Removing 20 year old paint

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Morningstar
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Removing 20 year old paint

Post by Morningstar »

Anyone know how to remove paint from a plastic model that was painted 20 years ago? Without hurting the plastic?

I saw someone using oven cleaner but I'm afraid I'll melt the plastic. Any experience?
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Rocketeer
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Re: Removing 20 year old paint

Post by Rocketeer »

I've had good results with Castrol Super Clean (now apparently "Purple Power"), but for the tough stuff I bring out the ScaleCoat Paint Remover.
DaveVan
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Re: Removing 20 year old paint

Post by DaveVan »

Cheap DOT 1 brake fluid.....no name brands from Dollar General....works well on hard to remove paint....messy.....
Chas
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Re: Removing 20 year old paint

Post by Chas »

I've used Easy-Off many times, Never on anything that old mind you, but it's never hurt the plastic at all. I just put the pieces in a Margarine tub and sprayed the stuff on till I couldn't see the pieces anymore, covered the container and let it sit. after a couple of days a toothbrush was all that was needed to get the paint off.

Plus 1 for break fluid too. (same process).
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southwestforests
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Re: Removing 20 year old paint

Post by southwestforests »

The model railroad hobby - in the US - has had plastic safe paint removers since at least the 1980s, for example, https://www.walthers.com/paint-stripper ... 3ml-bottle It is reusable. Works on plastic and/or metal parts. But --- it and resin do NOT play together well, in my experience.
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Morningstar
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Re: Removing 20 year old paint

Post by Morningstar »

Thanks for all the advice. I live in the Netherlands so I need to find the equivalent over here. Brake fluid I will try first but are the certain “ingredients”, (or solvents) for lack of a better word, I must avoid?

Btw wish I could put in a margerine tube but it’s the saucer section of the Enterprise-D. It’s big! :D
USSARCADIA
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Re: Removing 20 year old paint

Post by USSARCADIA »

Oven cleaner works quickly and won’t hurt the plastic. Whatever you use be sure to wear gloves, protect your face too(you might have a time finding masks). If you have time then a degreaser like Simple Green(less caustic) will take it off, just needs to soak a while.


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dizzyfugu
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Re: Removing 20 year old paint

Post by dizzyfugu »

Brake fluid should only be the LAST resort. It's very aggressive and WILL hurt the palstic, sucking out softener and leaving the material brittle. Not the best idea for a 20 year old model. My vote would go to a (soda-based) oven cleaner foam bath , too: Leave it under a foam cover for a couple of days and see what happens. The stuff creeps between the plastic and the paint, and this is a rather slow process, but with only little risk. Might have to be repeated, though.
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Morningstar
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Re: Removing 20 year old paint

Post by Morningstar »

Thanks for the advice and warning. I'll first look into a soda-based oven cleaning product. Seems like the safest way without hurting the model. Also I don't mind a little elbow grease. It's all part of the fun.
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southwestforests
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Re: Removing 20 year old paint

Post by southwestforests »

If you haven't already, even though the US here and Europe there are quite different, I'd suggest contacting the model railway community there in your country to inquire if there may or may not be paint remover products available there.
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starseeker
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Re: Removing 20 year old paint

Post by starseeker »

I've always used Easy-Off. You need to apply it somewhere well ventilated, preferably outside, and let the model sit for a few hours if it's a water-based paint, possibly a few days with re-coats if it's an enamel. Last year I stripped some of my AMT cars from the '60s. It took several coats and a couple of days to get rid of most of the paint. There were still a few very small spots of '60's vintage PLA enamels that needed to be sanded off. They knew how to make paint back then! I've also used Dettol, available as a hand cleaner in some pharmacies?? and it works really well, too. But it's expensive if you're doing more than one model, or a large model. And with Covid about to run over everything, it's probably all been bought up by now for gouging on EBay and Amazon anyway.

Same procedure for both: a stiff fingernail brush for large areas of tough old enamel, and a couple old toothbrushes for fine cleaning. It's amazing to see '60s car kits restored to bare plastic with all the paint gunged detail back to new. The plastic remains pretty stained but it's clean, and makes you remember the wonderful smell of the old AMT kit plastic when you opened the boxes. Wish it could make make the tube glue blobs go away.
Wug
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Re: Removing 20 year old paint

Post by Wug »

Morningstar
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Re: Removing 20 year old paint

Post by Morningstar »

Dettol might be an option to try first. If I can find any.

As I'm in the Netherlands I can't get my hands on American product like Super Clean. I have some HG Oven Cleaner, but I'm afraid that stuff might be too strong. And I don't know the correct amount to dilute it with.

I've only got one shot to get this right. If not a childhood item will be gone.
seam-filler
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Re: Removing 20 year old paint

Post by seam-filler »

Dettol is just a disinfectant - it might strip some acrylics but I wouldn't expect too much.

A paint stripper will more or less have to be caustic, which means that products may mot be shipped internationally.

Expo do an excellent model stripper (EXPO 44500 - Model Stripper) https://www.expotools.com/acatalog/4450 ... ml#SID=149 but I'm pretty sure this cannot be exported, unless you can find a distributor in NL.

Another product that is very good for removing acrylic paint is Fairy Power Spray - again, this is a UK product and you may be able to find out the NL equivalent.

The UK's Mr Muscle Oven Cleaner appears to much like the US "Easy-Off" - The Mr Muscle range looks to be pretty common throughout Europe, so that might be a solution.
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Morningstar
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Re: Removing 20 year old paint

Post by Morningstar »

I was looking at Mr Muscle, but there are so many varieties and I don’t have any parts painted with the old paint that I can test it on. Anyone have a Mr Muscle experience?
Stuart Wilson
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Re: Removing 20 year old paint

Post by Stuart Wilson »

I've used Mr Muscle oven cleaner foam for years and it works great. You need to apply it and then leave in a sealed plastic bag for a few hours, then rinse off with water, a little scrubbing with a thick brush helps. If the paint has been on for a few years it might take a couple of goes, It won't work with cellulose paint but then I don't think anything will. I use enamels and acrylics and it works fine with both.

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starseeker
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Re: Removing 20 year old paint

Post by starseeker »

seam-filler wrote: Mon Mar 30, 2020 7:59 am Dettol is just a disinfectant - it might strip some acrylics but I wouldn't expect too much.
To repeat, I used it on some of my auto models dating from the 60s, painted with Testors bottle and spray enamels, and it worked for me. I discovered it by searching the 'Net for paint remover suggestions and found several modellers on different sites that used and recommended it. You, too, can try typing "dettol - model paint remover" or some such and see what others have to say. But oven cleaner works about the same. Dettol would be my preferred choice, tho' if I could afford dettol, if I could afford larger quantities, as I often have to work indoors, and even the no fume oven cleaners leave my throat raw while applying and while brushing. Should wear a respirator mask, really.
seam-filler
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Re: Removing 20 year old paint

Post by seam-filler »

starseeker wrote: Mon Apr 13, 2020 9:47 pm
seam-filler wrote: Mon Mar 30, 2020 7:59 am Dettol is just a disinfectant - it might strip some acrylics but I wouldn't expect too much.
To repeat, I used it on some of my auto models dating from the 60s, painted with Testors bottle and spray enamels, and it worked for me. I discovered it by searching the 'Net for paint remover suggestions and found several modellers on different sites that used and recommended it. You, too, can try typing "dettol - model paint remover" or some such and see what others have to say. But oven cleaner works about the same. Dettol would be my preferred choice, tho' if I could afford dettol, if I could afford larger quantities, as I often have to work indoors, and even the no fume oven cleaners leave my throat raw while applying and while brushing. Should wear a respirator mask, really.
Well, you live & learn, and I stand corrected.

You're quite right about googling. I turned this one up... https://www.wikihow.com/Remove-Paint-fr ... ith-Dettol

You don't say where in the world you are, but Dettol is half the price (per litre) of Mr Muscle in the UK, so I think I'll be giving that a go.
"I'd just like to say that building large smooth-skinned models should be avoided at all costs. I now see why people want to stick kit-parts all over their designs as it covers up a lot of problems." - David Sisson
starseeker
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Re: Removing 20 year old paint

Post by starseeker »

I'm editing this one to put the most important bit from the end, at the beginning as well, as it's really a long and boring post:

Two years a chem major and I can guarantee that nothing you use to strip paints will be safe for your skin, eyes, or lungs, let alone children or pets. Always wear protective gloves and eye protection. And after my previous post, I suddenly realized that I will be wearing my air brushing respirator for my... future destructions.

After I posted last night, I started thinking about just how I did use the dettol. It was the middle of the winter before this last so my memories are a little vague. I have an ancient old plastic bowl that I reserve for paint stripping, about 30 cm in diameter and 15 deep. (Yes, I've horribly painted enough models in my life that this is now a dedicated necessary modelling tool.) The model gets disassembled as best as it can and in it goes into the bowl. Normally it gets sprayed with Easy Off, left to sit for a day, scrubbed with a stiff plastic brush, to get at least the first layer of paint off, sprayed again, and usually tooth-brushed after the 3d time to get the last traces gone. Depending on the size of the model, it might take two cans. Up next someday is my Young Astronauts 1/72 B52 X-15 carrier. That's going to be at least 3 cans worth of work, maybe 4 depending on the paint I used.

Easy-Off sometimes just takes one layer of paint at a time. In recent years I've switched over to automotive primer paints, as they're easily as smooth as Tamiya and about 1/4 -1/5 the price, and I've taken to building model rockets, increasingly stupidly large. I do not know if anything will strip automotive primers? Easy-Off sometimes won't strip model primers, or even 1960's PLA bottle or spray, at least not totally, the remaining thin haze or paint trapped under blobs of tube glue requiring sanding if you want to get all of it. Which you might, if you're concerned about paint incompatibilities. I doubt that just a haze left would hamper a new primer but better safe. And nothing I've ever tried, absolutely nothing, will remove the original Testors Model Master Acryl line. Not even from your airbrush, if you let it dry in there. Not even their own thinners. What was that stuff??

Two bottles of dettol went into said plastic bowl and two old, disassembled as best I could 1/25 scale car models went in to the dettol. I sealed the bowl with extra wide plastic wrap and let it all sit for a day. The liquid turned a sick brown color by the end of the first day and swirling the bowl I could see that paint was indeed stripping from the plastic. I think I watched and swirled the bowl and stirred and turned the parts for two or three days before I finally thought it was good enough. I have an old sprung fine stainless steel kitchen sieve that I strained the dettol through. Sometimes previously cemented small parts or even bits of plastic stressed by disassembly come loose and with previous easy-off experience I've learned to make sure I wash everything through the strainer. And wash the strainer with running water into a stoppered sink that you don't like. Amazing the little bits that can get away. And make sure clear parts are well removed before stripping.

I put the strained dettol back into the plastic bowl and threw in two more models and sealed the bowl again. The liquid was losing its power by then and I had to let the second pair sit for maybe 4 or 5 days before they were nicely stripped. Third try with the same solution wasn't work so well anymore. The third pair had to be finished with easy-off.

But still I was very pleased with how the dettol worked. Much less mess than the easy-off. If only it was way cheaper here.

I also seem to remember that I went to the store looking for a specific kind of dettol? I did not keep the empty bottles for reference. Luckily, the only kind they carried was the one I wanted. It was in the hand soap section??

Two years a chem major and I can guarantee that nothing you use to strip paints will be safe for your skin, eyes, or lungs, let alone children or pets. Always wear protective gloves and eye protection. And after my previous post, I suddenly realized that I will be wearing my air brushing respirator for my X-15 and future destructions.
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Tommy8008
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Re: Removing 20 year old paint

Post by Tommy8008 »

Another for Dettol.

I used it to strip the paint off of my Enterprise E. Left the saucer in Dettol over night, then next day the paint just peeled right off.
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