Filters fused together, need to separate

[Lars]

I have two 77mm Heliopan filters that seem fused together, a KR3 and a yellow-green filter. Both have brass rings.
Any suggestions? I tried heat and cold but brass is more thermally stable than aluminum so that trick didn't seem to work.
Soak in warm water? Something involving frickin' lasers? Magic spells?
Any ideas appreciated.

 

[fotophil]

I have applied a alcohol based moly-disufide lubricant to the thread area and then grip the filter rings with filter wrenches. If you lack such stuff visit International Camera Repair in Mountain View. Good luck

 

[f8orbust]

Two strap wrenches, top and bottom, will do the trick.

 

[JoelM]

Since they're both brass, they will likely be affected the same by heat and cold. The strap wrench is a good idea, but you can't grip them too hard. That will distort the filter while you are trying to turn it and that will work against you. Try something like Kroil around the center of the filter stack and let it soak for a few minutes and then gently grab the filters and turn or use the strap wrench. The nice thing about the strap, is that it applies pressure evenly around the whole filter.

Good luck,

Joel

 

[Cindy Flood]

I have two pieces of thin rubber (used for opening jar lids) that I keep in my bag. Sometimes when a lot of pressure won't work, I grip with the rubber and turn it with very little pressure and they come apart. Seems like if you are trying too hard, you are only driving them together.
If that doesn't work, then I run them under water. I have heard WD-30 (only a little on the threads) will work, but I have never had to resort to that.

 

[hot]

You can find a lot of them ... ebay.com, amazon ... for few bucks.
Search "filter wrench camera"
http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=filter+wrench+camera&_sop=15

 

[fotophil]

The relatively cheap plastic filter wrenches work well for me for unsticking filters. Sometimes I place rubber bands around the filter rings to increase the friction for the wrenches. Really tough jobs (especially aluminum filter rings) may also require the use of a thread lubricant such as "LubeCon". It is a dry film a product consisting of very fine moly disulfide powder suspended in alcohol. I periodically apply it to both lens and filter threads.

 

[Lars]

I got the plastic filter wrenches. Attempting to use the wrenches did absolutely nothing. I'm pretty sure I heard the filters laughing at me - a cold, dry laugh.
I tried heat and cold - ice from one side and hot aluminum surface from the other. No success.
I left the filters in water overnight. Nada.
Got desperate...
WD-40 in the threads, let sit overnight. Nothing. Repeated a second night - nothing.
Finally I used a tool to gently pry the filters apart. I worked around the circumference, and at some point the filters popped apart enough so I could unscrew.
Threads seem undamaged but some brassing now shows on the front of one filter.
Next I used dishwashing detergent to remove the WD-40 and clean the filters - glass was spotless, zero damage.

I was hoping to sell these filters but obviously they are far from mint in appearance anymore so might as well keep them.

I figure that what happened was that these slim-line filters has so little thread that the upper filter got all the way down to the retainer ring for the glass of the lower filter, which offered far too much friction and simply locked. Manually slowly threading them back together sort of confirmed this, there was definitely a point of locking up again although I was careful not to tighten at all.

Thanks everyone for practical and creative ideas!

Lars