Using 91% alcohol to strip paint - question

[jcopilot]

I'm trying to strip Tamiya spray paint from some Walthers building kit pieces.  I have and have used Scalecoat paint stripper, but it is dreadfully expensive and I'd like to find a cheaper alternative.  The pieces have been submerged in Super Clean for 3 days and the paint isn't budging even after scrubbing with a toothbrush.

Some people on this forum have said they use 91% alcohol but they don't describe the details, mainly, how long can you let the pieces sit in the alcohol?  Scalecoat stripper says 10 minutes.  I've had pieces in Super Clean for days.  How long is it safe for 91% alcohol?

Thanks for your help,

Jeff

[BigDaddy]

I've stripped cars and it can take a couple days with 91%.  I scrub them with a tooth brush now and then.   Never had any bad effect on the cars.

[peahrens]

I stripped some old Athearn heavyweight cars, not all from the same runs.  I used denatured alcohol (mainly ethanol) first, then Super Clean as the backup.  The results varied, I presume due to differences in the original factory painting approach.  Most cars responded to ethanol readily, with one or two multi-hour or overnight soaks plus some toothbrush scrubbing.  But some were very stubborn; fortunately, for those the Super Clean worked well enough, with some patience.  I did not try isopropanol (IPA).  So the cars got lots of soaking, with no effect that I noticed on the plastic (maybe a bit dull), certainly not after a coat of primer.

I was googling for a comparison of ethanol versus IPA for this purpose and came across this interesting video where the fellow experiments on 6 different paint / coating systems with 6 different potential solvents.  Not model railroad specific, it is well done.

https://www.youtube.com/watch?v=OqBjt1wKZfc

Do use proper caution.  Ethanol will dry out your skin quite readily.  Super Clean is very caustic and will burn it.  No good reason not to wear impermeable gloves.

 

[BigDaddy]

Denatured alcohol has methanol, which I believe is easily adsorbed and bad for you.  Wear gloves

[ckape]

91% isopropyl alcohol is pretty mild to the plastic, I've accidentally left items in for months with no apparent ill effects.  It's not as strong against the paint as scalecoat, though, so I use the alcohol for my first attempt and if that doesn't work then I try the scalecoat.

I've never used Super Clean, so I don't know how it compares in strength.

[jjdamnit]

Hello All,

I have used many different "solvents" to strip paint off of shells.

At first I will try 91% isopropyl alcohol.

I put the item(s) to be stripped in a zip-top freezer bag and add enough isopropyl alcohol to cover it/them.

Then I will press out all the air in the bag, seal, and place in a metal (not aluminum) baking pan in case of leaks.

About every 8- to 12-hours I will remove the shell and scrub with a toothbrush to see how the progress of paint removal is going.

If the paint is not being affected by the alcohol I will thoroughly rinse in warm water and move to the second solution.

The second solution is full strength PineSol®.

Using a fresh zip-top freezer bag, I will put the item(s) in the bag, fill with enough solution to cover, press out the air, place in the pan and allow to soak.

Because full strength PineSol® is caustic I use Nitrile gloves when removing, scrubbing and rinsing the items.

Others have used Laquer thinner or mineral spirits to strip paint. One aftermarket shell manufacturer recommends a soak in one of these solvents before painting to remove the mold release compound he uses in manufacture.

Many have recommended Super Clean. I have heard of good results but I have no experience with it.

Hope this helps.

[Doughless]

91% alcohol doesn't do much for removing rattle can paints, IMO.  Its useful for removing factory applied paint.

[ricktrains4824]

I've left them overnight, no issues.

However, if it's a custom painted piece, and it's done with solvent based paint, the Isopropyl really does not touch it.

My method is a little different, as I reuse an old gallon sized ice cream bucket with lid. (After I have eaten the ice cream of course.  ) Model goes in, then Isopropyl to just cover, then snap on the lid.

Check it in a couple hours, scrub with an old toothbrush, and repeat as needed. Most have worked overnight at most, save for a few items that were a bit more stubborn.

[AntonioFP45]

Hi Jeff,

Do you have photos of the structure that you can post? 

Suggestion to consider:  If your pieces have relatively smooth surfaces without a lot of detail, consider wet-sanding them with quality sandpaper (such as 3M). 

Wash first with warm soap and water to remove all traces of oils.

If the Tamiya paint that is on the surfaces is,generally smooth you could start with 600grit, then progress to finer grits (800g, 1200g, 1500g, and finish with 2000g). You can make the surface very smooth, but it would still have enough tooth for new paint to adhere to it. The painted surface would become your foundation for your new primer or colors.

But photos would be helpful for making a reasonable suggestion to help you.

jcopilot

I'm trying to strip Tamiya spray paint from some Walthers building kit pieces.  I have and have used Scalecoat paint stripper, but it is dreadfully expensive and I'd like to find a cheaper alternative.  The pieces have been submerged in Super Clean for 3 days and the paint isn't budging even after scrubbing with a toothbrush.

Some people on this forum have said they use 91% alcohol but they don't describe the details, mainly, how long can you let the pieces sit in the alcohol?  Scalecoat stripper says 10 minutes.  I've had pieces in Super Clean for days.  How long is it safe for 91% alcohol?

Thanks for your help,

Jeff

 

[Mark R.]

I've used EZ-Off over cleaner with good results as well. Liberally spray the part and put it in a sealed container (zip-loc bag / old tupperware) for a couple hours. You need to use the one in the yellow can, it is more aggressive than the green can version.

Mark.