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Thread: please help?

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  1. #1
    Join Date
    May 2004
    Posts
    10
    i started workin as a helper about a month ago, and the problem is everyday, they send me with different people....so i am confused as how is the right way to do some things..first of all ..after system is pumpdown , and u have soder , and want to test for leaks....do u connect low side or high side? i have seen them do both....and esch gives me a different explanation....second thing when doing duct work before u connect the flex to the collar do u have to mastyc the inside and then put the strap...or just the strap will do? thank

  2. #2
    Join Date
    Oct 2003
    Posts
    566
    You're going to test for leaks(pressurize w/ Nitrogen) before you evacuate system. When you evacuate system, you connect and open both Hi and Lo hoses pulling from both sides. With regard to duct, depends on area. We cut the hole, put the collar in, fold tabs over, tape flange with silver tape, put flex on, use panduit strap around flex liner, then pull flex insulation/exterior layer up around, and tape down. You can than mastic the outside around the tape, but you shouldn't put a panduit around the whole thing as this will lead to the duct sweating.
    Hey mosquito, quit biting (slap!!) me...
    Anyone like Josey Wales?
    C'mon, you know I'm right!

  3. #3
    Senior Tech Guest
    Leak testing...buy a good micron guage and learn anyway you can to use it...come here, we'll teach you.

  4. #4
    Join Date
    Dec 2003
    Posts
    1,195
    Duct connections these days, least to pass an inspection round these parts:

    Collar mastic sealed to plenum, mastic on collar stem, strap on inner lining. Outer lining tucked between fiberglass and inner lining by several inches, pushed into mastic against plenum, second strap.

    No ducttape nowhere no how. All seals mastic with fibreglas mesh if needed. Mastic over duct/foil tape is not a proper seal, just a painted leak waiting to happen.

    "That's good enough..." usually isn't.

  5. #5
    Join Date
    Oct 2003
    Posts
    2,866
    You'er going a hundred miles an hr. Slow down and hear. Don't think, just hear.

  6. #6
    Join Date
    Jan 2004
    Posts
    526
    do you have any pryer schoolin or are you startin out fresh

  7. #7
    Join Date
    Oct 2003
    Posts
    566
    [QUOTE]Originally posted by air of honesty

    Collar mastic sealed to plenum, mastic on collar stem, strap on inner lining. Outer lining tucked between fiberglass and inner lining by several inches, pushed into mastic against plenum, second strap.

    No ducttape nowhere no how. All seals mastic with fibreglas mesh if needed. Mastic over duct/foil tape is not a proper seal, just a painted leak waiting to happen.

    Two things: If its mastic'd properly, there isn't a leak there. We use silver tape, squeegee it down nice to the ductboard no duct tape, then mastic all around the duct extending "'s beyond tape, slapping it on nice, neat and thick.
    We don't recommend a second strap on the outside finished product, it 'squishes' down the insulation and causes a pool underneath the duct.
    Hey mosquito, quit biting (slap!!) me...
    Anyone like Josey Wales?
    C'mon, you know I'm right!

  8. #8
    Join Date
    Dec 2003
    Posts
    1,195
    Like I said, what passes an inspection round these parts...

    What I used to do and what I now have to do are two different things, by far.

    If the mastic is applied to the collar and plenum, what does the silver tape do? In the long run, the tape will let go in most cases, the mastic bonds. If the tape lifts, the mastic comes with it. No tape, no broken bond. The mastic IS the seal these days, tape is old school. No half steps.

    "That's good enough..." usually isn't.

  9. #9
    Join Date
    Oct 2003
    Posts
    566
    Well, we haven't had a problem with ours, the silver actually reacts well to the board, oh well
    Hey mosquito, quit biting (slap!!) me...
    Anyone like Josey Wales?
    C'mon, you know I'm right!

  10. #10
    Join Date
    Dec 2003
    Posts
    1,195
    Not knocking anybody. just know what I see.

    Used to think well squeegeed silver tape was the end all for ductboard. After x number of years going back to pieces I personally installed 10 years earlier and seeing the tape let go I began to question.

    Doesn't take more than the sweat from your hand to keep the tape from bonding. Might hold 6 months, might hold six years. Frequently lets loose when attaching to furnaces and coils due to machine oil on surfaces. Saw a coil change out just today where even Carlysle 'putty tape' with silver backing let loose from plenum to coil, taking a huge bunch of overlapped mastic with it. With just mastic, no 'might', just bond.

    Avg. 10-15 bucks a bucket, compares well to tape prices. More you use it, less mess and hassle as you get better and faster.

    Took me a while to retool, but I think the end product is more durable, and actually faster and cheaper to do.
    "That's good enough..." usually isn't.

  11. #11
    You are experiencing one of the main reasons there are so many "ol wives tales" in this industry!
    One guy does it like this, the next guy does it like that .. and so on and so forth.

    Each man you go out with, or woman, take along a notebook of sketch paper.
    Draw out each step. Just tell em it's for your records.
    Some will just laugh, others will freeze up. It is like they are all of a sudden being paid attention to and they are afraid of being found out.

    Some guys work is fine while others are slip shod.

    The turn in the notebook to your supervisor each week and have them look it over.

    This will tell you several things.
    First it will tell you what type of people are there trying to pass along info to you.
    Second it will tell you what kind of employer you have.

    Especially since he will get on anyone's case who is feeding you bad tips.

    Third, you will end up knowing whom you can trust and who is just a "bs"-er.

    It is one thing to be able to do the work. But it's another to be able to impart that knowledge to another person in a nuts and bolts level.

    Not everyone who tries is a Mentor.



    Bring their tips here each night and we will critique their advice.
    But dont tell no one you here each evening.


    Your co-workers will soon begin to think your learning beyond the level of what is being taught you on the job each day.

  12. #12
    Join Date
    Mar 2004
    Location
    NJ
    Posts
    1,214
    Wives tales or not what Fly's with the inspector's here is what Air of Honesty said. They (the government) did a durability study of what lasted longer for duct sealing cloth tape was actually better than foil as when the duct heated it melted on but tape joints all failed(meaning developed air leaks) in something like 3 months. Anyway there big conclusion after spending probably millions of dollars on this ever so important study probably overseen by some politicians brother was that --Mastic was better.

    Of course, it would have been too cheap and easy to just ask someone like Air of Honesty.

    Conclusion I have drawn from this:

    1)Anything can be accomplished with patience and government funding.

    2)If I want to pass inspection I better get the lil white bucket and disposable brush out.
    thehumid1-------I live in NJ, a state where it's free to come in but you have to pay to leave!

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