Escaping MEK-PAK : Is this a thing?

[Dunsignalling]

12 minutes ago, Not Jeremy said:

Apologies if I missed it in the maelstrom of chemistry and chest beating that followed this intriguing post, but what caused the problem and how can one avoid same if one is in possession of one of those big tins of Mek Pak?

 

Please, no theories or lectures, just a credible explanation.

 

If you don't know then there is no need to tell us, really, please.....

 

Simon

The reason is inevtably related to a chemical reaction. Post from Saturday at 22.34 contains the why and the wherefore.

 

Prevention/retrieval of situation is to transfer the contents to as many glass bottles as necessary. I fortunately had something suitable to hand when I noticed the pong coming from the cupboard under the stairs.

 

John

Edited November 14, 2022 by Dunsignalling

[JimC]

To put a little more meat on the above, this only applies to MEK Pak with the "contains halogenated aliphatic... " text on the safety label. 
It will eventually corrode tin containers from the inside out, but it take years. One precaution would be to sit the tin in a suitable ceramic or glass vessel so if it does escape its contained. Moving it to glass vessels will also be effective, but they do need to have lids without plastic that is susceptible to the vapour. 

[Dave John]

On a practical note is it one of the self assembly type bookcases? 

 

If so would it be possible to disassemble it and turn the shelf round or upside down so the damage can't be seen? 

 

Just a thought. 

[JimC]

20 minutes ago, Dave John said:

On a practical note is it one of the self assembly type bookcases? 

Sadly its part of the carcase rather than a loose shelf. 

[Not Jeremy]

1 hour ago, JimC said:

To put a little more meat on the above, this only applies to MEK Pak with the "contains halogenated aliphatic... " text on the safety label. 
It will eventually corrode tin containers from the inside out, but it take years. One precaution would be to sit the tin in a suitable ceramic or glass vessel so if it does escape its contained. Moving it to glass vessels will also be effective, but they do need to have lids without plastic that is susceptible to the vapour. 

Well that will be the current product then, having just looked at a tin I bought a couple of months ago from Eileen’s. 
 

so I’m none the wiser really, no change there then….

[JimC]

Checking my back email I ordered that can in Apr 2017. So date it, and if gets to more than say 3 years old consider decanting it.

 

 

[BWsTrains]

On 13/11/2022 at 08:11, Dunsignalling said:

I had exactly the same thing happen with a can of Mek-Pak a few years back. Once emptied, I left it outside to vent for a week. Back then, there was only the dustbin to put it in. Nowadays, I'd only put it in the recycling if no smell remained.

 

Consequently, I  switched back to using real MEK (aka Butanone) which Mek-Pak hasn't been for decades, as my default solvent. No problem with half-litre cans bought from plumbing merchants*, but my most recent supply came via a Web source and arrived in a polypropylene* bottle.

 

* MEK has been widely used for cleaning polypropylene pipes etc., prior to bonding but doesn't attack the material itself. 

 

John

 

John,

 

these days, polypropylene and other types of plastic can be treated to resist attack or permeation by various solvents. That probably explains how MEK can be supplied that way.

 

PS. Slaters may have inadvertently contributed to the confusion identified here by selling a product called MEK-PAK in the distant past which had nothing to do with MEK the chemical then later switching to a composition based on MEK and retaining the original product name. Today they can trade on the benefits of the established brand name.  

 

Edited November 14, 2022 by BWsTrains

[Michael Hodgson]

7 hours ago, Dunsignalling said:

The reason is inevtably related to a chemical reaction. Post from Saturday at 22.34 contains the why and the wherefore.

 

Prevention/retrieval of situation is to transfer the contents to as many glass bottles as necessary. I fortunately had something suitable to hand when I noticed the pong coming from the cupboard under the stairs.

 

John

I can't help noticing the pong coming from the cupboard under the stairs, but I've been blaming it on the cat litter tray.

Not for nothing is that cat called Pooh! 

[JimC]

Hmm, if your cat's litter tray smells like MEK your cat has a serious metabolic problem. If it smells like the chlorinated aliphatic hydrocarbon version of MEK-PAK  then something very unusual is happening. 

[Thorness]

On 14/11/2022 at 20:44, BWsTrains said:

 

John,

 

these days, polypropylene and other types of plastic can be treated to resist attack or permeation by various solvents. That probably explains how MEK can be supplied that way.

 

PS. Slaters may have inadvertently contributed to the confusion identified here by selling a product called MEK-PAK in the distant past which had nothing to do with MEK the chemical then later switching to a composition based on MEK and retaining the original product name. Today they can trade on the benefits of the established brand name.  

 

 I'm sure that Slaters MEK PAK was benzene in the mid 60s when I first inhaled it!

[BWsTrains]

6 hours ago, Thorness said:

 I'm sure that Slaters MEK PAK was benzene in the mid 60s when I first inhaled it!

 

Just about any organic solvent less polar (polar = water loving) than ethanol will dissolve polystyrene. No doubt many have been used at some point or other.

In the old days it was about cost / availability, these days HSE and its equivalents rule all. 

 

 

 

[polybear]

ISTR reading a story about George(?) Slater being found flaked out unconscious in the earlier days of Slater's MEK PAK after a leakage and at some point afterwards the magic mix was changed.  I could be wrong, of course (it has been known....).

[Dave Hunt]

13 hours ago, polybear said:

ISTR reading a story about George(?) Slater being found flaked out unconscious in the earlier days of Slater's MEK PAK after a leakage and at some point afterwards the magic mix was changed.  I could be wrong, of course (it has been known....).

 

Quite right Bear. It was shortly afterwards that Slaters changed hands and the recipe for Mekpak was changed away from MEK. It was never benzene.

 

Dave 

[BlackRat]

I buy the generic stuff from EBay…..in litre Polyethylene (?) bottles…..never had one leak yet.

[bradfordbuffer]

On 12/11/2022 at 11:19, JimC said:

Walked into the room I keep modelling stuff this morning to be greeted with a strong smell of solvent. Seems my tin of MEK has rusted out and sprung a leak. B******d up the bookshelf too. Is this a thing I should have been aware of. Going to get grief from SWMBO if the solvent smell doesn't clear too. 

That's nothing dropped.....9lts of dirty resin ipa from my wash and cure station whilst resin printing....lucky for me it was on to garage floor brought floor up lovely and clean....stank for weeks

[Barclay]

On 17/11/2022 at 23:20, BlackRat said:

I buy the generic stuff from EBay…..in litre Polyethylene (?) bottles…..never had one leak yet.

Me too but I did catch a whiff of it in the garage the other week and found the lid had split, so worth checking regularly!

[JimC]

Slaters have confirmed that this is a possibility, due to acid formed from reaction with atmospheric water.