I don't take off lids or caps on my thinners. I'm doing what I saw in a body shop that made sense -- I poke a small hole in the top of the lid and all becomes a handy squeeze "bottle". I cover the hole with a piece of tape. BUT... sometimes I forget and i was wondering as the evaporation of a substance continues, does it change its properties? Ex. If I were to leave the lid off the denatured alch, does it stay the same strength right down to the last drop?
-------------------- Bob Parsons 907-258-6283 rparsons@gci.net Posts: 118 | From: Anchorage, AK / USA | Registered: Aug 1999
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Bob, In the case of alch I'd say yes, it stays the same. I believe alch is just alch.....paint is another story. I'm sure the solvents would evaporate....then the driers work and you get a skin and then it stops. I'm not a chemist but I did sleep in my own bed last night!
So, how are ya doin?????
Joe,
Makin Chips and Havin Fun!
-------------------- Joe Cieslowski Connecticut Woodcarvers Gallery P.O.Box 368 East Canaan CT 06024 jcieslowski@snet.net 860-824-0883 Posts: 2345 | From: East Canaan CT 06024 | Registered: Nov 2001
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This is a question for Si Allen, our resident chemical engineer.
-------------------- Ricky Jackson Signs Now 614 Russell Parkway Warner Robins, GA (478) 923-7722 signpimp50@hotmail.com
"If I have seen further it is by standing on the shoulders of giants." Sir Issac Newton Posts: 3528 | From: Warner Robins, GA | Registered: Oct 2004
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The truth of the matter is that most body shops are no smarter than most sign shops as their prep solvents are petrolium based to begin with. As far as denatured anything you should read this:
I personally have experimented with enough solvents in my time to know that I don't need anymore crap which is harmful as well as outdated. I prep using just one waterborne product and it works for me. no sense in using 2 or 3 which counter act each other when one does a perfect job.
As far as your question about losing properties, you should first read what makes it what it is
-------------------- HotLines Joey Madden - pinstriping since 1952 'Perfection, its what I look for and what I live for'
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It absolutely changes its properties,and sometimes can change them up to 100%. No product is 100% pure,even paint which needs an external solvent still contains a certain percentage of whats called tail end solvents which evaporate at certain timeline rates to control paint flow,workability etc,and other substances used as solvents which are vehicle carriers that carry pigment,binders,particulates etc,and also a certain percentage of driers which can either be independent or attached to binders,pigments etc. Not everything stays in solution perfectly, and given the chance almost anything including water will evaporate out of solution if not handled correctly. Alkyds and Acrylics which dry thru oxygen exposure are particularly bad for this because once you get air intrusion into the can,the reaction starts taking place and you lose more than thru evaporation than you normally would,which is why one shot skins over,gets thick as molasses etc. You also get a "balancing" facotr by having the solvents in the correct ratios,it keeps everything suspended correctly and acts as a protectant to binder/pigment/whatever...ie you arent left with enuff of A to keep the binder/ in correct suspension ratio,B is now the dominant one in the mix and burns the binder/pigment,dissolves the pigmented coating on particles,cause the drier that maybe attached to those to fal into suspension prematurely and start to work before they should,or not get into the mix and work at all. Solvents(thinners) are also vulnerable to this,there is no such thing as a pure solvent,each one has several blends in it to give it controlled evaporation at certain temps under certain conditions,ie the temp ratings on the cans and the manufacturers recommendations. Its entirely possible to leave a thinner open,particularly cheap lacquer thinner and evaporate enuff primary solvent out so that the rest of the can is weak as mouse urine....the opposite can also happen with thinners/reducers and certain blended solvents can evaporate out and whats left becomes twice as strong as what it should be. Waterborne and isocyanate based products also are affected by this,isocyanate based products like catalysts will/can absorb at times 1-1.5times their weight in water from the air they are exposed to which is why they get gritty/sandy feeling and cloudy looking and fail to react the same way over time despite of what may seem to be happening. About 99% of the tape you will come across has some degree of porousity to it so air will get in thru it,and whats in the can will evaporate back up thru it the other way...probably better off with a screw.
-------------------- Gavin Chachere Plotter in the garage,New Orleans La.
"Sgts Shugart and Gordon again request permission to rope down to crash site two" Posts: 1223 | From: new orleans.la. | Registered: Mar 2000
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Maybe, one day, they will make a paint does not dry or skin up until you add a drying agent to it. But for now, I can only dream.
-------------------- Signs by Alicia Jennings (Mudflap Girl) Tacoma, WA Since 1987 Have Lipstick, will travel. Posts: 3813 | From: Tacoma, WA. U.S.A. | Registered: Dec 1999
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Alicia, HoK striping paints do not dry up or skin up and you don't have to add anything but the catalyst to stripe over any paint or clearcoat and the catalyst adds the gloss.
-------------------- HotLines Joey Madden - pinstriping since 1952 'Perfection, its what I look for and what I live for'
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Ohhhhhhh Gavin; I love it when you talk nerdy!
-------------------- Ricky Jackson Signs Now 614 Russell Parkway Warner Robins, GA (478) 923-7722 signpimp50@hotmail.com
"If I have seen further it is by standing on the shoulders of giants." Sir Issac Newton Posts: 3528 | From: Warner Robins, GA | Registered: Oct 2004
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I knew I was going to get a boatload of info on this one. But that's a good boatload. But I'm going to limit this reply to a "thanks" and have to ask, "What is that one waterborne prep stuff you use there Joey?"
bp
-------------------- Bob Parsons 907-258-6283 rparsons@gci.net Posts: 118 | From: Anchorage, AK / USA | Registered: Aug 1999
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