I'm concerned because the bellows on this camera fold up to almost nothing, the whole camera folds to maybe 1.5 inches thick, including the base.
The original bellows look to be made out of paper? I'm wondering if cameras made for plate photography were less concerned with absolute light-tightness?
Every type of duvetyne/commando cloth I've ever used has been way too thick to make a bellows that properly compacts. This Nylon Sheeting Rubberized Cloth is expensive ($45/yd), but it's very thin at only .005" thick. I've been using the Thorlabs BK-5 cloth for rollerblind shutters and it's not quite 100% lightproof, but sandwiched with another layer of BK5 or black cloth, it should be fine. It's very thin. Leather Supply House Online Store also sells a variety of rubberized fabrics.
I'm sorry - the cloth I used from freestyle was called Darkroom cloth - it appears to have been discontinued. I might be worth giving them a call to see if the commando cloth is a suitable substitute. I think Barry has some better suggestions.
I built a replacement bellows for an 8X10 B&J Orbit with the darkroom cloth.
I am currently exploring bellows cloth options as well.
I found that 4 coats of Plasti-Dip ( spray can version ) makes a 200 denier Oxford nylon ( $4.63/yd ) light proof and considerably improves the bond when glueing.
Outdoor Wilderness Fabrics also has a 100 denier nylon taffeta with a silver coating ( $9.89/yd ) that is close to light proof. I have not tried coating the silver side with the plasti-dip yet. The 100 denier would be a good thickness for a bellows that really needs to compress small.
For my 8x10 bellows I'm pretty certain I'm gonna go with the 200 denier Oxford with plasti-dip coating for the exterior and the 100 denier for the inner lining. I may give the inner lining a coat of plasti-dip over the silver just to improve the bond.
The black acrylic paint ( diluted 1:1 ) also improves light proof qualities.
Had not thought of Yupo for my ribs. Gonna check that out today. Any issues with glueing it?
I've investigated various bellows cloths for player pianos, as a friend of mine is a piano repairman. Most are way too thick and stiff for camera bellows. The super thin one mentioned earlier does sound promising, though.
Rob, why would you put silver coated cloth on the inside? If you coat it with something dark, which I assume you will, if the coating ever flakes, then you could have problems with stray light bouncing off of the silver fabric.
I'd be wary of any DIY coating. Bellows have sharp creases which are regularly moved. The coatings might fail in places in a fairly short time.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
I believe Ian Grant has some very good information on bellows construction, if he is about he may be able to give some tips.
..... Had not thought of Yupo for my ribs. Gonna check that out today. Any issues with glueing it?...
I have had no problems. The bonding strength of the contact cement between the two pieces of fabric that are sandwiching the Yupo ribs appears to be significant as well. One thing I did was round the edges of the ribs more than I would on cardboard ribs because the Yupo is quite rigid and could cause premature wear if the edges and corners are too sharp.
Building a large bellows is pretty tedious. Cutting, spacing, and gluing 80+ ribs... I admire the bellows builders. They must have some kind of system worked out or they aren't making much of an hourly wage.
We must remember there two types of bellows. The traditional instructions for replacement bellows are for "smart" outer layer, plastic/card spacers and thin dark cloth - making a sandwich. But lots of foldable cameras have just the one layer, often just of strong paper which has been prefolded - anything else will inhibit folding.
I would put the silver side in towards the ribs, so it won't be exposed in the bellows. The silver is a urethane coating, so I can't see how it could flake. It is very flexible.Originally Posted by Peter J. De Smidt
The plasti-dip is a rubber paint. Don't know if it is a synthetic or natural rubber. I burnished a spot on the coating until it blistered. When I pull on the loosened area it snaps right back and is still very well adhered at the edges.
Very true that it will get lots of abuse at the folds, but it seems it will be plenty durable and hold together even if it delaminates from the nylon.
Well, the only way is to try. I have no doubt about plasti-dip's durability when new. The question is if it becomes brittle with age.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
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