Webley junior piston screw won’t budge

[liamrose]

Hi
I picked up a pre 58 webley junior with the Bakelite grips recently which needed the seals changing and a good clean.

Ordered the bits I needed and got everything apart except no matter how I try, the screw in the piston won’t budge. I cut away the old leather seal squirted copious amounts of wd 40 over the screw and inside the piston…..won’t budge.
Next I tried heating the top of the piston with a blow torch and allowing to cool but it still won’t move.

Has anyone and ideas as to how the screw can be removed or am I going to have to drill it out?

[laverdabru]

Try standing the piston in a container face down in a container & filling the inside with WD/Plus Gas/solvent of choice. Then forget about it for a few days. And try again.
Also, the old fashioned manual impact driver is worth a try.

Hth

Bru

[liamrose]

I’m trying that at the moment. Been soaked overnight.

Wonder if I could drill a hole through the piston so I can grip it better with a screwdriver shaft as it’s impossible to grip the piston whilst trying to get screw out?

[Maple]

Forget WD40 ( very limited use ) heat the piston up and whilst hot stand it in plus gas covering an inch of the piston rod.

[laverdabru]

I’m trying that at the moment. Been soaked overnight.

Wonder if I could drill a hole through the piston so I can grip it better with a screwdriver shaft as it’s impossible to grip the piston whilst trying to get screw out?

You should be able to buy a 2nd hand vice for a few quid - much better solution, & it'll come in useful for other jobs. Try & get one with alloy covers for the jaws, so doesn't damage items being gripped.

Bru

[trajectory]

Check the manufacturers instructions & safety advice out. Many oils, lubricants, dismantling fluids are flammable additionally they can release dangerous or harmful fumes perhaps especially so when warm or in confined space. Flammability/ ignition with heat flame or sparks is possible, liquid or vapour.

It dosent sound as if you are using a vice, I'd suggest thinking about getting one & finding somewhere solid to fix it to. A bench if you have it or a portable work bench might be usefull for other jobs too not just for servicing air pistols etc. it will give you a more secure & safer way to work on things than hand holding them.

In the meantime let it soak in 3 in 1 or diesel or something like that & try it again when you get a secure & safer way of holding it. Depends on what tools you have at the moment or if you can get a loan of something from family or friends.

[edbear2]

Get someone to put a bit of weld (Tig is the most accurate + plus you can use a high strength rod) on the screwhead (if now scrap), or heat with a propane or gas ring (screw only) till dull red......allow to cool a bit, then a squirt of duckoil / wd /whatever and it will smoke a bit, but the heat remaining will draw in the fluid more then submersing etc.

Rinse and repeat, this will usually do it in very case, especally the weld thing;

https://www.flickr.com/photos/312284...57623019958012





ATB, Ed

[edbear2]

I’m trying that at the moment. Been soaked overnight.

Wonder if I could drill a hole through the piston so I can grip it better with a screwdriver shaft as it’s impossible to grip the piston whilst trying to get screw out?

If it's that tight the "seal" needs breaking, see my post above or you will end up with a snapped off screw, still that's an easy job for anyone with a lathe to sort out.....It maybe also someone has used a strong grade of threadseal in the past, so the heat as mentioned above will "kill " that and get things moving.

If one of the bearing grades of loctite has been used, they are oil resistant /tolerant so you are wasting your time with oils.

ATB, Ed

[laverdabru]

Any progress on the seized item?

ATB

Bru

[slim63]

I stripped a webley junior down today and had a similar issue

In the end I gripped the piston in a soft jaw vice, ground an old screwdriver to a perfect fit then forced down on the screwdriver with my left hand while turning on the flat of the screwdriver with an adjustable spanner in my right

It took a while but the constant pressure finally made it give just a little then i hit it with plusgas and turned it in and out a few times, it came out a little at a time for the first 3 or 4 threads then came out normally

Looking at the screw which is quite poor quality I think snatching it with an impact driver will do nothing more than either bend it or more likely shear the head and if you add too much heat as a last resort it will break even easier

best of luck!