Waterproofing method for no.32 scopes

[vintage hunter]

What was the original method used to waterpgoof a no.32 scope. How effective was it? Does anyone who services no.32's offer this option?

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[Peter Laidler]

There was no true waterproofing of the original No32's beyond what the spec called for 'a smear of grease across all of the mating surfaces'. As a result, they were pretty crap.

[Warren]

And then we have the GOD AWFUL mastic that completely petrified in the Canadian REL scopes when they tried to waterproof them. The REL Mk. III was horrible. Canada had a difficult time meeting UK waterproof specs and I'm not sure what the material is/was that we used, but MEK will just soften it and that is it. REL scopes were not for use in damp, humid climates at one time.
The UK mastic on the Mk. III ocular cell is not too bad (most of the time) and a bit of heat will normally loosen it up. Hoping of course that the balsam in the lens couplets does not melt first.

[Longshaor]

Peter,

In light of the above, what was done diferently in the "W" maked scopes?

Cheers!

[vintage hunter]

And while you're at it, may as well explain the lens blooming thing too.

[Peter Laidler]

I'll let you into a little secret V-H. The difference between a Mk3 and a Mk3W (and a Mk2/1 and a 2/1W too incidentally.....) is that they soon found that while the Mk3 was far better at retaining its waterproofability than the Mk1 and 2's, when it got the tropics, the changes in pressures meant that the thing leaked around the drums. So they changed the drums to incoroprate a tight fitting fibre or later a neoprene O ring.

But in truth, while it was 'better' it wasn't a cure because the monsoons, that lasted from mid September until the 31st August the following year, the rain just sloshed its way down the lead screw. We tested them after assembly with a gas test but......................

Anyway in temperate climes, you should treat your W telescope as 'not quite/nearly showerproof' and treat a non W telescope as 'not even remotely showerproof' And if you're taking it to the tropics, then don't!