Re: Liquid electrical tape for bellows repair
Things are getting more complicated. There appear to be two sources of light leaks where the bellows mounts to the back end of the camera (a Wista 45VX). The
1. It looks like the person who made the bellows used a clear glue to attach the bellows to the frame. It smells like Gorilla Glue. Where it's a thicker layer of glue, a bit of light can shine through.
2. The foam seals don't seam to be making good contact with the bellows frame. The seals aren't rotted out so they're either compressed, or someone replaced them with too thin foam.
For problem #1 a bit of silicone caulk should help by covering over the clear glue and filling in any spaces that weren't glued down properly. For problem #2, I could make thicker seals -- but that creates a whole new problem. The bellows already don't compress enough to easily fit into the body and allow the camera to fold shut. Making those seals thicker makes it impossible to close.
So now a new question... am I making a mountain out of a molehill? My test setup is a lightbulb equivalent to a 60W incandescent mounted to a lensboard and shining inside the camera. The light leakage is at the rear (sadly right next to the film) but it's within the cavity of the Wista 45VX body. It's only visible close in to the camera, looking straight into the body cavity from the lens side. I've been presuming that if I can see any light coming out -- anywhere -- then I can expect ruined shots due to light coming in, especially during longer exposures. What do we think? Are your cameras 100% light proof? Do you check?
Re: Liquid electrical tape for bellows repair
Problem 1 can be solved with painting the clear glue with black acrylic paint from the art store...
For #2, where exactly is the foam??? Is it on the inside or outside back??? Are you seeing light through them when the foam is compressed, or uncompressed??? Foam might have some light coming through the pores uncompressed, but will close when pressure is applied... Or is it just not making contact??? Depends, but there are options...
Steve K
1 Attachment(s)
Re: Liquid electrical tape for bellows repair
Foam seals are shown in the picture, below. The bellows simply press against that foam square. They clip in at the bottom and at the top; you can see the bottom clip but the top clip is out of view. By the way, this is the "body cavity" I mentioned earlier. The entire front standard and the bellows are stored in this space when the camera is closed. It's clever and well designed.
I've seen lots of rotten foam seals. These don't look rotten. They also don't look like replacements unless the person doing the work was extremely neat and careful. The bellows frame is nice and straight so that's not the issue. I'm starting to think this isn't so much a "bug" as a "feature". ;) That's why I asked about "zero tolerance". Is it even possible to eliminate 100% of possible light leaks from all sources (screws, film holders, bellows, etc.)?
And as a fun aside, I've also been searching the forum for advice on light leaks. It seems I'm not the first person to ask... Here's a great post from a couple years ago. The gist of it is "light leaks are a thing -- get over it and drape your dark cloth over your camera. Harumph." As usual we seem to divide nicely into two groups of people: those who have zero tolerance for imperfections (and light leaks), and those who throw their dark cloth over the camera.
https://www.largeformatphotography.i...our-dark-cloth
Attachment 186311
Quote:
Originally Posted by
LabRat
Problem 1 can be solved with painting the clear glue with black acrylic paint from the art store...
For #2, where exactly is the foam??? Is it on the inside or outside back??? Are you seeing light through them when the foam is compressed, or uncompressed??? Foam might have some light coming through the pores uncompressed, but will close when pressure is applied... Or is it just not making contact??? Depends, but there are options...
Steve K
Re: Liquid electrical tape for bellows repair
So that just seals the bellows to the frame???
It probably never much has been removed, so it probably compressed, even if still not melted, so I'd vote for replacement while parts are availible... It shouldn't cost too much for the foam kit...
I'm of the school of what can go wrong, will, so given the choice...
There are strip foams on a roll that might work at your home store if you can't get a kit... Even the grey light foam will seal off light once compressed enough...
Good luck!!!
Steve K
Re: Liquid electrical tape for bellows repair
On really close inspection, the foam looks to be in good condition, but it's definitely compressed in places. It's an easy repair if I can find the right material. I had some weather sealing foam strips handy for comparison. The concept will work -- I just need to find a slightly thinner one.
Thanks for all the advice folks. I think this is entirely and fairly easily fixable.
Rob
Quote:
Originally Posted by
LabRat
So that just seals the bellows to the frame???
It probably never much has been removed, so it probably compressed, even if still not melted, so I'd vote for replacement while parts are availible... It shouldn't cost too much for the foam kit...
I'm of the school of what can go wrong, will, so given the choice...
There are strip foams on a roll that might work at your home store if you can't get a kit... Even the grey light foam will seal off light once compressed enough...
Good luck!!!
Steve K
Re: Liquid electrical tape for bellows repair
I have had good results with urethane poron foam. It remains flexible through the range of temperatures that we work with. It can be found with pressure sensitive adhesive and in a multitude of thicknesses, lengths, and widths.
Michael
Re: Liquid electrical tape for bellows repair
I have used wetsuit repair glue.
Re: Liquid electrical tape for bellows repair
To close the circle on this thread, I fixed the light leak in the bellows. Following advice received in this thread, the product I used is called "Permatex Adhesive Sealant -- Black Silicone". It's an "Automotive grade RTV sealant".
The person who put the bellows together glued the bellows to the frame with a translucent glue, and may have also left some tiny gaps. That's obviously not good in terms of light leaks. A very thin layer of this black silicone product around the join filled the gaps and covered the glue. Not only does it look better, but also there are no light leaks. You and 30 of your friends can all fix your bellows from one 80ml tube of this stuff. ;)
I mentioned this in another thread, but part of the light leak in my bellows was due to a worn out light seal where the bellows met the camera body. If you happen to be using a Wista 45 series metal camera, the foam you want is 2mm thick. The one I used is either an open cell or semi-open cell; it's compressible, but it doesn't feel as thick and dense as closed cell foam that you'll find in the insulation aisle of your local hardware store; that stuff is too thick and too dense for this purpose.
Re: Liquid electrical tape for bellows repair
For micro holes I use Liquid Electrical Tape from the inside, very small portions, let dry 24hours and check, if still there (unlikely) do again. The bellows I face normally are from german folding cameras. I will try this other mentioned since I read it could have less odor.
Re: Liquid electrical tape for bellows repair
I use this product from Bostick-sullivan, it works!
https://www.bostick-sullivan.com/car...ab-description
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Bellows Patch Kit
$15.00
225ml black flexible bellows patch and 18 inches of Dacron white reinforcing fabric