Salt spray and telescopes

darkskybondi · #1 23-12-2008, 02:18 AM

Hi guys - please tell me if I should move this thread to the beginners' forum. I'm putting it here because I feel it may be useful to non-newbies, too!

I'll be observing here on the coast in Sydney and I'm wondering, since the salt spray coats your hands and face after an hour or two outside, will it get into a scope? I'm looking at getting either the Skywatcher 12" dob or the 10" collapsible dob. Is it easy to clean salt spray and other junk off the mirror and eyepieces? Is it worse for the open design of a collapsible?

Your thoughts, as ever, are much appreciated.

Cheers!
darkskybondi

bmitchell82 (Brendan) · #2 23-12-2008, 10:16 AM

Salt = NASTY for optics, though search the forums, or even in the projects & articals section, Mike (iceman) has done a few good ones about newt optics cleaning proceedures.! check it out

Dennis · #3 23-12-2008, 11:42 AM

A work colleague once mentioned that an electrician friend of his working on the Sunshine Coast (Qld) told him that in properties within 5kms of the coast line, he has seen evidence of accelerated corrosion due to the salt laden air.

We just got back from a week on Moreton Island and some of the exposed metal fittings (non S/S) around the resort showed evidence of rust due to the harsh conditions. A tourist there who lives right on the front said that their fridge and washing machine panels began to rust in less than 3 years and that they have to clean their windows daily due to the salt deposits.

Cheers

Dennis

darkskybondi · #4 23-12-2008, 01:05 PM

Thanks for the replies, guys. I mean, I'll be using the scope about 15 metres from the cliff, so there's some serious salt - but the question is, will it affect the scope given that I'm only taking it outside for observation sessions.

Cheers!
DSB

bmitchell82 (Brendan) · #5 23-12-2008, 01:16 PM

the answer is yes

Dennis · #6 23-12-2008, 02:47 PM

It was remiss of me not to add that the locations I referred to previously were ocean facing surf beaches, so they often get pounded by heavy seas, creating billowing clouds of salt spray.

In more sheltered locations, the effects may be lessened but I suspect anywhere near the beach will be susceptible to increased concentrations of salt spray in the atmosphere.

Cheers

Dennis

GrahamL · #7 23-12-2008, 04:04 PM

I observe a couple of kms from the beachfront and do have to clean
my primary fairly often beacause of the salt air.
The worst nights are when an inversion layer hangs around for the evening
you can tell beause the sound of the waves seem very close.. that air
trapped near the ground is just dripping with salt .

Brian W (Brian) · #8 27-12-2008, 01:29 PM

Hi, a friend of ours kept his scope at his beach house. Inside of 2 years the mount was nicely pitted with rust. (not that he ever used it he just left it inside) Electrolysis is going to be a problem because of all the different metals that are used in a scope. Wiring will corrode quickly.

I live in the tropics, I was a lighthouse keeper in Canada, I love the ocean and the beach and the thought of a telescope on the beach just makes me shudder.
Brian

darkskybondi · #9 27-12-2008, 02:24 PM

Quote:

Originally Posted by Brian W

Hi, a friend of ours kept his scope at his beach house. Inside of 2 years the mount was nicely pitted with rust. (not that he ever used it he just left it inside) Electrolysis is going to be a problem because of all the different metals that are used in a scope. Wiring will corrode quickly.

I live in the tropics, I was a lighthouse keeper in Canada, I love the ocean and the beach and the thought of a telescope on the beach just makes me shudder.
Brian

Brian - does this mean that taking it outside for periods of a few hours each night will have a disastrous effect on it?

Brian W (Brian) · #10 27-12-2008, 02:36 PM

Disastrous? That is a mighty strong word. But it may well apply. Salt is a mighty corrosive. It is also a nasty little grinder. Washing salt off every night will grind away coatings no matter how carefully it is done.

Observing at the beach will not 'instantly' destroy your scope but over time it will shorten its life and degrade the quality of your observing.
Brian

leon · #11 27-12-2008, 03:40 PM

I wouldn't even consider taking any good optical instrument anywhere near the ocean, and that includes cameras.

Leon

darkskybondi · #12 27-12-2008, 04:06 PM

Quote:

Originally Posted by leon

I wouldn't even consider taking any good optical instrument anywhere near the ocean, and that includes cameras.

Leon

This doesn't help! I live near a cliff!

Kevnool (Kev) · #13 27-12-2008, 04:35 PM

It dont matter where you live.
On the coast you get salt.
In the inland you get dust,Its a no win situation.
But instead of washing my Primary all i do is blow the dust off.
Cheers Kev.

ausastronomer (John Bambury) · #14 27-12-2008, 11:13 PM

Some of the replies are only guessing at the answer and the effects, IMO.

I live 50 metres from the salt water, with a house that faces the prevailing wind. All external fittings on my house have to be stainless steel, otherwise they disintegrate in a very short space of time.

I own two scopes and have done for several years. I keep both scopes in the garage and keep a cover over them when not in use. I don't have any "serious" problems with salt corrosion. As Nightstalker indicates, the most important thing is to clean your optics, particularly the primary mirror, on a regular basis. I clean mine twice a year. If I lived away from the coast the mirrors might get cleaned every second year.

Buy your scope with confidence and enjoy it.

Cheers,
John B

darkskybondi · #15 28-12-2008, 01:03 AM

Cheers Aus, great advice. I've pretty much decided to go for the 10" full tube skywatcher dob for its portability over the 12". Can't wait to pick it up next week!