Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

"Outgassing" plastics in EP covers, cases, etc.

accessories eyepieces
  • Please log in to reply
17 replies to this topic

#1 drum365

drum365

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 15 Jun 2017

Posted 18 July 2019 - 12:42 PM

I had a car whose windshield regularly developed a film of some sort on the inside - especially in the heat. I was told this was caused by gas being emitted by the plastic in the top of the dash. I worry that something similar could happen to eyepieces.

 

There are so many types of plastics near eyepieces:

parts of the EP itself (I assume these are okay)

translucent EP covers (cloudy white, at the scope end, also "bolt" cases)

soft plastic EP covers (usually bright yellow)

hard plastic EP covers (black ones at the eye end)

the ziplock bags new EPs often come in

various types of foam in multi-EP cases

different wood finishes used in DIY homemade EP cases

 

Am I being overly cautious here? Are any types of EP covers safer than others? What are "best practices" for storage of EPs? Keep them in the original packages, put them in a carrying case for observing, and then put them back? Replace the original packaging with something else?

 

Or, like I said, am I being overly cautious?

 

Thanks!



#2 havasman

havasman

    Cosmos

  • ****-
  • Posts: 9743
  • Joined: 04 Aug 2013
  • Loc: Dallas, Texas

Posted 18 July 2019 - 01:19 PM

Eyepieces aren't hard to carefully clean. The biggest threats IMO are my own fingers. First and worst is just dropping them and them smudging them is next. Outgassing happens but the effects are, again IMO, mostly theoretical.

And welcome to the forums!!


  • Steve Cox and db2005 like this

#3 Scott99

Scott99

    Fly Me to the Moon

  • *****
  • Posts: 5146
  • Joined: 10 May 2007
  • Loc: New England

Posted 18 July 2019 - 01:39 PM

I worry about outgassing as well.  Eyepieces are lenses that we have to clean on a regular basis though, so I think it's less of a concern than objective lenses & mirrors.  Also - I'm not sure what cleaning/wax products you use on your car but that could be the source of outgassing too.  Most car wash places will rub ArmorAll onto the interior surfaces if you let them.

 

I use my sense of smell- usually you can smell VOC's outgassing.  If you can't smell anything, it's probably not outgassing.  Harder eyepiece caps are from HDPE (I think) which won't outgas.

 

I did have a bad experience with the softer yellow caps.  They do have a strong smell when new.  I left them on some eyepieces with rubber eyeguard.  After a year I found the soft yellow plastic had interacted with the rubber eyeguard and stuck to it and left a stain on it.  So I don't like those anymore!  lol.gif


Edited by Scott99, 18 July 2019 - 01:41 PM.

  • db2005 likes this

#4 epee

epee

    Gemini

  • *****
  • Posts: 3353
  • Joined: 30 Nov 2006
  • Loc: Suh-van-nuh, Jaw-juh

Posted 18 July 2019 - 01:42 PM

My old Celestron Silvertop Plossls lived for over a decade in a case with open cell foam around them, in the heat of a garage. As I once again became more active in the hobby, I thought them inferior to the Plossls provided with my new scope. Then I noticed how hazy the glass surfaces had become. A bunch of Q-tips and some lens cleaning fluid rendered them good-as-new in about 15 minutes.


  • MortonH and db2005 like this

#5 SeattleScott

SeattleScott

    Fly Me to the Moon

  • *****
  • Posts: 5693
  • Joined: 14 Oct 2011

Posted 18 July 2019 - 01:50 PM

Haven’t heard of problems with eyepiece covers. Have heard of issues with foam packing material for scopes or glue used in scopes off gassing and clouding up the optics.

So yes it is an issue, generally in rare situations but more common when people stick a scope in a padded case when the kid is born, and pull it back out after the kid goes off to college. I wouldn’t worry as much about eyepieces as they are easier to clean.

Scott
  • db2005 likes this

#6 drum365

drum365

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 15 Jun 2017

Posted 20 July 2019 - 10:35 AM

Thanks for the replies, everyone! Aside from brushing off a little dust, I'm always a little afraid to clean eyepieces with stronger stuff like fluids, Q-tips, microfiber cloths, etc. I guess that goes back to when I was doing a lot of photography and heard lots of warnings about screwing up the coatings on the lenses.

 

Anyway, thanks again for your advice - it's much appreciated!



#7 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 42425
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 20 July 2019 - 12:48 PM

I worry about outgassing as well.  Eyepieces are lenses that we have to clean on a regular basis though, so I think it's less of a concern than objective lenses & mirrors.  Also - I'm not sure what cleaning/wax products you use on your car but that could be the source of outgassing too.  Most car wash places will rub ArmorAll onto the interior surfaces if you let them.

 

I use my sense of smell- usually you can smell VOC's outgassing.  If you can't smell anything, it's probably not outgassing.  Harder eyepiece caps are from HDPE (I think) which won't outgas.

 

I did have a bad experience with the softer yellow caps.  They do have a strong smell when new.  I left them on some eyepieces with rubber eyeguard.  After a year I found the soft yellow plastic had interacted with the rubber eyeguard and stuck to it and left a stain on it.  So I don't like those anymore!  lol.gif

Not to mention they get shoved in by the foam in cases and may contact the lenses on top and bottom and leave stains.

ES had that problem for a while, and APM has it now (but some dealers do notice and change the caps).



#8 pregulla

pregulla

    Ranger 4

  • *****
  • Posts: 331
  • Joined: 03 Sep 2018
  • Loc: Israel

Posted 21 July 2019 - 04:49 AM

I guess I am not a true astronomer. If I discovered plastics in my car were outgassing that badly, I would worry about me breathing this stuff first, and about possibility of it happening ot my eyepieces second ;)


  • drum365 likes this

#9 drum365

drum365

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 15 Jun 2017

Posted 21 July 2019 - 12:45 PM

About the "outgassing" problem in my car - it was a few decades ago. I haven't had the same problem (or at least, not to the same extent) in more recent cars. But that experience, plus concerns about PCBs and other chemicals leaching out of plastic packaging into foods and beverages made me wonder if it might be a problem in the types of plastics used to pack our eyepieces. But thanks again to everyone for their comforting advice!



#10 scadvice

scadvice

    Apollo

  • *****
  • Vendors
  • Posts: 1300
  • Joined: 20 Feb 2018
  • Loc: Lodi, California

Posted 21 July 2019 - 01:34 PM

 Most problems with window haze is not from the plastics outgassing but from the small radiator up under the dash and in the firewall having a very small leak. Air flow, as pressure builds up in the heat/cooling system during defrosting or even when the car is normally running, flows up over the inside of the windshield leaving micro-drops.

 

In bad leaks (a pin hole) you will notice a smell similar to that of spoiled meat or even fish as it leaks and then steam dries on the radiator surface.

 

Plastics out gassing will leave deposits on the windshield and also you will see some on the inside of the side and back windows. Whereas liquid drops from the cooling system tend to dry out before reaching the side windows.

 

Outgassing from plastic's usually is because they are not cured properly or a poor use of the type of plastic selected for the product.

 

In some cases you can eliminate or minimize outgassing by heating the part to the highest operating temperature listed on it's mechanical properties chart. You would do this in a vacuum oven for a period of time. Yep... we all have vacuum ovens sitting around.ohmy.gif

 

 

My answer to the op's question.

 

Most food grade zip lock bags are outgas free do to being  BPA and  dioxin-free. So they are the most convenient method of storage. The pink industrial static free zip locks are also considered free of outgassing. Small desiccate packages inside the package can also help as they absorb and hold moisture.

 

Finally, If you want to spend the money, you can buy silicone zip lock storage bags. They do not out gas but won't fold up as nicely as the thin standard zip locks when placing them back into the case holder or box.


Edited by scadvice, 21 July 2019 - 04:58 PM.


#11 Heywood

Heywood

    Viking 1

  • -----
  • Posts: 999
  • Joined: 03 Jan 2009

Posted 21 July 2019 - 04:14 PM

I had a car whose windshield regularly developed a film of some sort on the inside - especially in the heat. I was told this was caused by gas being emitted by the plastic in the top of the dash. I worry that something similar could happen to eyepieces.

 

There are so many types of plastics near eyepieces:

parts of the EP itself (I assume these are okay)

translucent EP covers (cloudy white, at the scope end, also "bolt" cases)

soft plastic EP covers (usually bright yellow)

hard plastic EP covers (black ones at the eye end)

the ziplock bags new EPs often come in

various types of foam in multi-EP cases

different wood finishes used in DIY homemade EP cases

 

Am I being overly cautious here? Are any types of EP covers safer than others? What are "best practices" for storage of EPs? Keep them in the original packages, put them in a carrying case for observing, and then put them back? Replace the original packaging with something else?

 

Or, like I said, am I being overly cautious?

 

Thanks!

 

I would not worry about outgassing, as long as the plastic in question is kept relatively cool. 

 

I keep my (expensive) eyepieces in zip-lock baggies, the kind that one keeps food in.  I store all the baggied eyepieces in a big, plastic storage container, which I would never allow to get hot.  

 

Heywood


Edited by Heywood, 21 July 2019 - 04:16 PM.


#12 Spikey131

Spikey131

    Viking 1

  • *****
  • Posts: 884
  • Joined: 07 Feb 2017

Posted 21 July 2019 - 06:23 PM

Out gassing from plastics.

 

Fogging windshields.

 

Who comes up with this?

 

In your car, the majority of volatiles come not from plastics but from your own body, and from the bodies of you passengers.  I am not referring to flatulence, but the normal respiration of humans.  The automotive plastics are remarkably inert.

 

The cheap plastics used for eyepiece cases are less predictable, but their role in fogging EPs is probably minimal.  



#13 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 42425
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 21 July 2019 - 06:31 PM

I have cleaned my car, inside and out, and left it to sit in the sun for 4-5 hours and found a haze on the windows when I came back.

You must not have had a new car in a while.  My car was almost 3 years old before it stopped hazing the windows.

Now that it's 5 years old, I can drive it 200 miles and leave it in the sun and the windows stay clear.

It's plastics, leather, foam in the cushions, and rubber, all giving off fumes as they get hot.

After all, it's what causes "new car smell".grin.gif


  • epee and Lola Bruce like this

#14 Cames

Cames

    Viking 1

  • -----
  • Posts: 892
  • Joined: 04 Aug 2008

Posted 21 July 2019 - 06:41 PM

If you are considering storing eyepieces within sealed storage, you must consider the possibility of microbial growth made possible by sealing moisture into the container along with the eyepiece.

 

Mold growth on lens surfaces has been known to damage the anti-reflection coatings.  You may remember the packets of absorbent material that is packaged along with your new eyepieces. I'm pretty sure that the absorbent is there to create a super-dry environment that helps keep the storage environment sterile.

-----------

C



#15 Heywood

Heywood

    Viking 1

  • -----
  • Posts: 999
  • Joined: 03 Jan 2009

Posted 21 July 2019 - 06:46 PM

If you are considering storing eyepieces within sealed storage, you must consider the possibility of microbial growth made possible by sealing moisture into the container along with the eyepiece.

 

Mold growth on lens surfaces has been known to damage the anti-reflection coatings.  You may remember the packets of absorbent material that is packaged along with your new eyepieces. I'm pretty sure that the absorbent is there to create a super-dry environment that helps keep the storage environment sterile.

-----------

C

 

That is a good point!!



#16 drum365

drum365

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 15 Jun 2017

Posted 22 July 2019 - 12:02 AM

...You must not have had a new car in a while. ...

Yes - this was a new car. And it was about 30 years ago, when plastics (and rules regulating them) were probably quite different than they are now.



#17 csrlice12

csrlice12

    ISS

  • *****
  • Posts: 24576
  • Joined: 22 May 2012
  • Loc: Denver, CO

Posted 22 July 2019 - 09:22 AM

Buy a set of Pentax XWs....overpower the smell of outgassing foam with the smell of outgassing rubber.....


  • Starman1 and Cames like this

#18 Cames

Cames

    Viking 1

  • -----
  • Posts: 892
  • Joined: 04 Aug 2008

Posted 22 July 2019 - 11:44 AM

Buy a set of Pentax XWs....overpower the smell of outgassing foam with the smell of outgassing rubber.....

 

The rubber smells like the gas mask they use at the dentist office.  unsure.png

--------------

C




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: accessories, eyepieces



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics