Anybody else notice this about JB Weld?

Discussion in 'Painting, Welding, Bending and Gas Tanks' started by jefuchs, Jan 29, 2013.

  1. jefuchs

    jefuchs Member

    This was driving me crazy. I knew I had mixed it right. Then I learned that the promise you see in the store is not in the directions you read at home after you open the package. Shame, JB Weld.


  2. roughrider

    roughrider Member

    Yeah, I noticed that before too. I always figured the 20-25 minute thing was with regard to its working time; that is, you can still move the parts and push it around. I go by the little bit of leftover I have on the mixing board to tell me when the actual hard set has occurred.
  3. Tanstaafl

    Tanstaafl Member

  4. jaguar

    jaguar Well-Known Member

    a classic case of reading what we want it to say.
    It actually says it "sets to a dark grey color", not "sets hard" in 20-25 minutes.
    Put it in the sun or by an incandescent light bulb to make it harden faster.
  5. jefuchs

    jefuchs Member

    Regardless of what it says, it was still soup after three hours. At 25 minutes, there was absolutely no change in consistency. I've posted this picture on three websites, and I consistently get comments telling me that I misinterpreted the label. But it clearly says it sets in 25 minutes on the package, then says it sets in 4-6 hours on the tube. If it's so simple, they would have said the same thing on both labels.

    Honestly, it stayed liquid for hours. There was no truth at all in what the outer label claimed. Absolutely nothing happened in 25 minutes. No change. Nothing. The tube was labeled honestly, the package was not.
  6. jaguar

    jaguar Well-Known Member

    one of the definitions of the word "set" is "to cause to assume a specified condition" which is the definition that applies in this case because they specified the condition it will set to: "dark grey color".
  7. jefuchs

    jefuchs Member

    You can split hairs all day, but trust me, nothing changed in the first few hours. Not the color. Not the consistency. Nothing. And even if you can make an argument that some unseen molecular change occurred in those 25 minutes, that is of absolutely no value to the customer trying to decide if a product will meet his needs.

    No matter what you've seen with your own eyes, or experienced first hand, somebody on the internet will tell you it never happened.
  8. Tanstaafl

    Tanstaafl Member

    There is no doubt one can get a bad batch. But OTOH, I have used JB Weld for many years and have never had a problem with it.
  9. grinningremlin

    grinningremlin Active Member

    OK, first I'm not there so I can't see what you're seeing.For it to be a bad batch the catalyst would have to out-gas, it's in a metal tube so that would be impossible (the molecules are too big) unless there was a break in the tin (very possible).My thought is you put too much of one or the other.Try small amount mixes to get the right consistency, should be a light gray when mixed correctly, I've noticed you need to use a bit more base sometimes.
  10. jaguar

    jaguar Well-Known Member

    the results are worth the wait. great product. when I use it I expect it to take all day to get good and hard.
  11. jefuchs

    jefuchs Member

    It was not a bad batch. Why is is so hard to make myself understood?

    It worked EXACTLY as the label said it would. Problem is, the OTHER label (the one you see when making a buying decision) made an unrealistic claim. It's kind of like a large print/ small print thing. The small print negates the claims of the large print.
  12. grinningremlin

    grinningremlin Active Member

    I was confused because you kept on about set up times "soup" and such, and it sounded like you were dissatisfied with the product.It's a pack of JB Weld that works like it always has, I don't know if it's something to get up about, no offense.
  13. Lee_K

    Lee_K Member

    The set time of epoxies has an affect on the bond strength. Higher strength epoxies tend to set slowly so the molecules have time to conform to the substrates surface on a microscopic level. If you accept that statement then its easier to accept the longer than advertised cure times. I always look for slow setting epoxies.
  14. Racie35

    Racie35 Member

    did it work? thats what should matter
  15. jefuchs

    jefuchs Member

    Yes, it worked fine. That's not the problem. It just made me believe I'd done something wrong, when it didn't start to set. Eventually it turned out okay.
  16. Bob K

    Bob K New Member

    I guarantee that if you give JB weld a 1 hour cure at 150 degrees F it will have MUCH better tensile and compressive strength.
    It will also have much better chemical resistance and be harder. I have a degree in Plastics Technologies and I have worked with
    just about every aerospace epoxy out there. JB weld is not as good as some of those exotic epoxies. But, if you "post cure"
    JB weld as I said, it's the best epoxy you can buy as a regular consumer. Also, if you are going to bond something important,
    buy fresh JB weld. All old epoxies will setup ( within limits) BUT, ( that's a big but) adhesive bonding power takes a nosedive.
    Good shop practice dictates fresh adhesives in general.
    JB Weld... Goo-ood sheet .
    ( up there with Duct tape and hose clamps):grin5:
  17. Saddletramp

    Saddletramp Member

    I use the product. My rule is make it, use it & forget about using whever I repaired for 24 -48 hours. It's never let me down.
  18. jefuchs

    jefuchs Member

    That's really good to know, Bob. Wish I'd known that a couple days ago. This is inside the cylinder (Jag's transfer port remedy) so proper application is important. The slow cure time is actually a plus, it just threw me off because of my expectations.

    But yes, it was straight off the store shelf. Not heated as you said, but as fresh as I could get.
  19. wally

    wally Member

    Okay, after 17 off-topic posts can we get back on topic please? :) je that is just a play on words to make the product look better, Happens all the time!.
  20. Fabian

    Fabian Well-Known Member

    Jaguar, can i plagiarize that line with my new girlfriend. She expects somewhat quicker results :whistling: