Isopropyl Alcohol (IPA) as paint-stripper

Steven B · June 04, 2024, 12:23:41 PM

Does anyone use isopropyl-alcohol (IPA) as a paint stripper? If so, what percentage alcohol did you use and how long does it typically take on a Farish or Dapol body shell? Have you noticed any ill effects, e.g. damage to plastic?

I currently use Phoenix Superstrip but the bottle's getting empty so needs replacing, possibly with Superstrip 2, possibly with IPA.

Steven B

njee20 · June 04, 2024, 12:51:23 PM

I use 99%, and usually leave bodies in for 12-24 hours.

I did open my (ice cream) tub of IPA the other day and it had a mk3 that had probably been in there a year. That was beyond saving, but I've left bodies in there for a week with no ill effects.

joe cassidy · June 04, 2024, 12:52:08 PM

In my opinion isopropyl alcohol might work on acrylics that have not been varnished but useless on solvent-based paint such as enamels.

Joe (PhD chemistry)

Newportnobby · June 04, 2024, 12:59:27 PM

No damage to the plastic but this is what one small drop did to a carriage roof............

njee20 · June 04, 2024, 02:06:33 PM

Yep, definitely won't work on enamels, but it does work on factory finishes from Dapol and Farish. If you've painted a model with Halfords primer it'll also end up working on enamels by default, just lifts the whole lot off!

steadfast · June 04, 2024, 03:11:39 PM

I hate to be the bearer of bad news, but IPA will take enamel and cellulose off.

The only paint I've struggled with is Molotow graffiti paint (cheap and ideal for scenery base colours etc) which is an acetone based paint.

Jo

David Burnell · June 04, 2024, 06:57:02 PM

whilst using the Isopropyl alcohol I accidently spilt on the body of my class 31 and it dissolved the colour and with my fingers unknowingly daubed with it, I finger-painted the roof BR green.

joe cassidy · June 04, 2024, 08:21:09 PM

I seem to remember a "few" years ago that oven cleaner - the foamy type in spray cans - was considered to be the best/fastest acting paint remover ?

zwilnik · June 04, 2024, 08:24:06 PM

Quote from: Newportnobby on June 04, 2024, 12:59:27 PMNo damage to the plastic but this is what one small drop did to a carriage roof............

With a touch of weathering powders that's not far off the distressed/weathered look Farish did on those special edition ones.

PaulCheffus · June 04, 2024, 08:50:45 PM

Quote from: steadfast on June 04, 2024, 03:11:39 PMI hate to be the bearer of bad news, but IPA will take enamel and cellulose off.

The only paint I've struggled with is Molotow graffiti paint (cheap and ideal for scenery base colours etc) which is an acetone based paint.

Jo

Hi

I've never had any success with IPA on enamels. What strength did you use and how long did you leave it?

Cheers

Paul

Papyrus · June 04, 2024, 08:51:25 PM

My solvent of choice is brake fluid. Seems to work in about 24 hours on most finishes and doesn't attack plastic. Also doesn't evaporate like IPA.

Cheers,

Chris

port perran · June 04, 2024, 09:11:13 PM

Quote from: joe cassidy on June 04, 2024, 08:21:09 PMI seem to remember a "few" years ago that oven cleaner - the foamy type in spray cans - was considered to be the best/fastest acting paint remover ?

Folk Singer Fred Wedlock has the answer :
https://youtu.be/KxZnWSNswgA?si=DwVYCQG-lLTZwtbQ
Sorry....I'll get me coat

joe cassidy · June 04, 2024, 09:45:45 PM

Water will remove any kind of paint - if you wait long enough.

Newportnobby · June 04, 2024, 10:13:53 PM

Quote from: port perran on June 04, 2024, 09:11:13 PM
Quote from: joe cassidy on June 04, 2024, 08:21:09 PMI seem to remember a "few" years ago that oven cleaner - the foamy type in spray cans - was considered to be the best/fastest acting paint remover ?
Folk Singer Fred Wedlock has the answer :
https://youtu.be/KxZnWSNswgA?si=DwVYCQG-lLTZwtbQ
Sorry....I'll get me coat

If Daz won't whiten it and Omo doesn't brighten it, Bugger it.
We'll not go into the Finest Universal.................................

steadfast · June 04, 2024, 10:44:01 PM

Quote from: PaulCheffus on June 04, 2024, 08:50:45 PM
Quote from: steadfast on June 04, 2024, 03:11:39 PMI hate to be the bearer of bad news, but IPA will take enamel and cellulose off.

The only paint I've struggled with is Molotow graffiti paint (cheap and ideal for scenery base colours etc) which is an acetone based paint.

Jo

Hi

I've never had any success with IPA on enamels. What strength did you use and how long did you leave it?

Cheers

Paul

Neat IPA, rubbed with a cotton bud for about 2-3 minutes. Took a patch of brown weathering and some red base paint off the test subject when I tested this afternoon to check I wasn't misremembering and it does work.

To strip N scale stuff, I normally use an ex Chinese takeaway tub (suitably degreased via the dishwasher when first used) filled about 3/4 full with IPA. Add the vehicles to be stripped, lid on and leave for a couple of hours. Lid off, gently attack with a toothbrush over the tub, (in the sink to catch any spatter) then resubmerge and pop the lid back on.

Any spatter can removed from the sink with neat IPA on kitchen roll before the wife finds out, and the stripping IPA, although tinted with paint can be reused many times. I store mine in a 250ml bottle.

When I first started with IPA, I measured it out to 93%, adding 7% water by volume. Now I just add a splash, and had no detrimental effects. I don't know if the water changes how effective a stripper it is or if it reduces the rate of evaporation?

Always wear gloves, as being a fast drying alcohol it evaporates off your skin quick and dries your hands out horribly.

Another benefit to IPA is that it doesn't fog clear glazing, and also weakens superglue so can help get stubborn glazing out. Obviously if in doubt test first!

Jo