Barrel install wiggle fix

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • Klem
    Chieftain
    • Aug 2013
    • 3509

    #46
    Originally posted by Keef View Post
    Home alone this weekend so I didn't get the stink eye for pulling the tool bag out. Lol.
    Just took it apart for the third time and it took a wooden down and mallet to make it happen. Here are the pics it's a super thin layer but it makes a big difference.
    [ATTACH=CONFIG]10858[/ATTACH]

    [ATTACH=CONFIG]10859[/ATTACH]
    According some bolt action rifle bedders it has less thermal expansion/contractions than some much more expensive products. But I don't really know.

    Upper face after truing. You can see much more material was removed from one side.
    [ATTACH=CONFIG]10860[/ATTACH]
    I'm familiar with JB Weld having used it on a few dive torch builds. We tried a few different single and two-part epoxies hoping to withstand salt water under pressure and after a few leaks settled on JB Weld for strength. That stuff sets rock solid and is impervious to pressure. Devcon makes a similar two part epoxy, also with metal particles. I'm thinking, in this bedding scenario you want something that is strong to withstand the constant hammering of rounds going off, doesn't shrink when curing, and withstands temperature. JB Weld's upper limit is 450 F for extended periods of time. JB also sells an 'ExtremeHeat' epoxy that withstands up to 2,400 F. It's a paste so it may not flow into all the space between the extension and receiver before curing (I have never used it so can't comment).


    Here's an example of JB Weld in underwater torches; swapping out the standard clicky for piezo switches in Maglite housings. because it's a viscous like honey going on it fills every little void for a hermetic seal and if it traps air in a void the weight of the glue displaces the air which bubbles to the surface prior to curing. I'm thinking if you held the barrel vertically in the vise while it cured it would do the same but you would have to do the barrel nut up at least hand tight or it will leak through the barrel/receiver join. If you want it thicker going on just wait a while after mixing before applying it. As you can see it resists pressure of several atmospheres. There's zero flex in it.


    JB can be a little runny before curing so for bedding a bolt gun it might be hard to work with and obviously not use the 10-minute stuff, but in this barrel/receiver application I would use it.
    Last edited by Klem; 01-20-2018, 11:56 PM.

    Comment

    • Crusty
      Warrior
      • Dec 2017
      • 237

      #47
      I knew a doofus that snapped off a water pump bolt on a 6 cylinder Ford, then when drilling it out he drilled all the way into his #1 cylinder (luckily the piston was down). He pulled the head, cleaned up the hole inside, removed all the metal fragments, rethreaded for a new bolt and then packed the bottom of the hole with JB. The next day he put it all back together and it ran fine, and he drove that car for 2 more years before he sold it.
      I'll be yer Huckleberry.

      Comment

      • olde sarge
        Warrior
        • May 2014
        • 247

        #48
        Crusty, I am one of those doofuss types I guess. Years ago I had a cross threaded sparkplug in a VW head pop out and no money to replace the head or buy helicoils. Sooo, I JB Welded a spark plug into the head and drove it that way for more than a year. Good stuff to have around but don't think I would use on my Grendel. Too darn permanent.

        Comment

        • Klem
          Chieftain
          • Aug 2013
          • 3509

          #49
          Originally posted by olde sarge View Post
          Crusty, I am one of those doofuss types I guess. Years ago I had a cross threaded sparkplug in a VW head pop out and no money to replace the head or buy helicoils. Sooo, I JB Welded a spark plug into the head and drove it that way for more than a year. Good stuff to have around but don't think I would use on my Grendel. Too darn permanent.
          Shouldn't be permanent if you coat one surface with a release agent, like boot polish or oil.

          Comment

          • Sticks
            Chieftain
            • Dec 2016
            • 1922

            #50
            Neutral Kiwi shoe polish, 2 coats at least. Good stuff.
            Sticks

            Catchy sig line here.

            Comment

            • Crusty
              Warrior
              • Dec 2017
              • 237

              #51
              Sarge, I didn't mention any "doofus type" but rather a particular individual who earned his stripe by continuing to drill deeper and deeper into his block until he drilled into a cylinder, without once ever checking the hole depth or knowing how deep he could go. That's DFC rank to me.

              If you don't know about it, E6000 is just as useful as JB in some applications.
              I'll be yer Huckleberry.

              Comment

              • ErikS
                Warrior
                • Dec 2017
                • 138

                #52
                knock it if you like.

                A skim of JB Weld on the extension exterior before inserting the barrel into the upper does a great job, it is permanent. JB weld is very heat resistant (600f +) and will stop any movement between the upper and extension.
                #shareyourspare

                Comment

                Working...
                X