Sharp Innova cracked breech

[jirushi]

After hitting the "send" button for my Sharp book yesterday (to the man who will do the layout), I decided to celebrate with a bit of tinkering.
4 guns to work on:
2x BSA Light Pattern, Crosman 622, Sharp Innova.

The Innova was lovely to work on. An early example, without transfer port tensioning screw, but with 3 screws through the trigger guard.
The stock needed a bit of CCL oil, and I adjusted the trigger. On test firing, I could feel quite a bit of air escaping from the side of the breech, with my usual four pumps.
On closer inspection, the breech appears to have a crack. Probably from the valve stem hitting the rear of the breech since the eighties. I have a feeling that the crack has worsened over the last few shots.
I wondered if there are fixes for this problem?

Cheers,
Louis

[colin g]

Looks like your block is almost in half Louis, I would finish the break then glue it. You have nothing to lose mate.. Col.

[jirushi]

That is a good idea Col. Cheers.
What kind of glue would you use?

[Jakestenx]

I also had one of these crack at exactly the same place, could not repair it unfortunately, a lovely rifle in it's day.

[colin g]

That is a good idea Col. Cheers.
What kind of glue would you use?

Probably J-B Weld 50139 Plastic Bonder. And it dries black. They also do super glue plastic bonding these days. Col.

[BC312]

You could seek a 3d modeller and get one printed, take a bit of computer work to get the measurements sorted, or get one machined. Plastic is a funny thing, it can break down deteriorate and go brittle and crack as in your cases. I wonder if other Innovas have or will go the same way.

[colin g]

You could seek a 3d modeller and get one printed, take a bit of computer work to get the measurements sorted, or get one machined. Plastic is a funny thing, it can break down deteriorate and go brittle and crack as in your cases. I wonder if other Innovas have or will go the same way.

Yes but normally with incorrect pumping methods, Pumping the rifle holding the pistol grip causes most fractures. Its just not meant to be pumped that way. It has to be held over the scope rail and will last more than a lifetime. Col.

[BC312]

The other way you could make a mould from it and cast in a stronger machinable plastic. You would have to do some research into the type of casting plastic that would be durable but it can be feasible. Theres some really tough resin plastics out there in the casting world. As for pumping the wrong way i wonder how many owners know the correct way.

[colin g]

The other way you could make a mould from it and cast in a stronger machinable plastic. You would have to do some research into the type of casting plastic that would be durable but it can be feasible. Theres some really tough resin plastics out there in the casting world. As for pumping the wrong way i wonder how many owners know the correct way.

Only the original owners know how to pump a sharp as they came with the destruction manual that nobody reads anyway. I have to admit that i snapped the stock on one in my early days through pumping it wrong, Its ok for a few pumps then can become dangerous as the pressure in each stroke increases. The rifle only has one way to go when it breaks and thats usually upwards into your face, Most only have the one screw holding the stock on so its the weak point if holding the grip when pumping it up. Col.

[WILBA]

That's why I bought an ace. Steel breech much better. Shame they did not do a steel or alloy breech for the Innova as I love the shortness of the gun.

[BC312]

That's why I bought an ace. Steel breech much better. Shame they did not do a steel or alloy breech for the Innova as I love the shortness of the gun.

Thats why i bought a Sharps Ace, hated guns with plastic, early 70s 80s plastic was crap not like plastic today but saying that who knows how long todays plastic will stand up in the future to the elements chemicals and wear and tear.

[jirushi]

I will follow Colin's advice to finish the break.
Just spoke to a plastic repair company here in Amsterdam.
I will go there on Tuesday to decide what is the best way to (try to) repair the breech.
Perhaps plastic welding will be possible.

I still think the Innova was Sharp's best design.
I have 8, and this is the only one with a (big, lol) problem.
All from the eighties, all working perfect. So light and compact, big smiles every time.

The manual is indeed clear that one must hold the breech whilst pumping!

[jirushi]

You could seek a 3d modeller and get one printed, take a bit of computer work to get the measurements sorted, or get one machined. Plastic is a funny thing, it can break down deteriorate and go brittle and crack as in your cases. I wonder if other Innovas have or will go the same way.

Thank you for your advice. That is a good idea. I will try to repair the breech first, to keep things original. But there is quite a big chance that it won't work. We'll see.

[BC312]

I reckon if you can knock out machine, cast or 3d print receivers which now you can do in a metal material to the correct identical spec pattern etc you could be onto a winner in the spares part world. Must be pretty devastating finding your prized Innova forming a crack on the body, bit like opening a gun case on your favourite airgun only to find it covered in rust, a good topic what members here would consider a air gun disaster, ie stock snapped in half etc.

[Robert j]

A pity Louis that you want to keep it original, I have a new plastic breech for you without any inscription that I changed for metal. I directly remove all plastic from my rifles if possible. I prefer to improve wrong designs that are usually based on cost reduction. I think that is no crime. It is more like a nice tribute.