Stuck Liner

The Rocketry Forum

Help Support The Rocketry Forum:

Kruegon

Well-Known Member
Joined
May 21, 2014
Messages
1,885
Reaction score
4
For two weeks I've been trying to get a liner out of my 38/600 case. It's a black phenolic liner. It slid in snug but pretty easy. I've tried pushing it. I've tried driving it out gently with a wooden dowel. I've currently got it in the freezer. Any other suggestions? The closures came off with no issues.
 

dhbarr

Amateur Professional
Joined
Jan 30, 2016
Messages
7,190
Reaction score
1,622
Boil it. Yank it out w/ a heatresistant nonporous glove and push it down over a close-fitting pipe or dowel.
 

Kruegon

Well-Known Member
Joined
May 21, 2014
Messages
1,885
Reaction score
4
That will be my next method to try. This time, I froze it, let it warm to room temperature, placed the seal disk back in, and tapped it down on a wood dowel. Seal disk looks fine and no damage to the case.

Will boiling it damage the anodizing?
 

dhbarr

Amateur Professional
Joined
Jan 30, 2016
Messages
7,190
Reaction score
1,622
No, it won't take it above 100C ( unless you use a pressure vessel ).
 

Zeus-cat

Well-Known Member
Joined
Mar 14, 2009
Messages
4,623
Reaction score
830
That will be my next method to try. This time, I froze it, let it warm to room temperature, placed the seal disk back in, and tapped it down on a wood dowel. Seal disk looks fine and no damage to the case.
Why did you let it warm up? When you use heat or cold you want to use the difference in thermal expansion rates of the two materials to help you separate them. However, in this case, I think heat would work better as dhbarr suggested. The metal should expand more than the phenolic when both are heated, thus loosening them up. The metal case will shrink more than the phenolic when cooled making a tighter fit.
 

cbrarick

Wildman CT
Joined
Jan 23, 2009
Messages
2,599
Reaction score
318
nope.

Get yourself one of these https://www.homedepot.com/p/Everbil...C-Channel-with-1-16-in-Thick-802657/204273938

now, cut the sides back about 3/4 inch and sharpen the sides.
use the tongue (from the bottom), slide it between the case and the liner, you will eventually need to use a hammer on the far end of your new tool to make it cut. Get 'r done all the way to the end, then the whole thing will pop out no big deals.

Don't use anything more substantial or you will mess up the case......
 

amarillo_rocket

Well-Known Member
Joined
Jan 20, 2009
Messages
292
Reaction score
0
Heat has worked for me. I had a stuck liner in a 76mm. I put it in my car on a hot summer day for 1.5hrs. Liner slid out with very little effort.
 

T-Rex

Ordinary Average Guy
TRF Supporter
Joined
Jul 22, 2011
Messages
3,007
Reaction score
57
How long has the liner been stuck? I bought a used case with a stuck liner, that had been in an unknown amount of time, and tried all the customary methods. Finally resorted to using a hacksaw to partially cut the liner lengthwise in several places around then using bamboo skewers wedged between the liner and the case wall to collapse/break the liner. The liner came out in pieces, but it is out and the case has been used since.
It's not quick by any means, and you have to be VERY careful when making the cuts. Obviously a last resort method.
 

markkoelsch

Well-Known Member
Joined
Mar 18, 2009
Messages
4,364
Reaction score
149
Is the seal disk still in it? If so, I would stand the case in end, insert a good sized dowel against the seal disk, and strike it with a hammer. Might need a new seal disk.
 

AlphaHybrids

Well-Known Member
Joined
Nov 29, 2009
Messages
1,570
Reaction score
86
nope.

Get yourself one of these https://www.homedepot.com/p/Everbil...C-Channel-with-1-16-in-Thick-802657/204273938

now, cut the sides back about 3/4 inch and sharpen the sides.
use the tongue (from the bottom), slide it between the case and the liner, you will eventually need to use a hammer on the far end of your new tool to make it cut. Get 'r done all the way to the end, then the whole thing will pop out no big deals.

Don't use anything more substantial or you will mess up the case......
I wouldn't even use this. I've seen some nice cases with tracks down the sides from cutters like these. I will take an oak dowel and use a miter saw to cut at a steep angle. Then I wedge this under the liner and slowly advance with a rubber mallet to break the liner up. Make sure you place the case on something soft - I use an old rubber floor mat to cushion the blows. For a 38mm case a 1" dowel will fit nicely. 1" SCH 40/SCH 80 slip fits nicely in 38mm cases. The OD is 1.315", the ID of the case is 1.334". You could use that also to brute force it out.

Edward
 

Kruegon

Well-Known Member
Joined
May 21, 2014
Messages
1,885
Reaction score
4
The liner was only in for two day to start with. Having trouble, trying different methods, asking around. That took another week +. All in less than two weeks.

I tried several methods from soaking to tapping to trying to start a split in the liner. The liner just chipped. And the tapping went to borderline pounding. No I never struck the case. I'm guessing when I let it reach room temperature, the expansion difference was just enough to release it.

I froze it. Put the seal disk in and tried to budge it with a dowel. No joy. Let the metal hit room temperature and tried again. Started moving after third tap. Five taps later I pulled it out by hand.
 

T-Rex

Ordinary Average Guy
TRF Supporter
Joined
Jul 22, 2011
Messages
3,007
Reaction score
57
Good to hear you got it. We all learn from the triumphs of others.
 

Zeus-cat

Well-Known Member
Joined
Mar 14, 2009
Messages
4,623
Reaction score
830
Thanks for the update; I was curious as to what happened.
 
Top