FUD FXD forming small crystals after time?

[Dave V]

@Lemosteam if there are I haven't looked lately (I'm at work) and I'm not sure I could attribute it even if it is there...it could always be my ham-fisted painting.

EDIT @tom mann I was going to share a photo but I'm getting "The uploader is full."

[Lemosteam]

@Lemosteam if there are I haven't looked lately (I'm at work) and I'm not sure I could attribute it even if it is there...it could always be my ham-fisted painting.

EDIT @tom mann I was going to share a photo but I'm getting "The uploader is full."

Chris333's video shows what it would look like- and it would show through any of your "ham fisting" um, "fisted", uh,  painting.  (hope the ham enjoyed it)

[Dave V]

...maybe?

[Lemosteam]

...maybe?

Nah, I don't see anything- you covered your roof with something right?

[Dave V]

Nah, I don't see anything- you covered your roof with something right?

Yeah, I think I used tissue paper or painter's tape to represent tar paper.

[SandyEggoJake]

It might be still too new, but has anyone seen this "FUD Frost" on the new Black High Definition Acrylate material yet?

Would seem to me in the year or this phenomenon has been known SW would have been able to collect samples and definitely determine the chemical composition.  Luckily, I've not seen it yet (he says, with a worried glance at the pile of newly arrived 3DP parts and wondering if he should pause designing more.) 

 

[Lemosteam]

Here are the parts that are almost three years to on year old.

@Chris333 There are some small iridescent flecks on some of the unpainted parts but nothing on the painted ones (the white spots on the painted trucks are worn areas from handling the parts).

I actually think some of the folks on the SW thread are mistaking the white fuzzy areas we all know are from the wax support for this, but Chris' pictures show something very different.

I've said this before, but FUD and FXD are very porous and it is because of the printing process. First they harden an outline for each sectional plane, then crosshatch inside of the outline, like a honeycomb. The laser does not always harden all of the material inside the hatches, and there can be gaps between the layers as well.  This leaves uncured material in the honeycomb that is cured during the post printing process. Usually.

I do not know if any wax gets trapped in the honeycomb, but maybe it does when the Bestine breaks it down and soaks into the pores.

I really do not think the bumps are wax, as I don't think they would be hard, I.e, I think the specks would smear on the paint when wiped off...

I wonder now if the leeched material is actually uncured resin weeping through the paint.

None of my parts are desintegrating like some of the SW thread posters fear.

Anyway, here are some closeupsMore of my parts.

[Chris333]

So do they have crystals? I only notice it on stuff I  paint, but the paint might just make it easier to see.

[Lemosteam]

It might be still too new, but has anyone seen this "FUD Frost" on the new Black High Definition Acrylate material yet?

Would seem to me in the year or this phenomenon has been known SW would have been able to collect samples and definitely determine the chemical composition.  Luckily, I've not seen it yet (he says, with a worried glance at the pile of newly arrived 3DP parts and wondering if he should pause designing more.) 

 

@SandyEggoJake , the hi def acrylate is a completely different printing process, and material.  Personally , I do not like that product, mainly because of the support attachment to the printed part, leaving pock marks and uneven surfaces.

[Chris333]

Just read in the paper that 3DS lost $153 million and the government is investigating them. 3DS was mentioned many times in the Shapeways link.

[SandyEggoJake]

@Lemosteam

Totally aware HDA (DLA) is a diff tech than FUD (aka VisiJet ® SR 200).  Also that the types of support used via DLA may be an issue with HDA for some complex shapes and a poorly designed orientations.  But such is beside the point. 

My question remains, as the biochemist in me is curious as to the composition of this "powder".  And acrylate monomers of HDA are also UV cured and likewise may oxidize.  Knowing the composition of this powder is the obvious step to exploring ways to avoid. 

I'm still a tad uncertain if it is an avoidable surface prep issue, or intrinsic to FUD/FXD material (via exogenous environmental oxidation and/or degradation via endogenous compounds in the FUD / possible under cured FUD).  I've read the thread, which towards pg 7 is clarified not all those reporting issues are seeing the same thing.  But to me (and others here I suspect) most concerning is the true crystallization (which a SW employee opines may be "degradation caused by the photooxidation of free radicals (a byproduct of UV curing and UV exposure), which react with oxygen in the environment and break down the cross-links created during machine curing").   

When I read this, I started pondering the if a bath in a cheap nontoxic soluble thiol-based antioxidant like NAC (acetylcysteine) to squelch free radicals on the surface region as an addition to my cleaning / stabilizing regime.  Might be over kill?  Might be useful?  Might be worth a test ... if we could find a way to other wise reliably and quickly trigger this FUD frost. 

Perhaps the plan is a) keep the fresh FUD/FXD part sealed and dark, b) dewax with Bestine (heptane) in ultrasound bath, c) stabilize with NAC (effervescent? In water made slightly alkaline via dawn dish soap?  why not?!), d) rinse with a distilled water, e) dry in sun for UV cure now that radicals have been squelched, g) seal with UV resistant acrylic primer (perhaps one containing Ti02) 

But till we know the cause, suggesting cures is pushing the caboose. 

[peteski]

@Lemosteam

My question remains, as the biochemist in me is curious as to the composition of this "powder".  And acrylate monomers of HDA are also UV cured and likewise may oxidize.  Knowing the composition of this powder is the obvious step to exploring ways to avoid. 

If someone sent you a sample of those crystals, as a biochemist, would you have the means to analyze their composition?

[Lemosteam]

@SandyEggoJake ,

To be honest, I don't think Shapeways will ever respond to my request straight away.

I suppose I'll wait for your inner biochemist to buy some parts, clean them, scrape them (pre-paint) wait for the crystals to appear to scrape that (post-paint), and find out the composition of all these artifacts and document the results.     

I don't have that capability.

All of the materials have (these are FUD/FXD) MDS and MSDS sheets available on the Shapeways site.  Surprised there is nothing about the material on the safety sheet, post process cured.

All of my parts in my pics had ample opportunity to oxidize unmolested in an open, oxygen rich environment for long periods of time, nor have any of my parts broken down, deteriorated, crumbled or otherwise failed their intended purpose.

NONE of my parts were post-cured in sunlight.

I am not a fan of bathing these parts in water because of the porosity.  it will take forever to evaporate (I suppose that could be expedited with an oven) and will leave further residuals on, and inside the model.

[Chris333]

I have a couple of these Nn3 tippers (the black one) that I can send for testing. They are crystallized like a mofo.

[wcfn100]

I have a couple of these Nn3 tippers (the black one) that I can send for testing. They are crystallized like a mofo.

Can you wipe it off like I was able to with my cabooses?  They were only in primer, I'm curious if more finished products are different.

Besides scrubbing with the toothbrush, I was also able to wet my finger and wipe it away.  If this is just surface stuff, I fell like it's at least a livable situation for now.

 

Jason