Old film cameras can last a long time with very little maintenance. One of the few things that fail, however, are lightweight foam seals. Fortunately, they are easy to replace.
A few months ago I bought a Canonet 28 from the early 1970s. Mechanically it worked perfectly, but it had very bad light leakage. As cool as the effect was in some shots, it was incredibly unpredictable so I decided to fix it. This is the camera for all the demo photos in this article.
A few warnings
Decomposing old lightweight seal moss is quite a gnarly material. It crumbles and the pieces that come off stick to everything. When removing it, be very careful not to drop it into the inner workings of your camera. It will only ruin the roll of film you shoot next. (I was a little lucky that the seals on my Canonet were so rotten that there wasn’t much left to remove.)
Also, although replacing the gaskets is a relatively easy task, you still need to be careful when working on older cameras. Take your time, don’t rush anything and you should be fine.
What you need to repair light joints
To replace your light seals, you need new ones. They are made of an opaque foam or felt that you can buy in strips or, for common camera models, in pre-cut kits. I bought this bumper pack from Milly’s Cameras in the UK, while Ebay seems to be the place to buy pre-cut kits. Choose the option that suits you best.
You also need a way to glue the new light seals into the camera. We recommend buying lightweight gaskets that come with pre-attached tape, but you can also use Pliobond – it might be a little messier.
To remove the old light seals, you need a few pieces:
- A soft scraper. I used a wooden kebab skewer because I couldn’t find my iFixit repair kit.
- Cotton buds.
- Cloth or paper towels.
- A solvent, such as isopropyl alcohol. (I used methylated spirits as they are easier to buy in Ireland.)
If you’re using a pre-cut kit, that should be enough. However, if you are cutting yourself, you will also need:
- An X-acto knife or similar.
- A pair of scissors.
- A hash surface.
- A metal ruler.
- A pencil.
Step 1: Remove old seals
Remove the old light gaskets and any remaining adhesive residue. Start by scraping as much as you can with your soft scraping tool, gently flipping it over your work surface as you go.
Once you’ve removed as much of the old gasket as possible, use a cotton swab to carefully apply your solvent.
Use a combination of your cloth, a scraping tool, and cotton swabs to get rid of any remaining residue.
It may take a little time, but eventually you’ll end up with a clean surface.
Also, make sure you don’t miss any of the camera seals. They are often both on the film door and around the film chamber.
Step 2: Insert the new seals
Unless you are using a pre-cut kit, measure and cut the replacement strips. Be sure to use the foam or felt that best matches the original gaskets.
Dry fit your gaskets to make sure they are the correct size. It’s easier to leave them a bit long and trim the edges at the end.
If you are using an adhesive, apply it now. If not, carefully peel off the backing paper from the foam and press it into the correct spot on your camera. (Your soft scraper will really come in handy for any tricky corners.)
Again, don’t miss any of the original lightweight seal points.
Step 3: Wait
As tempting as it is to load a roll of film right away, don’t. Allow the adhesive to cure for at least a few hours.
Then close the movie door and make sure everything is fine. If you missed cutting a light seam, you may need to cut or redo it.
Finally, load up a roll of inexpensive film to test your work. If all went well, the light seal issue should be gone.