Camera Repairs at Home

for FUN and not for profit

Foam/Lightseals

Revised 12/12/01

On most cameras older than 1980 the seals are pretty much nothing but mush or a tarry goo but sometimes you will find them dried up and powdery. Older cameras from 1960 and back may have felt or fabric seals of some kind and are usually in good usable shape unless attacked by mold, dry rot or some other microscopic critters.

A real mess in a Canonet G-III QL17

Protect your shutter or the rear element of your lens with a business card or piece of poster board cut to size and taped in place. I usually clean out all the old foam with alcohol prep pads and small screwdrivers, toothpicks, dental picks or any other tool that can fit the small channels that the seals are recessed in. Alcohol seems to be the best solvent for removing the old foam, it does not damage the paint and it leaves no residue.

Some of the tools I use

On some cameras, particularly the old Konicas, this is a real messy job.

If you think this is a mess, you should have seen my fingers.

It is very easy to cut a small piece of wood and fashion a custom size scraper that can be cut back to a fresh edge when it dulls down from use. Wood is very good at removing gooey foam but does not damage the paint or metal of the camera. I also wear a headband light so I can see inside the dark camera recesses easier. A swingarm lamp with a bright light is also very useful.

Removing the old foam seals from a Canonet QL19

Now that the old seals are cleaned out you must decide what to replace them with. In the past I have used yarn for the small channels that the camera door closes into. Acrylic yarn will last very long in this application. Felt makes a good repair for areas where a broad flat seal is needed as does thin velvet material but I have not been able to find any thin velvet at the local stores. Some people like to cut up mouse pads to use for the seals. The soft component of the 2 part velcro strips can reportedly be used but I have never tried it. These velcro strips are usually self stick too.

What do I recommend? For longevity I prefer the yarn/felt/thin velvet combination out of everything that I mentioned above to seal the camera from light leaks, but lately I have been using foam because it is so much easier to work with, quicker and looks much better. The only down side is that the foam will eventually break down like the mess you just removed. So plan on refoaming your camera's seals about every 20 years, maybe less, maybe much less. Who knows? A plus is that with foam you do not have to worry about fabric dust and strands all over the place. If you do use felt and yarn always carefully vacuum out the camera after replacing the seals. Broad felt seals may shed for some time after application so careful inspection and vacuuming may be necessary on a regular basis.

Cutting the replacement foam

Where do you find foam? 2mm thick foam is just perfect for seals and is available at Wal-Mart in the craft section under the brand name of Foamies for about 40 cents a 9 x 12 inch sheet. This is pretty dense and seems ideal for camera repairs. For most of us this sheet is a lifetime supply. I cut out the strips to size with a steel rule and an Olfa Multi Purpose snap-off blade cutter, this cutter will last longer than the foam as I have had mine for over 15 years and it is still going strong and a sharp blade is only a snap away - this tool is often poorly imitated, so don't buy the copies, buy the real thing. Getting back to the foam, it is also available in self-stick form but I prefer to use glue that dries slowly and allows me to slide or reposition the seals if need be.

Installing the foam is very easy. Apply glue (very, very, very sparingly) to a short section of the foam with a glue stick, insert it into the channel using a screwdriver, toothpick or blunt piece of wood and carefully move down along the channel pushing the foam into it. Continue to glue an inch or so of foam, insert, glue, insert, glue, insert until you reach the end of the recess. Then you make your cut (carefully measured) to the final length then glue and press in the last 1/2 inch or so of foam. If you are especially sloppy I guess you could glue your camera's back in place so be cautious of using too much glue and having it ooze out where you do not want it. Some folks do not use any glue and just rely on the foam's expansion and friction to hold it in place. Do this if you are not confident in your glueing abilities. You will have to use glue where there is no channel to lock the foam in place.

Installing the foam

Wider strips are cut to use around the hinge and latch areas if your camera needs these replaced. Thin velvet also works very well in these areas.

Sometimes I need thicker foam than 2mm so I glue up two pieces to give me a piece 4mm thick. Of course thicker foam is available but I have not been able to procure any locally. Old mouse pads to the rescue?

You can also use this dense 2mm foam in the mirror box on some cameras but on others they seem to do better with a very lightweight foam.

Leave the camera open overnight to let the glue dry.

The new seals may make it a little harder to close your camera's back but this goes away in a little while after the seals compress and take a set.

All finished and it looks as good as new.

Now get out there and use that camera to shoot some images!

Lens Fungus and Dust

I have cleaned a number of lenses that have had fungus or very heavy dust or film between the elements. This is really a very easy job if you are careful. Prime lenses are relatively easy. Zooms may be difficult or not worth the trouble if you have to totally disassemble the lens to get to an element.

Go slow. Be Patient. Sketch the elements, spacers and whatever else you remove. Always make a sketch, especially the lens elements and since they are rarely symmetrical on modern lenses it is easy to sketch which side is convex, concave or has more or less curve than the other.There is usually a starting point from which the lens are aligned by design, i.e., an assembly or threaded flange that is locked in place by screws that are usually locked in place by a dab of paint. Do not take these assemblies apart or you will have to completely align and collimate the lens elements to each other and this will probalby be beyond the home tinkerer's abilities.

You may have to collimate the lens for infinity focus after reassembly. This is also relatively easy. There was an excellent web page on this but I have lost the link.

Tools: coming soon

More detailed procedure: coming soon

Photos: yes, someday

more instructions, categories and links to follow

Disclaimer: Repair cameras and lenses at your own risk.
Wear safety glasses - there are springs under tension everywhere inside a camera and lens.
If it is too valuable or must be repaired at any cost please send it to a camera repair expert.
You will eventually break, drop, lose, scratch, crossthread, mangle or forget how to reassemble something.
Really, you will.
The good news is that you will always learn from your mistakes.
Well, you should learn from your mistakes.

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