Bobalu
Member
What is the correct way to dispose of old MEKP? Each gallon of Silmar 41 comes with a fresh bottle, but I'm only using about 1/4 of the bottle casting pen blanks. What to do with the leftover? 
Disposing of MEKP ???
- Thread starter Bobalu
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Justturnin
Member
You can offer it up here for the cost of shipping. Some folks that get there from local places have to buy it seperately. May have to be Ground Shipping or something.
juteck
Member
Most communities have a dedicated waste disposal day for things like this - contact your local public utilities waste management department. Otherwise, check if there are any fiberglass or boat or body shops around that might add it to their waste inventory for disposal. Maybe in exchange for a pen. Do not pour it down a drain or gutter where it can get into storm water.
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Holz Mechaniker
Member
make it inert by pouring it into cat litter. well that is what I do with certain paints. I would have to assume that it should work for this.
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Bree
Member
MEKP :
Disposal of Methyl Ethyl Ketone Peroxide (MEKP) :
1.Harden with polyester resin, and dispose in landfill.
2.Hydrolysis :
Incremental addition of MEKP to a rapidly stirred, cold 5 - 10 % sodium hydroxide solution. Reaction requires adequate agitation and temperature control between 30 to 40 °C. Note : NEVER add the caustic to the MEKP.
This procedure converts the MEKP to water soluble salts which can be disposed of as non hazardous waste.
Disposal of Methyl Ethyl Ketone Peroxide (MEKP) :
1.Harden with polyester resin, and dispose in landfill.
2.Hydrolysis :
Incremental addition of MEKP to a rapidly stirred, cold 5 - 10 % sodium hydroxide solution. Reaction requires adequate agitation and temperature control between 30 to 40 °C. Note : NEVER add the caustic to the MEKP.
This procedure converts the MEKP to water soluble salts which can be disposed of as non hazardous waste.
Bobalu
Member
Sounds like too much work for me. Besides, I flunked Chemistry. I'll just dump it in the trash. :biggrin::biggrin:
The idea of passing it along to someone that can use it sounds best to me. I'll take it to the December IAP meeting and see if anyone wants it. If not, I'll offer it to anyone in the group that needs it. A couple have already PM'd me about it. I will keep their PM's on file and get back to them if no one at the chapter meeting wants it. Thanks everyone.
studioso
Member
Sodium hydroxide is lye, which is what drano is made of.
Like we said all along, pour it down the drano.
Like we said all along, pour it down the drano.
its_virgil
Member
If it comes in contact with certain items(other chemicals or compounds...some wuite common) it can decompose and spontaniously combust. Do some searching for MEKP dangers and you may change you mind about the trash ... if you are serious. Not sure what the smiley faces mean. MEKP can be quite nasty. Mixed with sawdust and add a fuse and bombs away. For me it is safer in its container stored properly. Be careful and informed.
Do a good turn daily!
Don
Do a good turn daily!
Don
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dankc908
Member
Box it up. Wrap it in fancy gift wrap. Leave it in your unlocked car at the mall in plain view. Voila! It is now someone else's problem and not yours.
JUST KIDDING!
I did read about doing this several years ago when the NYC garbage collectors were on strike during the pre-Christmas season. One family got rid of all of their 'backed-up' garbage this way.
Dan
JUST KIDDING!
I did read about doing this several years ago when the NYC garbage collectors were on strike during the pre-Christmas season. One family got rid of all of their 'backed-up' garbage this way.
Dan
Bobalu
Member
No, Don, I wasn't serious about trashing the stuff. I'm old enough to remember Love Canal, and although I wouldn't consider myself an environmentalist, I try to do the right thing when it comes to chemical disposal. That was the reason I asked the question in the first place.
Not sure, but I think the "Grin" face is about as close as we have to show that we're just joking about what we type.
I'm sure there will be a couple of people at the next GA Chapter meeting that will take it off my hands and use it for casting.
I hope everyone is having a great Thanksgiving today.
Bree
Member
I used to be the Curator for the Chemistry Dept of a University in Chicago. A good rule of thumb is that if the name contains the word PEROXIDE... treat it with tender loving care or bad things can happen very fast. This is one of those "peroxide" chemicals... they are oxidizers.
While it is not a hugely nasty one, given the right amount of neglectful treatment you can blow something up or light the place up. So invest some resin and let it combine with the resin and it is pretty much harmless.
While it is not a hugely nasty one, given the right amount of neglectful treatment you can blow something up or light the place up. So invest some resin and let it combine with the resin and it is pretty much harmless.
jason_r
Member
So invest some resin and let it combine with the resin and it is pretty much harmless.
This is one thing that has always puzzled me. Since MEKP is a *catalyst* in the reaction, it shouldn't be combining with the resin. Which in turn leads to the question of "So where does it go?".
I'd always figured it was captured in the resulting solid somewhere, or that it evaporated. And wondered if this wasn't the root cause of the oft-cited connection between too much catalyst and overly-brittle blanks.
Bree
Member
So invest some resin and let it combine with the resin and it is pretty much harmless.
This is one thing that has always puzzled me. Since MEKP is a *catalyst* in the reaction, it shouldn't be combining with the resin. Which in turn leads to the question of "So where does it go?".
I'd always figured it was captured in the resulting solid somewhere, or that it evaporated. And wondered if this wasn't the root cause of the oft-cited connection between too much catalyst and overly-brittle blanks.
Not sure. I think the reaction decomposes it. You would have to ask one of the organic chemists in the forum. This might help give a little insight:
http://www.dsm.com/nl_NL/html/drs/grp_sub4.htm
:wink::wink::wink:
Sylvanite
Member
Technically, MEKP (methyl ethyl ketone peroxide) is a "hardener", not a "catalyst". MEKP is consumed by the chemical reaction. It breaks down into radicals that initiate a chain reaction causing the cure. The oxygen (from the peroxide) forms cross-links between the polyester polymers making a stronger crystal. Too much peroxide, however, can lead to offgassing - causing the resin to foam before setting.
For the purists, MEKP isn't a "promoter" either. Polyester resins, such as Silmar 41 are typically sold "pre-promoted" with either cobalt napthenate or dimethylaniline, which gives them a faster cure time and a shorter shelf life.
Note that the reaction is exothermic and temperature sensitive, so proper combination of promoter, hardener, ambient temperature, and pour thickness are necessary for a good result. Addition of other chemicals (such as dyes) can enhance or inhibit the reaction, necessitating a change to the mix.
I hope that helps,
Eric
jason_r
Member
So this is another case of the marketers using a term incorrectly.
They're as bad as lawyers.