Adhesive Coverage: Who's right?

Discussion in 'Tools, Equipment and Supplies' started by Chris Mha, Oct 27, 2015.

  1. Chris Mha

    Chris Mha Charter Member Senior Member

    Someone has there estimated coverage wrong. Either Karndean or Versa-blade

    Attached Files:

  2. TwoStar

    TwoStar Maybe Three

    I vote that Karndean is wrong. I have never had any luck following their coverage estimates. I always have to add at least 50%.

    ...although, I do believe that the trowel they recommend is a mistake. That's just my opinion.
  3. Jim McClain

    Jim McClain Owner/Founder Administrator

    Trowel rate may not be based on just the size of the notches in the trowel, but also the viscosity of the adhesive. You can test this by spreading an equal measure of 2 different adhesives, one very thin, the other very thick, on the same surface. Prepare the surface by drawing a grid pattern of 6" squares. Measure out exactly 1 cup of adhesive, which is 1/16[sup]th[/sup] of a gallon, and spread with a brand new side of a Versablade. Take pictures.

  4. Incognito

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

    One gives a specific RANGE. The other only gives a minimum coverage. So I would use the Gundlach estimate as a worst case scenario guessing they arrived at that by spreading the adhesive over the most porous substrate they could imagine.

    the 1/16" square notch is usually ridiculous overkill

    but you dont want to vary too far from that with expensive goods
  5. Jim McClain

    Jim McClain Owner/Founder Administrator

    I'd guess that most installers don't change trowels/blades after the one they are using wears down 25 or 50%. Not that I would have ever done that... :shifty:
  6. Chris Mha

    Chris Mha Charter Member Senior Member

    I change them a lot. I like the versa blades. It's cost effective
  7. kylenelson

    kylenelson You'll find me on the floor I Support TFP Senior Member

    I'd say it's closer to 125 feet a gallon, in my experience with that adhesive. A typical 4 gallon bucket goes about 600 sq feet on a concrete floor. I trust the versablade coverage projections over the bucket just about any day of the week. I have yet to find an adhesive bucket that came anywhere close to what they say you should get. If the trowel is brand new, forget it, not even close. Then the question becomes, should you adjust trowel size to ensure the coverage is closer to the recommend spread rate? Or should you just use the suggested trowel size? How about when the sales person, to no fault of their own, orders a special adhesive and trusts the bucket and it's not enough to do the job with the recommended trowel size?
  8. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    I think we got close to 140 with a slight worn 1/16". Residential wet set or dry. Wet will ooz, dry is sufficient amount and dries a bit quicker, also when it's rolled it dries quicker.

    We are bringing back some parabond that wants 1/16" notch and the plank is about a 1/16" thick for some eco bond 360 that uses 1/16"X1/32"x?, very small, adhesive is tenaciously sticky, dry set, not wet set, who's got time for that? Though I think wet holds better.

    I like versablades also, cost is negligible, having the right on hand is tricky. I throw away the clip on supplied with glue if I have the versablades notch.

    Adhesive amounts are annoying, there's probably 3 different opinions before the installer puts in his two cents.
  9. Hanover Fist

    Hanover Fist Pro Member

    Short answer:
    The job is right.
    Only that specific job - everything else is a suggestion or an educated guess.
  10. TwoStar

    TwoStar Maybe Three

    The problem is that the store only orders the adhesive using the chart on the pail. It's always a speciality order around here.
  11. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    Ours orders like they'll never use it again. We are always pulling adhesive from next weeks install. Just don't substitute duraceramic adhesive, other adhesive doesn't hold the edges down.
  12. Nate Hall

    Nate Hall Types With toes Senior Member Published

    Since we ripped open this "can of worms"...
    I saw a versa blade for carpet at CCS ( Carpet Cushion & Supply) and the notch was 3/32X 3/32 "V" notch with a pretty goo flat spot between the notches. Your basic 5 pic action back carpet requires an 1/8" V notch the get proper penitration into the backing. Is Versa Blade anticipating the trowel most installers use after spreading glue for 4 hours?
  13. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    I think I have 3 different carpet blades, 10 yards a gallon if I remember is what we used, rip ups are not easy that way.
  14. Nate Hall

    Nate Hall Types With toes Senior Member Published

    Like Versa blade doesn't know the proper notch size? When a guy starts off with a too small notch it's not going to get bigger as you go along. It just grinds my beans.:mad:
  15. Commercial Floor Rep

    Commercial Floor Rep I Support TFP Published


    We distribute for Gundlach, so I called our customer service person because I had never noticed that before.

    The reason the numbers are so far off is because when they were determining the spread rate for the notch, they used a jig that held the trowel at a perfect 90 degree angle. They did this because everyone holds a trowel differently and it was the only way to get a "baseline" measurement. It's nowhere near right. When you tilt your hand your obviously leaving less glue and the coverage is going to increase substantially. We probably carry 5 different adhesives that recommend that notch and on average you will get abotu 125 to 160 sq. ft. per gallon.

    Also, this is explained in their current catalog on page 86 at the top.

    Hope this helps, and happy halloweeny!!!!:yesss:
  16. Incognito

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

    There's some variety amongst installers as to the angle we hold the trowel and how hard we bear down. But the factory specs should be based on some middle of the road angle and pressure that the installers on the extreme could then FORCE themselves to adjust to meet the specified spread rates.

    If the manufacturer wants 100 square feet + or - per gallon our job is to make that work

    or just throw away the warranty and use your best judgement

    I'm not against you taking that responsibility if you think you're up to it. I do it all the time when I think my expertise is more trustworthy than something someone printed on a piece of paper on the side of a bucket.
  17. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    I held a worn 1/32" the FFA versablade to try and get more life out of it, at a 90 degree angle, it spread like a new trowel, I try not to press against the slab too hard to prevent it from wearing down. We got about 2000 ft per blade(4 sides) I have just enough blades to finish the job. I saw on tools4flooring they have a new handle, more like a finish trowel handle. The red one is ok, the blue uncomfortable, so I ordered it and a dozen ffa's.
  18. Incognito

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

    I still notch a lot of trowels. So I've repeated this here plenty of times. You start with a slightly heavy notch but a low angle. As the trowel wears you lighten up and increase the angle to achieve the same coverage. MEASURE the spread rate as you go to ensure accuracy. You can look at the notches on the floor and on the trowel to know when to re-notch. If you cant------JUST BUY THE VERSATROWELS
  19. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    Yes I know you re notch, I tried that long ago but gave up, mostly the carpet trowels with v notch and v file, rounded was the round carbide attached to hacksaw, my re notching was not pretty or precise.
  20. Incognito

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

    Glue down carpet is probably the LEAST sensitive installation as far as how critical the trowel notching is Mike. I've seen it all and there's really very little failure due to configuration of the notch. In other words HOW MUCH glue is quite important as well as TIMING, as well as HANDLING the goods. I don't give two craps whether it's a U-notch a square notch or a V-notch if you don't MANGLE the goods whilst delivering and folding back, get the SPREAD RATE correct and ensure TRANSFER to the backing------100 lbs roller or your fatass Uncle Luigi rolling back and forth on his belly.

    There's literally a hundred+ ways to make that happen without buying factory made, specialized trowels.

    Hard that's a whole different story.

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