Liner stuck, I mean really stuck!

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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.
 
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.
 
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!
 
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?
 
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.
 
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.
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.
 
Don't do any of that. Reverse forward bulkhead, attach all thread at least twice as long as case. Get a second case, can be shorter, butt it against the other case with all thread at least 4 inches past end when both cases are butted together. Get a piece of wood or metal bar stock drilled to fit all thread. Use nut and fender washers on all thread to the block and just crank down on the nut. Draw the liner into the second case. You can probably remove the liner after it starts moving. Trust me, this is the easiest liner removal tool known to man!

Jim,

Brilliant . . . What a great idea !

Dave F.
 
Another alternative I used when torch not available [as in hotel room] turn hot water on in tub and hold under spout while rotating and moving back and forth, till the tube is so hot you can barely hold it.[use gloves or towel] then proceed with liner removal. This always worked just as well, but takes longer for heat transfer,[about 15 minutes vs 4-5 with torch]

I'd love to see housekeeping's expression looking at That bathtub "WtH were they doing in here?...."
 
Don't do any of that. Reverse forward bulkhead, attach all thread at least twice as long as case. Get a second case, can be shorter, butt it against the other case with all thread at least 4 inches past end when both cases are butted together. Get a piece of wood or metal barstock drilled to fit all thread. Use nut and fender washers on all thread to the block and just crank down on the nut. Draw the liner into the second case. You can probably remove the liner after it starts moving. Trust me, this is the easiest liner removal tool known to man!

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


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?

hahahahahahahahaha
dat was a goodie,, lol..

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.

+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..

I'm really hoping this statement is not about your mother in law.

hahahahahahaha

Teddy
 
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.
 
I've always used the oven to free stuck liners. Works every time.
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
 
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.
 
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.

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
 
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.

May have to do with the type of grease. A high temp teflon grease should work fine I would think.
 
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.
 
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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