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For anyone who’s worked with Bostik’s BEST, how do you cover and/or reseal the 5 gal cans between uses? When I reused their foil cover and resealed the lid, the foil stuck to the rim and also formed a real thick cured urethane layer on top. Obviously it was an incomplete seal and started curing. Another time I tried 6 ml plastic, but that also formed a thick skin on top of the remaining adhesive, possibly from the air/moisture trapped in the half-empty can. It’d be easier if I could just finish a can each day, but I ain’t that quick. I do close it right after pouring out the amount I need for about 2′ of flooring. Thanks,
Jim
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Jim:
Ah, you've found the downside to using Bostiks. That stuff can be a bummer a few days later after working with it and hoping you've secured the lid. I've always tried to keep my working area and the amount left in the bottom of a bucket to a minimum at the end of the day. If there are 3" left on the bottom at the end of the day, it's a tosser. Sounds like you have a good batch?
Have you encountered any "new" buckets that have a 2" solid head on it, after lifting the foil and lid? That's some strong stuff. I haven't found a good method for keeping a good seal on a used conatiner.
*I had about 1" solid on the first I opened. I assume it's a good batch because it poured and troweled nicely. Used old urethane caulk once and new later, so I've had a comparison be/t old and new urethane. Thanks for the feedback, Ken. I guess I gotta plan real good so I avoid leftovers. At well over a hundred a bucket, gotta watch the waste, huh?
*One trick that is suggested for poly woodworking glue is to put a thin layer of mineral spirits on top of it. The next can that is almost empty you might try that and see how it is the next day.
*A suggestion. But first, a question. Why don't you get thick skins on the top surfaces of stuff in NEW cans? Recall that new cans are almost filled to the very top. There is very little gas volume above the liquid. Same thing w/ plastic multi litre bottles of carbonated beverages. Has to do w/ a thing called "Partial Pressure." Eons ago, a genius stated a chemistry theorem that the total pressure in a volume equaled the sums of the partial pressures of all the gases. A bit crude quote, but the essence is there. Open a new can of something w/ volatile solvents in it that cause curing or drying as they evaporate.pour out a bunch very quickly into another container. Slap the lid on perfectly tight. Wait a few days and re-open. SKIN on the surface! Volatiles evaporated to create the correct partial pressure for that gas in the "Empty" volume above. the partial pressure is a product of equilibrium conditions for the volatile in solution and as a gas above. You can jack up the pressure with air all you want, and it does not help. Solution - put something on the surface of the liquid to keep the solvent from evaporating - like a smaller can - or as suggested, mineral spirits. Remove the liquid-gas interface, and you solve the problem.Think about what happens w/ a multi-litre bottle of Pepsi. Partially empty it, and the Pepsi loses fizz; the carbon dioxide reaches equilibrium across the gas-liquid interface, no matter what you do to the pressure of air in the space above the liquid. Bigger void, faster the soda goes flat. Takes more CO2 to fill the void to its partial pressure.Or something like that.Don Reinhard
*Don and Bill:I'll have to try that mineral spirits idea. On ocassion I do get a few with a thick skin on the top of the can. The longer the stuff is not rotated in say a flooring supply house, the worse it is to work with. Thanks!
*DonThe problem is not with "solvents" leaving the material.The Bostick is a urethane which cures by reacting with moisture.
*Bill - You are correct about moisture cure on urethanes. Maybe a problem like this could be solved by sticking a dessicant pack to the underside of the lid?
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For anyone who's worked with Bostik's BEST, how do you cover and/or reseal the 5 gal cans between uses? When I reused their foil cover and resealed the lid, the foil stuck to the rim and also formed a real thick cured urethane layer on top. Obviously it was an incomplete seal and started curing. Another time I tried 6 ml plastic, but that also formed a thick skin on top of the remaining adhesive, possibly from the air/moisture trapped in the half-empty can. It'd be easier if I could just finish a can each day, but I ain't that quick. I do close it right after pouring out the amount I need for about 2' of flooring. Thanks,
Jim