How do you make a bag bellows?

[Ben R]

I need a bag bellows for my Gandolfi Varient. The owner of Gandolfi is pretty much impossible to get hold of so I tried Camera Bellows who quoted me a better price anyway. Problem is that I would need to get the front and back boards of the bellows made for them to stick the bellows to. If I'm already making the boards then methinks I might as well save the £100 and do the in between bit - the bag - at the same time.

Couple of questions. What would be the best material for the bag bellows to be light tight and not flop too much? I've read suggestions here via the search but have seen nothing that would be available in the UK. I have a huge light tight bag that is never used anymore (I use a tent now) that could be cut up..

Secondly what is the best shape to make it? I assume a tube of some sort but as the regular bellows is tapered so do I make the bag tapered too? More importantly how do I stitch the flat material into the tube and keep it light tight?

What kind of glue is used to attach the bellows to the boards?

Or do you think I should pay up and leave the work for them?

[Louie Powell]

Ben -

I made a bag bellows for my Zone VI Lightweight. It was an interesting/fun project, but alas not all that useful.

I started by taking the standard bellows off the camera and carefully measuring the frames. I made a set of frames for the bag from maple wood, gluing strips of wood as needed to get the dimensions and profile required to mate to the camera. This was tedious work, and I had to make several sets of frames before I finally got them right.

The bellows itself is a two-layer construction - vinyl "leatherette" on the outside, and black felt on the inside. While this combination is certainly light-tight, it is also too dense and not nearly flexible enough. So if I were to do it over again, I would certainly look for lighter material.

I found a bellows construction web site that had a good design for bag bellows. Unfortunately, I failed to keep the url, and a quick search this morning failed to turn it up again. I do recall that the site was in German.

But the basic design involved cutting two squares from both the inner and outer material. One pair had an opening dimensioned for the front frame, and the other had an opening dimensioned for the back frame. The bellows was actually constructed inside out - the outer vinyl layers were in the middle of the stack with their outer surfaces facing each other, and then the inner felt material was on the outside of the sandwich. One of the vinyl squares was about an inch larger in each direction than the inner layers, so that the edges could be folded over to assure a light tight seal when the outer perimeter of this sandwich was stitched. I also chose to round the outer corners of the squares to that the resulting bellows would be sleeker. I stitched mine by hand, and even that was difficult with two layers of vinyl (one folded) and two layers of felt. After stitching, the bag was then turn inside out to bring the vinyl layer to the outside.

I glued the bag to the frames using two-component epoxy glue. I had cut some "cauls" from the same maple wood used to make the frames, and these were wrapped in plastic sandwich bags to which the glue would not adhere. I mixed enough glue for two edges of one of the frames, and spread this on opposite sides of one of the frames. Then, I carefully embedded the bag in the glue, making sure that the outer vinyl was glued to the outside of the frame, and the inner felt was glued to the inside edge. The, I laid the cauls on the glue joint, and used sping clamps to hold it tight until the glue cured. Since I could only do two sides of a frame at a time, I had to repeat this process four times to attach the bag to all four sides of both frames.

Finally, after the glue had cured, I painted the exposed wood of the frames with matt black paint.

[Kirk Gittings]

http://www.apug.org/forums/archive/i...p/t-27588.html

http://www.largeformatphotography.in...llows+material

[Ben R]

Thank you to you both. Your explanation Louie together with the german website courtesty of Kirk's links made it all clear.

[Brian ER]

Ben

I have a Variant 2: 5 x 4 (Black Marine Ply Model) & when I purchased it from Eddie Hill I also purchased a set of Bag Bellows - These I seem to remember were in fact the smaller type manufactured by Cambo/Calumet and are tapered. Not leather but synthetic material - They work very well with 65mm & 90mm lenses

Possibly another angle to explore

Brian (A southerner from Hampshire now living in Scotland)

[Sandeha]

I used the German site as a guide and an old changing bag, but if I had to make another I'd use the Porter's material as it's softer. I didn't sew the last one, but used a staple gun with small staples - much quicker.