Bellows patching tape?

[nsurit]

What do folks use to patch a small hole in the exterior bellows skin? Gaffers Tape or something else? Bill Barber

 

[Rick A]

I've used liquid electrical tape, its similar to the liquid plastic dip for tool handles. I've read where others use acrylic fabric paint with success. If you use the liquid tape, extend the bellows fully and allow several days for full cure, and then dust it with some corn starch to make sure there is no stickiness.

 

[michaelbsc]

I have also used Liquid Electrical tape, available at home supply stores, for small holes - not tears. Not sure how well it would hold up to professional daily use, but for my hobby use it's been more than adequate. What Rick said.

 

[RalphLambrecht]

I used liquid latex before I ordered new bellows from Custom Bellows in the UK.

I attached two pictures:
1. the equipment to check bellows
2. the test result with leaky bellows

 

[John Koehrer]

Bookbinders tape works well & doesn't leave goop like gaffers tape.. For small holes I use acrylic paint dabbed on with a sharp pointy thing.

 

[Maris]

This has been posted before but the method keeps working. Even bellows I patched 10 years ago still function perfectly.

The key item is 3M polyester tape type #850 black. This tape is so thin, 0.05mm, that it does not bulk up the bellows even if you covered the whole thing. The tape is very flexible so it can be used to patch pinholes in the corners and then the bellows can be re-pleated easily. Best of all the adhesive is strong, doesn't bleed, doesn't creep, and never goes gooey.

The downside? It is an $$$ expensive roll of tape.

 

[Paul Kierstead]

I used a black masking tape designed for graphic arts purposes and designed to be opaque to mask up a bellows with almost every corner with a pinhole. It worked very well. The tape was a narrower version of this

 

[John Kasaian]

Equinox Photographic sells some stuff for patching pinholes. It works and it's cheap and looks a lot better than tape.

 

[Ian Grant]

There was a great Invisible mend tailors repair tape made in Holland, the black was almost light tight, self adhesive, very thin. I used it on a a couple of sets of bellows to repair quite badly damaged corners, internally and externally, a thin coat of acrylic black paint over the external repair makes it hard to spot where the repairs are. Unfortunately the Dutch company distributing it ceased trading 18 months ago.

It was similar to the 3M polyester tape type #850 black Maris mentions, and it may well be that all the Dutch company were doing was repackaging in smaller convenient sizes, it was expensive.

The important part was to repair internally as well as externally and the material was thin enough to have almost no impact on how the bellows compressed.

Sometimes even Ralph's testing method doesn't show up all the light leaks. Recently I investigated an MPP MicroPress, the owner hadn't been able to find the persistent light leak, I only found it by firing a flashgun into the camera with the lens panel removed and a film holder in the back in total darkness. Even then the leak was only just detectable and was where the Graflex bellows attached to the MPP body. (The MicroPress is based around some Graflex parts).

Ian

 

[Joe Mace]

I just went through a major bellows mending effort - an aging 5x7 Sinar tapered bellows that came with a cut-rate 5x7 conversion kit. The bellows had numerous pin holes in the corners, as well as several 2-3 mm corner separations. I tried black silicone adhesive, 3M 850 (1.9 mil) black polyester tape, "flexible" contact cement, and 7 mil vinyl electrician's tape. All in all a fairly expensive exercise.


First attempt was sealing the pinholes with the black silicone adhesive. Goopy stuff to work with. I tried using a toothpick, but the adhesive want to stay on it more than on the bellows corner, next was a cotton swab (Q-tip), I could get more silicone onto the bellows but cotton fibers went along for the ride - butt ugly. Cutting off the swab and using the paper Q-tip "stick" seemed to work fairly well and I proceeded to plug several holes. After letting the black silicone cure, I found several places where I didn't completely close the pinhole. Worse, some pinholes seem to turned out to be separations not just pinholes. Next I tried "painting" on the silicone with a small flat artists brush, but that just made an ugly mess worse.

Moved on, briefly, to flexible contact cement - the kind used for repairing vinyl tears. I quickly found, to my horror, this was disintegrating the weakest bellows corners!!

Managed to find an on-line store (Grainger) that sells single rolls of 3M 850 black polyester tape -- $15 for a small roll. I bought 2 rolls. (Most other sources expect you to buy it by the case.) The tape IS thin, very thin, but surprisingly strong. It's also shiny and not really sticky. I had a heck of a time trying to mold it into the V-shaped bellows corner folds. I consumed a whole roll, and only solved about a 1/3 of my pinholes. The bellows now looked like like crap -- shiny, ill-shaped corners that crinkled with a disturbing sound when I compressed the bellows. I found several corners that needed double and triple tape applications to completely seal them.

I started wondering how long it will take me to save up for new 5x7 Sinar bellows.

With little to lose, I bought a cheap roll of electricians tape at Lowes. A couple bucks for 7 mil, 3/4" tape. Best $2 I ever spent. I quickly learned how to mold the 2" strip around a corner to form perfect V-shaped folds. The tape molds so well!! It's a dull black, like the material on my black Graflex Graphic View II bellows. I ended up doing every corner on the bellows in one afternoon. They look quite good now (considering it's my first bellows repair) and are absolutely, 100% light-tight. No - the bellows do not collapse as flat as they were designed to. They're not going to work for my 90mm wide-angle. But for anything longer 120mm they'll work fine.

Bottom line, for me anyway, is to go immediately to good ol' cheap vinyl black electrical tape for future bellows repairs.

I hope this saves someone else from the aggravation and expense that I've gone through. If anyone's interested I'll snap some pics of my repair job and post them here.

Now I need figure out how to make a 5x7 and 4x5 Sinar bellows frames so I can fabricate a bag bellows.

Joe

 

[richard ide]

A word of caution on cheap vinyl tape. The adhesive begins to deteriorate after a couple of years and can leave a slimy mess. Buy the best quality from an electrical distributor and you will not have that problem. Also; I have been using a roll of #850 since 1969 and it is still as good as the day I bought it. No deterioration of the adhesive at all.

 

[nsurit]

A roll of 3M #850 tape arrived today. About $28 with shipping for 5 yards of tape. Sounds expensive for the 1 inch piece I need, however if it will keep me from having to buy a new bellows guess it is a bargain. Bill Barber