Removing Chrome

[Dale361]

Hello everyone. Hope I'm not wasting anyone's time and hoping I'm not repeating a post already out there, but I thought this may be useful info. I stripped chrome from plastic parts last week. The kit the parts came from was an AMT Ford Snowplow kit. From reading in the Forum, it sounds like AMT's chrome is the toughest to remove. I used several products. Here are the results.

       Brake Fluid. Soaked parts for 48 hours. About a quarter of the chrome was removed.

       Ammonia. Soaked parts for48 hours. About a quarter of chrome removed. 

       Windex. Soaked parts for 48 hours. About a quarter of chrome removed.

       La's Totally Awesome. Soaked parts for 48 hours. About 3/4's of the chrome was removed so I let it soak another 48 hours. Almost all chrome was removed. Maybe 90 percent. 

       Zep's Industrial Purple Degreaser. At 24 hours all chrome was removed. 

 So, I rinsed all the parts that still had chrome left on them and put them in the Purple Degreaser. 24 hours later all chrome was gone. With all the products, the glossy clear coating remained. 

This was my first attempt at removing chrome. It was because of the info I found in the Forum that I was able to add another tool to my model building hobby. THANKS EVERYONE! 

 

[peteski]

The truly toughest chrome to remove is on Trumpeter model car kits.  Those are actually electroplated with a fairly thick metal coating.

Other kit's chrome is just a couple of atoms thick layer of aluminum deposited in a vacuum chamber (process is called "vacuum metalizing")  Before metalizing the parts are sprayed with a high gloss clear (to provide a smooth surface for the metalization).  Not very often, there is also a top clear coat applied to protect the rather fragile thin aluminum coat.

While some of the methods you mentioned are used by some modelers, the indisputably best way to remove the "chrome" is a solution of Sodium Hydroxide (aka. Lye, or caustic soda).  It will both, quickly remove the thin layer of metal, and also because it also is good for stripping paint, it will also strip the clear coating, leaving just the bare plastic.  It will also eat human skin so rubber gloves are highly recommend (most of lye containing  liquids have warning labels on their containers).
Many household cleaning fluids contain lye.  Drain cleaners, oven cleaners, degreasers, all contain lye.  The Purple Degreaser (Often called "Purple Pond") is very popular in modeling circles for stripping paint and "chrome".  it contains lye.

Another hint:  warming the solution slightly (to around 90-90 deg. F) will increase the potency and speed up the stripping action).

And yes, this subject comes up here from time to time.  So far I have not seen any better methods than the old standby: Lye.

Edited February 22, 2023 by peteski

[jaymcminn]

23 minutes ago, peteski said:

The truly toughest chrome to remove is on Trumpeter model car kits.  Those are actually electroplated with a fairly thick metal coating.

Other kit's chrome is just a couple of atoms thick layer of aluminum deposited in a vacuum chamber (process is called "vacuum metalizing")  Before metalizing the parts are sprayed with a high gloss clear (to provide a smooth surface for the metalization).  Not very often, there is also a top clear coat applied to protect the rather fragile thin aluminum coat.

While some of the methods you mentioned are used by some modelers, the indisputably best way to remove the "chrome" is a solution of Sodium Hydroxide (aka. Lye, or caustic soda).  It will both, quickly remove the thin layer of metal, and also because it also is good for stripping paint, it will also strip the clear coating, leaving just the bare plastic.  It will also eat human skin so rubber gloves are highly recommend (most of lye containing  liquids have warning labels on their containers).
Many household cleaning fluids contain lye.  Drain cleaners, oven cleaners, degreasers, all contain lye.  The Purple Degreaser (Often called "Purple Pond" is very popular in modeling circles for stripping paint and "chrome".  it contains lye.

Another hint:  warming the solution slightly (to around 90-90 deg. F) will increase the potency and speed up the stripping action).

And yes, this subject comes up here from time to time.  So far I have not seen any better methods than the old standby: Lye.

Yup, stripping the aluminum layer but leaving the clear is only half the battle. That clear layer is usually pretty thick and, especially on engine parts, can obscure the molded detail. I've always used oven cleaner with lye and have been happy with the results. 

[dragstk]

The best stuff Ive found to remove chrome is Scalecoat. I got it at a hobby train store. Its a little pricy but it does well at removing that coating under the chrome. Ive been using the same bottle for 3-4 yrs now

https://www.hobby1.com/scalecoat-ii-wash-away-paint-remover.html

[Dpate]

The BEST product to use to remove chrome is 100% lye, and its cheap, and no more dangerous than other products folks use.  Basically get a little container, warm water, spoon, and slowly add the lye to the water.  The water will be cloudy for bout a min, and than it turns clear, and than you add your chrome parts, and than watch the chrome vanish in a mater of seconds depending on the brand.  The longest I've ever had to wait was about 2 mins, and that was on a old 1989 tamiya kit.  The reason these other products work good like oven cleaner, and superclean is because of the lye in it.  The product in the picture is not only amazing at stripping paint etc, but it'll take off the varnish that was under the chrome off  in mins.  Dries it up, and makes it stringy, and easily brushed off the part. I would only use scalecoat for removing paint, and use cheap lye for chrome. 

 

Edited February 23, 2023 by Dpate

[Dale361]

Well, as usual, I'm proved that there are more ways to skin a chrome plated cat. All because of the awesome knowledge here at The Forum. Dusty, I looked for the product you use but seems hard to get. Jeff, pricey, but thanks. Peter and Jason, 35 years of firefighting my nostrils are not thrilled with harsh fumes. I found a product called Crystal Lye drain opener. Available at Home Depot. Hope a mask is not needed!  Gonna head out tomorrow to pick some up. I'm hoping it works like Dusty, Peter and Jason said Lye works. Thanks guys. Your knowledge and this forum has advanced my building incredibly!!!!  I'll let you know how it goes. 

 

[Dpate]

1 hour ago, Dale361 said:

Well, as usual, I'm proved that there are more ways to skin a chrome plated cat. All because of the awesome knowledge here at The Forum. Dusty, I looked for the product you use but seems hard to get. Jeff, pricey, but thanks. Peter and Jason, 35 years of firefighting my nostrils are not thrilled with harsh fumes. I found a product called Crystal Lye drain opener. Available at Home Depot. Hope a mask is not needed!  Gonna head out tomorrow to pick some up. I'm hoping it works like Dusty, Peter and Jason said Lye works. Thanks guys. Your knowledge and this forum has advanced my building incredibly!!!!  I'll let you know how it goes. 

 

This stuff right? If so yes that will work 100% removing the chrome better and faster than all other products and it's cheaper.  You'll know when it loses it strength when it's slow at removing the chrome.  That's when you just make fresh new water or just add little more lye to water already made. Remember to add it to the water not the other way around.  This prevents a dust cloud - just take a plastic spoon or measuring spoon and scoop some up and sprinkle it in the water.  You can slowly mix it or let dissolve on its own if you want. Add chrome and watch it vanish like magic lol.  New kits chrome vanishes in seconds, and older kits can take 30secs to a min.  That's better than hours or days of waiting lol. My routine is basically after the chrome is off i use tweezers to grab the parts give a good swish around and put on shop towel or whatever and give them a good wash and scrub. This stuff will not remove the varnish though I've tried by leaving parts in for days, and doesn't touch the varnish.  Might need scalecoat for that or try 91%-99% alchohol. That other product i listed is hard to get cause it's all ways out of stock for some reason  but man does it work, and the only down side to it is the smell.  It's strong even stronger than lacquer thinner, but it doesn't hurt plastic at all unless it's left for days.  The max is 13 hours with that stuff, but I've never had to leave anything that long. 

Edited February 23, 2023 by Dpate

[Dale361]

Awesome. Thanks Dusty! 

[presnell]

I've  been using 409 cleaner (not the lemon scented) for about 40 years removing chrome it usually gets 90 to100 percent in 24 to 48 hrs.

[peteski]

Just be very careful with lye as it is very caustic.  Remember, in some old crime drama movies it was used to dissolve dead bodies.  Not sure how true that is, but it will attack your skin.  Also pay attention to the instructions on the container regarding how to mix it with water. And don't use metal containers to hold the solution.   Just for fun, drop a apiece of aluminum foil in the lye solution to see what happens, and as I mentioned, the kit's "chrome" is actually a very thin layer of aluminum (much much thinner than aluminum foil).

[Dale361]

OK. Peter. Help me out. I found a crystal drain cleaner that claims 100% lye. Filled a plastic container, about 4X6 with about an inch of water. Added about a tablespoon of the crystals. Swirled it around then added some chrome tree cuttings. It started working right away. I did not realize how hot it would get. My first container was one that fresh mushrooms are packaged in. Thin Plastic. It began to collapse. Poured everything into a container of thicker plastic. The chrome was coming off but then it stopped working. Repeated the steps only this time doubled the amount of crystals. It got hot enough that it was not possible to hold the container at the bottom. It did remove the chrome, but it took two try's, an hour and the yellow coating was still there. Where am I going wrong? 

[Dale361]

19 hours ago, jaymcminn said:

Yup, stripping the aluminum layer but leaving the clear is only half the battle. That clear layer is usually pretty thick and, especially on engine parts, can obscure the molded detail. I've always used oven cleaner with lye and have been happy with the results. 

Jason. I'd like to pick your brain too. I did go ahead and picked up some Easy Off to try. What is the process that you use? 

[Dpate]

3 hours ago, Dale361 said:

OK. Peter. Help me out. I found a crystal drain cleaner that claims 100% lye. Filled a plastic container, about 4X6 with about an inch of water. Added about a tablespoon of the crystals. Swirled it around then added some chrome tree cuttings. It started working right away. I did not realize how hot it would get. My first container was one that fresh mushrooms are packaged in. Thin Plastic. It began to collapse. Poured everything into a container of thicker plastic. The chrome was coming off but then it stopped working. Repeated the steps only this time doubled the amount of crystals. It got hot enough that it was not possible to hold the container at the bottom. It did remove the chrome, but it took two try's, an hour and the yellow coating was still there. Where am I going wrong? 

lol Don't use any kind of plastic use PET, and shouldn't have an issue.  Don't use full chrome tree's just the parts itself.  If it seems like it's losing it's power i.e chrome taking awhile to come off just make fresh batch of water & lye.  I also mentioned in previous post lye will not remove the yellow coating at all as I've tested that's why i do a 2 stage process. i only use the lye to remove chrome that's it. 

[jaymcminn]

4 hours ago, Dale361 said:

Jason. I'd like to pick your brain too. I did go ahead and picked up some Easy Off to try. What is the process that you use? 

1- WEAR GLOVES. Place parts/trees into a plastic container with a tight-fitting lid and spray Easy Off over parts, enough to cover them. Easy Off will cling to the parts, you don't need to submerge them completely. Do this outside and don't breathe the fumes. Place the lid on the container and give it a good shake. Periodically shake the container to make sure the Easy Off gets to all surfaces. After an hour or so, rinse the parts in water (gloves again), scrub with a toothbrush and let air-dry. 

Just make sure you don't have the fume-free stuff. Old school Easy Off has lye for its active ingredient, which makes it good for cleaning both chrome parts and your nasty oven!

[Dale361]

1 hour ago, Dpate said:

lol Don't use any kind of plastic use PET, and shouldn't have an issue.  Don't use full chrome tree's just the parts itself.  If it seems like it's losing it's power i.e chrome taking awhile to come off just make fresh batch of water & lye.  I also mentioned in previous post lye will not remove the yellow coating at all as I've tested that's why i do a 2 stage process. i only use the lye to remove chrome that's it. 

Thanks Dusty! The tree parts were my testing items. I had to look up what PET was and now it makes sense. As for the lye not removing the under coat, I got mixed up. Peter, PETESKI, made mention that the lye would remove it. Maybe his is a different brand. Anyway, I want to thank everyone for the info! 

[Dale361]

41 minutes ago, jaymcminn said:

1- WEAR GLOVES. Place parts/trees into a plastic container with a tight-fitting lid and spray Easy Off over parts, enough to cover them. Easy Off will cling to the parts, you don't need to submerge them completely. Do this outside and don't breathe the fumes. Place the lid on the container and give it a good shake. Periodically shake the container to make sure the Easy Off gets to all surfaces. After an hour or so, rinse the parts in water (gloves again), scrub with a toothbrush and let air-dry. 

Just make sure you don't have the fume-free stuff. Old school Easy Off has lye for its active ingredient, which makes it good for cleaning both chrome parts and your nasty oven!

Jason, thank you. I'm going to give it a go tomorrow. 

[Dpate]

39 minutes ago, Dale361 said:

Thanks Dusty! The tree parts were my testing items. I had to look up what PET was and now it makes sense. As for the lye not removing the under coat, I got mixed up. Peter, PETESKI, made mention that the lye would remove it. Maybe his is a different brand. Anyway, I want to thank everyone for the info! 

No i doubt the lye is removing the varnish.  Some other chemical in those products that contain lye is probably removing it, but it's not the lye. Think most of those products contain like 5% lye, and that's what removes the chrome, but not the varnish.  Isn't much more proof needed when 100% lye can't remove it lol. I use to use superclean when i first started, and it would remove both chrome and varnish because of lye and other stuff that's in it.  I quit using it though because when it failed to remove the varnish it would stain it purple. Maybe lye being mixed with other chemicals helps remove the varnish? Not sure, but when i tested it i left parts in 100% lye for days, and it didn't touch the varnish at all just made it cleaner lol. 

That paint remover product i showed earlier only has like 4-5 chemicals in it, and if i remember correctly one of them is acetone, but not like the acetone you get out of lowes etc.  Stuff bout smells like nail polish remover, but stronger.  Crazy thing is it will NOT remove chrome though simply cause it doesn't contain lye in it, but it will remove varnish and any kind of paint like no ones business. There is another product i got that i haven't tried yet, and it's this stuff in the picture.  I'll eventually be testing it out on removing varnish from chrome parts.

[Dale361]

37 minutes ago, Dpate said:

No i doubt the lye is removing the varnish.  Some other chemical in those products that contain lye is probably removing it, but it's not the lye. Think most of those products contain like 5% lye, and that's what removes the chrome, but not the varnish.  Isn't much more proof needed when 100% lye can't remove it lol. I use to use superclean when i first started, and it would remove both chrome and varnish because of lye and other stuff that's in it.  I quit using it though because when it failed to remove the varnish it would stain it purple. Maybe lye being mixed with other chemicals helps remove the varnish? Not sure, but when i tested it i left parts in 100% lye for days, and it didn't touch the varnish at all just made it cleaner lol. 

That paint remover product i showed earlier only has like 4-5 chemicals in it, and if i remember correctly one of them is acetone, but not like the acetone you get out of lowes etc.  Stuff bout smells like nail polish remover, but stronger.  Crazy thing is it will NOT remove chrome though simply cause it doesn't contain lye in it, but it will remove varnish and any kind of paint like no ones business. There is another product i got that i haven't tried yet, and it's this stuff in the picture.  I'll eventually be testing it out on removing varnish from chrome parts.

 

38 minutes ago, Dpate said:

No i doubt the lye is removing the varnish.  Some other chemical in those products that contain lye is probably removing it, but it's not the lye. Think most of those products contain like 5% lye, and that's what removes the chrome, but not the varnish.  Isn't much more proof needed when 100% lye can't remove it lol. I use to use superclean when i first started, and it would remove both chrome and varnish because of lye and other stuff that's in it.  I quit using it though because when it failed to remove the varnish it would stain it purple. Maybe lye being mixed with other chemicals helps remove the varnish? Not sure, but when i tested it i left parts in 100% lye for days, and it didn't touch the varnish at all just made it cleaner lol. 

That paint remover product i showed earlier only has like 4-5 chemicals in it, and if i remember correctly one of them is acetone, but not like the acetone you get out of lowes etc.  Stuff bout smells like nail polish remover, but stronger.  Crazy thing is it will NOT remove chrome though simply cause it doesn't contain lye in it, but it will remove varnish and any kind of paint like no ones business. There is another product i got that i haven't tried yet, and it's this stuff in the picture.  I'll eventually be testing it out on removing varnish from chrome parts.

Awesome! Please let us know how it works. Thanks again. 

[Dpate]

The Oden-Kan SC-02 I posted earlier works perfect at removing the under layer varnish. It does take little bit more time, but removes it no problem.

[Dale361]

 

7 hours ago, Dpate said:

The Oden-Kan SC-02 I posted earlier works perfect at removing the under layer varnish. It does take little bit more time, but removes it no problem.

Thanks again! Just ordered some to try. 

[Dpate]

16 minutes ago, Dale361 said:

 

Thanks again! Just ordered some to try. 

Sweet! It is a little pricey for 500mL compared to the other stuff, but it'll last a very very long time especially if you only use it for just removing the varnish.  I use a bristle brush iwata wash brush for airbrushes to clean off the varnish after it's done sitting, and a old tooth brush will work the same as well.   It's like a snake shedding its skin off lol, and i tested it on a crappy atlantis chrome part that was horrible and thick.  So taking that off makes it just as good as the other stuff ahem winner winner chicken dinner.

Edited February 27, 2023 by Dpate

[Dale361]

1 hour ago, Dpate said:

Sweet! It is a little pricey for 500mL compared to the other stuff, but it'll last a very very long time especially if you only use it for just removing the varnish.  I use a bristle brush iwata wash brush for airbrushes to clean off the varnish after it's done sitting, and a old tooth brush will work the same as well.   It's like a snake shedding its skin off lol, and i tested it on a crappy atlantis chrome part that was horrible and thick.  So taking that off makes it just as good as the other stuff ahem winner winner chicken dinner.

Absolutely! And I don't think I've ever thrown out a used toothbrush! 

[Mike C]

I use Easy Off oven cleaner. It’s removed chrome for me in 1/2 hour.