Locomotive Paint Stripping

Can't hurt!

At this point it's a crap shoot what might happen next irregardless of what you do or use. Let's just say, how much more can it hurt? Besides the immediate appearance of what's happened to that shell, you've no way of knowing the long term effect and/or damage done to it. As it dries over days, it might become extremely brittle and brake easily, or it might have shrunk to the point it may no longer fit the frame with screw holes or tabs properly aligning for reassembly or even once it is refitted on the frame what effect if any will the heat generated by the train's motor have on it.

What's happened is unfortunately a lesson well learned of what not to do when stripping a train of its paint.

You are correct... I just tried the oven cleaner method and I will let you guys know tomorrow how I make out... I guess you live and learn... I put a post in the wanted to buy forum and maybe I will get a hit. 

Sorry- Yeah, that's pretty bad, but as said, strip off the remaining paint and give it a shot coat of primer...though if that stuff is stuck in the vents like I thought I saw, you'd be better off spraying it with rust and using it as a side display on the layout...Lee would find a use for it I'd bet!

 " I've NEVER understood this hobby's FETISH with stripping paint. It's not like this is the first horror story I've heard of ruined shells.  Just remove (or sand smooth) any raised edges from lettering and striping, prime, and paint. It's not brain surgery!"

Yes and we have all seen THOSE kind of paint jobs after. Usually you can still see the old lines and lettering. Some guys "nice" paint jobs are others idea of poor. I have seen paint jobs that guys were really proud of that looked like a 5th grader did it. I guess it depends on what you are willing to settle for. The masters in the hobby NEVER paint over the old paint.

Maybe, but from the examples of Wowak's work posted in the forum, I'd say you can't argue with his craftsmanship as far as painting is concerned.

Well, everyones standards are different when it comes to repainting....and if an old paint is stuck that well it'll surely be a good base for the next..1:1 or scale- a solid base coat is always desirable. Add the huge difference between a 20k plus auto restoration and a "model train"....not comparing apples with apples there. If it's a smooth base- it's good enough for alot of folks to paint over and if done right no-one will ever know the difference....imho...your thoughts/results may vary.

After using a bead blaster, that's certainly a very neat way to remove paint, and it even does an excellent job of leaving the details on a plastic shell.  My future paint removal will doubtless be done that way.

Ok, honestly...what is this paint made of? Sprayed cold oven cleaner on it and that set all day...paint didn't budge. Soaked all next day in castrol super clean.....didn't budge. Just tried a Q-tip and lacquer thinner and it's ever so slowly coming off- That's darn fricken good paint!

Bano...how you holding up with this? LOL...I knocked my doodlebug shell off the end of the work table the other night...broke the r/h corner bad...I may be doing my alternate idea of a doubleheader body if I can cast or copy the front end well enough....."it" happens!

You can't chemically strip the paint.  It's most likely urethane based.  The only chemicals that will dissolve the binder will also dissolve the shell.  If you want to have the paint removed you will have to use some type of "blasting".  There have been a number of threads on the techniques/technology.  Try searching for "blasting".

Before you throw it away, try 91% rubbing alcohol found just about anywhere that sell pharmacy items.  Its the only thing I use for stripping.  It's cheap and works great.  I may take a little longer but has great results. It must be the 91% solution.  I've never had any problems with any plastics warping or crazing.

Patience is the key to any good paint job.  Rushing always creates bigger problems.  At least you learned a good lesson.

ABS has some porosity.  If you soak the shell for too long it starts to pull the chemical(s) into the plastic.  It will then try to sweat it back out after you pull it from the soak.  

If you do soak, allow it to "air out" for a couple of days for alcohol and possibly longer time for "heavier" solvents.  Some of these solvents can actually change the physical properties of the plastic if left on too long.  They can increase the brittleness (actually reduce the plasticity) or affect surface texture (usually becomes rougher).

If there is still solvent trapped in the plastic when you apply new paint it may attack it from the back side and make another mess.

I'm leaning towards Chucks thoughts about that paint...I was using lacquer thinner on a Q-tip and the stripes were barely budging...the lettering was a breeze, but not the stripes...then I went and busted out the corner...it budged then!{ouch}.

Bano- one quickly fnds out in life that theres two ways to learn- the easy way or the hard way. It's a setback, but far from the end of the world bud. 

Oh- I just posted the bay auction on your shell thread- options are a wonderful thing!

If the old "lettering" isn't raised you can probably top coat with a primer and then paint the new colors over the primer.  Sometimes it's easier to "feel" raised paint than to see it.  

Most of the modern equipment uses photo etched metal masks instead of decals, silk screen, pad paint or heat transfer.  In some cases you can use Poly Scale ELO to remove the decorations while leaving the base paint intact.  Since you will be priming over this any minor changes in surface sheen are not an issue.

Like Chuck said- run your finger over the lettering or stripes, if you can feel a slight bump there then you'll have to strip/sand/buff that edge down to keep it from showing on the new paint. Picture you painting the whole shell...red....and there was an old stripe there before that you didn't blend or remove- now that stripe, if raised, will show in your fresh paint...it won't bleed thru, it'll show as a raised area where the old stripe was. Think of it as if you were repainting an old car and left the pinstriping there and painted over it...smaller scale but same thing.

I was thinking of taking my dremel and using jewers rouge and a polishing tip to blend the lines if not totally remove them...heat will be the thing to watch here...not a problem on old motorcycle cases or forks, but a real issue if things get too hot on plastic.

One thing you might try before doing anything to the new shell is to get some white Tamiya primer and spray a thin coat over the shell. This primer is very thin and goes on perfectly. Drys in short order. Then you can maybe see what lines will have to be sanded before repainting.

Rob

It won't bleed through, but you will still see the raised areas where the stripes and lettering are.

I'm telling you the Air Eraser is still the easiest, safest bet for the plastic. $40, why not. There's no soaking, and no chemical reaction to worry about.

If you soak the shell in alcohol for a long period of time, it can make the plastic very brittle. Careful handling is all that is required, but if you bend or pry the body too far, it will crack.

This comes from a plastics engineer-

"For many plastics such as nylon, polyester, ABS, and especially solvent- sensitive polycarbonate (Lexan), isopropyl alcohol is recommended for cleaning purposes. In fact, because of polycarbonate's high solvent sensitivity, the only universally recommended cleaning solvent for this plastic is isopropyl alcohol." 

"Alcohols do NOT  "dry out" plastic, since there is no water (or any other substance) in plastic to "dry out" in the first place. " 

"alcohols are not damaging to any common plastics. "

"To summarize, when comparing the two, isopropyl alcohol is the cleaning solvent of choice for most plastics. Unlike normal-amyl alcohol, which is not easily available, 99% isopropyl alcohol is available at any drugstore. Isopropyl is better at removing oily deposits, and dries faster after use."

There you have it folks. But keep in mind alcohol will damage a shiny finish making it dull. I can verify that fact.

Rob

That's what primer is for.  Please don't ruin another she'll laboring under the delusion that you need to remove all the original paint.

I strip with Castrol Supper Clean or isopropyl alcohol. It will not harm the plastic and one or the other will strip most paint. I leave it in the tank for up to a week sometimes. I looked at the original post and from the time you posted your question until the time of the trashing of the shell was less than a day. Rome wasn't built in a day but burned in a night. Drop it in some alcohol and forget it for about a week.

"Alcohols do NOT  "dry out" plastic, since there is no water (or any other substance) in plastic to "dry out" in the first place."

There are plasticizers like the monomers that make up the "poly"-fill-in-the-blank chains that the plastic is made of.  Solvents that can cary away that material will affect the plastic.  It will lead to premature hardening, making the plastic seem like its 10-15 years old instead of one or two.

MTH decoration on plastic models older than about 2002 cannot be removed by chemical means.  It's like an automotive lacquer over some kind of barrier and anything that will soften the paint will soften the plastic. Also, I've been told it is a dye based paint rather than a pigment based paint.  If the usual suspects don't soften or remove it after about 24 hours it's not coming off.

Mechanical means like either a soda blaster or air eraser are the only ways.  And I've destroyed the plastic shells with a soda blaster trying to remove it from nooks and crannies so you need to be careful even then.

Dentil picks and scribes work best for nooks and crannies - a new exacto blade sideways is another way but watch what your dragging it over so it doesn't remove plastic- just paint. 

I agree, if it's post 2002 MTH then that paint, lettering, decals aren't coming off with a chemical remover unless it is some kind of blasting but there are hazards to that as mentioned. Their paint seems to bond with the plastic. I have had great success using fine grit sandpaper (can't remember the grit # but it is the hobby type that comes in a package with 5 sheets) to remove decals, numbers, lettering and stripes, anything with a raised edge.You can then use a thin primer. It's a lot of work but worth it in the end.

Never tried the air eraser but it sounds like it works. Any brand, part #?

Mike

I have used Dawn "Power Dissolver" to strip paint and decals on Lionel postwar plastic shells with sucess. 12.8 ounces for under $3.00. No smell, but can be hard on the hands.  There is a "Warning: Eye and skin irritant" on the  front label. This is not ordinary dish washing soap.

Well I wanted to give everyone an update on whats going on. I was able to get a shell for the cost of shipping from a fellow member. I went to the hobby store in Red Bank, NJ and I was talking to the gentlemen there and told him my story. I purchased plastic primer, base color, and 2 more colors I needed... However he did sell me Testors ELO paint and decal remover which he said is safe for plastics. I checked out there site and it says for model railroad stripping. Now I am a sucker for certain things and I hope I made a good choice. I am trying it now on the original shell I had and I am having no luck. Can it be from trying different chemicals?

Most likely all the various chemicals you used trying to remove the paint you changed the paint's chemistry morhing and hardening into a super paint unaffected by paint strippers formulated for plastic specific paints.

Kenn

I'd find someone with a bead blaster, that will remove any paint, and the experience on plastic shells is that it leaves the detail in great shape.  I've used the one at our club for a bunch of metal stuff, but Harry has stripped plastic shells and they came out perfect.  The nice thing is, when you walk away from it, the paint is 100% gone, no digging it out of the corners like with paint remover.