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Subject: 
Re: Which glue?
Newsgroups: 
lugnet.parts.mod
Date: 
Sat, 23 Feb 2008 13:36:19 GMT
Viewed: 
12461 times
  
In lugnet.parts.mod, William Webb wrote:
   In lugnet.parts.mod, Aaron M. Sneary wrote:
   In lugnet.parts.mod, John Neal wrote:
   In lugnet.parts.mod, Rob Hendrix wrote:

   Has Super Glue been used very successfully keeping ABS parts bonded over time?

AFAIK. Have you heard otherwise? I thought Super Glue was in the same type glue family as MEK.

JOHN

No they are quite different.
MEK is not even a glue or epoxy at all. It is rather a solvent that literally loosens the plastic molecules of the ABS, and allows them to intertwine between bricks. Once it evaporates, the ABS returns to a state almost the same as it’s original. MEK’d ABS is slightly more brittle than the original casting.

I strongly recommend only professionals with adequate ventilation and handling equipment use MEK with any regularity. It has some significant health concerns, and is being phased out of use by the LEGO company. It has been restricted from use in the European model shops for at least the past 5 years.

Most superglues I have used are CA or Cyanoacrylate based.
   Per Wikipedia:
Generally, cyanoacrylate is an acrylic resin which rapidly polymerises in
   the presence of water (specifically hydroxide ions), forming long, strong chains, joining the bonded surfaces together. Because the presence of >
moisture causes the glue to set, exposure to moisture in the air can cause a
   tube or bottle of glue to become unusable over time. To prevent an opened container of glue from setting before use, it must be stored in an
airtight > jar or bottle with a package of silica gel.

Except for very large, weight-bearing models, I would recommend people use SuperGlue over MEK. No need to expose yourself to the stuff unless it’s really necessary for it to be VERY durable.

Aaron Sneary Former Master Model Builder

As Aaron States, the use of MEK was BANNED from the Lego modelshops back in 1998, and GBL was introduced. Many health issues were being presented and an article written in the LEGO REVIEW magazine, a corporate magazine spoke about the transition, which was needed due to the concerns in negative health effects on employees using MEK. (Which I have a copy of)

Unfortunately or just plain negligence, some shops continued the use of MEK even as late as 2005, when I left the modelshop. I had already started to feel the negative effects as stated on the MSDS, and was growing intolerant of the chemical. I STRONGLY advise NOT to use this even with ‘proper ventilation’ the chemical evaporates very fast and is heavier than air, so it tends to settle down in the room. That is why an extractor is also placed on the surface of the special work tables at the modelshops.

At the modelshop in Mexico, we only had a proper shop for 2 years (under american management), then when moving to a new office, the system was reinstalled, but after a third move, the extraction system was never reinstalled, and the new people that were glueing models indoors with MEK and without ventilation were never informed of the irreversible health damage, which was many times discussed by the people making the decisions. It was usually said ” This is not stuff you want your kids to be around” as a selling line to get funding for the expensive extraction system set up in 1998 Unfortunately when trying to help this individuals, I was immediately sentenced to “shut the hell up, and feel the consequences” and mind my own business. I guess that if the big wheels had their kids doing the glueing, they would take the proper precautions to ensure health and safety, but cheap labor is always easily replaced.

In talks to more than a handful of danish builders, MEK did severe damage to the health of the first generations of model builders. But that is a very well kept secret story.

DON’T USE MEK if you love yourself and life.

There is of course an alternative, if you want to put up with the hassle. Buy a good respirator with a cartridges designed to filter out the MEK. But you need to be careful. You need to make sure that the cartridges are fresh as once in use for a certain amount of time, they of course lose their adsorbtion/absorbtion capabilility. Probably the best way to do it would be to set up a lot of glueing to be done, buy a new cartridge, and then at the end of the session throw away and begin the next session with a new one. Some of the more expensive ones are reasonably comfortable. They WILL protect you as long as you use in prescribed manner. There are many cartridges out there--each with specific properties for specific chemicals. Make sure the ones you buy are specifically state protectiong for MEK. Usually an organic vapor cartridge. Make sure OSHA approved. 3M makes a good one as do a few other companies.

The instant you begin to smell the MEK--and just a small concentration can be perceived--change cartridges. If you want to use in multiple sessions and are confident the cartridge is not used up,unscrew the cartridge and store in a zip lock bag. If one reads the extensive instructions and actually follows them, on will be adequately protected. One should also of course provide good ventilation to expel the fumes from the work area.

Do not skimp and buy a good one. With the new silicone rubbers that have been developed, there are some that are reasonably comfortable. Comfort is number one concern (after adequate protection) so one does not get fed up and say to heck with it.

Most cartridges will tell you the number of hours that they will last (based on the concentration of the contaminant>

Tommy ARmstrong The BrickEngraver www.brickegraver.com



Message is in Reply To:
  Re: Which glue?
 
(...) As Aaron States, the use of MEK was BANNED from the Lego modelshops back in 1998, and GBL was introduced. Many health issues were being presented and an article written in the LEGO REVIEW magazine, a corporate magazine spoke about the (...) (17 years ago, 4-Apr-07, to lugnet.parts.mod, FTX)  

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