Tight filters

[Guest Steve]

Any advice for how to avoid filters getting stuck?

I have my 2" Neodymium filter screwed straight onto the visual back on the C9.25 and the chunky Williams Optics diagonal and Hyperion zoom off that. All nice and tight.

When I tried to take the Neodymium off to do some solar observing it was well and truly stuck. I tried a lot of straining, but in the end had to use a massive pair of grippers - not exactly recommended for expensive optical equipment!!!

Vasiline? Oil? Some magic Astro grease???

[Guest Eddy]

I haven't had this issue nor can give 100% accurate advice but at a guess it's tightened up in the heat so I guess letting it cool somewhere cold should have done the trick.

[BAZ]

If it gets stuck again, try gently warming it up with a hairdryer, that should give it enough expansion to free it.

Don't be tempted to use any sort of lubricant, it will creep across the surface and may get into the optical bits. Wipe your fingers round the inside thread, there's usually enough natural oil on your skin to prevent sticking.

[Guest Eddy]

I'd have thought expanding it would make it tighter? shows what I know

[BAZ]

You need to expand the outer thread, so that it gives a bit more room for the internal thread to move. It doesn't need to be much, as it is effective around the whole length of the circumference.

It's not the filter you warm up, it's the outer part, which is trapping it.