Weathering Model - Crumbling Into Pieces In My Hands

Did you wash the parts in anything before you primed and painted?  If so, what did you use to wash it?

I cut the parts off the sprues, assembled the model in logical chunks. Primed, painted, washed.

That's all I did.

Well since it was primed then that would be the only product that actually contacts the plastic. Never heard of that primer before but it doesn't look like it should cause an issue. Did you thin the primer with anything before applying it?

Nothing stands out there  but I had something similar after stripping paint off a little 1/144 dc-3 by soaking it in testors ELO.  After a few hours I pulled it out of the bath and it just kinda fell apart like you described.

I've found several quite old Reddit threads on /r/modelmakers alluding to the fact that enamel thinner and the thinner contained within enamel washes can weaken, crack, and disintegrate the plastic used in Bandai kits. Threads here, here, here, and here.

This kit was heavily primed, painted with multiple coats, and sealed with a final gloss coat. Would have assumed this ultimately would have been enough to protect the kit from whatever in the enamels is damaging to the plastic. Seems not.

Perhaps someone in future might learn from this thread.

Weeks of work down the tube, extremely disappointing return to the hobby.

This forum remains an essential resource and continue to appreciate its wealth of knowledge.

I'm thinking it's your thinner? I looked up Ammo and saw it's enamel based, what were you using to thin it? Acetone can be used and is a strong enamel thinner but may have detrimental effect on plastic if used in a slurry and left to sit. But that's a total WAG, very odd - Please let us know if you figure this out.

Strange that that would happen Perhaps acrylic based paint would not disintegrate the plastic .

Hi Joe. Thanks for the response.

Take a look at my above post. Apparently Bandai kits, for whatever reason, are extremely weak to enamel thinners and the thinners contained within enamel washes.

This is apparently a very large issue within the Gunpla community which is quite a bit larger than the Star Wars kit building community, which is where my enthusiasm in the hobby primarily lies.

I have built a dozen or more Bandai Star Wars kits and use enamel paints all the time. I have never had a single issue. Never. 

Even if enamal was ithe problem it was over a primer coat so should have had little if any impact.

I would be far more inclined to blame the primer than the final wash. 

The Gov is correct about the plastic that Bandai now uses.  It is succeptible to enamel thinner.  Sometimes it is fine, sometimes it crumbles.  Priming does not seem to help, according to many who have experienced this problem.  Sorry I have no workaraound.  I have heard of water-based oil paints, which might help.  My sympathies go to your AT-AT.  The Empereor will not be pleased.

Yes their enamel washes are pretty hot,I've had them eat away the stubs that road wheels attach to on Dragon kits,break apart styrene Magic Tracks it definitely attacks the glue joints as well as fragile plastic.I found that you cant slop it on and work it in too hard,just a little at a time helps,it's hot stuff.

Real G

The Gov is correct about the plastic that Bandai now uses.  It is succeptible to enamel thinner.  Sometimes it is fine, sometimes it crumbles.  Priming does not seem to help, according to many who have experienced this problem.  Sorry I have no workaraound.  I have heard of water-based oil paints, which might help.  My sympathies go to your AT-AT.  The Empereor will not be pleased.

 

Ahhh if they changed the plastic then my guesses are way off since all the kits I have built were older ones. Still don't get how it works through a "heavy" coat of primer, a base coat of acrylic and a final glos coat though. That is a pile of layers to eat through and still impact the plastic. Guess I stick to acrylics for future projects.

Noobie follow up question incoming.

I've only used Ammo by Mig washes previously which are enamel washes.

Enamel washes are different than oil washes, correct? If the issue with Bandai kits is their weakness to enamel thinners, than theoretically an oil wash should be no issue, right?

I've got a tube of Abteilung 502 ABT510 Starship Filth lying around. If I'm understanding correctly, this is an oil rather than enamel paint. Could I mix the Abteilung 502 paint with some mineral spirits to create an oil wash?

If the problem was caused by your enamel wash, I highly recommend Flory products for washes.  Those are all water/clay based washes, so there are no solvents needed.  I ended up trying those because every other wash I tried took an extreme amount of preparation/care to use, and even then you weren't guaranteed that they weren't going to end up trashing weeks or months of your work.  Flory doesn't require all that brain damage to get good results with no risk to your paint work or plastic.  Its just another trouble-free tool to add to your arsenal that allows you to fight smarter rather than harder.

I think I had read about Flory washes once years ago but never used them. I'll look into them now, thank you for the recommendation.

I'm thinking my oil wash theory might also not work with Bandai kits. Found another resource that described applying white spirits to a Bandai kit and the model crumbled and disintegrated, exactly as happened to me with enamle washes.

Yup.  An oil wash using mineral spirits or white spirits is going to do the same thing as an enamel wash, because mineral spirits is essentially the main ingredient in most enamel paints.  Mineral spirits has a similar effect on things like latex gloves and clear Lexan plastic...Lexan will actually shatter after soaking in mineral spirits.

Flory is great stuff.  I just slop it on with a big brush, wait about 30 minutes for it to dry, then wipe off the excess with a damp sponge or other similar tool.  The amount of staining on the paint can be controlled by the type of clearcoat you use.  The flatter the clearcoat, the more staining will occur.

Not sure where you are located, but if you're in the US, High Altitude Hobbies in Leadville, CO is a Flory distributor that sells on-line.

I was reading up on Flory washes and was literally just about to ask if there was a US distributor. Thank you for that!

So the process is essentially

• Prime.
• Paint.
• Gloss coat to seal.
• Apply Flory wash.
• Wipe off Flory wash after roughly 30 minutes.

Can a dry rag/cotton swabs be used to wipe off the Flory wash or should something damp always be used to remove it?

Also want to just take a moment to thank everyone who has responded. As disappointing as today was, it was awesome to be able to stop by this forum for the first time in roughly three years and receive so much assistance.

I feel like I've learned a tremendous amount from this thread alone.

Think there's a good chance I'll be settling on a Flory product for a full wash/sludge bath on my next Bandai kit.

I suppose one of my final questions is what about things like streaking grime, running rust, rain stains etc.?

Would something like an Oilbrusher from Ammo by Mig be an option in this case since the amount of oil paint and thinner needed to create these effects is so minimal? 

From what I can tell, it looks like Flory products are more suited to something like a full wash/sludge bath rather than creating streaking effects.

You'll need your removal tool to be damp, and remember that the type of clearcoat you use will determine how much of it stays behind on the surface of your model.  If you use a gloss clearcoat, the wash will remain in the panel lines, but none will remain on the other surfaces.  Semi-gloss clearcoat will result in a little more of it remaining on the surface after wiping.  A flat clearcoat will result in the greatest amount of it remaining after wiping.  If you want a more stained look to the flat surfaces, you use flatter clearcoats.

You also don't need to worry about how long it sits on your model if you end up having something else come up and you forget to wipe it off.  It can literally sit on your model for months and you'll still be able to remove the excess just as easily as you would have if you had wiped it off 30 minutes after applying it.

GovernorTarkin

Would something like an Oilbrusher from Ammo by Mig be an option in this case since the amount of oil paint and thinner needed to create these effects is so minimal? 

I have used the Abteilung oil paints and low odor turpentine to do streaking effects.  Used black and brown for the streaking on the insides of this F-16 engine exhaust.  

Used powdered graphite for the gun gas streaking on the same F-16.  All of the surface wash and panel lines on this one were my first time using Flory.  Never going back to other washes.

Do you generally do a final matte coat over the Flory wash?

I have no extensive data to prove anything, but turpentine MIGHT be safe with oils.  I did some Bandai mini Star Wars kits with oils thinned with turpentine, and had no problems.

Bandai has some weird issues, like the brittle plastic thing, their insistence on switching to KPS plastic for "no polycap construction" which does NOT work, and their continued use of stupid stickers.

GovernorTarkin

Do you generally do a final matte coat over the Flory wash?

 

Generally, yes, but that just depends on what you want your final sheen to be.  For cockpits, after I do a Flory wash, I clearcoat those with a semi-matte.  Landing gear and gear bays I do semi-gloss over the Flory.

I second the Flory stuff. Makes for fun pics too ;)

I've got this set - not cheap though

Using mineral spirits or white spirits with an oil wash is (at some point) eventually going to cause the plastic to  self destruct.

I did that once many years ago and the plastic (Tamiya) became brittle just like a striped candy cane that has been broken.

I always use Turpenoid IN THE BLUE CAN...........

    ⬇⬇

never EVER the green can.

Works on everything so far. Never had a problem since.

How long do let the oil and turpenoid wash sit on the model before remove? I had a user here twenty four hours.

GovernorTarkin

Noobie follow up question incoming.

I've only used Ammo by Mig washes previously which are enamel washes.

Enamel washes are different than oil washes, correct? If the issue with Bandai kits is their weakness to enamel thinners, than theoretically an oil wash should be no issue, right?

I've got a tube of Abteilung 502 ABT510 Starship Filth lying around. If I'm understanding correctly, this is an oil rather than enamel paint. Could I mix the Abteilung 502 paint with some mineral spirits to create an oil wash?

 

Yes enamel washes are hotter,the artist oils and their thinner are milder.

Mineral spirits are enamel,turpenoid is what you want,like this

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GovernorTarkin

I was reading up on Flory washes and was literally just about to ask if there was a US distributor. Thank you for that!

So the process is essentially

• Prime.
• Paint.
• Gloss coat to seal.
• Apply Flory wash.
• Wipe off Flory wash after roughly 30 minutes.

Can a dry rag/cotton swabs be used to wipe off the Flory wash or should something damp always be used to remove it?

Also want to just take a moment to thank everyone who has responded. As disappointing as today was, it was awesome to be able to stop by this forum for the first time in roughly three years and receive so much assistance.

I feel like I've learned a tremendous amount from this thread alone.

 

If you decide to try Flory,use a new brush and only use it for Flory,other paint and thinners will contaminate the Flory.

A damp swab works well

GovernorTarkin

How long do let the oil and turpenoid wash sit on the model before remove? I had a user here twenty four hours.

 

I wouldn't use that combination as a wash as it would very likely have the same results as your enamels.  When I used oil paints for streaking effects, I put a tiny drop of it where I want to begin the streak and use a Q-Tip to pull it into a streak.  After that, I use Q-Tips that are barely damp with Turpentine to remove whatever thickness of the oil paint needs to be removed for the desired effect.  I wouldn't let anything like that just sit on the model for any length of time.  But...that's me.