lufthansa 747 Yellowing Cure??

boeinglover · 10-25-2000, 12:45 PM

Hi fellow Herpa Premium collectors,

Bet some of your Lufthansa models' white fuselage have turn yellowish. Does anyone tried or have found a solution to rectify this problem? This issue is a real pain in the neck!!! Help!!!!!!!

todd · 10-25-2000, 03:34 PM

From what I've heard, its the chemical fumes in the foam that the planes were shipped in. This reacted with the plastic and caused the white to yellow and the grey to turn green. Because it is a chemical reaction, i'd have to say that the process is irreversible.

Later models in the series didn't have this problem at all. Also, i'm not sure if it is limited to those shippped in grey foam lined boxes or those shipped in hangers with white foam. I have both types, and neither have turned so far (thank goodness). Although my A300 is not as brilliant white than by B737. White plastic also tends to turn yellow under certain lights too.. So maybe we shouldn't display these models?

I'd say the best solution is to replace the foam ASAP! The longer they sit in the foam the worse it will become. Also, you may want to contact Herpa and get replacement foam. They currently are shipping the 4 premium models in foam lined boxes, don't see why it would be a problem to send you the foam inserts.

-t

[This message has been edited by todd (edited 25 October 2000).]

[This message has been edited by todd (edited 25 October 2000).]

David Malmgren · 10-25-2000, 04:31 PM

Also..... Keep them out of sunlight. I had a model displayed that got about 2 hours a day of sunlight and it is now a cream color. It was only out for a week. Another I had sitting in it's dark gray foam packing and it turned gray as well. The one I've had on display for over 1 1/2 years in a display cabinet that gets no direct sunlight are still white and grey.

boeinglover · 10-26-2000, 03:27 AM

The Premium Models that turn yellow caused by the packing foam, does it means that these yellow modell edition models are considered worthless (less or no resale value) when compared to a white one?

Has anyone tried to get compensation from herpa? As it is one of their supplier's foam that caused the so-call irreversible chemical process. What are the comments from Herpa as to assist the ill-fated collectors' problem on their models.

Comments pls.

todd · 10-27-2000, 07:41 AM

All,
I wrote to Herpa, and tried to get foam inserts.. here is their answer which blames the yellowing on "aging plastic" rather than the foam:

"...and as far as I'm told, it's not the foam that causes discoloration. There was a letter to the editor in one of the last issues of WingsWorld, and we answered the question with great care. To put it in a nutshell: discoloration of plastic is sometimes an effect that can be compared to rusting metal, and that's why telephones and computers are always beige or gray."

Granted I agree that plastic can and does change color.. I have a Wooster 1:250 LH 747 that sat out on my desk at work for about 1.5 years.. Where it was exposed to the flourescent lights it has turned yellow, on the belly, it is white.. Anyone think that ultra-violet could dish out this type of discoloration as well?

-t

Joe Wright · 10-27-2000, 08:30 AM

You asked whether UV light can cause yellowing. UV will result in all types of color changes which is why car manufacturers now clear coat auto paint jobs.

I have several Matchbox models which are one shade of pink on one side and dark red on the other due to sunlight (eg UV) exposure.

Just to confuse the issue, I've seen several posts regarding "sun bleaching" of Herpa premiums that were stored in the foam and had yellowed.

Bottom line is that PERHAPS the yellowing is due either to the foam which will emit VOC's or due to UV. Suggest storing these out of the foam and away from direct sunlight or fluorescent lights.

Best - Joe

egonzinc · 10-27-2000, 09:43 AM

I imagine this is not a perfect science but I was wondering:
Are the new Premium models at risk if lft in their foam packaging?
Are old models that HAVE NOT YELLOWED, at risk if left in their packaging?
I thought if it was an old LH premium model that was ok they would be ok in mthe future....is this the case?

If I wrap the model in tisue and then place in the foam, might this be ok?
I would like to hear your comments.
Would hate to see them yellow, but also I want ot store them safely!
Thx in advance,
Eduardo

todd · 10-27-2000, 11:40 AM

Eduardo,
I'd say that if it is the foam packing than tissue paper isn't going to do a thing. The fumes will go right through the paper and attack the plastic. I read once that if you models hadn't yellowed by now and they were stored in their original foam, they would never yellow from the foam. And I also had read that herpa changed the foam later in the LH Modell Edition and uses different foam for the premium models now.

All,
Correct me if i'm wrong but there are two ways of packaging the premium models. The boxes w/attached lids and grey foam liners. And the hangers with the white grey foam holders.

Pardon all my questions, but I am putting together a Herpa 1:200 Premium website, so i'm gathering all info I can get.. Hope to have it online in 1-2 weeks.

Todd

Dieter Mosler · 10-28-2000, 01:09 AM

Eduardo,
in the course of the years a lot of these models went through my hands. I have got models which had been stored for many years in the foam inside the box. There was no yellowing at all. And I am sure that these models will not yellow in the farest future. Other models, also still originally packed and for sure never displayed, were yellowed. I myself am convinced, that Herpa had either several suppliers for this packing foam or the one supplier whom they used changed the components of the foam, and only this foam of a certain production caused the problem. But luckily only a little percentage of the B747-400 LUFTHANSA models were hit by this problem and only a very little percentage of the B727-200 LUFTHANSA models were hit. Also a few B737-300 of the very rare LUFTHANSA EXPRESS "Reutlingen" models (which were delivered without the plastic hangars) yellowed inside their packing boxes. There is no chance to reverse that yellowing process. The models of the A300-600 and of the B737-300 series were not hit by this foam problem as they were packed inside their hangars in a styropor device which did not cause any problems. These models can only yellow when exposed to either artificial UV light or bright sun-light. I myself am convinced that Herpa, although they would not admit that the foam caused the problem, did care that the packing foam of the new Premium Series will not cause any yellowing in future.
Dieter

Dr. Edmund H. Carus · 07-15-2002, 02:18 AM

As a material and polymer scientist of many years standing I would venture to say that some foams if not completely cross-linked (cured) can emit VOCs which in the case of PU foams comprise toluene di-isocyanates in particular. These foams will react with plastics causing a permanent discolouration.

Since Herpa used PU foams in the DLH Modell Edition a/c (some) it can be fairly safely assumed that an inadequately cured batch of foam was used to package some models causing their rapid discolouration.

If your DLH models are still undiscoloured they will stay that way if kept away from direct or indirect strong sunlight or other UV sources. I recommend display of ANY models in UV resistant glass showcases in a darker place in the home.

I hope that this settles the matter.

B-huj · 07-15-2002, 06:00 AM

thanks for clarifiying such a problematic issue long discussed.

so we have to assume that all models that have not yet discouloured in their original packages, will not "turn yellow" if kept in the package...but when u say that UV rays may damage the colour...how do i know which kinds of light (apart from natural sunlight) emit UV rays?

Dr. Edmund H. Carus · 07-15-2002, 06:43 AM

Most strip lighting emits UV as do many "spot lamps". Best to check at your electrical store.

B-huj · 07-16-2002, 01:14 AM

thanks for your help!

Dr. Edmund H. Carus · 07-23-2002, 03:36 PM

I got this message from Herpa today. They know of my "polymer interest" and it took a week to get this useless response. There has been a change in plastics, from ABS to PS but this was/is a "cover" I'm sure for the foam problem - which, knowing foam technology, could happen again in the future unless PS is used in the models!

Dear Sir
For the new Premium Series a different kind of plastic was used for higher
durabilty.
Sincerely
Mit freundlichen Gruessen

Public Relations
Herpa Miniaturmodelle GmbH
Tel.: +49-(0)9824-951-957
Fax: +49-(0)9824-951-4957

www.herpa.de

Gunship01 · 07-23-2002, 11:26 PM

Great thread as I am new to the 1:200 world and have a good liking for Lufthansa. Thanks for the info guys.

upholsterygal · 09-01-2007, 10:52 AM

In doing furniture upholstery, I have found that all colors of foam will yellow. White foam only takes a matter of hours in florescent lighting.

Dr. Edmund H. Carus · 09-01-2007, 01:55 PM

True. Most polyurethane foams yellow due to the oxidation of toluene diisocyanate - the true chemical name for PU foam. UV speeds up the process as does heat.

This should not affect models if the foam is fully cross-linked! I suspect that the Herpa Modell Edition problem was made worse by a batch of partially cross-linked foam!

Cheers!

10-25-2000, 12:45 PM	#1
boeinglover Collector Join Date: Oct 2000 Location: SINGAPORE Posts: 60	lufthansa 747 Yellowing Cure?? Hi fellow Herpa Premium collectors, Bet some of your Lufthansa models' white fuselage have turn yellowish. Does anyone tried or have found a solution to rectify this problem? This issue is a real pain in the neck!!! Help!!!!!!!

07-15-2002, 02:18 AM	#10
Dr. Edmund H. Carus Master Collector Join Date: Jul 2002 Location: UK/Germany Posts: 801	Foam/Yellowing of Plastic As a material and polymer scientist of many years standing I would venture to say that some foams if not completely cross-linked (cured) can emit VOCs which in the case of PU foams comprise toluene di-isocyanates in particular. These foams will react with plastics causing a permanent discolouration. Since Herpa used PU foams in the DLH Modell Edition a/c (some) it can be fairly safely assumed that an inadequately cured batch of foam was used to package some models causing their rapid discolouration. If your DLH models are still undiscoloured they will stay that way if kept away from direct or indirect strong sunlight or other UV sources. I recommend display of ANY models in UV resistant glass showcases in a darker place in the home. I hope that this settles the matter. __________________ Edmund (now UK/IOM residency)

07-15-2002, 06:43 AM	#12
Dr. Edmund H. Carus Master Collector Join Date: Jul 2002 Location: UK/Germany Posts: 801	UV Most strip lighting emits UV as do many "spot lamps". Best to check at your electrical store. __________________ Edmund (now UK/IOM residency)

07-16-2002, 01:14 AM	#13
B-huj Insane Collector Join Date: Jul 2002 Posts: 1,638	thanks! thanks for your help!

07-23-2002, 03:36 PM	#14
Dr. Edmund H. Carus Master Collector Join Date: Jul 2002 Location: UK/Germany Posts: 801	Herpa still sticking to its guns! I got this message from Herpa today. They know of my "polymer interest" and it took a week to get this useless response. There has been a change in plastics, from ABS to PS but this was/is a "cover" I'm sure for the foam problem - which, knowing foam technology, could happen again in the future unless PS is used in the models! Dear Sir For the new Premium Series a different kind of plastic was used for higher durabilty. Sincerely Mit freundlichen Gruessen Public Relations Herpa Miniaturmodelle GmbH Tel.: +49-(0)9824-951-957 Fax: +49-(0)9824-951-4957 www.herpa.de __________________ Edmund (now UK/IOM residency)

10-25-2000, 03:34 PM	#2
todd Junior Collector Join Date: Aug 2000 Location: Massachusetts Age: 34 Posts: 11	From what I've heard, its the chemical fumes in the foam that the planes were shipped in. This reacted with the plastic and caused the white to yellow and the grey to turn green. Because it is a chemical reaction, i'd have to say that the process is irreversible. Later models in the series didn't have this problem at all. Also, i'm not sure if it is limited to those shippped in grey foam lined boxes or those shipped in hangers with white foam. I have both types, and neither have turned so far (thank goodness). Although my A300 is not as brilliant white than by B737. White plastic also tends to turn yellow under certain lights too.. So maybe we shouldn't display these models? I'd say the best solution is to replace the foam ASAP! The longer they sit in the foam the worse it will become. Also, you may want to contact Herpa and get replacement foam. They currently are shipping the 4 premium models in foam lined boxes, don't see why it would be a problem to send you the foam inserts. -t [This message has been edited by todd (edited 25 October 2000).] [This message has been edited by todd (edited 25 October 2000).]

10-25-2000, 04:31 PM	#3
David Malmgren Junior Collector Join Date: Jul 1999 Posts: 13	Also..... Keep them out of sunlight. I had a model displayed that got about 2 hours a day of sunlight and it is now a cream color. It was only out for a week. Another I had sitting in it's dark gray foam packing and it turned gray as well. The one I've had on display for over 1 1/2 years in a display cabinet that gets no direct sunlight are still white and grey.

10-26-2000, 03:27 AM	#4
boeinglover Collector Join Date: Oct 2000 Location: SINGAPORE Posts: 60	The Premium Models that turn yellow caused by the packing foam, does it means that these yellow modell edition models are considered worthless (less or no resale value) when compared to a white one? Has anyone tried to get compensation from herpa? As it is one of their supplier's foam that caused the so-call irreversible chemical process. What are the comments from Herpa as to assist the ill-fated collectors' problem on their models. Comments pls.

10-27-2000, 07:41 AM	#5
todd Junior Collector Join Date: Aug 2000 Location: Massachusetts Age: 34 Posts: 11	All, I wrote to Herpa, and tried to get foam inserts.. here is their answer which blames the yellowing on "aging plastic" rather than the foam: "...and as far as I'm told, it's not the foam that causes discoloration. There was a letter to the editor in one of the last issues of WingsWorld, and we answered the question with great care. To put it in a nutshell: discoloration of plastic is sometimes an effect that can be compared to rusting metal, and that's why telephones and computers are always beige or gray." Granted I agree that plastic can and does change color.. I have a Wooster 1:250 LH 747 that sat out on my desk at work for about 1.5 years.. Where it was exposed to the flourescent lights it has turned yellow, on the belly, it is white.. Anyone think that ultra-violet could dish out this type of discoloration as well? -t

10-27-2000, 08:30 AM	#6
Joe Wright Junior Collector Join Date: Jul 1999 Location: Shrewsbury, MA, USA Posts: 21	You asked whether UV light can cause yellowing. UV will result in all types of color changes which is why car manufacturers now clear coat auto paint jobs. I have several Matchbox models which are one shade of pink on one side and dark red on the other due to sunlight (eg UV) exposure. Just to confuse the issue, I've seen several posts regarding "sun bleaching" of Herpa premiums that were stored in the foam and had yellowed. Bottom line is that PERHAPS the yellowing is due either to the foam which will emit VOC's or due to UV. Suggest storing these out of the foam and away from direct sunlight or fluorescent lights. Best - Joe

10-27-2000, 09:43 AM	#7
egonzinc Insane Collector Join Date: Nov 1999 Location: Guaynabo,Puerto Rico, USA Age: 52 Posts: 1,732	I imagine this is not a perfect science but I was wondering: Are the new Premium models at risk if lft in their foam packaging? Are old models that HAVE NOT YELLOWED, at risk if left in their packaging? I thought if it was an old LH premium model that was ok they would be ok in mthe future....is this the case? If I wrap the model in tisue and then place in the foam, might this be ok? I would like to hear your comments. Would hate to see them yellow, but also I want ot store them safely! Thx in advance, Eduardo

10-27-2000, 11:40 AM	#8
todd Junior Collector Join Date: Aug 2000 Location: Massachusetts Age: 34 Posts: 11	Eduardo, I'd say that if it is the foam packing than tissue paper isn't going to do a thing. The fumes will go right through the paper and attack the plastic. I read once that if you models hadn't yellowed by now and they were stored in their original foam, they would never yellow from the foam. And I also had read that herpa changed the foam later in the LH Modell Edition and uses different foam for the premium models now. All, Correct me if i'm wrong but there are two ways of packaging the premium models. The boxes w/attached lids and grey foam liners. And the hangers with the white grey foam holders. Pardon all my questions, but I am putting together a Herpa 1:200 Premium website, so i'm gathering all info I can get.. Hope to have it online in 1-2 weeks. Todd

10-28-2000, 01:09 AM	#9
Dieter Mosler Junior Collector Join Date: Sep 1999 Location: Bad Homburg, Germany, close to FRA Airport Posts: 3	Eduardo, in the course of the years a lot of these models went through my hands. I have got models which had been stored for many years in the foam inside the box. There was no yellowing at all. And I am sure that these models will not yellow in the farest future. Other models, also still originally packed and for sure never displayed, were yellowed. I myself am convinced, that Herpa had either several suppliers for this packing foam or the one supplier whom they used changed the components of the foam, and only this foam of a certain production caused the problem. But luckily only a little percentage of the B747-400 LUFTHANSA models were hit by this problem and only a very little percentage of the B727-200 LUFTHANSA models were hit. Also a few B737-300 of the very rare LUFTHANSA EXPRESS "Reutlingen" models (which were delivered without the plastic hangars) yellowed inside their packing boxes. There is no chance to reverse that yellowing process. The models of the A300-600 and of the B737-300 series were not hit by this foam problem as they were packed inside their hangars in a styropor device which did not cause any problems. These models can only yellow when exposed to either artificial UV light or bright sun-light. I myself am convinced that Herpa, although they would not admit that the foam caused the problem, did care that the packing foam of the new Premium Series will not cause any yellowing in future. Dieter

07-15-2002, 06:00 AM	#11
B-huj Insane Collector Join Date: Jul 2002 Posts: 1,638	thanks for clarifiying such a problematic issue long discussed. so we have to assume that all models that have not yet discouloured in their original packages, will not "turn yellow" if kept in the package...but when u say that UV rays may damage the colour...how do i know which kinds of light (apart from natural sunlight) emit UV rays?

07-23-2002, 11:26 PM	#15
Gunship01 Lufthansa Skyshark Join Date: May 2000 Location: San Diego Age: 45 Posts: 1,401	Great thread as I am new to the 1:200 world and have a good liking for Lufthansa. Thanks for the info guys. __________________ Now where's that 747-400 club? More Lufthansa and Virgin Atlantic 744s!! By all that is holy.... MORE JET BLUE AND US AIRWAYS(NC)!!

Thread Tools
Show Printable Version Email this Page
Rate This Thread
Rate This Thread:

09-01-2007, 10:52 AM	#16
upholsterygal Junior Collector Join Date: Sep 2007 Posts: 1	Re: lufthansa 747 Yellowing Cure?? In doing furniture upholstery, I have found that all colors of foam will yellow. White foam only takes a matter of hours in florescent lighting.

09-01-2007, 01:55 PM	#17
Dr. Edmund H. Carus Master Collector Join Date: Jul 2002 Location: UK/Germany Posts: 801	Re: lufthansa 747 Yellowing Cure?? True. Most polyurethane foams yellow due to the oxidation of toluene diisocyanate - the true chemical name for PU foam. UV speeds up the process as does heat. This should not affect models if the foam is fully cross-linked! I suspect that the Herpa Modell Edition problem was made worse by a batch of partially cross-linked foam! Cheers! __________________ Edmund (now UK/IOM residency)