Remove Paint From Cars

Ricky,
As for the paint removal:
Do not use either of those!
The lacquer thinner will melt the plastic. The Simple Green might also (just ask Lee Willis)!!!
Do yourself a favor and see this thread: "Weaver Paint Stripping Question" and decide for yourself.

As for painting, the next time DO NOT leave it out in a cold garage after painting! That was a big No-No! With a room at 70°F or above temperature, you should have been good with the Scalecoat paint .
If you use a lacquer based paint, you DO NEED to first spray on a sealer. Scalecoat makes one. A "primer" per-se is not needed. However, I use a light gray base coat in order to get an even color all over. Use a good hobby paint. I do not recommend Rustoleum or anything like it to paint a plastic model (my personal preference) for several reasons. It too can attack the plastic, even though it says "plastic safe" and the paint tends to hide fine details. 
Just my honest opinion, your results may vary. 

Wet paints can have trouble curing correctly in cold air.  Most need over about 50° to cure close to right, but you cant double or triple advertised dry times too. It varies, but 70° is "perfect" if anything is.  (bold just decided to turn itself on... can't kill it..pay it no mind)

  I like alcohol, Castrol Super Clean, or brake fluid. In that order.

   I hate the collecting and disposing of brake fluid. I'm one of those "part-time tree huggers"; I prefer not to risk contaminating the environment to save myself a few minutes during the next drive past the DPS chemical dump.  I did enough brakes at work to know; you can "just tell" the stuff is nasty. Your instincts say so, the labels just confirm it

Pre-heating an item and use of a fast dry paint can conteract the effect, but fast dry often involves a more volatile paint type.    (more of metal trick I picked up hot rodding, heat it till you can't hold it then spray quick)

Hi,

Yes I waited a day. Thanks. 

Ricky

Brake fluid ,worked for me .As said above ,disposal ? I put it in a plastic container and added dry cat litter ,till absorbed. also I read somewhere boiled water and detergent?

Boiling water in a pot and laundry detergent (powder) works great on tinplate, but I sure would not try it on anything but tinplate.  Takes it right down to shiny new tinplate, paint just floats up to the surface.  Don't use your wife's good cookware to do this though like I did, the paint sticks to the sides of the pot.  She is still looking for that pot 15 years later.

Chris S.

Hey guys and gals. New to the forum - This is my first post!

Not new to painting. Temperature can affect paint curing but does not cause the symptoms exhibited in your photos - It's clear you have a paint lifting problem.  Not familiar with scalecoat II. A "google search" for Scalecoat II reveals xylene/naphtha as the solvent. Both have super slow evaporation rates which means the solvents stay active for a good amount of time on subsequent coats 2nd, 3rd etc.. Enamels with plastic safe solvents (naphtha/xylene) are some of the hardest paints to work with and require a lot of patience. Enamels by nature have a very long cure time.

The problem you're having can be caused by contaminates on the surface prior to painting the first coat. Or more likely the 2nd coat was sprayed to heavy and the long active solvent attacked the first coat causing the lifting. I don't have a paint removal recommendation for plastic. I do however have a repaint suggestion. After paint removal clean, clean and then clean again. Do not handle the car with bare hands while cleaning. Use tight fitting non powdered disposable gloves. Clean the car with naphtha. Allow the car to dry thoroughly before spraying. Apply multiple light coats over several days. Save the heaver coat for last after several days of cure. (Patience part). Pay close attention to the rattle can nozzle distance from the car when spraying the first light coats. This will help you judge the best (results) distance on the final coat. Rattle can enamels are "heavier/thicker" and have larger orifices in the nozzles and more times than not need a 12" or more distance when spraying.

All advice meant to helpful not critical!

Thanks - Wayne

Adding - Ideal temps and more importantly humidity will affect the finish in other ways. Colder temps 50 degrees or so equal sloooooow cure times. As stated above 70 degrees is ideal.  Humidity of 50% or lower is best. Higher humidity will affect the gloss and can cause hazing or dulling.

A another tip. Don't spray in the evenings or damp rainy days when the humidity is always higher. Mid to late morning on a clear, sunny day is best even if you're in a garage. The humid air doesn't care if you have a garage door it will crash you spray paint party without being invited. Spraying during super high humidity can cause the moisture droplets in the air to get caught up in the spray as it's propelled to the object being painted. This cause all sorts of issues including durability.

Wayne 

Wayne, you must paint cars for a living, all good sound advise by you, and Adriatic....Ricky, you’ve got a bit of a hot mess on your hands buddy, but let’s see if we can get you through this...first, what’s under the scale coat now? Having been a car painter for 35 years, I can tell you it’s what’s under the finish that matters first. Try a small amount of brake fluid (as much as I hate to admit it) on one panel and have a toothbrush and bucket of clean water ready. As the green paint lifts from the brake fluid, I’d clean that small area with the toothbrush then dunk in the clean water, dry the piece with paper towels and move on to the next spot, repeat. Don’t rush, you’ve got to see how things are reacting. If successful, you should be able to get down to the bare plastic. What does worry me is the prep work that appears to be hit or miss on the side of the car pictured....I see bad sand scratch swells along with the paint crazing in your car. Looks like you attempted some sort of sanding. It also appears some of the rivet detail has been sanded away in that process....was this before or after the craze? If you are successful in the paint removal, all of the fellas above advise is good sound advise. I’ll only add, everything you paint on and paint with and the area you paint in must all be equalized. Your best results will come when the piece you are painting, the paint you are using, and the area you are painting in are the same or near the same temperatures. Warm paint on a cold panel will make its own humidity even at low atmospheric humidity levels......follow Wayne’s advise, clean, clean and clean again...if you do manage to get all that ruined scale coat off, and whatever’s under it, use grey scotchbrite to abate the entire piece. No need to dig in, we just want to scuff the area to create a mechanical bond for the initial coating. Now, on to those nasty sanding scratches.....after the primer has dried and cured, fashion a tiny block and block sand with super fine paper (1000 grit) staying between the rivet detail. Re- prime the small areas with light coats, allowing each coat to fully cure and repeat this process till you blend out the area. Once your satisfied with the repaired areas, I’d again, very lightly scuff the entire piece with the fine scotchbrite again insuring a good mechanical bond. Use materials from the same mfr. ...if your using scalecoat finishes, use their primer, etc., etc...might seem like a lot on paper, but it’s really just common sense....biggest thing is I’m not here to condem your work, just hoping you can save those cars.................Pat

Hi,

Thanks all for your help. Not sure if I can use brake fluid, but I’ll have to see. If I can use it, I’m going to need to wait a few weeks till the weather warms up. Under the paint, there was old paint on there for my guess 20 years. I want to save them too. What kind of spray primer is best? Thanks. 

Ricky 

   Neat to hear where the experience comes from (welcome Wayne) and I'm always interested in the other persons methods for comparison or to learn a new trick. (which can vary by region, climate, etc)  (ha ha, two more that can hold thier breath a loooong time )

 FWIW,  for near a decade I painted new, high end homes (all priced over a million, and up to about 6 mil. ) when the wood finishing was slow (mostly oil based, I have a laytex allergy) (mahogany loves and fears me, my real talent). I did that for a while just to to get off work by 2pm to better paint/ restore/soup up hot rods and dune buggies with a few former automotive pro friends... I've got 4- 100% solos, and a few dozen total (about 40)  shared efforts under my belt; done with everything from "30 yr old junk paint" to House of Colors custom hot pink pearl at $70 a PINT "back then", if I recall right. (that pink hurts your eyes and leaves you snowblind in seconds with all the sanding lights on or a sunny day.... "evil pink" shoulda been the name).  No awards, we were judges and rat rodders at the shows.  

Plus, I have years of commercial art/ graphics/ printing experience and even some map making, and automotive manual work too.

Ricky,  I haven't used it myself to know how well it feather sands, etc., but if you wiped out some rivets you want back, there are rivet tapes you can apply to get the detail back. Individual dots too, but tape keeps a nicer spacing; a trade off of efforts (another way is glue dots shaped by files and/or sandpaper or using thick masking with hole(s)).

 Take the cat litter to the hazard dumpster. I don't think they actually recycle the stuff yet, but they prefered liquid at the dump last I was there. (It has been years now though. I had to quit driving.  I had to quit about everything really. I ripped my diaphram real good one day; pratically just a yawning stretch upwards that did it.)

Ricky S posted:

Under the paint, there was old paint on there for my guess 20 years. I want to save them too.

Are you saying that you want to save the original paint underneath? If so, why?

Hi,

The paint under I don’t care about. I want to save the cars. Thanks. 

Ricky

Then strip it down to bare plastic.

 Old paint can take longer to remove, but should still come off unless you chose something like an industrial enamel/aklyd/etcher/etc.. 

harmonyards posted:

Wayne, you must paint cars for a living, all good sound advise by you, and Adriatic....Ricky, you’ve got a bit of a hot mess on your hands buddy, but let’s see if we can get you through this...first, what’s under the scale coat now? Having been a car painter for 35 years, I can tell you it’s what’s under the finish that matters first. Try a small amount of brake fluid (as much as I hate to admit it) on one panel and have a toothbrush and bucket of clean water ready. As the green paint lifts from the brake fluid, I’d clean that small area with the toothbrush then dunk in the clean water, dry the piece with paper towels and move on to the next spot, repeat. Don’t rush, you’ve got to see how things are reacting. If successful, you should be able to get down to the bare plastic. What does worry me is the prep work that appears to be hit or miss on the side of the car pictured....I see bad sand scratch swells along with the paint crazing in your car. Looks like you attempted some sort of sanding. It also appears some of the rivet detail has been sanded away in that process....was this before or after the craze? If you are successful in the paint removal, all of the fellas above advise is good sound advise. I’ll only add, everything you paint on and paint with and the area you paint in must all be equalized. Your best results will come when the piece you are painting, the paint you are using, and the area you are painting in are the same or near the same temperatures. Warm paint on a cold panel will make its own humidity even at low atmospheric humidity levels......follow Wayne’s advise, clean, clean and clean again...if you do manage to get all that ruined scale coat off, and whatever’s under it, use grey scotchbrite to abate the entire piece. No need to dig in, we just want to scuff the area to create a mechanical bond for the initial coating. Now, on to those nasty sanding scratches.....after the primer has dried and cured, fashion a tiny block and block sand with super fine paper (1000 grit) staying between the rivet detail. Re- prime the small areas with light coats, allowing each coat to fully cure and repeat this process till you blend out the area. Once your satisfied with the repaired areas, I’d again, very lightly scuff the entire piece with the fine scotchbrite again insuring a good mechanical bond. Use materials from the same mfr. ...if your using scalecoat finishes, use their primer, etc., etc...might seem like a lot on paper, but it’s really just common sense....biggest thing is I’m not here to condem your work, just hoping you can save those cars.................Pat

I've painted a few vehicles in my time and just about everything in between. I learned how to paint from my uncle (mom's brothers) when I was a young man. More importantly, I learned how to prep, prep, prep, clean, clean and clean again. He taught me a great paint job was 98% prep 2% spraying.

Wayne

Adriatic posted:

Wet paints can have trouble curing correctly in cold air.  Most need over about 50° to cure close to right, but you cant double or triple advertised dry times too. It varies, but 70° is "perfect" if anything is.  (bold just decided to turn itself on... can't kill it..pay it no mind)

  I like alcohol, Castrol Super Clean, or brake fluid. In that order.

   I hate the collecting and disposing of brake fluid. I'm one of those "part-time tree huggers"; I prefer not to risk contaminating the environment to save myself a few minutes during the next drive past the DPS chemical dump.  I did enough brakes at work to know; you can "just tell" the stuff is nasty. Your instincts say so, the labels just confirm it

I like using brake fluid but hate the mess and clean up

Ricky S posted:

Hi,

Thanks all for your help. Not sure if I can use brake fluid, but I’ll have to see. If I can use it, I’m going to need to wait a few weeks till the weather warms up. Under the paint, there was old paint on there for my guess 20 years. I want to save them too. What kind of spray primer is best? Thanks. 

Ricky 

Ricky S.

I've learned a lot of hard painting lessons over the years.

I have a couple recommendations:

1. Spending a little more time & money up front can save you a lot of heartache in the long run. 
2. Primer: SEM brand offers some of the best "rattle can" products available. Their products are auto related but I used them on many types of substrates including plastic not related to anything automotive. I would stay away from "high solids" primers as they can easily cover small details. If I were you I would order a can of SEM Plastic Adhesion Promoter 39863. You can get it from Amazon ground shipped. This product is compatible with many topcoat paints including enamel. Apply a couple light mist coats. Follow topcoat wait times listed on the can or product data. This is good stuff especially on hard to paint plastics. SEM does offer adhesion promoters that are specific to certain types of plastics. I would stay away from those unless you are willing to follow the tests to determine the type of plastic your cars are made from. The tests for the latter can be destructive to the plastic and require testing in an area that will never be seen.

Wayne

  Experiences can differ.  I can only say I've not seen any platics adversly effected by the brake fluid, but it's a poison. The Castrol is better for health reasons I think, but I see it lightly soften some plastics temporarily. But again, nothing to cry about ether imo, it's temporary.  And it's been 20yrs since some were done by me, the worst was an original AMT 1/24 Caprice model and you can still see the faint line in the key door in the tumbler. It was soaked for two days an stayed sort of soft on the surface for about a week. Actuall made some plastic flash ridge removal go faster.

  Alchohol is kinda weak on some paints.... which reminds me, Gi-raffe Mitch uses 'Lectric Shave to remove paint/ink from plastic cars( lettering mostly) so I tried 40 year old Old Spice and it works very well too; like a stronger version of alcohol .     (I can't really wear scents, and was long overdue to git rid of those old gifts. Now I finally have a use for those stanky bottles )   

  Paint can be forgiving if your not picky or torturous if you are.  If you are at all worried about finish outcome, like the man said, clean clean and clean again. And I'd really clean a job like that (scented strip) especially well as scents tend to be fine oils that could embed themselves on a surface pretty well. (Ugg..fisheye)

  Reminds me: Keep silicon away from anything that is going to be painted. It was banned from even being in our good painting garages. The stuff gets airborne like dust, and solvents just seem to chase it rather that remove it. It embeds itself on raw metal, etc.. 

  But I picked up a trick for spraying from an old timer that helps. Add a drop or two of a contaminate to the paint just before spraying and mix well. Compared it to marrying pasta and sauce by adding starchy water to the sauce and sauce to the pasta water.  They now have some similar chemical content and will want to blend and stick more rather than seperate and slide .. it's a sponge effect here I guess.  It was really scary to try first time out with thoughts of similar looking oil/water nightmares in printing going through my mind. And we over did it once eventually too; and had 2 eyes that I blame on a second drop and the learning curve factor. But my buddy does one drop out of habit now with a "better safe than fisheyed" motto. (that garge seems like it bleeds contaminates out of the plastic ceiling panels or something)

The comment on solids goes goes further too. Model paint topcoats will need a small pigment to look correct. Some auto/rattle can pigment will be too large. You won't be able to figure out why at first, it just looks odd. Different metallic finishes are where you can usually see difference well. (metalflake size range is like 1/16" on fiberglass gel coats down to a microscopic size)

I've used easyoff oven cleaner on factory painted boxcars with good results. 1/2 hour took the paint off.

With the comment on sanding and some new folk being here, I think it's prudent to point out that a digital camera will highlight any flaws beyond what the eye will normally pick up. While it sometimes makes work look worse than it is, it can also be a tool for improvement.

E.g. I painted two figures the other day using my usual magnifying lamp and machinist eyeglass magnifying monical. After taking pics, I could see even more mistakes. I ended up using all three, detrmining stroke needs by the photo, and repetition on edges to get it "right"... or at least way better....I've seen some amazing eyes and have decided I need to brush up to get at least that small again. (I used to paint needles and hashmarks at the least on my 1/24 speedometers, etc.)

Adriatic posted:

Model paint topcoats will need a small pigment to look correct. Some auto/rattle can pigment will be too large. You won't be able to figure out why at first, it just looks odd. Different metallic finishes are where you can usually see difference well. (metalflake size range is like 1/16" on fiberglass gel coats down to a microscopic size)

I think it's prudent to point out that a digital camera will highlight any flaws beyond what the eye will normally pick up. While it sometimes makes work look worse than it is, it can also be a tool for improvement.

When he says "small pigment"...read "fine pigment". When he says " large"...read "course".
Adriaric,
I've been trying to get this point across ever since I have been on this forum, and, for whatever reason people just don't want to listen. I learned 50 years ago what a dramatically better finish the fine pigment of Floquil paint made to the quality of a paint job compared to the rattle can paints! 

I have also found it amazing what one can see just by posting a photo of your work online or looking at it on your computer screen. It is definitely a teaching/learning tool to be used in improving one's work!

  Yea, fine &coarse would more likely be the labeling; being away from "living it" the vernacular suffers. Things like that also change from shop to shop, mfgs, over time, and by type to (ink, home, auto, industrial).

   A look at me here or my work isn't necessarily a great reflection the extent of of my past ability or experiences. I've really lost a ton of fine motor ability as well as the drive to be that tight with my own stuff. I could once hide my signature as period at the end of a page. I'd have trouble with type the size of a coin's now.

Remeber the rat rod comment? Along the same line of imperfection, I also have a thing for (as well as the fiscal necessity for) the low buck folk-art approach. It seems I loose interest in shiny new things anyhow. The craft acrylics are something I used to hate but now embrace the easy cleanup, color wash ability, texture ability, and soft dense look of the pigment with a good coat. I can do more with it, despite the weakness. (I think they have improved over the years too)

I guess I kinda see pigment, finish, and texture as differnt elements, each unique and appreciated or dismissed at will vs "a paint job" as most people see them. I'm bored with finish and have a strong thing going for texture and pigment  that began with painting foam rocks and my "harelequin" dockside.

  The combo of skill-drop and thick craft paint makes face painting a little harder, lol.  I don't know that I ever used Floquil. Maybe. I tried a few brands suggested by shops over the years but none impressed me enough to warrant the cost change outside of some metal colors. What I did have didn't store well like the small testors bottles did either. 

Compare a bottle of testors to the cap of a similar automotive rattler the next time your at Wally World and it'll all make more sense fast if it doesn't already. Sure an automotive rattler may be fine, but not always.

....

I have had the same problem with some MTH passenger coaches that I am trying to re-paint and re-letter. Can the entire coach body be soaked in brake fluid or does it take some rubbing with the brake fluid to remove the "orange-peel" textured paint?

Randy,
Yes, you can soak the entire body if you want. You will need to find something big enough to put the car in, like a wallpaper trough. The problem with O scale, people don't realize that their volume is eight times as large as HO scale. You don't need to get the object entirely under, just enough to get the longest side under a bit. From there you can rotate the part to work with it.
You will need an old tooth brush to help work the surfaces and detail corner areas. Soak, rub, soak, rub, etc.

BIG JIM: Thank you for the great information. How long will it take soaking before I begin the work with a brush? Should I protect my hands in any way when handing the brake fluid?

You will live unless you take it internally, no imediate pain, maybe mild irritation but usually not, rubber gloves are ideal, keep it off your skin as best you can; but : ☠️ POISONOUS ☠️ Gather, contain, and dispose of contaminated wastes properly, etc. etc.

 Agitate paint (with 99.9% of strippings this is needed with near any method)

Just minutes to many hours depending on paint and cure. After about 10min of nothing, go eat, and hour later check and see if you think you can go shopping a while, 3 hours later decide if your gonna sleep now or after a bit removal, etc etc..

Stripping can't really be rushed except maybe by scoring paint with abrasives to speed penetration, etc. Some strippers use molecule and binder pentration, others creep between surface and paint and seperate, or both to various degrees. Brake fluid both penetrates to dissolve, and creeps under edges; lifting paint.

  (be careful around your autos too when checking and filling brake fluid, clutch fluid, and other hydraulics. I've only seen industrial paints resist it at all, and the creeping tackles that eventually too. I've seen some nice new rides ruined because somebody choise to wipe fingers on a hood rather than sacrifice, or maybe just wash that sock, tie, shirt etc.. Also from setting a bottle on the car wet from a rim drip, and not flushing it off well, or quickly enough. )

 Brake fluid tends to lead to corrosion on steels in ways.  Though a protective if atmosphere isn't present, it absorbs moisture so as it migrates and thins atmosphere with the tapped moisture there too is a transitional condition that lets it start. Cleaning and drying directly after use on metal is suggested.

Also, I think there is a silicone presence possible too, in some brands anyhow, maybe just in the higher dot rating I forget (stay with d-3 fluid or match for d-4+ design. Don't change from 3 to 4 or more without reaserching the pressure, moisture, life, temp, flow, etc. differences first. a test vehicle might have like 72 gauges reading pressures, it's more than a matter of a singular "best". If you do, for an emergency, easy does it & flush the system asap.)

Hi everyone,

Thanks for your help. This gave me good advice. Have a great day!

Ricky

Adriatic posted:

 Brake fluid tends to lead to corrosion on steels in ways.  Though a protective if atmosphere isn't present, it absorbs moisture so as it migrates and thins atmosphere with the tapped moisture there too is a transitional condition that lets it start. Cleaning and drying directly after use on metal is suggested.

Also, I think there is a silicone presence possible too, in some brands anyhow, maybe just in the higher dot rating I forget (stay with d-3 fluid or match for d-4+ design. Don't change from 3 to 4 or more without reaserching the pressure, moisture, life, temp, flow, etc. differences first. a test vehicle might have like 72 gauges reading pressures, it's more than a matter of a singular "best". If you do, for an emergency, easy does it & flush the system asap.)

Dot 4 will eat the rubber in a dot 3 system. Back about 98 I had to rebuild an entire antilock brake system in an 89 Buick Reatta because a shop put Dot 4 in it. The damage was not apparent for a week or two. The brakes seemed fine one stop back and then no brakes at all. Lucky I was not going very fast and had plenty of room to stop so the parking brake was enough. That was the last time I paid for a brake job.  I have done it myself since then. I buy all new pads and rotors and follow the shop manual chapter and verse.  Dead motors make you curse. Dead brakes make you dead.  Back on stripping plastic, I would stick to Dot 3 for paint removal. Mainly since it tends to be cheaper than Dot 4 and you can find dot 3 store brands much cheaper than name brands. AND, I know what to expect from it. Anyone want to test Dot 4 on several types of plastic and let us know the results.   I still like sodium hydroxide better than alcohol and brake fluid for paint removal.  I vary the dilution and make it as fast or slow as I want. A weak solution is even good to take the high gloss off Williams diesels.  I soak the shell five ~ ten minutes then rinse well and let it air dry if it is still too glossy I give it another soak. When doing this weaker is better and don't try it with silver or gold paint or trim. When you try this for the first time use a weak solution and short soaks, till you get a feel for the process.           j