Removing Airfix chrome

Well I,m still at it, after the ammonia, I rinsed it off very well and the into the bleach for about 4 days, had to change out the bleach every day because that turned black and parts flaked off as of to their is what looks like black soot, settled into all the wonderful nooks and crannies. I rinsed it carefully and have been scraping of the black stuff. The is so much flash on this stuff that it pretty much has to be done regardless. Under some of the black there appears to be a very well adhered copper layer which is really tough to get off! Kinda have to chip it off or file it away. Finally down to base plastic, but this will take time.

tatonka

 

I am going to beat this thing!

 

Kurt

 

I played this game with an AMT kit.  I was determined to win.  After 2 weeks and more chemicals, I put the parts back in the box and moved on to a new build. Still has chrome. 

Good luck. 

T e d

tatonka

I can't figure out how to properly insert an image to show my progress...

You need to use a hosting site of some kind; this forum doesn't have the functionality to allow attaching images to posts.  I use PostImage, for example.

The photo host will give you links of various kinds to embed in your posts here and in other websites, that will then show your image when the post is saved.

No, it did not turn blue.  It remained colorless, and I could not see anything looking like dissolved material in it.  The part was clear of chrome, and the ammonia showed no sign of discoloration, or any thing dissolved in it.  Very Strange!

Did the ammonia turn dark blue?

Glad to hear this!  Plain ol' Windex or ammonia has always worked for me, but it has never taken as long as this.  Maybe this is due to variations in the plating material or process.

I can't figure out how to properly insert an image to show my progress. The parts have been soaking continually for the past several days in ammonia. The chrome is about 95% gone. The ammonia turned blue! Made sure that didn't touch me. I put the pieces back in with the little ammonia I have left as I'm in no hurry. Then I'll see if the traditional ways work on any undercoat. The plastic seems to be fine.

Drano gel was one of the first things I tried.

I've never tried to get chrome off a kit like yours but on standard Revell and Monogram kits etc Drano Gel is what I've used and it has come off fast, with a little light brushing it has come off in minutes. It basically just dissolves.  Maybe your chrome is tougher though, I have no idea. Just putting Drano Gel out there is all.

Progress. Good.

You mention changing out the ammonia every day. I kept meaning to mention that whatever I use to strip, it seems it takes very little to contaminate it. Whether it be Purple Power, brake fluid, Easy Off, it seems if it gets a couple drops of water it in, or something worse, it's all done. Change it out and I have clean parts in minutes. It's baffled me.

Okay. I’ve been soaking the parts in ammonia in a bowl covered with plastic wrap for the past several days. I’ve been changing out the ammonia for fresh stuff every other day. 80 percent of the chrome is gone !!!! The plastic is brownish, but seems okay. The rest of their plastic is light gray, so I’m guessing tthe brown is the undercoat. Once the chrome is gone I’ll try using bleach. And there will be no way the ammonia and bleach are getting near each other.

Kurt

I am not a chemist, my understanding is that "chrome" plastic model parts are obiously not electroplated, or chrome, but it's some type of vacuum process using aluminum.

I'm checking in here periodically just to make sure you are still ok, what with all the nasty stuff you are experimenting with (as Steve mentioned before me).

Y'all be careful, hear?

This got me to thinking of once back in the 70's, my dad was figuring out how to set up a passivation process in our shop. Don knows what this is, in essence it means dipping stainless steel airplane parts in acid to remove surface impurities. I think it might have been muriatic acid, not sure.

Anyway, he was experimenting over the weekend. We all came in at 5:30AM to open the place for our 6-4:30 day shift, every bit of metal within 30 ft of where Dad had been working was rusted, as I remember it. Poor Dad, we called him Mr Wizard for quite a while after that, bless his heart and soul.

So don't do that.

Maybe those sprues are solid chrome...

You're correct about that. I've been very respectful of them and as careful as I can be, gloves, ventilation, making especially sure one doesn't meet the other. Something works. Most of the builds online of this kit were done soon after it was re-released in 2011, and I've only found one person in a different forum that seems to be actively online. So I'm hoping he'll respond with how he succeded.

Airfix is now owned by Hornby, I should give them a query.

A chemist would definitly help.

There are many super-nasty chemicals mentioned in this discussion.  I don't think it's necessary to use something strong enough to eat a hole in a battleship.  I would be afraid to mess with that stuff.  The key is knowing the chemistry of the plating and what is needed to dissolve it.  And we don't.  I wonder if there is a chemist in the group who could shed some light on this.

As I have mentioned, just plain ol' Windex off the supermarket shelf has always worked for me.

I mixed the lye solution to 2x what was called for to clean drains. 30ml lye to 500ml water. I used 60ml to 500ml and in 2 hours, nothing happened to my sample. So maybe soaking in ammonia for a couple of days, will make a difference.

That was my plan.

I'd definitely do some testing on the chrome sprues. You will hit a point I am sure, where all of this caustic material will start to dissolve the plastic.

I know what you mean! Okay, Lowe’s has a professional strength drain cleaner Crystal which is 100% sodium hydroxide (lye or caustic soda), the Drano I used does not list a strength. So maybe that’s next.

Kurt

Just when I thought I had this removing chrome thing all figured out.

Hope you get this sorted out, and a big for your patience and perserverence. I might have tossed the sprue to Kingdom Come by now.

I tried a second several hour soak in East-Off with no change then a overnight soak in Bleche-White with again no change. Next is again another soak in ammonia. There are no strength listings on the bottle and I can’t find anything listed at Lowe’s or Home Depot that are any different. There used to be a supplier of janitorial supplies near me, but that closed. I don‘t if that type of ammonia is the same or stronger in strength. 

I guess I’ll look into lye, if that’s still available. By the way everything gets washed away with coupious amounts of water in between products to prevent any interactions. 

Kurt

That sounds like a good sign.  I think a longer soaking in ammonia and perhaps in a stronger solution will finish the job.

Well soaking overnight in ammonia at least did something.  The sheen is gone and it has a very faint brownish tint to it now. Now I’ll try Easy-Off again and I’ll see if it has any effect this time.

I am going to beat this thing!

Kurt

Easy-Off usually works in a few minitues I put the parts in ziplocks and sprayed Easy-Off several times and left it in it for 2 days and nothing at all happened. The Draino has done nothing, so I'll try ammonia. I'll let you know how that goes.

tatonka

I recently got an Airfix 1/12 scale Bentley Blower off of EBay ( to make a poorman's Pocher, which I never could afford ((justify)) ). The kit was made in 2011 and the Chrome has to go. I've soaked it in Clorox for a day, Super Clean degreaser for a day and Easy-Off for 2 days and nothing happens. Now it's soaking in Draino so far nothing. I haven't use Brake fluid yet because I've read it can effect the plastic somewhat. Does any one have suggestions, besides leaving the chrome as is. I will be reworking the pieces somewhat so that's kinda out of the question. Other people have removed it so something has to work.

Kurt

I don't know what process Airfix used to plate that sprue, but I used SuperClean to strip the chrome from the chrome frets in the Monogram Red Baron hot rod.  It took the chrome off in two minutes.  I could see the chrome dissolve into the solution.  From that point, I've used Super Clean to strip paint from styrene, resin, and metal.

Italeri motorcycle kit- Easy Off spray. Took about 15 minutes.

Please let us know what finally works for you.  I have never failed with ammonia, but it takes a long time soaking.  The strange thing is, that when the chrome is finally gone, there is no sign of anything dissolved in the solution.  It's just GONE!

I looked on Britmodeler and another Airfix forum. Apparently the big Bentley is infamous for having tough to remove chrome.

The solution (pun intended) that most folks seem to settle on is anything containing sodium hydroxide (lye).

Both oven cleaner and drain cleaner are primarily that. I would try again with Easy Off and lett it sit an hour or so.