Ricoh 500G & 500GX Light Seal Replacement

The following instruction set is somewhat hastily put together for the time being but should hopefully serve as a useful guide to replacing the light seals in a Ricoh 500G or 500GX 35mm rangefinder camera. Both these models have the same light sealing layout. The Ricoh 500ST has a far simpler layout illustrated towards the end of this guide. Other Ricoh 500 camera models I have yet to see.

Hopefully much of what is covered here will be of use when replacing the seals in other camera models from other manufacturers also though it certainly doesn't cover rail seal replacements that often crop up with various camera types.

Should you spot any obvious errors in the following or have better solutions to share please do email me at the address provided at the bottom of this page.

Materials

The first thing to consider is the materials you'll need to do the job and in terms of the light baffling foam itself I heartily recommend purchasing a kit from eBay seller interslice. I buy all my material from this seller and due to the high quality of service provided I have absolutely no inclination to spend time looking for any other source.

Whilst waiting for your foam sealing kit to arrive you may also wish to piece together a few simple 'tools'. I use a surface to cut on (ie: one that can sustain damage from sharp blades with no concerns - some thick card or whatnot), a metal rule to measure and to guide a blade when cutting foam, a sharp craft knife, some white spirits or lighter fluid (depending on my mood!) and some disposable cloths. The interslice kit also comes with a particularly useful pre-cut bamboo tool that proves great for all manner of tasks but in the absence of this you may wish to put together some things like tooth picks etc. I'm not too sure what would work best as the bamboo tool has seen me through some pretty gory reseals so I'm sold on it as THE tool for the job.

STEP ONE - INSPECTION

Open the film door and avoid touching the existing light seal material if it's obviously in a state of decay (even if it isn't obviously in a state of decay you may find yourself with some thick dark gooey gunk sticking to your fingers upon touching it). If you detect any perished foam sticking to the actual body of the camera carefully remove it with a small piece of cloth dipped in white spirits or lighter fluid.

Unless the camera has been resealed in recent years, and resealed properly at that, you're almost certainly going to have to replace the exisiting seals even if they appear on first viewing to be fine. The latest 500G I came by had the original seals in place and they looked perfect, so I closed the camera door again. Later I opened it to put a film in and saw that just this brief exposure to air had triggered breakdown of the old seals and parts were coming off and sticking to the camera body.

You should remove the film tensioner back plate from the door for ease of cleaning and seal replacement. It is also feasible to remove the rear door entirely but I always choose to avoid this (purely based on childhood experiences that convinced me I'm great at taking things apart cleanly but beyond inept at putting them back together again). I prefer instead to carefully cradle the door during certain operations in order to avoid putting undue pressure on the hinge.

STEP TWO - INITIAL FOAM REMOVAL

Using the bamboo tool from the interslice kit or whatever you have chosen in its place gently probe the exisiting foam and remove any that easily comes away (the first couple of times I resealed a 500G I went straight in with the solvent and ended up creating enough crude oil to fuel ... anyway). If none comes away easily on brushing it with the tool then it seems you don't actually need to replace the seals.

Keep probing away and removing old foam until you can't remove any more without danger of damaging the door in some way. Apply some degree of caution and common sense but work with the fact that this is a reasonably strong metal door (whilst cradling it carefully or better still having removed it from the camera first).

STEP THREE - DISOLVENT

I use either white spirits or lighter fluid, depending on my mood (do I want a white spirits hangover when it's too cold to keep all the windows open? Can I afford lighter fluid over the former option that week? Do I want to refill my Zippo or am I happy using generic plastic disposables a while longer?) and flood the rear door a little to ensure all the remaining seal material gets a good soaking.

Tilt the door to ensure the solvent gets in to all the corners and soaks all the sealing thoroughly.

Then, if you haven't removed the door from the camera, balance it in some way so the solvent is as equally distributed as possible around the inside of the door. Leave it soaking for about five minutes or so.

Now imagine how it would have been had you gone straight in with the solvent when most of the old sealing foam was still in place!

STEP FOUR - FULLER REMOVAL

This step probably takes the longest out of them all and is, I have to say, my least favourite step BUT it has to be done and it has to be done well in order to ensure the longetivity of your new seals, particularly in the first instance that they get the best possible grip on the door surface.

Using the sharp end wedge of the bamboo tool scrape away at the remaining seal material. It is particularly useful to get to the underlaying sticky tape like layer as upon lifting this you can usually remove larger portions at a time.

>From time to time you may have to resoak the remaining material with your chosen solvent and leave for several minutes before continuing with cleaning. This process can easily take up to an hour or more.

STEP FIVE - FINER CLEANING

Having cleaned away as much of the old sealing material as I believe I can with the bamboo tool I tear up a disposable dish cloth into small strips ready for finer cleaning of the remaining seal deposits.

Adding more solvent as required, scrub away at the remaining residue (ensuring the film door is securely cradled to avoid undue strain on the hinge).

Keep at this task until the door is as clean as possible.

STEP SIX - NEW LIGHT SEALS

Clean up your working area and prepare to measure and cut your new sealing material. I prefer to use 1mm or 1.5mm open cell foam (from the interslice kit).

As a rough guide:

  • The hinge end piece will measure approximately 68mm by 22 or 23mm
  • The latch end piece will measure approximately 68mm by 8mm
  • The door base piece will measure approximately 86.5mm by 5mm
  • The door top (incorporating viewfinder hole) piece will measure approximately 86.5mm by 20mm

  • I recommend however cutting pieces slightly over size, by a millimetre or more, and fine trimming them to fit, placing them in place without removing the paper backing to check that each fit is flush.

    Once you have the right dimensions remove the paper backing from each piece, liberally lick the sticky back to delay its sticking power for a minute or more, and position in place, sliding about a little as necessary. The bamboo tool is particularly useful for placing the latch end seal correctly. The hinge end seal should curve around with the moulding of the door towards the lip of the door itself.

    DO NOT place the door top seal yet.

    You will need a space in the door top sealing to accomodate the viewfinder slot. You may choose to do this by using four separate pieces of sealing material for the door top, cutting each piece to surround the viewfinder hole, or for a far neater solution place the strip of sealing material in place (with the paper backing still in place), hold this firmly against the inside of the door and from the rear of the door use a fine tipped marker pen to mark the shape of the viewfinder hole on the paper backing of the seal material.

    Using a steel rule as a guide and a your sharp blade cut around this guide outline, BUT ...

    ... Make sure to leave a millimetre or slightly more around the guide, as the markings you have made indicate the inner edges of the viewfinder hole and not the outer edges of the plastic moulding that form the eyepiece.

    Once all sealing material is in place leave it to dry for about thirty minutes then use your fingertips and the bamboo tool to ensure it is pressed securely to the door at all points. Then close the film door and leave closed for a number of hours.

    You may also wish to replace the film tensioner backplate.

    STEP SEVEN - BUY A 500ST INSTEAD

    It has the same great lens, zone focusing is fine in most situations, and the seals are an absolute doddle to replace when compared to the 500G!!!



    If you have any suggestions for better approaches or spot any errors do please contact the author at phill_abroad@hotmail.com