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"Russell Duffy" <13brv3@bellsouth.net> wrote:
"""
If you're trying to prep for bonding and have used and continue using epoxy
for the layups then the best degreaser is methylene chloride.
Hi Marvin,
Is this the main ingredient in any product I'd know by name, or is it just
packaged as methylene chloride? I've heard this is a particularly nasty
thing to work with. Do you know that to be true?
Thanks,
Rusty (just took the rest of the week off, gotta get busy now)
"""
MC is THE "corrosive" (to paint, for lack of a better term) material which is the main ingredient in Strip-eez and all those other paint stripping products. They basically gel it with a cornstarch-like additive and that's what you got... although some of them will also add other solvents (MEK, toluene, etc) to help keep the gel wet and jump-start the stripping process on paints that are more susceptible to damage from them. Once the surface opens up to the MC, however, it's hell-on-wheels and is what causes the paint to blister instead of melt.
As for where to get it... there's a link to a text file of MC sources on my Lancair Mail List site at www.lancaironline.net/lmlmatl.html (direct URL for the page involved) that points out all the places I've found (through the LML) around the country that sell it in quantity. I buy it in 5gal pails from a place in Tampa, don't remember the name, for about $13.50/g. Finding it in smaller quantities is a little problematic (it IS an industrial fluid) but not overwhelmingly so. I purchase it in large quantities because I do a LOT of glass work. Anyway, for smaller quantities, find one of those places that fabricate plexiglass thingies (you know, napkin & brochure holders, acrylic fish tanks, file holders, etc) and ask them to sell you a quart... it's the glue they use on plexi... melts it right together, like liquid welding, only cleaner.
As for toxicity... the MSDS is downright scary. Personally, I don't buy all of their analysis. It is heavier than air, so it settles to the floor and displaces O2. It has a sweet smell (it's a chlorinated solvent) and burns like hell if you get it in your eyes... a definite no-no... always wear safety glasses or a shield when working with it. As for getting it on you... it burns if you get it in a cut, but just on your skin it gets very cold as it evaporates, (it used to be used as a refrigerant back in the pre-freon days) and it removes your natural oils, so your hands dry out if you don't protect them. It also burns your skin if you let it sit there (remember the paint), so treat it with respect and you shouldn't have any problems. I hate to admit it, but back when I ran glass factories, there were times when I worked with the stuff up to my elbows without protection, as it was the only thing we could use to clean the pumps we used for the organic sealants used on insulated glass (thermopane) units. I've had lots of direct contact with it throughout my career, and my liver is still working, I haven't grown another head or foot, and I know of no particular long-lasting effects I'm suffering from as a result. My most instense contact was probably 20-25 years ago, and I'm sure something would have fallen off by now if it was as truly nasty as they say. That being said, however, don't do as I do, do as I say. Wear heavy rubber gloves (not latex or vinyl surgical gloves... it just eats those), an organics respirator (or open the doors and start the fan... ventilation is the best thing) and eye protection and you'll be fine. Technically you should do these things when working with any solvent.. most of the MSDS's read very similarly for those types of chemicals. One nice thing about MC is that it's non-flammable. I know, that's one-in-a-row.
I hope this helps.
<marv>
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