Subject:
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Re: Which glue?
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Newsgroups:
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lugnet.parts.mod
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Date:
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Sat, 23 Feb 2008 13:36:19 GMT
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Viewed:
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12467 times
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In lugnet.parts.mod, William Webb wrote:
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In lugnet.parts.mod, Aaron M. Sneary wrote:
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In lugnet.parts.mod, John Neal wrote:
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In lugnet.parts.mod, Rob Hendrix wrote:
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Has Super Glue been used very successfully keeping ABS parts bonded over
time?
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AFAIK. Have you heard otherwise? I thought Super Glue was in the same
type glue family as MEK.
JOHN
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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.
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Per Wikipedia:
Generally, cyanoacrylate is an acrylic resin which rapidly polymerises in
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the presence of water (specifically hydroxide ions), forming long, strong
chains, joining the bonded surfaces together. Because the presence of >
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moisture causes the glue to set, exposure to moisture in the air can cause
a
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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
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airtight > jar or bottle with a package of silica gel.
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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
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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.
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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
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Message is in Reply To:
 | | Re: Which glue?
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| (...) 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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