Sinar Norma light trap material?

[Greg]

In going over my 8x10 Sinar Norma, I am finally confronted with having to replace the front carrier's light trap material. Probably 15-20 some years ago, I replaced the fibrous light trap material on the 8x10's back with thin strips of foam tape that were sold specifically for this purpose. I would do so the same with the front 4x5 standard but I lost the supplier of that thin foam tape. Does anyone know who sells those thin strips of foam tape made specifically for this purpose? If not a supplier of strips similar to the OEM fibrous tape? Or..... I am thinking that I do have a roll of adhesive backed 1mm thick black flocking (used inside telescope tubes I believe) that I used to replace the seal on the back of my Pentax 67. It worked so far with the Pentax 67, now going on one year. The OEM light trap material seems to be thicker than 1mm but it's hard to measure its thickness. Has anyone used adhesive backed flocking to replace the light trap's material with?

Any help/advice much appreciated.

[Daniel Unkefer]

Hi Greg,

I have been busy light trapping four Sinar 5x7 Norma Standard Bearers; I used foam adhesive sheets I cut down to 3mm wide in my Rotary Cutter. Spent a long time cleaning the channels to remove all the debris. Those are now good as new

I have been using 1mm 2mm and 3mm thick sheets cutting them down. I don't think they are big enough sheets to light trap my 8x10 Norma

https://www.ebay.com/itm/20329910021...UAAOSwxX1Zw52D

I have ordered the 1mm 2mm and 3mm sheets from this fellow several times

[Drew Wiley]

Be selective with foam rubber gasketing. Some types break down with moisture or UV or get gummy. Never use open-cell or vinyl-based foam. It should be of the right type for cameras. I seem to recall Micro-Tools selling camera light gasketing.

[Greg]

Decided to use the roll of adhesive backed 1mm thick black flocking that I already have. I used it about a year ago to replace the foam rubber gasket near the hinge on the back of my Pentax 67 and also along the sides of the back of my FUJI GSW690III. Looked at both today and both still look like when I put them in. Drew: It doesn't look to be open celled. I have no idea if it is vinyl-based foam but it sure doesn't look like it to me. Got out my digital micrometer and measured the dimensions of the light trap on the Norma's front 4x5 standard, and the 1mm thick flocking should work out just fine. From what I can tell the flocking is compressed to maybe 0.03-0.05mm when the bellows frame or a lens board is locked into the standard.

Sidenote: When I Googled something like Sinar light trap material, I was directed to one Web site that offered removing and replacing the light trap material in an 8x10 Norma rear carrier frame for $500.00!!!

[Daniel Unkefer]

Redoing 5x7 Sinar Norma Standard Bearer Light Traps 1 by Nokton48, on Flickr

Redoing 5x7 Sinar Norma Standard Bearer Light Traps 2 by Nokton48, on Flickr

I think this came out about perfect. 2mm depth Camera Foam from UK Vendor is on the money, compresses nicely when cut into 3mm wide strips. Then use a single edge razor blade for a tight fit You can see the thin grey strips installed above on my 5x7 Twin Lens Norma. I built this camera from the best pieces in my collection and it is rock solid in every aspect. I have four 5x7 Standard Bearers so I had to cut thirty-two strips to redo the cameras I'm presently using. Took a while!

[CreationBear]

Excellent, I really appreciate the pictures as well. A question: what is the preferred tool for cleaning out the old gunk from the channels? I'm thinking something like a dental pick, but am curious what works well without a chance of too much collateral damage.

[Daniel Unkefer]

The blue cap to a Bic Ballpoint pen works excellently for stubborn digging. It's a yucky job No wonder Glenn charges $500

Also bigger jewelers screwdriver flat point

Work over a trash can

[Daniel Unkefer]

Now I'm working on flocking my Norma Shutters.

[Drew Wiley]

I haven't had to replace any on my Norma. But when I replaced the seals on my Pentax 6X7, I just bought them pre-cut, and the whole set cost me less than $10, and works well. And it does look like good quality closed cell foam. So decent uncut sheet material can't be all that expensive to begin with. But if you ordered a ballpoint pen like Daniel uses, and it was labeled a Sinar Ballpoint Pen, you'd probably have to pay $500 for just that! - about the same price as a pair of Sinar branded shoelaces. For digging out old gasketing, I have a few various dental-looking hooks and scrapers left over from days we used em for O-ring removal in pneumatic tools. Then some Q-tips for the solvent to remove any old gummy residue (PEC film cleaner works well). Then a fine tip air nozzle from the compressor to remove any lint after the solvent evaporates. Not a fun chore, but not all that hard either.

[CreationBear]

Excellent, thanks gents--I wouldn't put it past Sinar to actually have had a purpose-built tool in one of their old catalogs. Sounds like a good project for what we used to call "shop days" back on the farm.