PRR L1 project has begun

[glakedylan]

hey Pete....what I always use:
Scalecoat I Railroad Paint - 6 Ounce Spray Can

never have had a problem with it.

the warp happened over night
everything looked good after last light coat


was kept in the cardboard box on stand in which i sprayed it
on kitchen table from around 5PM yesterday to 10AM today
climate controlled, nothing but air dry in that room

found it warped this morning after primer on Friday and
Scalecoat I Railroad Paint on Saturday

thanks
Gary

[peteski]

Scalecoat I is a "hot" paint, *NOT* plastic compatible. Scalecoat II is plastic safe.

Of course there are many flavors and formulas of plastics and acrylic or urethane resins. Some are "hardier" than others and might not be affected by Scalecoat I.  But I only have Scalecoat II  paints -- I can use them on plastic, and metal.

From the damage, it seems to appear that the Scalecoat I solvent went through the primer and affected the resin.  Or maybe it was a combination of the Scalecaot I solvent, and the traces of the primer's solvent.  But while I have never used it in this way, I would say that Scalecoat I and the Shapeways resin is a no-no.

Hopefully this thread will serve as a warning to others.

BTW, what made you say that Scalecoat I is "acrylic"?  Going by the smell, it seems to be an old-fashioned alkyd enamel.

[C855B]

>> Scalecoat I

It's not an acrylic, like Pete said it's an alkyd enamel. Scalecoat II isn't much better, it's still an enamel, just slightly less "hot". HOWever... I've been using Scalecoat II over Tamiya Fine Surfacing Primer on FXD shells with no bad effects, and suspect the aromatic solvents common to both Scalecoats are probably OK in general. My experience so far is the main bad guy is isopropyl. So put me in the "confounded and puzzled" column as well.

[glakedylan]

Scalecoat I is a "hot" paint, *NOT* plastic compatible. Scalecoat II is plastic safe.
BTW, what made you say that Scalecoat I is "acrylic"?  Going by the smell, it seems to be an old-fashioned alkyd enamel.

Pete...well that seems to explain a lot. The sales rep at the hobby shop answered in the affirmative to my asking, "is this acryllic and safe on FXD?"
I think, IIRC, I had been using Scalecoat II in the past and in my head and with the info I was given thought I had the same paint that I never had a problem with.
Next time I will make sure it is II and not I 

It's not an acrylic, like Pete said it's an alkyd enamel. Scalecoat II isn't much better, it's still an enamel, just slightly less "hot". HOWever... I've been using Scalecoat II over Tamiya Fine Surfacing Primer on FXD shells with no bad effects, and suspect the aromatic solvents common to both Scalecoats are probably OK in general. My experience so far is the main bad guy is isopropyl. So put me in the "confounded and puzzled" column as well.

Mike, it would make sense, as Pete noted, that the Scalecoat I had reaction with the primer and the FXD creating the problem.
My mix up with Scalecoat I, thinking it was the same I had been using previously (which was actually Scalecoat II) that I never had a problem with.


A lesson learned. It's a shame it was a costly error.


Sincerely
Gary

[glakedylan]

so, this is where things are at today


i soaked a few minutes in hot water


the shell becase a bit flexible and i held it firmly while trying to undo the warp


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the shell is with much less warpage, not exact, but much better


the handrails and piping are a total loss (reconsidering Doug's post to construct such from wire)


the treatment seems to have made more striations and rough areas visible


so, do i:
1. go with what i have, adding details that are now missing (will be within 3ft test for these eyes)?
2. try a coat of Scalecoat II to cover up some of the artifacts from the printing?
3. chalk it up to experience and move on?


thinking i will remove the KATO shell and in placing this shell on the chassis see how it looks
and go from there.


thanks for all the suggestions and information. they proved to be helpful.


sincerely
Gary

[Chris333]

Well seriously strip the paint and use it for the test dummy next time you paint FUD. 

But still I haven't had a problem with paint. Sometimes to fill in all those lines a use automotive primer that I know has a strong solvent and never had a problem.

[Chris333]

Edit: That hot water seemed to work. And you can help "set" it by using cold water right after. Sometimes you need to bend it back a little further than needed to end up straight.

[C855B]

Well seriously strip the paint...

You can't. At least I've never been able to strip FXD. Paint anchors into the porous matrix.

[Lemosteam]

Agreed- stripping is a non-starter.

Instead sand as much as you can smooth ahd re-use the Tamiya primer sand, primer, sand primer, unitl you are satisfide with the surface.  Then use the tru-color or Scalecoat II for the DGLE topcoat.

[Cajonpassfan]

Gary, first of all, what a bummer! Man! No wonder you were so discouraged...
Still, I’m amazed that you were to straighten the shell as much, wow.... there may yet be a good outcome here. Some of the freestanding detail was useless and impractical anyway.  As suggested, I’d hit it lightly with Tamiya’s light gray surface primer (I swear by the stuff, it’s is wonderful). iThe light coat will show you all the imperfections and then you can decide whether a fix is doable (no point putting a lot of effort into new freestanding detail if the shell is fundamentally flawed).
Don’t get discouraged, we’ve all been there. Good luck!
Otto