Jason Antman , Aug 21, 2004; 05:54 p.m.
The Beseler 23C-II is a GREAT enlarger. I use one and love it. I'm pretty convinced that it's at LEAST one of the best 2x3 enlargers out there. They're built like a tank and never quit. And they even do wall projection.
As to a cleanup, you want NO dust in it. So, what you do, you take the enlarger OUT of the darkroom, and vacuun it off, including opening up as much of the enlarger as you can and cleaning it. Be sure to clean out the bellows. And the color head if it has one.
The condenser CAN be cleaned. Raise the lighthead to the highest (2x3" / 6x9cm) setting. The name plate (which says Beseler) is hinged and can flip up. Now pull down on the upper bellows. It will pop off of the condenser. Pull the condenser unit forward and out. Now, prepare a sogft surface such as a few sheets of paper towel. In order to keep fingerprints off of the glass, a pair of CLEAN latex or cotton gloves helps. Hold the condenser unit upside down (with the flat metal flange down) over the paper towel, with your thumbs on the flass facing up, and your fingers on the transparent white plastic facing down. Push on the glass with your thumbs, the plastic should pop free of the metal housing. Very farefully lower the unit to the paper towel and allow the contents to empty out. First will be the plastic. Next are two convex pieces of glass. The first one the fall out, the one touching the plastic, will fall out with its convex side up, and the flat side against the plastic. That's fine. The next one though, the one that you had your thumbs on, will have the convex side DOWN, so you must keep a grasp on it to prevent it from rolling (and possibly cracking/smashing). Now just clean the glass off with a brush and soft microfiber towel, as you would a lens. If need be, use lens fluid. The plastic can be wiped with a wet (soft and lint free) cloth.
Once clean, reassemble.
That's the condenser unit. Now, I could give you more instructions, but I need to know what type of light head the enlarger has. There are two original types - a bare bulb and a color head. The color head is a large rectangular box that sits on the enlarger, and is marked as a Dichroic Color Head, Probably a "DGA". It has three dials on the front for CMY (cyan, magenta, and yellow) filtration. The other head is a very small piece that sits over the condenser and has a single incandescent lightbulb (as opposed to the halogen reflector bulb of the Dichro).
There are also aftermarket light heads, which are usually identified with a brand and model.
If you can post the type of head, I will reply with more detailed cleaning info for the head.
Oh, and if you send away to Beseler, they still sell parts and a reconditioning kit for the enlarger, which includes new springs, knobs, and some other stuff.
If you have any more questions, feel free to ask them here or drop me an email (using the email on my web site).
To directly answer your last question, it may or may not affect your prints. If it did affect them, it would most likely appear as a localized change in exposure.