AT J180T Problem

I recently burned an AT J180T with normal motor function. When I attempted to clean the motor hardware, after it cooled, I discovered that the phenolic liner was essentially welded or melted to the inside of the motor casing and can not be removed. I did use a generous coating of Super Lube on the outside of the liner when I assembled the motor about an hour before the flight and I'm certain that I followed the assembly instructions correctly. I've never had this happen before and was wondering if anybody else has. Does anybody know any procedure for removing the liner in this situation without damaging the hardware or am I just going to have to buy a new 54/852 case?

I would use freeze spray/canned air turned upside down JUST on the Phenolic (spray the inside). Get it REALLY cold and then if you have a dowel or something similar push it out.

put the seal disc in on one side and push it with a dowel or something. Should push the liner out (hopefully)

I had something similar with an I59. Used seal disc and some PVC to push it out.

You greased the liner, now it's glued in. The C-slot core allows heat build up on the side with the slot.You will need a seal disk without O-ring, some WD40 or other penetrating oil, and a piece of wood dowel at least 1" diameter.
Apply WD40 to both ends of liner and allow it to suck in between liner and case. Let sit for at least an hour. Insert seal disk into one end of liner. Put other end of case on a soft surface and push out the liner. If it still won't move, use a hammer on the wood to get it started moving, then push it out. You can use steel wool to get the remaining gunk out of the case.

I like Super Lube (I buy it in a spray can and spray the inside of the motor case) but it isn't the thinnest of lubricants. Especially when cool.

Preheat oven to 200F. Turn off. Place case inside. Wait. 10 minutes should do it.

This will reduce the viscosity of the Super Lube and should allow you to remove the liner.

In the future, remove the used up bits from your motor case before it cools.

Thanks all for your suggestions. I successfully removed the liner using a seal disc and wooden dowel.

RobCamele said:

Thanks all for your suggestions. I successfully removed the liner using a seal disc and wooden dowel.

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You're welcome. Do not grease the liners on offset core motors. Bates motors can be assembled either with grease or without.

grease=superglue when heated and cooled.
I don't use any, other then snap ring cases where you don't want to dork the orings or threaded cases on threads and orings only.

cbrarick said:

grease=superglue when heated and cooled.
I don't use any, other then snap ring cases where you don't want to dork the orings or threaded cases on threads and orings only.

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+1 I quit using grease on liners when it seemed to glue them into the case more times than not.

I "used to" grease all my liners, until I started flying longburns. You're much better off NOT greasing the liners, especially if they're phenolic... they'll come right out if you push it out with the seal disk. I don't even grease my AT HL 29/40-120's anymore.

I use Super Lube grease on all my liners, never had a problem, liners push out with finger until I can grab them from the rear end and pull out. I clean all motors used for the day the same day after use no matter how late it gets to be. They shine like new inside after every cleaning. Those with problems removing the liner, how clean/ how scratched up are your cases inside? There has never been metal to metal contact inside my cases. All my cleaning brushes are plastic, hardly ever use anyway as a bunched up rag with wood dowel to push through the case a few times does the job. I clean the threads with a tooth brush and re-grease after cleaning.

rcktnut said:

I use Super Lube grease on all my liners, never had a problem, liners push out with finger until I can grab them from the rear end and pull out. I clean all motors used for the day the same day after use no matter how late it gets to be. They shine like new inside after every cleaning. Those with problems removing the liner, how clean/ how scratched up are your cases inside? There has never been metal to metal contact inside my cases. All my cleaning brushes are plastic, hardly ever use anyway as a bunched up rag with wood dowel to push through the case a few times does the job. I clean the threads with a tooth brush and re-grease after cleaning.

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Have you ever used an end burner, as in an I59? That’s the only liner I ever struggled with. Based on all these recommendations, I’ll skip the grease.

I don't use grease on any of my APCP reload liners, only the o-rings. I do however, use Mobile 1 grease on my Contrail hybrid motor liners, as recommended.

Never ever use grease on liners. Or you glue your liners in.

I use Blaster Dry Lube with Teflon and spray it into the motor casing, closures, and seal disk. Makes cleanup a breeze. Home Depot has the best price but I've also seen it at auto parts stores.

Jim

Used to use Dow 111 with Kosdon motors. Lubed the liners every time and never any "glue" problems.

It really boils down to selection of lubricant. Some lubes will turn into glue. Others can deal with the heat. I prefer to use heat-tolerant lubes for rocketry.

I’ve had liners ‘glue’ themselves in with lithium grease, badly. Better luck with Super Lube, but use it mostly with 29mm and below. However, I’ve had perfect results with dry lube, like ‘Garage Dry Lube’ spray with Teflon at Lowe’s or Home Depot. Quick, easy and it works.

I use Dollar Tree cooking spray most of the time. No issue in 5 years I've been using it.

https://www.dollartree.com/healthy-chef-canola-non-stick-cooking-spray-5oz-cans/223403

Tony

Get a pan and fill it with hot water, soak the casing in it

Viperfixr said:

I’ve had liners ‘glue’ themselves in with lithium grease, badly. Better luck with Super Lube, but use it mostly with 29mm and below. However, I’ve had perfect results with dry lube, like ‘Garage Dry Lube’ spray with Teflon at Lowe’s or Home Depot. Quick, easy and it works.

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Grease the threads and O-rings, Dry lube the liners?