What grease should I use to reduce seepage from loading tap leak?

[andrewM]

Sometime ago, someone posted a thread to say they used a particular grease to reduce to almost nil, the air leakage from his loading-tap. I cannot recall the date or member.

Recently, the loading-tap lever was very stiff on one of my two Webley Mk3s. I therefore opened up the loading tap assembly, removed the parts and the hardened grease that caused the problem and then reassembled. Alas, in so doing, I then noticed that after cocking the rifle and then switching the loading tap into the upright (loading) position, the seal did not take the pressure from the released air as it previously had. Instead, whereas the cocking lever was previously brought to a near halt, despite the pressure of the air under pressure from the spring, the cocking lever now swiftly returns to its position against the barrel.

I doubt this has any impact on the velocity, but I thought I would see if I could restore the ability of the rifle to hold the pressure when slowly releasing the cocking lever (with the tap opened after cocking the rifle and then pulling the trigger and slowly releasing the cocking lever).

This rather special characteristic still operates on my other Mk3.

Does anyone have any ideas?

Rgds
Andrew

[Thegreg]

I know damping grease has been mentioned in the past, and apparently that was what BSA used at the factory on the Airsporter taps. Rocol Kilopoise if I recall correctly, no longer available unfortunately.

I remember looking for an alternative myself once and drawing a blank, regular lithium/calcium based greases seemed to do the trick though.

Cheers
Greg

[dvd]

I had occasion to use boiled linseed oil on the wooden handle of a very old screwdriver I was restoring and I noticed that the small scratches and pitting were nicely filled with the oily residue which yellowed and hardened appreciably on the metal parts of the tool. I wonder if it will do the trick to seal a leaky tap without making it too stiff to operate. I would think it should work ok unless the scoring is very deep.

[wild boar]

its not long since i got some damping grease for lenses , it might have been radio spares but i had to look around for it , if i can find the stuff i will let you know

[PhatMan]

AndrewM,

High-vacuum greases do a good job - e.g. Dow Corning High Vacuum Grease, or one of the Apiezon greases (e.g. 'L').

These tend to be 'stiff' NLGI 3 or 4, and all seem to be uniformingly scalping in price !

Have fun

Best regards

Russ

[Dornfelderliebe]

Sometime ago, someone posted a thread to say they used a particular grease to reduce to almost nil, the air leakage from his loading-tap. I cannot recall the date or member.

Recently, the loading-tap lever was very stiff on one of my two Webley Mk3s. I therefore opened up the loading tap assembly, removed the parts and the hardened grease that caused the problem and then reassembled. Alas, in so doing, I then noticed that after cocking the rifle and then switching the loading tap into the upright (loading) position, the seal did not take the pressure from the released air as it previously had. Instead, whereas the cocking lever was previously brought to a near halt, despite the pressure of the air under pressure from the spring, the cocking lever now swiftly returns to its position against the barrel.

I doubt this has any impact on the velocity, but I thought I would see if I could restore the ability of the rifle to hold the pressure when slowly releasing the cocking lever (with the tap opened after cocking the rifle and then pulling the trigger and slowly releasing the cocking lever).

This rather special characteristic still operates on my other Mk3.

Does anyone have any ideas?

Rgds
Andrew

This might have been me but I have to clarify now although I had some success my .177 airsporter was so bad that it blew the grease out.
Now the good news. On there is a seller on A bey doing very small pots of Nyogel 767a damping grease they are only a fiver and at first you think the quantity is too small. You only need a minute amount on an Airsporter tap.
This is what I used.
Your port might be better, it is worth a punt for 5 quid to try.

[Mzee]

I use assembly lubricant on the loading taps of my collection of old BSAs to great effect. It's a sticky oil, a bit like runny honey. A friend used it on the engine of a 1928 Hillman he was rebuilding & gave me a small jar to try. It stays on the tap, making a good seal, & doesn't get sucked back into the cylinder.

[greenwayjames]

STP works very well indeed. John Bowkett told me that he used it in the 1980's on all the Airsporters that he did his conversions on even the FAC versions which ran at 18ft/lbs with the original Eley Wasp He said a slight leak will make no difference at all to velocity. I hope they haven't changed the formula

[andrewM]

Thank you, everyone. Happily, there are some very innovative people on the BBS! So far, I have a few possibilities to ponder but I must be careful not to seize up the lever that opens the tap (I tried Abbey LT2 grease but this does nothing):

1 Dow Corning High Vacuum Grease or one of the Apiezon greases (e.g. 'L') - 'stiff' NLGI 3 or 4.
2 Nyogel 767a damping grease (and perhaps another from wild boar).
3 An 'assembly lubricant'. Mzee, do you happen to know the brand of the oil you use, here?
4 STP - with a good plug from John Bowkett too.

I wonder what Webley used around their taps at the time of production.

I also wonder why I have a near perfect seal on the tap of my other Mk3. Both are made to the same specifications, within two years of each other. Perhaps the original grease solidified and clogged up the tap-lever on one of them.

Rgds
Andrew.

[Mzee]

Sorry, Andrew. I've no idea what the make of the assembly oil was. Peter gave me some in a small screwtop honey jar with the original label removed & replaced with one saying "OIL. DO NOT EAT", just in case I get confused in my old age.
Cheers, Glyn

[AC99]

If the tap is badly worn or gauged etc an old trick was to (copper) electroplate it using copper sulphate as the electrolyte - can be bought on-line. At the end of the process the tap diameter will increase marginally and the soft copper deposit will fill in any slight imperfections on the surface. Only a very thin coat is required and can be made a perfect fit in the receiver by turning the tap in the hole in a 'reaming' action and since the copper is relatively soft it will bed in and then the tap can be lubricated as normal.

I bought an old mk3 many years ago which had a copper discoloration around the loading port and I queried this with the owner who described (above) what he had done to correct the original leaky seal and it worked perfectly. I have not actually done this myself so it is not a personal recommendation but I have since been told by someone else that they had success using this method. Fortunately all my mk3's have good seals.

After removing the tap and thoroughly degreasing it, connect it to the negative terminal of a small (6v) battery and suspend it in a small jar of coper sulphate solution ensuring the hole is masked off by inserting bluetac or something similar into the pellet hole and also ensure the tap lever is clear of the liquid surface otherwise it will get plated as well. Connect the positive lead to a small piece of copper pipe (anode) for example and suspend this in the solution ensuring it doesn't touch the tap. The longer the plating process continues the thicker the plating and you will not need very much. Every so often take the tap and try it in the hole for fit.

Having said all that you could try some of the earlier grease recommendations which will clearly work for a while especially if the rifle does not get much use but the grease will presumably need to be replaced frequently. The electroplating idea is more of a long term fix.

Aubrey

[Dornfelderliebe]

This and a link from Lakey wrt BSA pre war underleavers set me thinking about DIY copper plating, enough to send off for some copper sulphate. The only sticking point being how to mask off blued surfaces of Airsporter taps. Maybe your taps won't present this problem.
I'll be giving it a go in due course.

[andrewM]

Thanks chaps.

The electroplating (and method) is an interesting possibility and it got me thinking. So, I wondered how the air was escaping, which it had not done before. This suggests that either it is coming out of the loading tap, or out of the left side (around the metal plate) or from the right (around the tap lever), or it could be leaking backwards, behind the washer and piston.

Some talc powder might determine the first three but not if it is coming back via the washer. I have put some drops of neatsfoot through the transfer port, via the loading tap, which might cause the washer to expand, assuming it had dried out (although I doubt this is what happened).

The rifle is a 1974 model and does not appear to have had enough use to wear the loading tap. I don't think the leak reduces the velocity but, from a mechanical viewpoint, it would be pleasing to fix it back to how it used to be.

Rgds
A

[Turnup]

Don't have a gun with a tap, but has anyone tried gas tap grease? It seems to be readily available and is nice and thick.

[bill57]

I have used Nyogel 767 on my Webley Ospreys for several years and would never use anything else now. I bought a tube of it (it wasn't cheap) after I realized that Rocol had ceased manufacture of Kilopoise grease, which would have been my first choice - and it was very pricey as well.

It's difficult to describe how effective this grease is in this role, you have to try it yourself to understand that everything else is basically a waste of time. Buy some, if you're a tap loader fan you will never regret it.