Lunt B600 Issue

[niallk]

Hi,

I've the dreaded corroded 'blue glass' B600 issue, and have contacted Lunt in the USA who advised me to email Wolfgang in Bresser with my details. 

Anyone else recently have to do this??

I'm wondering about 3 things:

a) Did you have to pay?  It's a relatively low cost component anyway, but just wondering. 

b) What sort of lead time was involved?

c) Any issues removing the original one and replacing with the new one?

 

Here's a pic of the state of mine - remarkably I still get enjoyable views - a nice bit of activity and beautifully fine details on-view today, but it is like I'm looking through thin cloud - very noticeable scatter.

 

Any comments on my Qs would be much appreciated!

Thanks,

-Niall 

PS I keep the scope in its metal case with silica desiccant pouches right at the B600 in a bedroom - it's treated very well, not left out in a shed or anything!!

Edited March 6, 2022 by niallk

[Peter Drew]

My understanding is that you scoop off the dob of sealant from the retaining plate, unscrew the plate, drop out the filter and pop in the new one.  Keep the old one as they can be cleaned, it will be a spare if you have to repeat the process in the future.  No idea currently on the other questions.     🙂

[Laurin Dave]

I had the same issue a year ago..  The Blue glass filter was free and took about 10 days to arrive from Germany. As Peter says easy to remove - I used a lens spanner to unscrew it.  And the deposit cleans off the old one with lime scale remover Cillit Band or Mr Muscle as myself and @tooth_dr have found.

Dave

[niallk]

Great - thanks @Peter Drew and @Laurin Dave!

I'll hang on to see if I get the replacement before attempting to clean - as I can still enjoy the views despite the appalling look of it 😂

I'll post back on my experience obtaining a replacement- in case of interest to anyone. 

I've been anticipating this issue would manifest itself.  I wonder if the 'new' blue glass has an improved coating or whatever... or is this likely to reoccur every few years? 🤔

Despite this, I still love my LS50DS - it's so amazing to be able to see the detail it shows.  Great little scope 😉

[Merlin]

I have a similar problem with my B600. Could you give me the website of the German supplier?

[niallk]

1 hour ago, Merlin said:

I have a similar problem with my B600. Could you give me the website of the German supplier?

Sure - here's the prompt + helpful response I received from Faye @ Lunt:

 

Hello Niall,

 

I hope this email finds you well!  Thanks for the details you have included.  For the replacement filter please contact our distributor Bresser in Germany.  Wolfgang and his team will know the part you need.  From you he will need your scope model and serial number as well as your address.  Here is the contact information:

 

Bresser GmbH
Gutenbergstrasse 2
46414 Rhede

T +49 (0) 28 72 - 80 74-140
F +49 (0) 28 72 - 80 74-540
wolfgang.quere@bresser.de
www.bresser.de

 

Here is a link to a brief video on the procedure as well.  I am happy to assist you further if you have any technical questions, so please let me know!

https://luntsolarsystems.com/solar-telescope-basics/

Thank you,

Faye Romàn

Lunt Solar Systems

(520) 344-7348

f.roman@luntsolarsystems.com

sales@luntsolarsystems.com 

www.luntsolarsystems.com

[LDW1]

8 hours ago, niallk said:

Hi,

I've the dreaded corroded 'blue glass' B600 issue, and have contacted Lunt in the USA who advised me to email Wolfgang in Bresser with my details. 

Anyone else recently have to do this??

I'm wondering about 3 things:

a) Did you have to pay?  It's a relatively low cost component anyway, but just wondering. 

b) What sort of lead time was involved?

c) Any issues removing the original one and replacing with the new one?

 

Here's a pic of the state of mine - remarkably I still get enjoyable views - a nice bit of activity and beautifully fine details on-view today, but it is like I'm looking through thin cloud - very noticeable scatter.

 

Any comments on my Qs would be much appreciated!

Thanks,

-Niall 

PS I keep the scope in its metal case with silica desiccant pouches right at the B600 in a bedroom - it's treated very well, not left out in a shed or anything!!

I haven't had any issues with mine yet. If you belong to CN in north america post your concerns in the solar forum, there are a huge number of experts on it that can probably address your concerns. Its just another great source of info, of help in conjunction with this site.

[niallk]

13 minutes ago, LDW1 said:

I haven't had any issues with mine yet. If you belong to CN in north america post your concerns in the solar forum, there are a huge number of experts on it that can probably address your concerns. Its just another great source of info, of help in conjunction with this site.

Cheers - yep I'm familiar with CN 😉

My main concern is lead time... lots going on with the sun these days, and hopefully will get sorted quickly. 

I'll either have to fashion a tool, or purchase one to remove the glass.

I don't recall reading that replacement glass has addressed the root cause of the corrosion... but maybe I've missed it.

[inFINNity Deck]

I had the same issue with my B1200 and that was solved as indicated above by others. Perfect service by Lunt and Bresser! I cleaned the old filter using descaling agent and keep it as a spare. Although the descaling worked fine, I still can see some unevenness in the area where it was affected most.

Nicolàs

 

 

[Louis D]

2 hours ago, niallk said:

I'll either have to fashion a tool, or purchase one to remove the glass.

I bought a version of this lens spanner wrench for such jobs.

[Buzzard75]

I had to replace mine this past summer on my B1200. It's easy to do as has already been said and yes, I did have to pay for it. I paid more for shipping than I did for the actual item. More than twice as much in fact. I live in the US so turnaround time for me was relatively quick. I ordered on a Friday, it shipped on a Monday and I think I had it by Wednesday or Thursday. Transit time to Ireland will probably be a bit longer and probably more expensive. At least it's an easy fix and they have parts on hand as they know it goes bad over time. I have to wonder though, what exactly causes it?

[LDW1]

To all those who had the problem, what was the average length of time in months or years that the problem started to show up ? That way I can start to monitor mine, my scope is not yet a year old.

[Louis D]

Just a guess, but the blue film is probably caused by oxidation (rusting) of whatever element was used to coat the glass for whatever filter effect they were going after.  It kind of looks like cobalt blue mixed with copper green.

[Merlin66]

It's associated with the construction of the filter, the glass is hygroscopic, similar to the older photometric green V filters.

https://glassfab.com/wp-content/uploads/2015/08/schott_filter_catalog.pdf

(see sect 5.5)

 

Edited March 7, 2022 by Merlin66

[inFINNity Deck]

1 hour ago, LDW1 said:

To all those who had the problem, what was the average length of time in months or years that the problem started to show up ? That way I can start to monitor mine, my scope is not yet a year old.

I discovered mine was overdue after some two years and a half. I remember reading about this issue when I had the scope for about a year and at that time it showed no degrading. The replacement was done end of September 2020 (installed the scope in May 2018). Incidentally I checked the new filter three days ago and it still looks fine.

Replacing the filter is fairly simple and is shown in this video. The retaining ring was fixated with a small drop of silicon. So I first removed that and could then already rotate the ring without tools. It has to remain fairly loose, so a simple pair of compasses should do the trick.

Nicolàs

[Merlin66]

The filter can fail within months, or years.........

No guarantees.

 

[Pete Presland]

I removed and cleaned my filter last summer, wasn't quite as bad as yours. no problems at all

[Pete Presland]

[swsantos]

I first purchased my Lunt LS50THa in 2014 and the blue filter went bad within about 2 years, then I ordered another one which they sent me for free and it also went went bad in about two years. I cleaned the original one easily so I would have a spare.

Then the replacement went bad and when I ordered a replacement for the replacement they sent it for free again but this time they told me that it had been redesigned with a coating so that it would not happen again and that appears to be true.

Just checked the replacement's replacement and it looks new and its about 3-4 years old now.

I am reminded of the Monty Python quote "When I first came here, this was all swamp. Everyone said I was daft to build a castle on a swamp, but I built in all the same, just to show them. It sank into the swamp. So I built a second one. That sank into the swamp. So I built a third. That burned down, fell over, then sank into the swamp. But the fourth one stayed up. And that's what you're going to get, Lad, the strongest castle in all of England."

The third blue filter is still standing.

[Pete Presland]

16 minutes ago, swsantos said:

I am reminded of the Monty Python quote "When I first came here, this was all swamp. Everyone said I was daft to build a castle on a swamp, but I built in all the same, just to show them. It sank into the swamp. So I built a second one. That sank into the swamp. So I built a third. That burned down, fell over, then sank into the swamp. But the fourth one stayed up. And that's what you're going to get, Lad, the strongest castle in all of England."

The third blue filter is still standing.

just 2 more to go then 🙂 🙂 🙂 Not seen the Holy Grail for years

[LDW1]

One more question, when this damage occurs is there a noticeable degradation in the views or is a lot of it just cosmetic, its appearance ?

[Louis D]

14 hours ago, Merlin66 said:

It's associated with the construction of the filter, the glass is hygroscopic, similar to the older photometric green V filters.

https://glassfab.com/wp-content/uploads/2015/08/schott_filter_catalog.pdf

(see sect 5.5)

 

In that case, it looks a bit like copper sulfate pentahydrate.

[swsantos]

3 hours ago, LDW1 said:

One more question, when this damage occurs is there a noticeable degradation in the views or is a lot of it just cosmetic, its appearance ?

Yes the view gets slowly hazy and Ill defined. The first time I blew it off to poor seeing and only after I read about the problem on Cloudynights did I discover the problem in the first place. Upon replacement there was an immediate improvement back to like new.

Then it happened a couple of years later and believe it or not it didn’t occur to me to check it again for a while then suddenly I remembered what had happened before and sure enough it happened twice.

The third one still looks new I am told that it’s a new coated design to prevent it from happening again and it still looks new about 2-3 years now after replacing it.

 

[niallk]

7 hours ago, LDW1 said:

One more question, when this damage occurs is there a noticeable degradation in the views or is a lot of it just cosmetic, its appearance ?

You can see in my pic, the filter is quite bad looking.  Now, I still got very nice views - BUT it was obvious something was amiss.  There was uneven light scatter, and it was like observing through mottled light cloud... or when a secondary mirror on a dob begins to dew up!

I'm looking fwd to getting it fixed - fingers crossed for a reasonable lead time 🤞

[niallk]

18 hours ago, LDW1 said:

To all those who had the problem, what was the average length of time in months or years that the problem started to show up ? That way I can start to monitor mine, my scope is not yet a year old.

Fwiw, I purchased my scope in early 2017.  I noticed it beginning to corrode in early 2021, and it degraded a helluva lot in 1 year... despite silica pellets etc.