Sporasub One Air Assembly (and other related stuff)

[Diving Gecko]

I just took apart my One Air to change the piston and another part that Spora/Omer had sent to me. And... just to have a look at how it is put together of course

Some things are quite nice. Some less so. But we can take that as it comes.

First five pix are an introduction to the major parts (at the top is my modified Seac Hunter 90):

 

[Diving Gecko]

This is not a full assembly in the sense that the gun was not fully disassembled. EG. the sear lever mech was not taken part - I am leaving for a spearing trip in one day and did not want to risk messing up too much. Also, the handle was not taken apart this time, but there is another post about that.

Let's move on to the assembly. I started at the handle end:

 

[Diving Gecko]

The next three images are of the inner barrel and the lower (handle end) parts being mounted into the tank:

The fiber reinforced nylon part which tapers from the pump valve and into the outer tank was the part that was replaced by Spora. It is a tiny bit more bulky than the old part.
It took a bit of force for the outer barrel to go into the seat of the plastic part.

 

[Diving Gecko]

Next images are of the front "plug" and piston being put in. The piston was the other replacement part. The new piston comes with an internal reinforcement bridge. It was difficult to photograph, but I will upload some pics of the piston later.

 

[Diving Gecko]

Last frames are of the muzzle and front float being put back on.
The spanner is 22mm but it has to be quite slim (max 7.5mm) to fit.
(I will upload more pics of muzzle later)

 

[Diving Gecko]

COMPRESSION FACTOR
If some of you want to figure out the compression factor, then here are the dimensions.
Outer tank (only the circular middle part is used): ID 34mm
Inner Barrel: ID 11mm & OD 16mm.

 

[Diving Gecko]

NEW PARTS
As said, the piston and the back "plug" has been updated and I got replacement parts.

It's hard to tell in pics, but the plug is a bit beefier on the bottom. I don't know whether they added more fiber to the plastic but it has a bit more material.

The new piston has a small bridge on the inside.

(It's the new plug on the left and in the last pic):

Here are the pistons (last pic is the new one):

 

[Diving Gecko]

MUZZLE
Sorry, forgot to take it completely apart at the front of the muzzle, so you can't see the seal - but it is one of those designs where the pistons slams directly into another plastic part:

 

[Diving Gecko]

TRIGGER PIN
This is one of the things I like. The trigger pin on the side of the air chamber is 1.5mm but is 2mm at the outside:

 

[Diving Gecko]

SO, SO SEALANT
Well, it's not leaking but I was a bit surprised to find this...:

 

[popgun pete]

Great photos, now we can see what is inside one of these guns. The side tanks appear to contain some white stuff which I have not seen any reference to before, previously they were considered to be "empty". What do you think it is (e.g. foam) and does it fill each side tank? The photos are loading slowly, so this may be the sealant that you are referring to, but the photos are yet to appear and I noted this stuff further up the page.

Well now I can see it and it looks like some sort of grease, but is it soft or has it set?

 

[Diving Gecko]

Hi Pete,
Yeah, the light grey stuff seems to me to be a silicone sealant. I would say it is the hardness of most silicones I have come across.
I don't know if it only plugs the ends of the side tanks or whether it fills them up completely.

Also, it seems like the silicone is put in just before assembly as some of it is on the inside of the main tank. But the goo on the inside is a bit softer - I think perhaps the oil somehow kept it from fully curing. That at least made it easy to remover with a fingernail for when I put it back together. There were small pieces of it in the gun oil as well.

And yes, the gun def had oil in it. I thought I had read something about the Airbalete having a grease, so was a bit surprised to find oil in this one.But maybe my memory is playing tricks on me.

 

[popgun pete]

Grease is what was used at first, Omer made mention of it as a special type of grease which made oil unnecessary, but that soon changed once the problems of not having a coating over all the internal parts to both lubricate and protect them became obvious.

 

[tromic]

Great photos and useful informations!

 

[popgun pete]

Does tapping the outer wall of the side tanks produce a hollow sound? They may contain foamed blocks made to fit neatly inside the tank's crescent-shaped cross-section and then filled up and leveled off with sealant at each end to stop any water wicking in along the resultant gaps between the foam blocks and the interior metal wall of the side tanks. I don't think that they would fill the side tanks up with sealant, too heavy, but unless there was something underneath them pressure at depth would tend to push the sealant plug ends further into the side tanks.

I note that the flattened and slightly conical outer nose cone is just a shroud that indexes on the lateral flanges on the outer face of the front pressure bulkhead and is affixed there with two vertical pins on either side. So the construction there is different to what I had imagined it to be, especially when looking at the early prototypes, but this has made the gun simpler to manufacture as it is essentially a gun with a slightly smaller pressure tank flanked by ballast tubes-cum-lateral anti-lift paddles on either side.

Rear body sections may have been thickened up to resist bending, most pneumatic spearguns have the inner barrel running completely from front to rear, but in the "One Air" the inner barrel stops forwards of the handle section and the latter may tend to apply a short lever arm on the barrel section sitting directly in front of it.

 

[DuncM]

Hi, I just opened up my One Air to replace the oil and when I took the piston out to have a look, noticed it's a bit rusty at the tail. Do you think it needs replaced?

 

[popgun pete]

You can clean the rust scale off with some "wet and dry" paper by rotating the tail, or the paper, using some oil as a lubricant, but just a single drop. The tail should be OK unless it has some pits in it once you wipe the removed material away and can take a better look at it. More importantly there should be no rust there as oil lubrication inside the gun is intended to stop that. The "One Air" uses a locked sear lever which is otherwise unstable, unlike the catch hook used in most other pneumatic guns. The slope on the face of the mushroom head looking towards the piston body is there to push the sear lever aside when the sear lever is unlocked by you pulling the trigger.

 

[DuncM]

Thanks,
Do you think it will be necessary to remove the sear lever too and check and clean it?

 

[popgun pete]

If you can easily see it then it may be worth checking, but I don't think that it will be rusty. When a pneumatic gun is stored standing on its muzzle the oil in the gun pools in the front end of the tank and also in the inner barrel with the piston tail sticking up out of the "oil pool". If the oil in the gun was contaminated with seawater then this could cause the piston tail to rust, especially if the gun had been stored like that for some time. The seawater may have got into the gun by unwittingly shooting it with a flooded barrel as with no muzzle relief ports the water has nowhere to go until the spear tail exits the muzzle. It is a good idea to put the old removed oil into a jar and see if a water layer settles out over a period of time on the bottom (as oil floats on water).

 

[Diving Gecko]

DuncM,
Wow, that's not nice to look at.
I would send that pic to Sporasub as I think they should send you a new one. Not so much because you can't fix it yourself but also because they might want to know about this. And then ask their thoughts on the sear lever. Make sure you mention you have never taken your gun apart before (if you haven't). That way, there is no way you can be faulted for this.
They have sent me some parts in the past that were silent upgrades.