HELP MILDEW!!!!!!

[Manxstar]

Have found mildew on my 6 inch lens:eek: Any ideas on what I can do????? Any advice would be greatly appreciated!!!!!

[beetlejuice]

Have found mildew on my 6 inch lens:eek: Any ideas on what I can do????? Any advice would be greatly appreciated!!!!!

Depends on how bad it is. Removing it can cause more damage if you don't know what you are doing. Get it professionally cleaned would be my advice. Mildew fungus can etch the glass and definately damage the coatings if left too long.

Are you bringing the scope in from the cold and leaving it with the lens cover on? Don't do it - it creates the perfect conditions for what you've got.

[Merlin66]

If it's an air spaced doublet then there's some hope of cleaning; if it's a cemented achromat then it's basically a professional job.

Is it "growing" on the outer surfaces or inside the lens??

[Manxstar]

Hi, thanks for the replies, really appreciated!! I have the old Helios 6 inch refractor.The mildew appears to on the lens surface inside the tube, not on the outside surface. Do you know anyone I could contact who can solve the problem? Many thanks.

[Doc]

Someone once told me that after you bring your scope indoors leave all mirror covers off for the rest off the night.

Give the mirrors time to reach ammbient temperature before resealling them.

Hope you get it off OK.

[beetlejuice]

Hi, thanks for the replies, really appreciated!! I have the old Helios 6 inch refractor.The mildew appears to on the lens surface inside the tube, not on the outside surface. Do you know anyone I could contact who can solve the problem? Many thanks.

I suggest giving Bern at Modern Astronomy www.modernastronomy.com a ring. He may be able to point you in the right direction. You could also try Telescope House. www.telescopehouse.com

[Kaptain Klevtsov]

My 120mm one did that. Just carefully unscrew the lens retaining ring and clean it. I used two small drill bits in the holes and a steel rule to unscrew the retainer. I would gues that the 150mm design is similar.

Kaptain Klevtsov

[DemonicOmelette]

Should you also leave the covers off your EP's when you bring them back inside, or just your scope?

[beetlejuice]

Should you also leave the covers off your EP's when you bring them back inside, or just your scope?

I leave the covers off everything. I do cover the corrector plate end of the scope with a well washed tea towel draped over the end to keep dust off it though.

[FLO]

The Helios 6" refracter is an air-spaced doublet, which is good news as it means the growth can be easily wiped off the optical surface (if it were the cemented type the the mould would be 'eating' the cement which is much more difficult to remedy).

If you are lucky the mould will be on the inside outer-surface so unscrewing the complete lens cell will allow you to easily reach it. If it is between the two elements then you can still reach it but it is an altogether more scary job. If necessary Telescope House have an optical bench, give them a call and ask for Steve Collingwood.

HTH

[Manxstar]

Thanks everyone for the great advice, it is really appreciated, as I having being getting very down about it!!!!! You have all helped to make this weekend a calmer one:)