MEKP

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Neeves

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For those that read the original recommendation on YBW, without any warnings, that MEKP, makes a good solvent, has some in a bottle or who thinks it all a bit of a joke.

https://nj.gov/health/eoh/rtkweb/documents/fs/1259.pdf

Some stockists are sufficiently wary of the liquid they store it in the fridge.

Most people would not even think of using it in a 'leisure' application, there are cheaper ways of being a menace.

With thanks to Coopec, again.

Jonathan
 
For those who may not be aware MEKP is the hardener used for polyester resin. Like 2 % by volume. The P means peroxide which makes it all happen producing heat. I hope no one would think of using it as a solvent just because you get such a small bottle. Dangerous especially to eyes. Now long ago I came across MEK (no P) which was used as a solvent. Apparently not especially harmful. A long time ago. I suspect Coopec got his letters out of order in his attempts to warn us all. Or is it something else he was trying to warn us about. ol'will
 
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Neeves said:
For those that read the original recommendation on YBW, without any warnings, that MEKP, makes a good solvent, has some in a bottle or who thinks it all a bit of a joke.

https://nj.gov/health/eoh/rtkweb/documents/fs/1259.pdf

Some stockists are sufficiently wary of the liquid they store it in the fridge.

Most people would not even think of using it in a 'leisure' application, there are cheaper ways of being a menace.

With thanks to Coopec, again.

Jonathan
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As William points out I think there is confusion between MEKP (methyl ethyl ketone peroxide) and MEK (methyl ethyl ketone, aka butanone)

MEK is a common and useful solvent similar in many of its properties to acetone (aka propanone)
 
MEKP is nasty stuff. One of the problems is that resin suppliers normally send out free catalyst with polyester resins. You never use anywhere near the amount you are supplied with so have the stuff kicking about for years.
It is a powerful oxidising agent & rags or cardboard soaked in it can & do catch on fire spontaneously.
I saw this first hand when working at Thames Marine in 1979, I was doing some laminating in a cockpit locker on a Mirage 28, Boat was near the roller shutter door which was open. Hooter went for lunch, I finished up & looked out into the yard, lovely sunny day just a heap of rubbish up against the factory wall.
Turned round & washed my brush & roller in the bucket of acetone. Looked up There was a 30 foot high inferno of flames. All in about 4 seconds.
I shouted Fire & shot down the ladder, a bunch of lads came out of the bogs & 5 of us grabbed extinguishers & went at it. Fortunately we got it out.
MEKP does not like any acidic chemicals & will react violently with epoxy hardeners & Worst of all with Cobalt accelerator when the reaction can be explosive.
 
GHA said:
Features large in "This Old Boat" but I`ve never seen any in Europe, under that name anyway - is it something you can get down the local B&Q type place?
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No I don't think you will find MEK,, or acetone for that matter, in the DIY sheds.
 
Acetone is also available in 5 litre containers in our local builders merchants - sold as a cleaning agent for tooling in association with polyester resin based roofing products
 
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I bought MEK from Inflatable Boat Supplies, it's used to clean PVC before gluing.
Also to thin the glue.
I believe it softens the surface of PVC.
I think it's quite commonly used as a cleaner in automotive paint shops, but may be blended with other stuff.

MEKP is polyester resin catalyst.
 
Donkeys years ago but i was a plastic fabricator/tinbasher, we used lots of MEK, we used it to clean off pvc, polyethene and nylon before welding, it came in Grey square cans about half a litre, we were not allowed to store more than 4 cans for insurance purposes, but of course carried plenty! it was highly inflammable, no one at the time considered health and safety issues, but the stuff buggers your hands up and can cause dermatitis related issues, it was certainly good at cleaning plastic before welding or solvent joints.
 
VicS said:
No I don't think you will find MEK,, or acetone for that matter, in the DIY sheds.
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Bought my Acetone from the rib store. Arrived in the post after a couple of days.

Inflatable Boat Repair & Cleaning, Parts & Supplies

Samantha the boss has been around ribs for a life time. Her dad was the late Paul Tilley or owned Tilley Ribs specialising in new and replacing rib tubes. Good stuff for cleaning the tubes before glueing.
 
Is MEK used as an electrical cleaner? I am not at home but I have an old, white tin, red letters, which contained a fluid that was used for cleaning electrical contacts. The MEK designation and slow evaporation appear to be familiar?
 
RunAgroundHard said:
Is MEK used as an electrical cleaner? I am not at home but I have an old, white tin, red letters, which contained a fluid that was used for cleaning electrical contacts. The MEK designation and slow evaporation appear to be familiar?
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Possibly more likely to be Carbon Tetrachloride (Carbon tet) also was used in fire extinguishers. Used by the gallon on electrical equipment in the 50's early 60's. Don't know how my lungs survived!o_O
 
Alex_Blackwood said:
Possibly more likely to be Carbon Tetrachloride (Carbon tet) also was used in fire extinguishers. Used by the gallon on electrical equipment in the 50's early 60's. Don't know how my lungs survived!o_O
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Heating Carbon Tet creates mustard gas the was used in WW1.

If you smoked while using Carbon tet the fag would heat the fumes and you would breath in Mustard Gas.

Very nasty stuff
 
rogerthebodger said:
Heating Carbon Tet creates mustard gas the was used in WW1.

If you smoked while using Carbon tet the fag would heat the fumes and you would breath in Mustard Gas.

Very nasty stuff
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The same applies other halocarbons which have been used as degreasing solvents. eg 1:1:1 trichloroethane and trichloroethylene. Also to dichloromethane ( aka methylene chloride ) used as a paint stripper.

However it is carbonyl chloride (aka phosgene ) that is formed . Mustard gas is something different. Mustard gas - Wikipedia
 
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