnishes (apart from the clip together joint plugs and sockets) but the Chinese style container building above is the worst of the pieces I have, the pale area visible on the underside of the roof is all soft and spongy but no signs of moisture, It is disintegrating from the inside.

Yikes.  Makes me kinda glad I did not jump on that particular band wagon! 

Yeah, this is the only terrain set I have in 3D print and I will not be buying any more. I have several boxes of card and paper terrain that is considerably older than these and are lasting better.

[zemjw]

That's rather worrying/annoying

I'm now trying to think how much 3d printed stuff I have, and how long before I may start to see problems.

Most of my pla printing these days is slottabases and 6mm tank bases, and I've generally avoided buildings (mainly due to the print times required). I don't think I have much commercial stuff, and now it looks like another reason to avoid it

[Dolnikan]

PLA (or polylactiv acid) is an amazing polymer that does have some issues. It's not the most stable and I'm very sorry to tell you, there isn't really anything that can be done to reverse or even stop this process. It basically starts the moment you use the material and over time, it will just keep going until you get what you have now. That said, even the smallest parts can be biodegraded, so at least it's not toxic or anything like that. The paint and varnish probably are more of an issue there.

Theoretically you could try to sterilise the material or dry it thoroughly (as in, remove all the humidity from it) but neither of those approaches are in any way practical.

[robh]

..... even the smallest parts can be biodegraded, so at least it's not toxic or anything like that. The paint and varnish probably are more of an issue there.....

Yes, It seems to be made from Cornmeal and Turnips and after a year or two is best off in the Compost Bin 

Although I store it dry with desiccant packs just bringing it out into the humid and warm air around a game table will shorten its life by days or weeks. Fully encasing it in a non-porous paint and varnish shell has helped delay the decomposition,  but as you say, once it starts to go you cannot restore it.

I wish I had read up on it BEFORE paying for anything made from it, and am really grateful to whatever turn of fate prompted me to spend the extra money on a resin cast 3D dungeon set than the cheaper FDM printed option I was very tempted to get.

[Daeothar]

I had been temped before to get a filament printer, but now I'm sort of off on the idea. If I invest time, effort and money into terrain and/or miniatures, I'm of the mindset that my models should last at least as long as I will (hopefully more than the 8 years the offending terrain lasted ).

As it is, I currently have 2 items that have been FDM printed: an imitation Armorcast Tyranid Exocrine which I purchased on an auction site recently because the originals are just ridiculously expensive, and the parts to assemble a 1:1 scale Space Marine Bolter (intended to be a wallhanger).

Both still need to be painted, but with the above horror story, I do not know if this will be worth the effort (to me)... 

[Silent Invader]

If sealing a PLA print that has been painted, what sort of spray varnish should be used?

I've just finished building a building but there is a PLA printed product at it's core. I wasn't going to seal it with my usual acetone based Matt in case it goes sticky,

Thoughts anyone?

[Dice Roller]

Yikes.  Makes me kinda glad I did not jump on that particular band wagon!

Yup, I feel pretty much the same.
The idea of a 3D printer for the end user to make products to use as is, always seemed a bit 'Emperor's New Clothes'.
For use in industry as prototypes or as masters to make moulds, then sure - that's where the strength lies.
But as something so the everyday person can print out anything they need? Well, looking aside it just adds more wretched plastic to a world already drowning and polluted by the stuff, it just seemed to run before it could walk.
Like you say, rather glad it's something I've let pass me by.

[pixelgeek]

Is there any type of filament that won't do this?

[Mammoth miniatures]

Is there any type of filament that won't do this?

ABS shouldn't. Everything except PLA basically.