Alcohol

I've never heard of alcohol reacting with metal.  It's a pretty innocuous paint stripper, so that's what I'd use.  a soda blaster is nice for stubborn bits of paint which don't want to come off any other way, but I'd hate to try to use one to strip a complete model.

Alcohol

I'll give it a try and see what happens. I have some left over parts that I will try it on first just to make sure.

Thanks.

Many years back, one of the

Many years back, one of the preferred methods for stripping paint off was brake fluid.  The item to be stripped was placed into a container of brake fluid over night.  The paint would dissolve and be wiped off next morning with no harm to the metal or plastic item.  I never tried it myself, but was told it worked well. (be sure NOT to get the brake fluid on anything you don't want the paint stripped off of)

Alcohol is, normally, about 30% water. Methyl Hydrate is pure - no water.  Methyl Hydrate may dull the plastic, but will not melt plastic.  But than, you do plan on re-painting the item, so no problem if the surface is dull by the Methyl Hydrate.

Of course, it all depends what type of paint (and primer if any) was originally used on the item.  When in doubt test your method on an small area not normally seen.

G. T.

Alcohol

I've always had success with alcohol, with the exception of one Shapeways FUD product that actually warped and cracked.  It's taken paint off of some GHQ white metal vehicles before, both those had thin coats of paint on them to start with.  Let it soak overnight and then start scrubbing the paint with an old toothrush.  Once you break into the paint, the alcohol will penetrate better and it will be easier to strip.  I use 91% isopropyl from the drug store, it seems to work best as far as all the concentrations go.

As G.T. says above, it all depends on the paint they used originally, but it shouldn't hurt to try alcohol first.  I've heard of the brake fluid method as well, though have never used it myself.  Other chemicals people say work are Castrol Super Clean and sometimes Simple Green.

Easy Off

My go to paint stripper has always been Easy Off over cleaner.  Use the full strength stuff. Soak the body thoroughly and let it sit in the sink for 20-30 minutes. Clean the paint off with a toothbrush, works great and doesn't harm plastic.

Since they're metal

I didn't suggest Easy-Off, since the OP asked about alcohol, but that would be my first choice as well.  It is somewhat more reactive than alcohol, so some testing and care would likely be in order.  I find alcohol to be quite safe, unless it's taken internally while operating machinery.

My paint stripping adventure

You might find some useful info in my own venture into paint stripping.  https://forum.mrhmag.com/post/paint-dcc-and-sound-in-an-older-walthers-sw1-12193290

Easy-Off ?

I never heard of the Easy-off treatment. Always great to hear of other methods.  In this case, though, I would wear a mask and have a fan in the window for lots of ventilation or apply it outdoors.

Alcohol based paint will come off easy, of course,with alcohol. Example: Most corrugated plastic signs (the election type) have alcohol based ink on them.

If you need corrugated plastic for a project, just wait until the election is over, and help by cleaning up the signs, Take them home and wipe them down with Methyl-Hydrate, or Alcohol and you will have clean corrugated plastic sheets, should the need arise, for a project.

Also, they make great temporary work spaces on top of your work bench or desk - they are easy to keep clean especially if you are wiping up spilled drops of oil.  They also clean up well if you are doing a small paint job.

Corrugated plastic sheets are great if you are using "push-pins" to hold some thing down temporally or, stick one on the wall for a bulletin board. (using push-pins or removable tape)

G. T.

P.S.  Don't store them in damp areas.  Small spiders & bugs think they are ready-made caves.

Easy-Off

I do remember my dad would leave model cars in plastic containers with Easy-Off for months and never had a problem.  Some of the plastic would get brittle, but nothing ever melted.  He also had a very good set of rubber gloves to protect his hands and multiple brushes to help remove the paint.

Easy-Off

In the 1:1 world Easy-Off is a popular trick used to remove painted on pin stripping, sign maker lettering, and other assorted painted on stuff from cars and trucks. It softens the single component air dry paint the sign painters use but does not damage two component high bake paint used by the OEMs. If you try to just sand off the lettering work before repainting it will leave a shadow in the new finish. 

Easy Off - NOTE WELL/CAUTION

There are two types of Easy Off,  one that gets sprayed on the oven and the over turned on, it's very corrosive and the gas is dangerous. 

The second type is the one that works for modeling, this type is sprayed on, let sit and then wipe off. It works the same way with models. It's less corrosive but it still gives off gases so don't lean directly over the model while you're scrubbing with that toothbrush. . Also I suggest you wear latex gloves when handling the model. It washes off with water. 

Brake Fluid is a great paint remover but the only thing to note is that it will make styrene plastic brittle. It to can be washed off with water. Be very careful not to get it on any painted surface or furniture, it will attack the surface.

Ralph

Brake fluid alert

As Ralph mentioned, brake fluid is not compatible with all plastics.  I used to use it, but some manufacturer's styrene plastics are different.  After I stripped one loco shell, cleaned, washed, and repainted it, the brake fluid that had been absorbed into the plastic caused a chemical change in the plastic polymers that ruined the shell.  The damage was not apparent until some time later.

I have used brake fluid in

I have used brake fluid in the past dot 3 type and the paint falls right off. I rinse the items in water and in fact soak them in a container filled with water for a few days. I do nearly no scrubbing but use a denture brush to clean up hard to reach areas. It cleans models very well. after they soak in water for a few days I rinse and let them air dry and repaint.

Rob in Texas

Thanks

Thanks for all the comments.

As I built these two engines from parts from 4 junkers, I have many pieces that I can experiment on with different techniques. I will  report back on the various results.

Paint stripping

Alex,

You can strip it one of two ways, either use brake fluid or paint thinner.  Neither will harm the diecast and with either you will have a clean surface to paint.

Now if you go the brake fluid route you need to make sure the label has a warning about not to spill it on the paint. Newer types of brake fluid no longer have the chemical make up that will harm the paint.  I used the store brand from Auto Zone.  

Remember that once you strip the shell you will need to primer it with primer made for painting metal.  

Good luck with your project.

Andy H

Minooka, IL

Success

I took 2 pieces of the left over parts and sprayed one with oven cleaner and soaked the other in a container of alcohol. Both worked without doing any damage to the die cast, which was my main concern. This is the report of my trial.

Oven Cleaner - no name brand from the local Independent Grocery store, works cold or at a temp of 200 degrees in the oven; I used it cold, sprayed the part and let it sit for 2 hours. It turned the paint back to a liquid (gummy) state and was easily washed off, some picking required in corners and around fine details. Overall not a bad result; however, it did leave the metal with a very dark grey, dull appearance.

Alcohol - I don't have any 90% on hand (as I have read this is the strength that you should use) so tried just the 70% strength. Soaked the part in a tub of alcohol for 2 hours. At first glance it appeared to do nothing but when handled the paint came off in sheets. The alcohol seems to have attacked the bond between the paint and the metal. A lot of picking will be required around fine details but I have a couple of brass brushes in my outdoors workshop and will try them tomorrow and see how that goes. It also left the metal with a bright shiny appearance, almost like brand new.

Andy, I will go to town tomorrow and look for brake fluid. Here in Canada we do not have Auto Zone, but I will try NAPA Auto Parts and Canadian Tire.

Alan-Easy-Off

Nice to see another old fashioned lettering man. I have done sign work since 1960 and have yet to find any vinyl lettering that will stand up to what good old paint will. I'm still doing some hand over hand lettering. Snappers will never die.

Paint remover

A friend of mine found that soaking over night in Windex, or it's generic, worked quite well. It also is a surfactant so makes wet water. I wet a paper towel strip 1"-2" wide and lay it over the track on a small circle track to clean wheels. It is a good cleaner too.

Glen Wasson   aka   Armchair   http://armchairmodelbuilders101.com

Castrol Super clean degreaser

Castrol Super clean degreaser works great. It does a great job stripping off pretty much any kind of paint and wont harm plastic. Follow up with the soda blaster and you'll have a nice bare canvas.

Alcohol

Do not use anything stronger than 91% alcohol on any plastic.......I found out the hard way a year or so ago.........I had used Denatured alcohol to strip paint on some P2K SD45 shells.........cracks all over the shells............also cracked and warped the walkway/sills.

Scale Coat II Wash Away

Scale Coat II wash away, safe for plastics. I've never tried it on plastics, but i use it to strip off all the crappy paint jobs off the brass engines i get off of ebay. And its reusable. Strain out all the washed off paint, and put it back in the bottle, and use it again on another engine.

Ill be using it again shortly to strip some bowser steamers soon.

Cheap ultrasonic cleaner and 91% alcohol

About 8 years ago my wife found me an ultrasonic cleaner that was on sale for $5.00 at radio shack. It was very versatile and could be used by setting the tip just inside the included container. I filled the container with 91% alcohol and stuck in a shell ( Bachmann N scale) to strip. I at first just turned on the cleaner with it setting in the container. That appeared to be too slow, so I grabbed the cleaner and played it along the shell surfaces. I was very surprised to see it completely stripped in 45 minutes! A few minor remains that came off quickly with a toothbrush.

This cleaner originally sold for $29.00, is no longer made, but I just found 2 on Ebay. Both new, one for $10.00, the other for $25.00.

Soda blaster if it's metal

I'm not a huge Harbor Freight guy but they do have an "Air Earser" for liek $20 that works well

Steve