Stuck forward closure hobbyline case

ScrapDaddy

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Hey guys I broke the cardinal rule and forgot to clean out my 40/120 case after a launch yesterday. Now the forward closure is stuck. I tried soaking the thing in WD 40 and also tried using pliers and rubber bands to try and get a grip.

Do you guys have any tips?
 

3stoogesrocketry

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Hey guys I broke the cardinal rule and forgot to clean out my 40/120 case after a launch yesterday. Now the forward closure is stuck. I tried soaking the thing in WD 40 and also tried using pliers and rubber bands to try and get a grip.

Do you guys have any tips?

Hot water ( 200ish ) for a few minutes.
 

markkoelsch

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A penetrating oil- try Kroil.


Sent from my iPhone using Rocketry Forum
 

Buckeye

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Hey guys I broke the cardinal rule and forgot to clean out my 40/120 case after a launch yesterday. Now the forward closure is stuck. I tried soaking the thing in WD 40 and also tried using pliers and rubber bands to try and get a grip.

Do you guys have any tips?

One day without cleaning should not be a big deal. Are you sure nothing else is is going on? Crossed threads?
 

ksaves2

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Be careful. The threads can get torn out no matter what you do. I had a well worn 38mm AT 240case I ran 2 grain research loads in that were kinda hot. I twisted off the aft closure and a few aluminum shards were seen. Next load I fired, aft closure blew off, rocket went up the rail 3 feet and came back down. Since I was using electronic deployment of an apogee main (Galejs MAD unit) rocket just sat there. I used a spring steel clip like with bp motors so the aft closure
was able to blow past it. Funny launch I got closest to the pad award that day. Kurt
 

Handeman

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I had a similar issue. I now have a forward closure with tool marks on the upper part. I used a strap wrench on the tube and a slip wrench on the closure. I figured the closure was cheaper to replace.
It's been several years and the gouged closure is still working fine.
 

Tonimus

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I had a similar issue. I now have a forward closure with tool marks on the upper part. I used a strap wrench on the tube and a slip wrench on the closure. I figured the closure was cheaper to replace.
It's been several years and the gouged closure is still working fine.

Gouge it evenly, then it just looks like wicked knurling.
 

cavecentral

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If you have one of those AT brand wrenches, it may help get a decent hold on the closure without too much damage. Alternately a screw driver across the cut out sections to make a T handle.

Various solvents or penetrating oils other mentioned may help. I agree that this is worse that normal for a day without cleaning. I have some closures that work well with the casing they came with - not sure much on other casings.

I'd really rather see more 29/60, 29/100, 29/120 offerings with the HPR version of the case (At hobby line prices). Core burners are much nicer than C-slots for fitting igniters. The cases and closures are higher quality etc.
 

ksaves2

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If you have one of those AT brand wrenches, it may help get a decent hold on the closure without too much damage. Alternately a screw driver across the cut out sections to make a T handle.

Various solvents or penetrating oils other mentioned may help. I agree that this is worse that normal for a day without cleaning. I have some closures that work well with the casing they came with - not sure much on other casings.

I'd really rather see more 29/60, 29/100, 29/120 offerings with the HPR version of the case (At hobby line prices). Core burners are much nicer than C-slots for fitting igniters. The cases and closures are higher quality etc.

Just don't rip the threads out of the Aluminium case like I did above in #7 with the well used AT 38mm case I ran some hot research propellant through. Not so much worried about the closure but if the OP sees Al shards coming off the end
of the case, the threads might be stripped and the case trashed. I didn't recognize that and won the closest to pad award. Kurt
 

swatkat

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This works every time. Get a can of compressed air at Fry's, Staples, etc. Turn it upside down and spray, it will blast out the propellant which under pressure comes out at something like -20... use this spray to freeze the end of the case. Get it good and cold... (10-12 seconds). Then wipe off the ice and take two rags or non-slip gloves and open'r up.
 

Handeman

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This works every time. Get a can of compressed air at Fry's, Staples, etc. Turn it upside down and spray, it will blast out the propellant which under pressure comes out at something like -20... use this spray to freeze the end of the case. Get it good and cold... (10-12 seconds). Then wipe off the ice and take two rags or non-slip gloves and open'r up.

Sounds like a great field fix. Do you think dropping it in a deep freeze (a real freezer, not the freezer section of a refrigerator) overnight would work too?
 

0011001100

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Sounds like a great field fix. Do you think dropping it in a deep freeze (a real freezer, not the freezer section of a refrigerator) overnight would work too?
No because that would freeze both parts and wouldn't help. What he is suggesting is to freeze just the closure and keep the case warm.
 

Handeman

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...use this spray to freeze the end of the case.

No because that would freeze both parts and wouldn't help. What he is suggesting is to freeze just the closure and keep the case warm.

Sounds like he was saying the opposite, freeze the case. My instinct says your way might be better by making the closure shrink and not the case. Guess I'll have to try out each method next time I have a stuck closure.
 

Tonimus

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I believe he meant the closure, being on the end of the case. But yeah, you want to cool the closure down and not the case itself.
 

rcktnut

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I still don't see how properly greased threads on the motors, properly assembled (no cross threading), and properly operating (no o-ring breaches), can cause such a problem. Can it be the grease used? Over tightening? Lack of thorough cleaning the threads? I've never had that problem, closures on all Hobbyline and HP motors have always been very easy to remove.
 

swatkat

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Sounds like he was saying the opposite, freeze the case. My instinct says your way might be better by making the closure shrink and not the case. Guess I'll have to try out each method next time I have a stuck closure.

I'm saying freeze the closure, and no, deep freeze just shrinks the whole thing.
 

ScrapDaddy

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Any updates? Has the OP gotten the closure out?

I took the advice of getting a rubber strap wrench. It was a nice $5 investment and got the closure off in short order! Thanks for all the help guys!
 
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