BrickLink Discussion Forum

In Help, randyf writes:

In Help, Adjour writes:

Anyone know why this happens? I notice the also melt the bricks they are sitting
against, so I'm presuming some sort of chemical reaction.

The LEGO wheels are most likely made from styrene-butadiene rubber (SBR). To
process SBR, plasticizers are usually added to it to help with the flow of the
material into the molds (they literally make the SBR more plastic). These plasticizers
usually include some type of mineral oil derived from petroleum and some type
of ester (a type of chemical compound). Over time, these plasticizers can leach
out of the SBR under certain storage conditions. You are most likely seeing and
feeling mostly the mineral oil, but I would absolutely think that the ester is
also leaching out with the mineral oil. Why? Because esters can dissolve ABS.

Cheers,
Randy

Great to know, thank you Randy

Visually, they absolutely look like they are covered in mineral oil. These were
not commingled (they were in a set box/clean) so they are not covered in dirt,
the others I encounter were covered in *stuff*

I've run into various amounts of the tacky feel, so I would imagine that
is the second compound coming out in various amounts.

Author:

randyf

Posted:

Nov 5, 2019 19:24

Subject:

Re: Sticky/ oily vintage wheels...trash?

Viewed:

41 times

Topic:

In Help, Adjour writes:

Anyone know why this happens? I notice the also melt the bricks they are sitting
against, so I'm presuming some sort of chemical reaction.

Author:

axaday

Posted:

Nov 5, 2019 14:02

Subject:

Re: Sticky/ oily vintage wheels...trash?

Viewed:

40 times

Topic:

In Help, Adjour writes:

Anyone know why this happens? I notice the also melt the bricks they are sitting
against, so I'm presuming some sort of chemical reaction.

I'm guessing heat? I've run into this 3 times now one the lots also had
heat warped baseplates. I've never seen it on my own/original lego which
has never experienced a hot garage.

Are they trash? Can I clean them?

I just got some

2346 Tire 30 x 10.5 Offset Tread
Parts: Wheel, Tire & Tread

in light grey and was pretty stoked (only came in 3
sets) and they are awful gooey messes, I have more on the way and I don't
want it to be a total loss. The weird color on a common part is so neat in person.

Thanks everyone

Crystal

I often find it in old, old sealed sets. Sometimes the tire is ruined and sometimes
I don't think so. I think it can be fixed with armor-all, but I just sell
them as-is with a comment.

Author:

Adjour

Posted:

Nov 5, 2019 12:45

Subject:

Re: Sticky/ oily vintage wheels...trash?

Viewed:

33 times

Topic:

In Help, runner.caller writes:

In Help, Adjour writes:

2346 Tire 30 x 10.5 Offset Tread
Parts: Wheel, Tire & Tread

Weird! I've encountered oily tires before, but just assumed it was a coating
to help them pop out of the mold at the factory or a light coating to help guard
against dry rot.

I've seen the leaching before in my fishing tackle box when old plastic "twister
tails" would start to leach through the plastic baggies and even start to melt
the plastic in the utility box they were inside.

I didn't know this could happen to lego tires too!? Makes me nervous about
my stored childhood sets.

So too much air, and they dry out and get dry-rot, not enough, and they melt.

Nice....

I'll note that the tackle box spent many a thermal cycle in a garage, whereas
the lego temps have always been more stable.

Don't stress too much, I have TONS of old tires and I've only found this
buying lego from people who were obviously not collectors. I strongly suspect
some sort of really bad storage (decades in a hot cold hot cold garage or storage
unit (which are live ovens)

I think I'm going to toss these.

Author:

Adjour

Posted:

Nov 5, 2019 12:42

Subject:

Re: Sticky/ oily vintage wheels...trash?

Viewed:

34 times

Topic: