Flash Off?

Discussion in 'Flooring Potpourri' started by TwoStar, May 27, 2011.

  1. TwoStar

    TwoStar Maybe Three

    So what exactly is adhesive flash off and how do I know when I've achieved it?
     
  2. Incognito

    Incognito No more Mr. Nice Guy! I Support TFP Senior Member

    It's a very general term Sean. Another expression we use that I believe means the same thing is "gas off." It's about getting whatever chemical or solvent reaction to the air completed so the adhesive turns from what you find when you open the bucket, or begin mixing as part "A" and part "B" to the tacky, thicker quality we know will grab the goods and hold it where it's supposed to stay while we cut, roll with the 100 lb. roller, seam and anything else.

    These acrylics come out of the bucket very watery and have a very modest tack even at their ideal flash off point. The main thing you should think of when they mention "flash off" is that if you throw the goods right in there will be a battle between you and the air bubbles.

    Sometimes you'll win. Sometimes you wont.

    I hate those types of adhesives. But I'm sure they're environmentally friendly.
     
  3. RFI

    RFI Mr. Nefarious Senior Member

    When I panic and realize I let it set up to long.............Then I flash off in fustration. :blink:


    Rob
     
  4. Peter Kodner

    Peter Kodner Inspector Floors Charter Member Senior Member

    It is that elusive time that precedes "open time" and "Oh crap, the adhesive has set up".
     
  5. TwoStar

    TwoStar Maybe Three

    I was really hoping you guys were going to say..."What a doofus. Its when this happens or when that happens". Is there a technical status of troweled adhesive that is defined as flashed off or gassed off?
     
  6. Elmer Fudd

    Elmer Fudd Administwative Asst. Charter Member I Support TFP Senior Member

    I always tried to judge it as the time when the trowel ridges were still wet, but the areas between ridges were dry. Was always taught that you wanted to lay the material into the glue, roll it, and break the ridges to maximize transfer.

    I believe the absolute correct time is only a nano-second in the stream of the day!!:eek:
     
  7. Incognito

    Incognito No more Mr. Nice Guy! I Support TFP Senior Member

    **
    There would be some ideal technical status measurable under laboratory conditions with the proper equipment and procedures. I don't think that helps you out in the field. We have to use the instructions, our experience and then discretion.

    Usually we use the color and texture of the glue feeling it with our fingers for firmness and tackiness that from experience we know to be ideal. As the job progresses you pay attention to open time and working time as it relates to temperature, humidity and porosity of substrate.

    It's always an experiment in progress.
     
  8. Barry Carlton

    Barry Carlton Senior Member Published

    Not that it matters (but it kinda does) are you asking about tile or vinyl installation.
     
  9. Elmer Fudd

    Elmer Fudd Administwative Asst. Charter Member I Support TFP Senior Member

    As a PS: I have been known to "gas off" on occasion!!:eek:



    :yesss: :D
     
  10. Daris Mulkin

    Daris Mulkin The One and Only Charter Member I Support TFP Senior Member

    Occasion??? Don't you mean constantly?:eek: :help::help:

    Daris
     
  11. Bearman

    Bearman Pro Member

    The only true way I know is to test it THAT day, on that floor, with that glue trowel, with the temp & humidity of that day's air that is standing, or your pushing that day, etc.
    With Cork adhesives for instance that is very critical to get it right, not to wet, and not to dry. I do an actual flash test first thing. I clock the actual setup time of skim over. With that information I know my max & deduct my working time about 40% of that, knowing I have to get it down before that time. Usually about 20 minutes of flash & I'm good to go, and have about 20-30 min working time.:)
     
  12. Elmer Fudd

    Elmer Fudd Administwative Asst. Charter Member I Support TFP Senior Member

    That may be!!!!:eh:


    Daris, why is your wife searching for a good price on Depends? :p
     
  13. cproader

    cproader All over T's last nerve Senior Member

    I'm about 15 min fer ideal conditions over porous, and about 30 over non. But the size of the spread area, has to be workable in the same amount of time. Always best to glue backin away from coverin. But that ain't always doable. Good topic.....:yesss:
     
  14. kylenelson

    kylenelson You'll find me on the floor Senior Member

    I was thinking of this very same question this week as I installed unitary in some Highschool classrooms. Lots of flash of time, and the second day it was raining so it took even longer with the high humidity.
     
  15. TwoStar

    TwoStar Maybe Three

    About 8 years ago we did 800 yds of unitary in a school. We troweled out glue, waited hours, sometimes 6, for it to flash, played baseball out in the yard, helpers smoked, it was the most fun, frustrating job of ever! I explained to the principal what was going on. It was very hot and humid, the school had turned off their AC for the summer, etc. We did a fantastical job. I never got a call back to do more work. I found out about 3 years later that the principal was bad-mouthing us for being lazy slack-offs.

    Frickin' flashtime!!!!!!!!!!!!!
     
  16. TwoStar

    TwoStar Maybe Three

    hmmm...now you got me thinking? Would a test piece of underflor or underlayment troweled when I walk in the door and then set in the corner to see how long the set up time is on that particular day, be helpful? Any thoughts? I'm thinking specifically about PSA, but any adhesive could be considered here.
     
  17. kylenelson

    kylenelson You'll find me on the floor Senior Member

    Haha, yeah. We had some 'splainin to do as to why it was taking longer than originally figured. Come into the job expection action-bac and get unitary.:rolleyes: It's not like it uses a ton more glue and takes more time or anything...

    Anyway, last summer I did a middle school with a bunch of classrooms and it was hot as can be...flash times took about 20-30 mins. Gotta love the dry mountain air. That was shaw ecoworxs broadloom though, and the adhesive was also thick, not a lot of water.
     
  18. Daris Mulkin

    Daris Mulkin The One and Only Charter Member I Support TFP Senior Member

    Cut you flash time in half.Just drop material into the glue and pull it back out. Let it flash and use like a contact. Works great on unitary. I was the 2nd guy in the area to install unitary. The first job failed with bubbles all over the place. I did it like I just said and had not one problem. Did all unitarys the same afterwards. Also rolled it with a 150 lb roller. It was the only one I had at the time. Got good transfer with that one you betcha.:yesss:

    Daris
     
  19. Lo Down

    Lo Down Old as dirt member Charter Member Senior Member

    hint:
    Windows
    Ladders
    Second story once.............. somebody was coating the new hardwood floors downstairs with some stinky Swedish finish, so we were getting the heck outta Dodge via the Werner connection.
     
  20. Bearman

    Bearman Pro Member

    That's exactly what I do on some.
     
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