Shapeways FM switchers: Cleaning FUD

[havingfuntoo]

Has any one tried using oven cleaner ......... it is a close relative to alkaline based degreasers (ones containing NaOH caustic soda), not that I am suggesting it ..... just asking. I am a little surprised that a high level alkaline would have much effect on the wax, I would be concerned about it attacking some of the base material. I don't have any first hand experience here to quote from but I do know my cleaning stuff. 

[peteski]

WD-40 contains mineral spirits ..... nothing special .... some surfactants (surface acting agents) that assist with the water displacement and penetration of the product in to tight, dry and dirty areas, (that is the dark amber material you see left behind when the solvents evaporate) and some inhibitors to help control surface corrosion. As a substitute to WD-40 for this application try using plain old kero and good quality hand dish washing liquid mixed together. I would suggest a ratio of 20:1, Kero:Dishwash.     

If the amber liquid is only "some surfactants (surface acting agents) that assist with the water displacement and penetration of the product in to tight, dry and dirty areas", how do you explain its lubricating properties (touted on the WD40 website).

Specifically: "WD-40 Multi-Use Product is a unique, special blend of lubricants"and "WD-40 Multi-Use Product it is not a grease, it is formulated with strong lubricating oils and other ingredients, and is a terrific product to use for bike maintenance."

To me this sounds like there is some sort of petroleum lubricant in there (which will remain on whatever surface WD40 is applied to.  I do realize that all this info is really going astray from the topic but I wouldn't want someone using just WD40 to de-wax their FUD items.

[peteski]

Here are some photos which should clear up (pun intended) some misconceptions.  This is the White Tower building from ESM.  While is IS NOT FUD FROM SHAPEWYS, itis produced by a very similar process on a similar machine as it is used for FUD.

The building is fully de-waxed.  It has been immersed in VM&P Naphtha (in an ultrasonic cleaner), heptane and acetone. I also moistened it with other solvents (like Methylene Chloride) to see if I can melt the resin .



As shown in this picture, the building is printed from the bottom of the photo up.  Notice the frosted and clear areas.  As mentioned in the earlier posts, if there is wax needed to be built up which ends up in contact with vertical surfaces, those areas will end up rough (resulting in a frosted appearance when the wax is later removed).  The features where the vertical areas are transparent were the areas on the extreme edges of the printed object, so no wax was needed to support any of the features above those.

You can also clearly see on the bottom of the photo (at the green arrows) where the ledge around the building is mostly transparent, but one area directly under where the window ledge will be printed further up the building is frosted. That is because wax had to be printed at that location all the way up to where the window ledge protrudes further out of the building.



This is the close-up showing the large transparent area on the top of the printout and the window ledge (red arrows).  Again, because no wax was needed to be built-up in that area of the building, the resin is transparent.

The point I'm also trying to make is that even after the resin was subjected to all sorts of solvents, the transparent areas remained transparent even with all the wax removed.

I also believe that the Batmobile shown earlier is really transparent, even with the wax removed. That is because (if it was printed in the upright orientation) no wax was needed anywhere over the top surfaces (as none of its features needed any support under them to be printed).

Triethylene glycol dimethacrylate ester                                         45% – 55%
Urethane acrylate polymer
26% reactive monomer (CAS# proprietary)                                 35% – 45%
74% urethane acrylate polymer (CAS# proprietary)

If this is the FUD the resin then it makes sense for me why it is so resistant to solvents.

Acrylic was mentioned earlier but in my experience all the acrylic resin items I worked with (including Plexiglas and Polycarbonate) is attacked by solvents like Methylene Chloride.

But most urethane-based resins are much more resistant to solvents. The above list seems to indicate that FUD would be more of a urethane than acrylic resin.  That explains why it is very resistant to solvents. This to me is not beneficial as I don't have a solvent which could melt and smooth the rough frosty surfaces smooth.

This sure turned into a lively thread! 

[DKS]

What is being argued is that Bestine is unduly affecting the surface finish and making it rougher than other less caustic, but still effective cleaning methods.

So I just took an RP model that had been cleaned in heptane, and examined the surface under a microscope. The smooth parts of the surface, although white, looked extremely smooth. So, I must ask: if the claim is that heptane "damages" the surface, how could it have any bearing on the outcome of a painted model if the damage, assuming it's real, is microscopic in nature? Please explain how this is going to negatively impact the final result.

If anyone can demonstrate that the white coloration caused by heptane cleaning has any detrimental effect whatsoever on a finished model, then I will (as will others, I'm sure) be convinced this is not the best method. We have a few modelers here who consider themselves vastly superior to the rest of us mere mortals; now, how about some photos proving to us you're right? So far I'm not seeing any such evidence.

Back up your assertions with proof. Otherwise, all of these "solvents are bad" claims are just so much hot air.

[Sokramiketes]

We have a few modelers here who consider themselves vastly superior to the rest of us mere mortals; now, how about some photos proving to us you're right? So far I'm not seeing any such evidence.

Back up your assertions with proof. Otherwise, all of these "solvents are bad" claims are just so much hot air.

Oy.  What you're not understanding is that I'm not taking a side.  I'm trying to explain that neither side has offered definitive proof yet.  There is nothing about what you've offered that would pass any sort of peer review. 

Per your "Back up your assertions with proof." comment... YES.  That's what I've been waiting to see from either side! 

Peteski's analysis of the White Tower above might be the best explanation I've seen all thread.  And can explain why katfudgirl sees clear parts from the machine and we see more white parts. 

[bbussey]

... As shown in this picture, the building is printed from the bottom of the photo up.  Notice the frosted and clear areas.  As mentioned in the earlier posts, if there is wax needed to be built up which ends up in contact with vertical surfaces, those areas will end up rough (resulting in a frosted appearance when the wax is later removed).  The features where the vertical areas are transparent were the areas on the extreme edges of the printed object, so no wax was needed to support any of the features above those.

You can also clearly see on the bottom of the photo (at the green arrows) where the ledge around the building is mostly transparent, but one area directly under where the window ledge will be printed further up the building is frosted. That is because wax had to be printed at that location all the way up to where the window ledge protrudes further out of the building....

The theory certainly appears to hold true most of the time.  Except, the examples I gave above are exceptions, and they were printed on the same machine to the same resolution as the White Towers.

The G32C gondola masters were rendered upside down.  With the top belt rail of the car (and the mold separation membrane) extending far beyond the dimensions of features above it, the entire car (with the exception of the floor top) should be clear if following the theory.  Also, the bottom of the floor membrane is smooth, with the appearance of porcelain.  Actually, even the floor membrane top is smooth, with a matte finish, and that was supported fully by wax.

The NE5 body was formed from a series of flat pieces assembled together.  All are smooth, and all are opaque.  The floor/underframe was printed top-side up, which means the bottom of the stairs is the widest point.  Yet that part is all white as well.  All of the parts for the Keyser Valley caboose master, also rendered as parts that were assembled later (either as flats or body halves), also turned opaque after the Bestine soak, and also were smooth and detailed.

And finally, I've soaked at least a dozen of White Towers.  Some end up with clear roofs, most don't.  Some have other areas that stay clear, such as the tower and window sills, most don't.  All of the buildings have been printed in the same orientation.  So the consistency isn't there to say definitively that any area not supported by wax will not turn opaque.  Conversely, the parts I mentioned above refute the theory entirely.

[bbussey]

Oy.  What you're not understanding is that I'm not taking a side.  I'm trying to explain that neither side has offered definitive proof yet.  There is nothing about what you've offered that would pass any sort of peer review...

I provided plenty of proof.  The G32C bottom side and NE5 parts and the KV parts are as smooth as porcelain under magnification.  The sides of the 1950s White Tower sold in the ESM Sovereign Modeler Series, also printed as flats, is as smooth as porcelain.  There is no Bestine damage.

[John]

This is a great and informative discussion - but like all discussions, opinions will vary.  Let's make sure it doesn't devolve into a negative thread. Thanks ...

[DKS]

I'm trying to explain that neither side has offered definitive proof yet.  There is nothing about what you've offered that would pass any sort of peer review. 

While it's perhaps been inadequate for a scientific journal, I've seen some reasonably convincing evidence produced by Bryan and Peteski. For myself, I've just ordered a fresh new batch of FUD products (everything I have on hand has either been cleaned or painted) so that I can (hopefully) photograph it through a microscope for some more definitive evidence. Yet with all of this persistent talk of "solvent damage," there hasn't been any evidence produced at all to support the opposing point of view.

My secondary point is that, even if there is "damage," so far as I can tell it's microscopic. So my question is: what discernible impact would microscopic surface features have on a model, particularly one that will almost certainly be painted?

[Sokramiketes]

Yet with all of this persistent talk of "solvent damage," there hasn't been any evidence produced at all to support the opposing point of view.

The evidence is clear parts turning opaque.  The evidence is the same for both sides.  Clear parts turning white can point to *either* removal of wax revealing an opaque surface *or* that a clear surface is affected by solvent to turn it opaque. 

Why is that aspect so hard to understand and being taken so harshly by you and Bryan?

You say the batmobile isn't clean because it's still clear.  I'm pretty sure I have parts that are clean but still clear.  Yet I'm supposed to soak until they turn white?  I don't think that's necessary, but if that's the indicator, then I'm playing devil's advocate and asking why there can't be some other explanation of the results. 

There are multiple interpretations of the same set of final data here.  That's the beef and should be open for debate until we have enough data to understand what's going on. 

[DKS]

Why is that aspect so hard to understand and being taken so harshly by you and Bryan?

Because so far, barring access to electron microscope imagery, we have not seen any evidence of physical damage. The opposing camp assumes guilty until proven innocent. I am asking for hard evidence of real damage, not just a color change, because color change does not represent any sort of damage that impacts the structure of the model in any fundamental way. And based on Peteski's photo showing clear areas even after exposure to solvents, I'd say things may be stacking up against physical damage. Why is this so hard to grasp, and being attacked by those dead set against using solvents?

And why is no one even touching the point of possible microscopic damage? Someone please tell me how microscopic damage changes the outcome of the model. Is anyone going to see this? Yikes, many modelers working in brass deliberately "damage" their models (with an acid etch) in order to achieve better paint adhesion. Are we to mount a program against this practice, because it harms the model? And, no, this is not an absurd extrapolation; this is an issue that would appear to involve surface features of equivalent scales.

You say the batmobile isn't clean because it's still clear.

I have said that I have doubts it's clean; I made no assertions. Subtle yet significant difference. I am open to the possibility it is indeed clean, but it may require chemical analysis to determine this.

[havingfuntoo]

Short of extensive testing on the materials before and after you will find it hard to get an answer on solvent damage quickly. But ........ if you are prepared to take a model with angular sections
and solvent clean it as per the 'David method' (for want of a better description ... sorry Dave not giving you any ownership here)  then leave it unpainted and exposed to good air circulation and maybe some sun light for an extended period of time (not sure of how long, suggest 3 months to start with), the evidence of solvent damage should become apparent. Surface oxidation and the model becoming brittle would be some of the tell tale signs. For the trail to more conclusive you would expose a similar piece from the same model to an alternative cleaning process and place the two side by side.   

Peteski, does WD-40 claim to be a long term lubricant ..... I'm not sure ...... kero will act as a lubricant under certain conditions and as an abrasive under others, just as water based materials will also lubricate ...... what was that Johnson & Johnson product from years ago???? No no no let's leave that one alone.

[Hornwrecker]

I did the letters in clear, but soaked them in heptane.

[Dave Schneider]

Notice the crappy texture on the Deathstar!

Best wishes, Dave

[DKS]

I did the letters in clear, but soaked them in heptane.

Too funny! I love it!