Liner stuck, I mean really stuck!

Discussion in 'Propulsion' started by Bat-mite, Feb 16, 2019.

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  1. Feb 19, 2019 #31

    Zeus-cat

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    If you use the oven do NOT tell your wife, girlfriend or mother about it or that $45 case you saved will become a $600 replacement oven.
     
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  2. Feb 19, 2019 #32

    blackjack2564

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    You must have a very large oven, i could not get a 7600 [6xl grains] in mine.
     
  3. Feb 19, 2019 #33

    manixFan

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    How about an industrial hot air gun? I'm pretty sure the one I have would get the case hot enough pretty easily. It would be a lot easier and safer than using a torch.

    They run anywhere from $30-$100 and are probably more useful than a torch.


    Tony.
     
  4. Feb 19, 2019 #34

    Bat-mite

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    Okay, to finish the story and respond to posts.

    It is a 38/480, not a 76/7600.

    I did not use the oven because Scott K. reminded me of the stink and toxicity of burning phenolic.

    I have a heat gun and maybe could have used it, but didn't think of it.

    I bought a cheap propane torch (< $20) at Home Depot and used that. It worked perfectly.

    For anyone reading this down the road, here are the details.

    • After the motor was launched, I did not clean it at the field. I let it cool, took it home, and then tried to clean it days later.
    • I used PVC against the forward bulkhead to try to knock the nozzle out. The liner moved just enough to get the nozzle to where I could pull it out.
    • I then used the PVC against the liner at the nozzle end to try to push the forward closure out.
    • While this was successful, it, however, left the 1" PVC pipe stuck in the casing. I think the liner got wedged between the PVC and the casing.
    • I tried many times to get the PVC out, and with lots and lots of banging, finally did.
    • But the liner would not budge. That's when I started this thread.
    • I held the casing in a leather glove, ignited the torch, and put the flame as close to the middle of the inside of the casing as I could.
    • Once I felt the heat of the casing start to make my hand inside the glove a little uncomfortable, I removed the torch.
    • I put the forward closure upside down into the casing, then used a 3/4" PCV pipe to bang out the liner.
    • I immediately cleaned the inside of the casing with acetone.

    So, I saved my casing and ended up with a new tool. Not bad.

    Please buy Loki motors. Scott is awesome to deal with. This was not his fault or his problem, but he texted me, e-mailed me, and offered to help me over the phone. Great guy!
     
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  5. Feb 19, 2019 #35

    Zeus-cat

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    How many times did you have to hit it to pop the liner out? Gentle hits or "that looks like my mother-in-law" whacks?
     
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  6. Feb 19, 2019 #36

    rcktnut

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    Great to hear it worked out for you. Out of curiosity, how did the liner fit when you assembled the motor? The first step I do when assembling is check the fit of grains into the liner and the liner fit into the case. If at all tight I do what is necessary to make sure there is a nice fit, no effort needed to insert the the components together, especially the liner into the case.
     
  7. Feb 19, 2019 #37

    Bat-mite

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    :D

    I'd say it was pretty easy once it was hot.
     
  8. Feb 19, 2019 #38

    Bat-mite

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    True. For me, it went together without issue, and I truly believe that if I had cleaned it at site while still warm, this wouldn't have happened.
     
  9. Feb 19, 2019 #39

    djs

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    I'm really hoping this statement is not about your mother in law.
     
  10. Feb 20, 2019 #40

    Ez2cDave

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    Jim,

    Brilliant . . . What a great idea !

    Dave F.
     
  11. Feb 20, 2019 #41

    Nytrunner

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    I'd love to see housekeeping's expression looking at That bathtub "WtH were they doing in here?...."
     
  12. Feb 20, 2019 #42

    Onebadhawk

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    Holy smokes is this a fantastic idea...
    I hafta remember this one..
    See what age and experience does,, lol..


    hahahahahahahahaha
    dat was a goodie,, lol..

    +1.....
    All should fit properly,
    if it doesn't, instead of forcing it,
    make it fit properly,
    a bit of sanding oughta do it, lol..

    hahahahahahaha

    Teddy
     
  13. Feb 21, 2019 #43

    jimzcatz

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    I have to give credit where credit is due. While I had an idea, I just couldn't figure it out so I asked Alan Whitmore if he could come up with some kind of liner removal tool. This is that him and Jim Livingston came up with. It works. Preston Noble had a 2 grain 75 liner stuck. We really had to use a bunch of elbow grease, but we got it out. So here's proper credit to Alan and Jim, thanks guys.
     
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  14. Feb 23, 2019 #44

    GlueckAuf

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    I only had this happen once, on a Loki 38/1200 case that had cato'd by burning through the center of the forward bulkhead with the K1127. Thankfully there was no damage at all to the case, but the phenolic liner would NOT budge. Until I heated it up in a 350F oven for about 30 minutes.

    Holding the hot case with a glove, I used a new forward bulkhead as a drift and tapped it with a wooden dowel and hammer. Two or three blows and the liner broke loose, thereafter sliding out easily.

    Loki's Scott K thoughtfully called me after I emailed him about the cato, and he suggested I use heat, but warned the oven approach might cause some noxious fumes to fill the kitchen. But I guess 350F was below the stink threshold, so it wasn't an issue. (And the good Mr. K promptly replaced all the damaged parts of the motor along with a new reload kit. What a guy!)

    By the way, in the grease/no grease argument, I did use Superlube to grease both the liner and case ID when I assembled the motor...and still will. MOST of the liner didn't stick, only the forward end near the failed and burned-through bulkhead. I'm pretty sure a dry liner would've stuck a whole lot worse.

    Good skies,
    GlueckAuf
     
  15. Mar 7, 2019 #45

    Bryan S Snyder

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    Another suggestion... I would use a heated vibratory tank. I have a long 9L one for gun parts that I use for a number of things. Heat, high frequency vibration, and the proper solution can work miracles.
     
  16. Mar 7, 2019 #46

    Ez2cDave

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    Jim,

    Here, for all to see and share, is the article showing the mechanism and the procedure . . .

    Dave F.


    STUCK MOTOR LINER REMOVAL TOOL - 1.PNG
    STUCK MOTOR LINER REMOVAL TOOL - 2.PNG
     
  17. Mar 7, 2019 #47

    Bat-mite

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    It's a great idea if you like making tools and plan to need to do this over and over. I'll stick with the blow torch.
     
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  18. Mar 7, 2019 #48

    ChuckH

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    Was that the one I caught Preston beating up my range box with? :D
     
  19. Mar 10, 2019 #49

    Dave A

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    I guess I have been lucky, I grease all liners from one end to the other. Never had one stick, although I try to remove them before sundown on flight day.
     
  20. Mar 10, 2019 #50

    Bryan S Snyder

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    May have to do with the type of grease. A high temp teflon grease should work fine I would think.
     
  21. Mar 10, 2019 #51

    Dave A

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    Jim,
    That is an awesome liner remover.
     
  22. Mar 11, 2019 #52

    Jim Green

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    I use Dry Lube, a dry PTFE (Teflon) spray. Made by Blaster. I get it from Home Depot. It leaves a white powder of PTFE inside the casing and the liner just falls out. Cleanup is a breeze.
     
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  23. Mar 11, 2019 #53

    Bat-mite

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    As an FYI, I launched a Loki L840 on Saturday and could not get around to the motor clean-up until Sunday night. This time I had greased the liner with white silicone grease, and the liner slide right out. The 38mm that got stuck did not have a greased liner.
     
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  24. Mar 11, 2019 #54

    Dave A

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    If my vendor does not have any then I keep this in my toolbox as a bckup.
    I am sure there are others, but this stuff can be had about anywhere.
    I get it form the local Advance Auto Parts Store.
    If you search their site you get automatic 20-25% off.
    I use this to grease my o-rings, threads and the entire length of the liner.
    It works great as an anti-seize on dissimilar metals, i.e. AL to Steel, brass, etc.
     

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