Fun with Acetone

[Fotoguy20d]

I have a Gundlach rapid rectilinear (3 cemented glasses), around 1.5" diameter, soaking in acetone as I type this. In under an hour, I already see a yellowing band around 1/4" forming on the perimeter. Any idea how long it should take before the acetone gets through all the balsam? How long do I need to leave the lenses sitting there soaking? Will the acetone dissolve all the balsam or will I need to peel the lenses apart? How do I clean them off? What are the handling precautions for the acetone? Anything else I should know? Where do I get something to glue the glass back together when it's clean?

Thanks,
Dan

[goamules]

Ha! You're asking a lot of questions for already having the lens soaking in it!

Here are some more:
- Is acetone explosive?
- Can you drink it?
- Will my lens be more valuable with half the lens separated?
- Should I use the dog water bowl for soaking?

Just funnin ya.

[Fotoguy20d]

Always jump in with both feet...

In order:

Yes (or at least very very flammable)
Yes (you can, technically. should you drink it - no!)
Yes (you should have seen it before I started, and, I cut off the peened over brass long ago)
Yes (I don't have a dog and my neighbor's dog is a yappy little thing)

[Curt Palm]

Always jump in with both feet...

Hopefully not into the acetone!

[rdenney]

Hopefully not into the acetone!

If my wife can use it to remove nail polish, it must not be that bad. She's sensitive to a range of chemical smells but the acetone doesn't seem to bother her. It drives me out of the house!

Rick "who has a couple of gallons in the garage, however" Denney

[Jim Fitzgerald]

"I love the smell of acetone, it means carbon printing!" I have gallons of it also. Acetone is fun, but I always have a fan on it!!

[John Jarosz]

Did you mark the orientation of the two elements with respect to each other?

[John Jarosz]

Norland Optical Cement

[James E Galvin]

I have usually used MEK. It may take a couple of weeks. When done, the elements will slide apart, maybe slowly since the balsam is not gone yet, just softened. Clean up with the acetone and a soft tissue or soft cloth. You need to get the glass very clean.
Re-cement with UV curing epoxy, available from Edmund Scientific Co. You will need to make a fixture to hold the elements aligned, for a lens that size I have used 3 pieces of microscope slide and a rubber band. It is helpful to tape the slide pieces together so that the 3 can be handled with one hand while you adjust the rubber band. Put a drop of the epoxy on one element, place the other on top. After a while the epoxy will flow to the edges. Press down. If there are bubbles and dirt, redo. The epoxy doesn't start to cure until exposed to UV, so there is no rush.
With the elements well aligned, expose to UV for (a UV fluorescent lamp works) for a few minutes. The epoxy is now set, but still soft enough to easily clean up with a tissue moistened with the acetone, or take back apart with a short soak in acetone. Now give an hour or two exposure. Done.

[Merg Ross]

"I love the smell of acetone.....!"

Me too! Metol/Acetone film developer is my favorite for large format.