Image of the day

Captured by
Tommy Wlasichuk

Cygnus Wall

My Account

New to Astromart?

Register an account...

Need Help?

STUCK

Started by bobblack, 04/24/2008 05:13PM
Posted 04/24/2008 05:13PM Opening Post
I recently purchased a 2" lumicon deep sky filter.
I then screwed into my celestron 6.3 reducer/flattener. Now, I can't get it off.
I have tried 2 pair of waterpump pliers to no avail. Thankfully, I haven't marked them. I am afraid to put too much pressure on them in case I break the glass.
I sent lumicon an email to see if they had run into this problem before and apparently they have. They suggested something that looks like a small oil filter remover but I have no idea where to get this.
Any suggestions would be appreciated. Not only how to get them apart, but how to prevent it from happening again. Many thanks, bob
Posted 04/24/2008 05:39PM #1
A strap wrench (or better yet, a pair of them) like this one should do the trick:

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200306401_200306401?cm_ven=Aggregates&cm_cat=Google&cm_pla=Hand%20Tools%2C%20Wrenches&cm_ite=1501539&ci_src=14110944&ci_sku=1501539

They are generally available at hardware stores and any place that carries a wide variety of tools.

Joplin
Posted 04/24/2008 05:41PM #2
robert black said:

I recently purchased a 2" lumicon deep sky filter.
I then screwed into my celestron 6.3 reducer/flattener. Now, I can't get it off.
I have tried 2 pair of waterpump pliers to no avail. Thankfully, I haven't marked them. I am afraid to put too much pressure on them in case I break the glass.
I sent lumicon an email to see if they had run into this problem before and apparently they have. They suggested something that looks like a small oil filter remover but I have no idea where to get this.
Any suggestions would be appreciated. Not only how to get them apart, but how to prevent it from happening again. Many thanks, bob

The cause of your problem is likely a bur on the threads of either the filter or the reducer. You can figure out which if you have used the reducer threads before. I had this happen with a brand new astronomiks uhc filter. The pressure of the water pump pliers can deform the perimeter of the thread circle, making it harder not easier to turn the threads. I think that I finally got it off with a screw driver and an impact (ie small hammer) at a low angle. This certainly impacted the cosmetics of the filter, and could have broken it (so its defintely a last resort, and don't try it even then unless you really understand what I meant).
Posted 04/24/2008 07:47PM #3
Robert,

GENTLY warm up the filter, perhaps with a hair dryer. The threads MAY loosen enough to break the lock.

Rick

8" Zhumell Dob
90mm f11 achro refractor
4-1/2 f4 rich field newt reflector
Posted 04/25/2008 02:18AM | Edited 04/25/2008 02:19AM #4
I sent lumicon an email to see if they had run into this problem before and apparently they have. They suggested something that looks like a small oil filter remover but I have no idea where to get this.

If this filter was purchased new, then I would call Lumicon and ask them what they suggest doing. I think they bear some responsibility, particularly if you have successfully used other filters with your reducer/corrector. IMHO, they ought to be suggesting that you send it back to them and they will handle the problem.

Jon

Jon
Posted 04/25/2008 03:32AM #5
Another low tech option to try, there are rubber jar opening disks that you should be able to get a grip on the ring without touching the optical surface of the filter while using. Grip firmly and twist just like opening a pickle jar if its not to bad, viola you're back in action. Good luck and I hope something works out for you.

Real men play Golf
Posted 04/28/2008 07:43PM #6
Sometimes it is hard to hold a strap wrench on something as narrow as a filter. Try a big fat rubber band wrapped around the filter cell until it stays (ie not loose) and grip on that.

Try to avoid spray oils and lubes, AR coatings and the dielectrics on the filter could easily be damaged by these. When you do gte them apart use a tiny bt of graphite lube on the thrads (the powdered stuff for locks works nice). Be patient and careful!

Dave