This was very interesting ;
Now be warned , my fellow modelers . I am about to say things you won't agree with . I've been doing this since " Duco " cement in the tubes was the only thing in the house .
the first thing is , YES , tube cement can harden without being opened ! I have seen this to many times in hardware stores and other places that sold it ! Why ? it's really simple . the stuff doesn't like to be stored in any temp above 75 degrees or below 40 for extended periods ! It says so right on the box or even the individual tubes .
This applies to ALL adhesives . In tubes , bottles or cans !
Any product containing ether , phenol , acetone , acrylinytril or any of the exotic compounds are finicky products indeed . This is because , All these have very low and common evaporation points . Even the best machine seal can break down over time .Even just sitting there !
A good test for those of you new to modeling in any form and all those old dawgs out there , me included . Take a bottle of your favorite glue .Or tube . Open one and leave the other nice and brand new tight ,or sealed . Now sit on a shelf in the sun for six months .Outside or on the porch !
Chances are you'll see a difference .
Now for contamination . How many of you use lacquer thinner to do a final chemical clean , on brushes , tools or airbrushes ? What do you do with the thinner left over ?
If you've ever taken that thimble sized container of dirty thinner and dumped it back in the container and figured , " well that isn't enough to hurt it , it's a whole quart or pint " WRONG ! !
From the time you did that , the compound starts breaking down and losing its strength .
If you apply glue with the brush in the bottle , you do this every time you put the brush back in the glue . Why ? Well , it's easy . Each time you apply that glue to a piece , the brush picks microscopic particles of the plastic as the chemical reaction started . Hard to believe ?
Well , it only takes one - thousandth of a second for the glue to react with the surface it's being applied to , especially if it's a clean , virgin product surface .
Okay , you can say , how the heck does he know , all he's ever done is design and build things ? Well , I worked for three years as a quality control specialist at a plastics company .This was a position that had me doing Q.C. Not on the product , but the glues and resins we used in manufacturing .
I was surprised at the amount of waste and did my best to reduce it . No more " Pots" on the line that could not be sealed after use . No more buying adhesives , six months to a year before they got used .
The upside ? the product got better and the cleanliness of the employees and work areas improved one hundred per-cent . Nothing's worse that a sticky , stringy work-station or tools , when working around plastics of any kind !
In closing , use a different applicator than the brush in the bottle and a clean tooth-pick with tube glue or resins and two - part epoxies . You'll be glad you did , Then store your glues in a cool dark corner of your bench . and loss from evaporation and contamination can be cut ALMOST to zero in you modeling workplace . I hope this works for you . Tanker - Builder P.S. I realize some of you , are like me and cannot work in your shop in the blistering heat or freezing cold . Your paints and glues can't either . Get a large fishing tackle or tool box and move them inside in those times . You'll be glad you did !