Restoring a French Guerry Shutter

[Steven Tribe]

French Guerry Shutters were an important part of Photography until they were put out of business by the genial Grundner shutter (for studio use) and T-P focal plane shutters (for higher speeds) after 1905.
I have a catalogue listing for the single panel Guerry, as well as the double panel system (much less common). NORKA (short for Nordisk Kamera) also produced the same design shutter.

I have a number of both Guerry and Grundner (often called eye-lid) shutters and the Grundner is definitely best for mounting inside studio cameras, like the Pickard shutter.

The design is really simple. The "barndoor" is held down by a long coiled spring in the compartment to the right of the opening. There is a thin piece of wood which is attached by cloth tape to the wooden spindle to which the barndoor is attached. When this wooden piece is depressed at the top, the spindle turns just enough to counteract the spring tension, raising the barndoor. The actuation is accomplished by an pneumatically operated rubber cylinder attached by tubing to the usual release bulb. The assembly is by no means a precise design and fixed to the fine walnut cover is a block of soft wood which has been whittled with a penknife to provide "factory" adjustment!

The usual problem with using these shutters to-day is that the natural red rubber internal cylinder will have hardened to a point where it cracks and becomes non-flexible. The same system is used with Grundner shutters with the same U/S rubber.

The Guerry I am working on has this standard rubber problem, but also has a "barndoor" which is both distorted and has numerous pin holes. I'll do the barndoor first and finish up with pneumatic action problem. This is no just a question of putting antique stock into working condition, these shutters are just about the only shutters which can manage the 10cm plus lenshoods of big Petzvals.

I wrote about the Guerry pneumatic repair back in 2011. Unfortunately all attached photos from this period were lost in a LFPF data crash.

http://www.largeformatphotography.in...rbishment-quot

I will post some pneumatic solution photos again, but the "barndoor" problem is new!

[Tin Can]

Yes, interesting. Emil's link inside your older post was also interesting. I look forward to this thread's expansion.

[Steven Tribe]

The barndoor is essentially a wire frame covered with velvet on both sides. The two wire pieces have two exensions at the top which fit into two holes in the wooden spindles. These have been wedged into the spindle by two small wooden wedges, apparently without use of glue. The velvet is continued around the spindle and must have been glued, originally.

Dismantling the barndoor shows that the velvet piece is, in fact an envelope and hand sewn to fit on the top section of the wire frame. The frame itself has the two pieces bound together with heavy duty thread - good old fashioned cottage industry, I think.

The surprise was that used to be a light secure piece of paper between the two velvet layers - now just a few fragments. Velvet was used as a light trap, but across the pile - not through the pile!

Now upstairs to my sewing machine with the velvet I have scrounged from one of my family!

[Steven Tribe]

The velvet envelope has been completed. This has to be quite precise, as the wire frame must fit inside without being distorted and an oversize envelope will foul the walnut frame. The edges look a little rough as velvet sheds a lot of loose threads. I have applied glue along the cut edges to prevent trouble in the future. I placed a piece of black card between the two velvet layers before sewing. This is real time DIY, by the way!

[Steven Tribe]

Whilst glue is drying, a little more on Guerry shutters.

You don't have to keep pressure on the bulb to hold the open position. The spindle has a bent arm which can be engaged by a latch to keep it open.

The shutter, like the Grundner shutter, can be modified to activate electronic flash. There is plenty of room to place diverse springs and contacts. I have a smaller Grundner which is modified with due thought - even to the matter of protecting the live parts from unintended open circuits!

[Steven Tribe]

The replacement cycle tube is still not ready!

Some more info about the Guerry!

The first photo shows the original style expanding cylinder - raised slightly to show the pleats. This one is still working as better rubber must have been used. The top cover on the side has quite a lot of useful information underneath. First of all the date of manufacture, in this case, 1900. And a tiny stick in label giving the size number of the replacement rubber cylinder, so Guerry was dealing with failing cylinders as early as 1900!

[MMELVIS]

Very nice work on restoring. I have a barn door shutter with a bit of different way of opening the shutter. Could you post pictures of your Grundner shutter?

My shutter

[Steven Tribe]

There was an illustrated thread.

http://www.largeformatphotography.in...light=grundner

Now without any illustrations!

The Grundner does have a rubber bellows that looks as if it is similar to yours.

I show two of mine. One assembled, and the other with the cap removed showing the expanding rubber bellows. I have used the cycle tube system to solve the lack of original (working) natural rubber bellows.

[Steven Tribe]

As I have a very poor record of repairing cycle tubes for my children, I just a a double folding glueing system for making the replacement expanding bellows. I keep well away from the valve attachment which I know is pretty unrepairable if damaged!