Taking the end cap off a Haenel 28

[45flint]

Have had one off that was easy and obviously done before. Is there any trick to getting one off that has never been taken off. Obviously I don't want to mare the serrations. It's not yielding easily!

[Benelli B76]

Wrap a strip of leather around it and use curved jaw mole grips.

Baz

[draitzer]

To the above, add penetrating oil and a hair dryer to help it loosen the stuck joint. If you really want to get fancy, bore a block of oak to a little over the cap diameter, split the block, pad the cap with leather and use the block squashed in a vice to hold it all while twisting.

[Benelli B76]

Something I have always thought of trying is slightly warming seized caps and freezing the compression chamber with a liquid nitrogen dispenser. May ask my dermatologist to help me next time he blasts my skin !

Baz

[rancidtom]

You can buy cans of pipe freezer from any good DIY shop, no need for liquid nitrogen! Get the male threaded part cold and the female thread warm, spray some penetrating fluid in and let it work for an hour then warm/cool the parts again before unscrewing.

[Phil Russell]

All the above offer good advice. When faced with similar problems (challenges?) one of the key issues is that you may well have two items to grip ... the cylinder and the end cap. To grip a cylinder I use plastic tube e.g. kitchen wastepipe cut in half along its length (about 3") and glue 3mm rubber sheeting on the inside. This apparatus when fitted around the cylinder and gripped firm in e.g. a bench vice will grip without risk of marking the cylinder. For the end cap I use smaller plastic tube and maybe only 1" long, again lined with 3mm rubber sheet. This time I use the curved mole grips to grip the outer plastic tube with no risk of harming the end cap. I have tried leather inside mole grips but you need to be ultra careful that the serrations on the mole grips do not eat through the leather to scratch the cap. It all depends on how tight the cap is on the cylinder.
Cheers, Phil

[Benelli B76]

You can buy cans of pipe freezer from any good DIY shop, no need for liquid nitrogen! Get the male threaded part cold and the female thread warm, spray some penetrating fluid in and let it work for an hour then warm/cool the parts again before unscrewing.

Pipe freezer is liquid nitrogen. Was hoping to get mine free from the doctor as I pay him £180 a visit.

Baz

[dvd]

Wrap a strip of leather around it and use curved jaw mole grips.

Baz

+1 on the leather strip and curved locking pliers technique.

Parallel locking pliers jaws can do more harm than good and can deform the cap and tube due to the localized pressure they exert on a smaller area.
The larger the surface area of the cap that is grabbed by the leather, the better and less chance of slipping.

I have found that when I tried to apply anti-clockwise rotation to undo the occasionally very stubborn end-caps of Giss type Dianas, they are harder to undo twisting them in just one direction, than when I initially apply a rocking two directional close-open rotational force on them till they turn.