Looking for suggestions on how to get rid of severe yellowing.

[Minelayer]

Hello All,

 

I Purchased a used Tomix set #92624 a few years back only to discover that it had severe yellowing in certain areas, particularly the area around the couplers.

 

I've never attempted to fix such an issue and am hoping someone has some experience/thoughts and how I should proceed.

 

Thanks in advance for any thoughts.

 

Ray

 

[VJM]

The only solution I ever saw was to simply paint the whole section white (with appropriate masking where required).  As far as I know, you can't really reverse the yellowing.

 

Interested if anyone else has any better solution.

[cteno4]

ray,

 

wow thats some odd yellowing. only on the diaphragm coupler not the body shell. i'm guessing the diaphragm piece is not painted where the white is but the train body is so the plastic on the train body was protected, but the white areas on the connectors were not. plastic yellowing is usually from bromine coming up out of the plastic (used to keep the flammability down during moulding) due to uv and heat exposure. you can get rid of it by using some chemical treatments, but i expect these may attack the blue painted stripes.

 

i think your best solution would be as VJM suggests to reverse mask the stripes and lightly repaint with a good flat white lacquer enamel.

 

cheers

 

jeff

[Minelayer]

What's interesting is I received the set like this from the seller (unknowingly) so I just put it away. Since then I've always made it a point to check the coupler condition, especially on Tomix bullet trains and the other day I saw another 92624 on Ebay with the exact same issue. Had i not looked for it I'm sure I would have missed it...perhaps the seller purposely made the picture small so it could not be detected? In any event, seeing that recent auction made me think about the one I had so I decided to take it out and do something about it.

 

VJM and Jeff, thank you for your input. Any thoughts on using spray paint instead of paint? Back in the day when I used to paint Gundam models I remember having some trouble applying the paint evenly. With spray paint I just have to mask the blue area as well as the body and can spray away. I'm sure it's not that simple but...

Edited April 7, 2013 by Minelayer

[hectorton]

Would replacing the diaphragms with new replacements not, be an option? just wondering, hectorton.

[Minelayer]

I didn't know that was an option. I checked my Tomix catalog (granted it's from 2009) for such parts but never found an offering for diaphragms.

[hectorton]

I honestly don't know and won't have access to my tomix parts catalog until I return home in about three weeks. Maybe another JNS member could take a quick look at their catalog.

[DCCLED]

I got a train set in two weeks back and it was an Ice train Minitrix.

 

The owner had given up basically and sent it to me with a set of 2 other engines to put DCC decoders in.

 

I soaked the shells in Rubbing Alcohol for 4 lots of 2 hour stints interchanged with wash down in water and they came out perfect,

 

No prizes but it is worth a go if you have tried every thing else.

 

The guy who I sent item on to has promised me 4 doubles next time I am in Norway.

 

hope this helps

 

Leo Maxim

[keitaro]

i had look through all parts and didn`t see those available.

 

one would think tomix would as they sell the coupler hmm

 

I will look more into it.

[cteno4]

Isopropanol can take off paint with soaking, so you would most likely loose the bile stripes.

 

Yes you would need to do spray painting to get a nice even coat. An airbrush would be the best bet to get a nice light and even coat. Spray can would work, but they don't give the lightest spray so you need to be careful.

 

Jeff

Edited April 9, 2013 by cteno4

[keitaro]

if you had a tray and sat it in the isopropanol so it didn`t touch the blue it might help ?

 

you would have to do both sides. and the litle white stripe in the biddle of the blue would still be yellow.

 

I only suggest this as i suck at air brushing and im sure other people do too :)

[KenS]

You can get masking fluid (brush it on, let it dry), which might work to protect the stripes.  I don't think I'd go for immersion with that, but using cotton swabs soaked in isopropanol to rub the yellowed areas with the stripes masked seems like it would be safe, or safer anyway.

[cteno4]

I don't think isopropanol will take out plastic yellowing, that's bromine coming from within the plastic and I don't think iso is going to do much on that. Iso might work for yellowing due to cig smoke.

 

Jeff

Edited April 10, 2013 by cteno4

[Ochanomizu]

Hello Mr Ray,

 

The product has been stored on the layout or in the display.  It is from the long period of exposure to light.  It is the result of the chemical reaction.

 

All attempts to clean will fail.

 

Painting is your only solution.

[Minelayer]

Thank you everyone for your input. I will take my chances and try to paint it. If it goes well I will post the pictures. If not, I won't say a word and hope no one asks about it. :)

[Ochanomizu]

Hello Mr Ray,

 

I have given thought to your problem since my last post.  This will be a common problem with the model that has been on display.  If purchasing secondhand my recommendation is to avoid the product advertised as being on display if finished in light color.

 

Further, if you wish to display your models for a lengthy time my recommendation is to use UV protection glass.  I believe it is called "picture frame quality".  The choice of artificial lighting must also be considered.

[VJM]

You could try Gundam Paint Markers if you are not confident with a paint brush.  I've seen quite good touch-up jobs with these.  You may want to test on a small area first to make sure you get an even finish.

[cteno4]

given the stripes were painted on last most likely, it should be not too bad to just mask off the stripes and airbrush white between them. good thing is it will be all at the same level then!

 

this is what they do on uber fancy car racing stripes so the final paint is all one level, looks cool but pain in the ass to do. a friend took a couple of months doing this on his camero when we were in high school and boy did it look nice!

 

anything that will act as an oxidizing agent to remove the stain will most likely attack the paint.

 

cheers

 

jeff

[Minelayer]

Again, thank you all for your input.

 

I don't display any of my trains anywhere near sunlight but I do know this can and does happen, especially with white colored plastic. In fact, it doesn't even need to be in sunlight in some cases.

 

I remember when I had a Nintendo the top portion of the console would turn brown while the bottom portion remained cream? All my friends who had one experienced the same thing.

[cteno4]

Minelayer,

 

This yellowing is usually due to bromine being released for flame retardant compounds in the plastic near the surface. This is due to uv light and/or heat. The yellowing on the Nintendo bottom was probably due to heat.

 

Jeff

Edited April 15, 2013 by cteno4

[Minelayer]

Gonna give it a shot.

 

[E6系]

I look forward to seeing before and after pic.