What Causes Lego Bricks to Deteriorate?

[Bricked1980]

Over the past couple of years I have been going through the process of cleaning up and restoring my large collection of vintage Lego sets from my childhood. Most of these had been stored in my parents attic for 20 years or more in their original boxes. Apart from being dusty and grimey they are all in tip top condition and I've been able to clean them up to a very good standard.

Recently though my in laws were had been clearing out their house and gave me a copy of Black Seas Barracuda which used to belong to my wife when she was a child. This had been stored in it's original box with all the parts sorted in to plastic bags, the kind of bags you'd use to store food in the refrigerator. It had been left on top of a wardrobe in their spare bedroom for many years without being moved. The temperature would be pretty constant in this room without any excessive humidity.

The set looked in great condition. The sails were all perfect and hardly any dirt on any of the bricks. When I began to build the set recently though a problem became immediately apparent. Almost all of the flag pieces had gone brittle and the clips snapped off as soon as tried to put them together.

Has anyone else ever experienced this or got any ideas why it would have happened? I've never seen it with my old sets which had been stored in a cold dusty loft for 20 plus years, but my wife's set which had apparently been kept in a much better condition was the only one which has deteriorated.  

I've since replaced all the broken parts but I just wondered if anyone can offer any tips or advice to prevent the pieces from going like this again.

[NathanR]

Storing Lego has been a great worry to me lately.  You said your bricks weren't dusty and grimy, so I guess that means they were just loose in a box? I guess that's what has saved them.

Your wife's set had been stored in "the kind of bags you'd use to store food in the refrigerator", do you know what kind of plastic the bags were made of? Have the plastic bags gone yellow with age at all?  Many food-freezer bags are made from an acidic plastic, which won't affect food being stored for a few weeks but can be dangerous longer-term.  For example, PVC (polyvinyl-chloride) plastic bags tend to break down over time and release hydrogen chloride (better known as hydrochloric acid). If the bags are completely air-tight, there is no way for the gas to escape, so it slowly builds up and attacks whatever is being stored. I'm not sure how badly this affects Lego bricks, but I've been finding that 6 months in a freezer food bag leaves my Lego bricks feeling a little sticky.  

 

[Bricked1980]

I'm not sure what plastic the bags were made from but they were definitely the sort of things that are designed to store food. Each one was then tied up at the top using a cable tie. All of the pieces were fine apart from this one.

https://rebrickable.com/parts/2335/flag-2-x-2-square-thin-clips/

The clips on almost all of these and the printed flags had become brittle and could be snapped very easily just by squeezing them between my fingers.

I'm wondering if it could be the chemicals in the plastic bags as you suggest. I work for a printing company and I always store my Lego pieces in clear polythene bags I get from work which are designed for holding sheets of paper. I thought this would be a good option but after a few months I've noticed that if I take the bricks out they do have an almost oily or greasy feel to them, similar to how you say it makes yours feel sticky.

I might have to look in to other options for storage then. Maybe paper bags would be a safer option. My old sets had survived very well in my parents attic for over 20 years and it would seem a shame if my attempts to protect them are actually having the opposite effect. 

[AFOLguy1970]

I have a MOC which uses a lot of those white flag parts.  Over a few years of having the MOC, I have had a terrible time with this part.  Several of the flags became brittle and broke.  The MOC is kept at room temperature in a room which does not receive any direct sunlight.  In fact, most of the parts were in the MOC's interior and were not even handled.  They might have been stressed from being connected to other parts, but I thought that was what they were designed for.  

As for the plastic bags, I will have to study this more since most of my collection has to remain in storage.  There just simply is not enough room to build and display my sets.  I definitely need some type of safe long term storage.  

[Bricked1980]

That's interesting what you say @AFOLguy1970. I assume the broken parts on your MOC had been left assembled on display? When I first took ownership of my Black Seas Barracuda it had been taken apart and bagged up but some of the pieces hadn't been completely disassembled. Some of the flags were still attached to the flag poles. I guess over the years the ABS can shrink and expand due to changes in humidity and temperature. If the Lego bricks are left clipped together this can cause too much stress especially on delicate parts like the clips on the flag pieces.

Although my set was boxed up in storage, prior to this it had been left assembled for many years on a shelf at my in-laws house. Even after my wife had grown out of Lego, her parents still left it on display as it is such an attractive set.

I think leaving the sets constructed for long periods of time is probably the worst thing for Lego bricks long term. Much more damaging than any potential chemical damage from the storage bags. This causes a problem with MOC's though and large sets like Creator Modulars which are obviously designed to be left on display.

[Grrr]

Those flags are made of a different type of plastic to regular Lego; and weren't especially strong even when new. They are stressed slightly when clipped onto the flagpole or other Lego parts; so if the model has been built for years, then it's likely to break when next touched.

[LEGO Historian]

I've had old 1980s and 1990s LEGO parts assembled in MOCs for over 20 years.  When I took them apart (just bricks and windows/doors), all was fine... none broke, none were warped or cracked.

So I agree this issue is part specific.

[Bricked1980]

Yes I think it must be part specific then as all the other bricks in my set were fine. I believe that old flag piece has since been replaced with a newer version which has slightly thicker clips. So perhaps this was a common problem with that specific part back in the 80's and 90's.

The funny thing is I've got a large selection of old Pirate sets and loads of those flags pieces. The only ones that have deteriorated were the ones from Black Seas Barracuda. This was originally my wife's set though so has been stored in a different house under different conditions for all these years. So perhaps environmental factors or chemicals in the plastic do have a role to play as well.

[Carrera124]

I've learned that most of the ABS lego parts react to vegetable fats.

So, if you have residue of chocolate bars or cream on your fingers, touching lego bricks afterwards is no good idea.

[Bricked1980]

4 hours ago, Carrera124 said:

I've learned that most of the ABS lego parts react to vegetable fats.

So, if you have residue of chocolate bars or cream on your fingers, touching lego bricks afterwards is no good idea.

So Lego and food are not a good combination. So this would be a really really bad idea then. 

[Carrera124]

No, this isn't a good idea.

[NathanR]

47 minutes ago, Carrera124 said:

No, this isn't a good idea.

Looks nice though... 

[splatman]

Just make sure those pieces get a good washing after the party.

It would not hurt to wash your hands before doing the LEGO thing.

[LAKAbricks]

17 hours ago, Grrr said:

Those flags are made of a different type of plastic to regular Lego; and weren't especially strong even when new. They are stressed slightly when clipped onto the flagpole or other Lego parts; so if the model has been built for years, then it's likely to break when next touched.

 

14 hours ago, Bricked1980 said:

Yes I think it must be part specific then as all the other bricks in my set were fine. I believe that old flag piece has since been replaced with a newer version which has slightly thicker clips. So perhaps this was a common problem with that specific part back in the 80's and 90's.

 

Many of the clips on my flags from Castle and Pirates (80s/90s) broke already in my childhood. I remember attaching them with sticky tape and maybe even glue to continue using them.

From what I have been reading about storing LEGO in plastic bags, I consider stop using it. And for the plastic bins I mainly use, I thing about making some air holes for ventilation. I do not know if the problem is existing, it just to be on the safe side 

[dr_spock]

I think anything that harms ABS plastic like esters will harm LEGO bricks.

I had a couple of sets assembled since the 1980 and were in direct sunlight for years.  They seem to be ok although the white isn't as white any more.  Clutch power is mixed.  Some plates seem to have lost some grip but the bricks seem to be mostly fine.   The chemicals in the rubber tires have etched tire imprints into the base plate.  It's probably a good idea not to let your town fire trucks sit in one spot on a road base plate for decades.

 

[koalayummies]

Another issue of age-related deterioration is this tire (and a few others) Edit: dr_spock just mentioned it:

(87697)

They do not age well becoming both greasy and sticky at the same time and transferring the sticky-grease while yellowing pieces they are left in contact with. In fact even new they feel a bit slippery and leave fingers feeling unclean after mounting to wheels in my experience. I avoid that tire for MOCs now and replace all instances of it (and wheels) with its same-fender-fitting cousin:

(11209)

A little bit of a shame as I'm not a fan of the low-profile tire look but I very much dislike the grossness of the tire-shine-like-secretions. 

[AmperZand]

15 hours ago, LEGO Historian said:

I've had old 1980s and 1990s LEGO parts assembled in MOCs for over 20 years.  When I took them apart (just bricks and windows/doors), all was fine... none broke, none were warped or cracked.

So I agree this issue is part specific.

Agreed on both counts.

I've got some sets (or parts of sets) that have been assembled since the early-to-mid '90s and they're still fine. For most of their lives, they have been stored in Really Useful boxes.

ABS - the plastic from which most LEGO parts are made - is pretty resistant to acid. It's unlikely the acidity from decaying baggies would affect them even after decades. Even if it did, the acidity would affect the exposed surfaces of the LEGO first. It would make the LEGO parts rougher and/or duller before it affected the structural integrity of the ABS. So if a part feels and looks fine, it isn't suffering from acid damage.

In theory, as @dr_spock says, ABS parts might be affected by esters. They wouldn't necessarily affect the appearance of ABS, so you wouldn't be able to tell your LEGO was affected. My guess is that the first affect would be to cause the part to deform leading to a loss of clutch power. An interesting experiment would be to take a whole bunch of LEGO parts, e.g. 1 x 1 plates, and store them in various liquids (and none) for a long time, say a year, in otherwise identical conditions to see what affect the experimental conditions had. You would want to control for colour and preferably batch of the parts - though those would also be interesting variables to test.

     

[Grover]

As an organic chemist, I found this to be the most informative:

http://icl-ip.com/wp-content/uploads/2012/01/ABSGnlICLIP.pdf

There are a number of flame retardant materials that are useful for ABS, and if you read the PDF, you can speculate on what TLG used to use and what they currently use.  Looking up these chemicals by CAS number is the easiest way to find the structure.  I kind of want to stick a bunch of old and new bricks into headspace vials, heat them up, and then run GC on them now...

[Bricked1980]

Thanks to everyone who has replied to this thread and given advice and tips on how to store lego.

It might seem as if I'm obsessing too much but it does worry me to think that things like plastic bags and even sunlight could be damaging my lego collection. I have got lots of old sets where the white bricks have become brown from being kept in direct sunlight. I would be gutted if this happened to my creator modular sets and some of the more expensive sets in my collection. What's the point in buying sets like this and not keeping them on display though.

I think I will carry on storing them as I have been but will keep a close eye on them. Think I will look at getting some plastic bags that are more suitable for storing lego as well.

[LEGO Historian]

On 2/10/2018 at 7:40 AM, Bricked1980 said:

Thanks to everyone who has replied to this thread and given advice and tips on how to store lego.

It might seem as if I'm obsessing too much but it does worry me to think that things like plastic bags and even sunlight could be damaging my lego collection. I have got lots of old sets where the white bricks have become brown from being kept in direct sunlight. I would be gutted if this happened to my creator modular sets and some of the more expensive sets in my collection. What's the point in buying sets like this and not keeping them on display though.

I think I will carry on storing them as I have been but will keep a close eye on them. Think I will look at getting some plastic bags that are more suitable for storing lego as well.

Most of my LEGO has been stored in a dark basement for over 30 years, and I find that yellowing of white parts happened anyway.  For some odd reason this was especially true for old Homemaker era (1979-82) LEGO sets where I had purchased about 50 USA Homemaker sets (261, 268,269, 5233, 5235)... and the bricks from these sets had a tendency for the white parts to yellow (almost to the point of looking beige) more than other parts.

[TechnicRCRacer]

I have had a fairly recent ambulance plane (I don't know the set number, but I got it two years ago) and yesterday I found that the two clips at the back had broke! I have no idea why, it was stored on a top shelf for a bit then on a dresser at room temperature.

[Bricked1980]

10 hours ago, LEGO Historian said:

Most of my LEGO has been stored in a dark basement for over 30 years, and I find that yellowing of white parts happened anyway.  For some odd reason this was especially true for old Homemaker era (1979-82) LEGO sets where I had purchased about 50 USA Homemaker sets (261, 268,269, 5233, 5235)... and the bricks from these sets had a tendency for the white parts to yellow (almost to the point of looking beige) more than other parts.

Many of my old sets had been stored in a pitch black attic for years and after sorting through them there are lots of white bricks that have taken on a brown/beige tone. Not sure if this had happened whilst they've been in storage or whether the bricks had already gone like that before they's been put in the attic.

One interesting thing I noticed is that in some cases only half of the brick had gone brown. The most likely scenario I can think of is that it must have been sunlight damage that occurred whilst the set was fully assembled and on display in my bedroom when I was a child, and only the exposed sides of the bricks that were in direct sunlight had been affected.

[Mechbuilds]

If i might add. I suspect that internally the structure of the plastic itself if left sitting as a singular part without any stress on it. The structure of the plastic starts to harden and become more fragile because it's constantly on a relaxed state.
 
But when you have a clamp under stress when it's stored, the added stress will squeeze the structure of the plastic and thus keeping it more alive and not let it harden. 
That's why the flag piece clamps broke when you tried to assemble it and the other guy had no problems cause he had left a moc sit for years with a clamp piece attached. 

This is all theory though.. 

[Japanbuilder]

I worry about this lots as well. Living in Japan the weather changes wildly in summer and winter. Construction of homes here is strict due to earthquakes so what we would call "insulation" is rather scant and rooms can in many cases get hotter or colder than the outside temperature. Add to this the rainy season which blows humidity through the roof and things get wonky fast. 

For a bit over 2 years I have kept my growing LEGO collection in plastic drawer/shelf things for storage and my display sets on regular shelves and tables in a darkened room. So far the LEGO has held up but I worry about the hands on my minifigures getting brittle from holding accessories through all these weather changes. Already things I display that are made of PVC have partially melted and had paint run off them in the rainy season. 

I know LEGO is ABS but such temperature extremes can't be good. Maintaining the rooms at comfortable temperatures is also out of the question as that would get awfully expensive awfully fast. I only hope the quality of the ABS lasts at least a decade or more but it is a constant worry. Stuff stored in bins also worries means as they trap too much heat and humidity during summer and get just as cold as the room in the winter. 

Moulding is also a problem, stuff gets pale white with mould and other fungus just growing on nearly everything which is nasty but with so many bins and so many damp dark places it gets tough to control. Collecting things made solely of PVC or pleathered items like say Hot Toys would be an expensive gamble around here. 

The only plus side seems to be no yellowing bricks have popped up so far. I do try to shift as many of my figures as I can, specially the ones holding things in their hands but at over 400 figures that gets a bit difficult to keep up with >.< 

[LEGO Historian]

This comment is just pure speculation... but I wonder what CMFs will look like in 20 years... especially those put into shadow boxes and used as wall displays.  These are are Chinese made... and there's a lot of diffferent materials used... most manmade materials.  I wonder how well they wil hold up over time, and also with indirect lighting...  I have a few classic space minifigs from 1979-85 that I  never played with, and I find that the designs on their torso has often faded pretty badly... especially the metalic finishes.