48 replies to this topic

[TOMDEY]

Stainless steel will rust, look it up..........

It depends on the material and type of exposure. I sure wouldn't worry about a stainless eyepiece barrel rusting.    Tom

[Rigel_10]

It depends on the material and type of exposure. I sure wouldn't worry about a stainless eyepiece barrel rusting. Tom

That's true but, Rust Never Sleeps! 😶

[Don25]

Stainless Steel can rust.......that's why it's called stainLESS rather than stain free. I believe the addition of Chromium to iron, makes it less likely to rust.

[azure1961p]

Siebert Optics makes some nice brass eyepieces. I will order a 2" 35mm Observatory Series eyepiece in brass someday...

prage.jpg

 

brass 2.jpg

Gotta love Siebert!!!

 

Pete

[Jon Isaacs]

Mike W, on 08 Apr 2025 - 08:04 AM, said:

Stainless steel will rust, look it up..........

I know a little materials science.. Under some conditions stainless steel can rust. It also depends on the particular stainless 

 

An eyepiece will never see those conditions.. If it does, you've got bigger problems.

 

Stellarvue Optimus eyepieces are at least partially Stainless.

 

Jon

 

[TOMDEY]

Storing your eyepieces in a vacuum chamber prevents rust. But it slows things down when you want to switch eyepieces.    Tom

[izar187]

Procyon, on 07 Apr 2025 - 4:51 PM, said:

    Siebert Optics makes some nice brass eyepieces. I will order a 2" 35mm Observatory Series eyepiece in brass someday...

    attachicon.gif prage.jpg

    

    attachicon.gif brass 2.jpg

..................................

 

Gotta love Siebert!!!

Pete

__________________

 

They work even better than they look.

Whether in brushed aluminum or brass.

[Jon Isaacs]

OK, you win Jon. If I post black you post white. If I post white you post black. I'm not going to play this game anymore. 

I never said barrels can't be made out of SS, for Gods sake Losmandy parts have been made out of stainless for decades. 99.999999% of barrels are chrome plated

 

 

I'm not playing a game, I want to discuss viable materials for eyepiece barrels. Brass is a viable material as are stainless steel and aluminum.

 

I believe you know that 99.999999% of eyepiece barrels are not chrome plated brass. That's 1 in 100,000,000 would not be chrome plated brass. 

 

The KUO XWA's and UWA's, the Baader Morpheus's are among a number of eyepieces that appear to have barrels made of aluminum and then black anodized, definitely not chrome plated. My 20 mm ES 68° has a barrel that appears to be stainless steel.

 

All these materials can corrode under the right circumstances but an eyepiece is very unlikely to be subjected to those conditions. Personally I think that for heavier eyepieces, black anodized aluminum makes the most sense. 

 

Jon 

[Jon Isaacs]

How much time did you spend researching that Jon! LOL

 

I just looked at my eyepieces. It probably took about 5 minutes.  I pretty much knew everything, I just wanted to verify it. 

 

I have a full set of Morpheus's, they were a gift from a Secret Santa.. I know who it is but I am not sharing that.  I have a full set of XWAs, a full set of UWAs, I looked at the 20mm ES 68 degree.  

 

I have a nearly full set of 1.25 inch Naglers plus 22 mm, 35mm and 41mm Panoptics and 31mm Nagler.  I believe they have chrome plated brass barrels.  I have the 13mm, 10mm and 8mm Ethos. The 1.25 inch barrel appears to be chrome plated brass, the two inch, barrel is aluminum.  The Astro-Tech Paradigms seem to be chrome plated brass.  

 

I have others I did not look at.  

 

10 years ago, I had one set of eyepieces, the 35mm Panoptic, 31mm Nagler, the 20mm, 16mm, and 12mm Type 2 Naglers, the 9mm, 7mm, 5mm and 3.5 mm Type 6 Naglers plus a 2x 1.25 inch TeleVue Barlow and an original Paracorr with a Tunable Top.  I could do just about anything with that set.. I also had a lightweight set.  This was a earlier incarnation, the 4.8mm Nagler instead of the 5mm and different Barlows. 

 

 

Then all he!! broke loose... It started with the 20mm ES 100 degree.. 

 

Jon

[SandyHouTex]

Stainless steel won't rust under normal conditions.  Near the ocean, special formulations must be used to retain the rust resistance, and only certain stainless steel alloys must be used.  In an Oxygen atmosphere it forms an oxide layer which protects it.  If used in space, the oxide layer eventually disppears.  Initially NASA used stainless steel screws to fasten things down with the things they screwed into being stainless steel as well.  After a time, when the oxide layer disappeared, they couldn't unscrew the screws because they galled (cold welded) with the threads they were fastened too.  At least you didn't have to worry about something coming loose.

[doug mc]

Back in the day Meade released a range of research grade plossls. They were made from a very lightweight metal but it was very hard. I've forgotten what it was. A heavy eyepiece conveyed quality, was a good idea for sales purposes. Those Meades were and probably still are very good. 

Edited by doug mc, 08 April 2025 - 08:40 PM.

[Dobs O Fun]

Let's stop the bickering please.....

[Starman1]

Stainless Steel can rust.......that's why it's called stainLESS rather than stain free. I believe the addition of Chromium to iron, makes it less likely to rust.

There are non-rustable stainless alloys and rustable ones. There are over 20 different "stainless steel alloys".

[John O'Hara]

Back in the day Meade released a range of research grade plossls. They were made from a very lightweight metal but it was very hard. I've forgotten what it was. A heavy eyepiece conveyed quality, was a good idea for sales purposes. Those Meades were and probably still are very good. 

My 20mm RG Wide Angle is very light. I'm pretty sure it's aluminum.  

[Tom Masterson]

My 20mm RG Wide Angle is very light. I'm pretty sure it's aluminum.  

My Meade RG Erfle definitely has an alluminum barrel. It too is very light.

 

Lets take the Wayback machine back in time to aluminum barreled eyepieces, to a lesser extent brass, and the era of set-screws. I've made a mess of some of their aluminum barrels - Nagler type 1s, when it either got stuck in the focuser, or was somehow twisted a bit in the diagonal. Cranking down on set-screws to secure heavy eyepieces tended to leave dimple too, which then could cause an eyepiece to get stuck.... I had one focuser that seemed to like messing up aluminum barrels. It was like a Sharkbite fitting. The eyepiece went in easy, but could be holy heck to remove. 

 

As someone who used to do some machining, I just loved to machine brass. It's cut so nicely, and didn't build up on the tool like aluminum can, which can gouge the work. Sure, machining aluminum is easy when you treat it right, but brass, was just soooo nice, as long as you didn't get any chatter. No long curly chips to wrap around the tool either.

 

My guess is brass fell by the wayside due to it's cost compared to aluminum. When you are making lens housings out of aluminum, it makes sense to do the same with the barrels. CNC machine would crank them out much cheaper too. Thank goodness for the proliferation of compression rings. Seems like I remember brass being more common in the 70s, into the 80s. Chrome could tend to peel where there were sharp edges. My 32mm UO Widescan from the 80s has a small spot of missing chrome. Not a problem with anodized aluminum.

[RichA]

I noticed every single eyepiece made from brass are either old vintage eyepieces or are marketing off nostalgia.  Is there a reason why so many companies from Celestron to TeleVue don't use brass for their eyepiece body anymore if they ever did in the case of newer manufacturers.

Price of copper keeps rising.  Brass is a stupid material, a dated material.  In winter they fog up MUCH more easily than aluminum barrel eyepieces.  But thirdly, maybe the kooks in California declared brass causes cancer if you consume more than a kg of it a day?  

[quilty]

Brass used to be locksmith's gold formerdays. Aluminium is just silver.

Aluminium has become much cheaper and is nearly as easy to machine as brass, and it weighs less. I think these are the reasons.
I prefer brass anytime. Brass provides a special service, it's antiseptic and I think it acts a fungicide, too.
That's why door handles in public buildings used to be made of brass. Nowadays they prefer plastic as bacterial spreading sources
But aluminium, specially when uncoated, may look more beautiful than uncoated brass (or silver, which is antiseptic, too)

Edited by quilty, 15 April 2025 - 03:42 AM.

[Mike W]

Price of copper keeps rising.  Brass is a stupid material, a dated material.  In winter they fog up MUCH more easily than aluminum barrel eyepieces.  But thirdly, maybe the kooks in California declared brass causes cancer if you consume more than a kg of it a day?  

Just how did you test the IQ of brass?

[RichA]

Just how did you test the IQ of brass?

I asked it, how can you be an eyepiece material when you weigh 2x as much as aluminum, that you tarnish without plating, which impacts precision fit which in modern steep-curve lens eyepieces is a no-no, that you smell peculiar, that you hold onto heat and cold.  It had no problem with any of that.  

[The Rigger]

But aluminum is easy to machine, does not rust....

Well... Technically, yes it does.

We just call it "oxidization" rather then "rust." Same basic chemical reaction, though, albeit much less damaging to the aluminum than ferric oxidization (i.e. "rust") is to steel.

 

Also, stainless steel does indeed rust; ask any boat owner. Some alloys are more resistant than others, but SS isn't rustproof, just rust-resistant.

Edited by The Rigger, 18 April 2025 - 10:14 PM.

[RichA]

Well... Technically, yes it does.

We just call it "oxidization" rather then "rust." Same basic chemical reaction, though, albeit much less damaging to the aluminum than ferric oxidization (i.e. "rust") is to steel.

 

Also, stainless steel does indeed rust; ask any boat owner. Some alloys are more resistant than others, but SS isn't rustproof, just rust-resistant.

Not the same as iron rust.  Iron / steel will rust and continue to rust in any moist atmosphere. Aluminum will develop an ultra thin oxide coat and stop at that point, unless exposed directly to corrosives like salt or acid.

[Starman1]

Not the same as iron rust. Iron / steel will rust and continue to rust in any moist atmosphere. Aluminum will develop an ultra thin oxide coat and stop at that point, unless exposed directly to corrosives like salt or acid.

and anodized aluminum is pretty much corrosion-free.

[doug mc]

Back in the day Meade released a range of research grade plossls. They were made from a very lightweight metal but it was very hard. I've forgotten what it was. A heavy eyepiece conveyed quality, was a good idea for sales purposes. Those Meades were and probably still are very good. 

Sorry everyone, they were research grade orthoscopics. Titanium I think. Could be wrong on that. Very hard but light. Definitely not aluminium. 

[quilty]

no staniless steel, no titan, it's about brass or aluminium. Brass is easier machined than aluminium. Corrosion is the only drawback.
There's a special aluminium blend, like 7076 or so. As hard as steel.