How to file out negative carrier

[bence8810]

Hello,

I got myself a spare negative carrier for 6x6 and I'd like to file this one out to allow for black borders on my prints.

What's the best way to go about it? Obviously the last thing I'd like is some leftover stuff scratching my negatives.

Thanks,
Ben

 

[bence8810]

But test your negative carrier, first. Very often they are already larger then the negative.

Thanks Ned! I already have one and it's the right size exactly - so that's why I purchased another one to be filed out.

I also have a glass carrier - was thinking about removing the glass and filing out the metal underneath. That way there will be no scratches when I put the glass back.

Do you print with glass carriers or without?
Ben

 

[Dan Daniel]

To make a filed or machined edge safe for a negative (or a human finger), you do what is called 'deburring.' Basically you round over any corner to eliminate sharp edges. For a negative carrier, you don't need to maintain tight tolerances when deburring. so you have many options. After getting the opening you want, scrape and smooth the edges with sandpaper or a metal scraper. To check if there are any burrs left, lightly rub a cotton swab (q-tip) around the filed edge. Burrs will catch the cotton fibers.

Put a flat black paint on the metal edges to avoid reflections.

 

[bence8810]

To make a filed or machined edge safe for a negative (or a human finger), you do what is called 'deburring.' Basically you round over any corner to eliminate sharp edges. For a negative carrier, you don't need to maintain tight tolerances when deburring. so you have many options. After getting the opening you want, scrape and smooth the edges with sandpaper or a metal scraper. To check if there are any burrs left, lightly rub a cotton swab (q-tip) around the filed edge. Burrs will catch the cotton fibers.

Put a flat black paint on the metal edges to avoid reflections.

Thanks for this, good point on the Q-tip. I'll be sure to do so.
I will go to a DIY store and get a metal file to get the job done.
I assume you file the two sides (top / bottom) separately?

Ben

 

[Dwig]

I have a set of these:

http://www.amazon.com/EZE-LAP-PAK-C...ie=UTF8&qid=1432730483&sr=8-4&keywords=ez-lap

... that I have used for the final finishing stages on projects such as this.

 

[Colin Corneau]

File for Metal. Then, when you're happy with the size, use a 600 grit sand paper for metal and sand it by hand until it becomes super smooth.

Good advice, this is what I did for 2 metal carriers to accomodate Widelux and XPan negatives. It works...running a Q-tip over the edges afterwards and painting it black to avoid reflections is also good advice.

 

[FrankS]

I filed top and bottom together with the carrier held in a vice. File just the edge closest to the vice jaws, then reposition the carrier with another side close to the vice jaws and file that side. Repeat. When the opening is what you want, use the file to round off/debur the edges.

 

[Ronald M]

The trick is to make the edges STRAIGHT so a fine 1" file for the edges and a smaller one for corners.

If you want a sharp border, the edge needs to be tapered.

Mark it off first to keep it square so you do not get something like the lower right corner in sample above.

Burnish and paint dull black.

 

[bence8810]

Hi All,

Just wanted to post back with results so in case anyone in the future looks for the same information, there'd be some references recorded.
The whole job took about 45 minutes for the two carriers. It started out slow and as I got the hang of the process it went a lot faster.


1. I took the necessary tools as it was suggested by Ned above (thanks!!!) from my local DIY store. It cost less than $10 in total for the Metal file and the 600 grit sand paper. I also prepared the two carriers to be filed out. As I mostly shoot 135 and 6x6 I bought spare carriers for these, just in case I mess up the job I could still print with the originals. It all worked out though so spares were not necessary.

2. I prepared a small box with a plastic bag in it to hold the fine dust that comes off the carrier. This was mostly not to set off an alarm in my wife's head.

3. I marked a rough guide as to how far I want to go with the filing with a permanent marker.

4. As I had no vice I had to hold the carrier in my other hand while filing away. It felt awkward at first but got the hang of it quick. In order not to bend the carrier I was only pushing the file and never pulled on it. This kept the two sides of the carrier constantly pushed together.

5. This shows one side already filed out nicely.

6. And with both sides filed.

7. I then took the 600 grit sand paper and made sure the edges were sanded until they were completely smooth. I especially paid attention to the side where the negative comes in contact with the carrier.

8. Here you see the fine dust that was the result of my filing.

9. I then ran a Q-tip along the edges and made sure no fibers were caught from the cotton tip by some leftover burrs. (Thanks Dan for the tip!)

10. For testing I placed some negatives in the carrier I didn't really care for. This one had a light leak so the top and bottom edges of the frame can't be easily seen but if you look carefully you'll see all 4 sides show some extra film beyond the photo which is what I was after.

11. The same with the smaller 135 carrier.

12. The last step was to color the exposed metallic edges black to eliminate the unnecessary reflections. As I had no model paint or anything else, I went for a permanent marker and it worked remarkably well. It was a bit of a hassle to apply and I am not sure how "permanent" it'll end up being. If you can - do this with some model or gun pain instead.

If any questions just fire away!

Cheers,
Ben

 

[skibeerr]

Very interesting, thank you for your effort.