Does Lego get less tight over time?

[Richard Dower]

I have recently bought the 7160 drop ship and Technic 8048 for spare parts, the sets themselves were in excellent condition....but i have noticed with these two and other second hand sets that the pins and axels or beams with crossholes are always lose, they are not as tight as you would see with a new set.

When you buy a new set and push a 3L axel in to a crosshole it usually takes a bit of effort, but prebuilt/old sets they just slide out......?

[Zerobricks]

When bricks are new all the fits are very tight. Over time if the bricks are built the plastic slowlsy warps and they loose grip. Some bricks even crack! (cheese slopes). Also high temperature softeness the plastic so NEVER leave bricks on a car dash or such.

[CptPJs]

I was rebuilding a (okay it was wasn't Technic it was Belville) set from 1994 just yesterday with all the original pieces, and I was surprised that the grip actually if anything was stronger than what brand new stuff has. But it might vary by colour, year, the way the bricks have been treated, all kinds of things.

[Zerobricks]

Bricks do get stiffer and less flexible over time. Thats why old ones are so grippy yet more brittle.

[nicjasno]

That's normal. The plastic has "softener" in it, which evaporates over time.

[Cumulonimbus]

Plastics (or thermoplastic polymers) are subject to a phenomenon called "creep". When a force is applied on a plastic for a long time, it will tend to deform under that load. Old pneumatic hoses for example, are still expanded at the ends after being disassembled.

The amount of creep depends on the stress (the amount of force), the temperature and the type of plastic.

Edited September 4, 2014 by Cumulonimbus

[talos]

Wear and tear has its effects too. I had some bricks when I was a kid that got so worn that they would fall apart if held upside down. Lots of wear in a short amount of time...

[VintageLegoEra]

No..they dont get less tight over time if they are not disassembled too much

[EvilBlackSheep]

I've recently started cleaning my stock of Lego from my childhood and I faced the other problem regarding a particular piece, that little black technic pin thingy that goes in the bricks that have holes. Some of them, who stayed assembled and untouched for maybe the last 20 years, gave me a hard time to separate. Actually some even let a black mark inside the yellow technic brick they were inserted in.

[TWO2SEVEN]

I have noticed that some of my sets from the late 80s/early 90s are a little more loose than my new sets.

[Zerobricks]

  On 9/4/2014 at 9:31 PM, EvilBlackSheep said:

I've recently started cleaning my stock of Lego from my childhood and I faced the other problem regarding a particular piece, that little black technic pin thingy that goes in the bricks that have holes. Some of them, who stayed assembled and untouched for maybe the last 20 years, gave me a hard time to separate. Actually some even let a black mark inside the yellow technic brick they were inserted in.

Must be the old pin type that has those fat friction ridges along the entire length,

[Paul B Technic]

Yes this does happen :(

[EvilBlackSheep]

Also, I'm not sure I'm in the right place to ask that but was not sure i should make a new thread just for that... Does it happen that some tires get kinda 'sticky' over time (there again 20 years in a box) and is there any way to fix this ?

[alois]

I encountered this too. Some 30 year old large technic tires (the oldest, soft type) I own are like glued onto the rim.

[EvilBlackSheep]

Oh this is it then, because it's the same tires I'm talking about. It stuck to some pieces and made some weird things. It removed the color on a red and yellow door (now the red ahas a missing pattern of the side of the said tire) and it stuck to 2 yellow regular 1x6 on the side, making a weird reaction like 'melting' the plastic. After cleaning, those 2 bricks have now some missing matter where the tire stuck.

I was surprised because those tires were the only pieces that seemed to have a weird reaction over time and i was sure no glue was involved in my legos. I'm glad to see it didn't happen just to me.