How to cut Phenolic plastic sheets?

[JasonC]

More specifically, how should one cut Phenolic plastic sheets up to 1/8" thick using only hand tools? Thanks.

Jason.

 

[eclarke]

Glass shops use a scribing cutter (similar to a glass cutter)and break them on the score line. One can probably be purchased at the hardware store. I think it depends on what you are making and the accuracy and smoothness required..EC

 

[JasonC]

I am trying to make dark slides, and maybe some septums for film holders.

Jason.

 

[Donald Qualls]

I wouldn't think phenolic very good for dark slides -- too brittle (same as Bakelite, though often reinforced with fiberglass, cotton, or linen fibers these days -- sometimes even paper). Unfortunately, the ABS sheet I've seen that was thin enough to fit existing dark slide slots wasn't opaque enough for unlimited exposure (IMO), or that would be the first recommendation (and in that thickness, you can cut ABS with heavy scissors). If you have a TAP Plastics in your local area, I'd suggest visiting them and looking at their sheet plastic stock; you can probably find something that will be opaque enough and much less prone to breaking at the wrong time than phenolic.

FWIW, you can also cut cloth reinforced phenolic with a fine toothed bandsaw or hacksaw as if it were thin plywood, or with a backsaw (as used in high quality miter boxes) applied on the flat face; circular saws or coarser blades applied to the edge are likely to result in unacceptable breakage.

The film sheaths and dark slides in old plate cameras were almost universally steel, and that's a hard material to beat -- opaque even in extremely thin sheets, easy to cut (tin snips or a metal shear, or Dremel with cutoff wheel), easily shaped with low-tech tooling, and it takes and holds paint well. It's also cheap...

 

[Bob F.]

The thin plastics I have had occasion to cut responded to scoring deeply with a lino cutter (or a Stanley knife with a hooked blade (http://www.diytools.co.uk/diy/Main/Product.asp?iProductID=16510) ) and then snapping it over the edge of a table.

Have fun, Bob.

 

[Dave Wooten]

A scouring tool will cut it nicely, use a good metal meter stick for a straight edge....I cut Wilsonex (like Formica for counter tops) this way.

Got mine a home depot...

scour a good deep line and just snap off...

1/8 thick might be a bit much for a darkslide?

 

[Dan Fromm]

Jason, for curiosity are you thinking of using Garolite XX? If so, it is available from McMaster-Carr in 1/32", 1/16", 3/32", 1/8", ... Its been a while since I measured my dark slides' thickness, am pretty sure they're all thinner than 1/8". You should probably check a few before buying anything.

Donald, I can't be sure, but I think this is the material used in my Adapt-A-Roll 620s and in my film pack adapters. And no, I don't have any film packs, just the adapters.

 

[eclarke]

I am trying to make dark slides, and maybe some septums for film holders.

Jason.

Black vulcanized fibre sheet is the ticket and may be cut with a good sharp exacto knife. Most plastic supply houses can get it for you. It will not be abrasive like a linen phenolic...EC

 

[JasonC]

Thanks for all the useful information. I am trying to make replacement dark slides for my 7x17 holders. One of my holders also needs to have its septum replaced. I read somewhere that phenolic is the material to use. The dark slides are 1/16" thick, but I am not sure how thick is the septum. That's why I ask how to cut up to 1/8" thick. Thanks again.

Jason.

 

[JasonC]

Dan,

I am thinking of using Garolite XX from McMaster-Carr. After spending more time at their site, do you think delrin would work?

Jason.

 

[noseoil]

A large micrometer would be able to straddle the sides and give you a reading if it is the correct size. This is the only way to be sure of the thickness. You might also look into aluminum sheet stock. Once it is cut, edged and ready, a black anodized finish would be about as good as it gets, although 1/16" might be a tad too heavy for everyday use. It would certainly stop the light.

What was the original material made out of for these slides? Does anyone know exactly what it was? tim

 

[JasonC]

Sorry, I should have mentioned that they are Korona holders. The original dark slides seem to be made out of card boards.

Jason.

 

[Mick Fagan]

I use Delrin on my LASER for manufacturing seals like the notary ones in America.

The material I have is 1.5mm thick which is close to 1/16" (I think). Delrin is available to me 0.7mm thick for signage purposes.

There is another really thin version which is 0.2mm thick which is designed for stencils. Generally the stencil stuff is a semi opaque type, but I have seen it in black.

As I'm in Australia and most of this stuff originates from America, you may have a greater range to source.

I would suggest that the 0.7mm Delrin I have would do the job, as long as you are careful sliding 17" without buckling, and therefore risking it snapping.

The really thin stuff (0.2mm) is reasonably flexible and will wrap around 4 litre metal drums easily without any problems

Mick.

 

[JasonC]

Mick,

Could I cut delrin sheets with a scoring knife? Thanks.

Jason.

 

[Mick Fagan]

Jason, I just tried a piece of the 1.5mm thick stuff.

At first I didn't think it was scoring, it's a hard material, but after about 5 or 6 runs of the knife, I thought I would give it a bash.

Held the score over the edge of the bench, no problems.

Clean break!

Mick.

 

[JasonC]

Mick,

Thank you very much for your help. Would you say that 1.5mm is better suited for dark slides than 0.7mm, since you said 0.7mm sheets are easy to buckle?

Jason.

 

[Mick Fagan]

Jason, I just measured out 430mm which is close to 17", man that's quite long!!

The thicker 1.5mm will not move, it is quite strong laterally, yet I have just given it a bend in my fingers like you do when you are bending back a slightly bent dark slide.

It doesn't stay bent by the way, I just did that to check it's relative lateral strength.

I'm a rubber stamp manufacturer and if any rubber stamp manufacturer in your area has a LASER engraver, chances are they will have some delrin in stock for manufacturing notary seals.

Anyone with a Royal Mark LASER machine would be able to cut your delrin to within 1/600 of an inch accuracy in about 30 seconds.

The Royal Mark LASER was put out by M&R Marking in Piscataway near New York. The brand of stamps and seals are called, "Ideal".

Hope this helps, I'm off to bed now as it's just nearing midnight, see ya!

Mick.

 

[Mick Fagan]

Jason, I just realised I didn't answer your question, The thinner material would be alright, just. It's rigidity over that length is a bit of an ask, from what I can tell by bending the sheets I have.

I woudl suggest the 1.5mm material would be a better proposition if you can get it to fit into your slides grooves.

Mick.

 

[Dan Fromm]

Dan,

I am thinking of using Garolite XX from McMaster-Carr. After spending more time at their site, do you think delrin would work?

Jason.

Y'know, Jason, the idea of using delrin never crossed my mind. When I looked at my roll holders' fragile black dark slides and started thinking about replacements the idea of reinforced phenolic entered and left room for no others. But if it is opaque enough, why not?

Cheers,

Dan

 

[Jim Chinn]

Jason, for curiosity are you thinking of using Garolite XX? If so, it is available from McMaster-Carr in 1/32", 1/16", 3/32", 1/8", ... Its been a while since I measured my dark slides' thickness, am pretty sure they're all thinner than 1/8". You should probably check a few before buying anything.

Donald, I can't be sure, but I think this is the material used in my Adapt-A-Roll 620s and in my film pack adapters. And no, I don't have any film packs, just the adapters.

I have used the Garolite XX in 1/16" and 3/32" for darkslides and found it to be very well suited. I have had most of mine precision cut with an abrasive waterjet but it does cut easily by hand with a fine tooth hacksaw or even a coping saw. It is very similar to what I have found in other film holders. It is a composite and with something like a jig saw you might get some seperation at the edges. I suppose with a fine tooth blade a table saw might work fine.

Delrin is qutie a bit denser then a composite like Garolite. it will add some additional wieght to the holder if that is a concern.

 

[JasonC]

Anyone knows if phenolic (Garolite XX) could be sanded like wood? Thanks.

Jason.

 

[Donald Qualls]

Phenolic materials I'm familiar with do sand, though the edges tend to chip (sand along an edge, rather than across, to avoid this). I wouldn't say it sands "like wood", however; the effect you get is more like sanding vitrified, but unglazed ceramic, only softer.

 

[barryjyoung]

Jason:


Sanding the linen reinforced phenolics is a pain because of the fuzz that eminates from the edges when you do. It is better to use a really sharp as in new high speed steel endmill. It will not cut well with carbide.

Barry Young
Young Camera Company

 

[Jim Chinn]

After I have the garolite xx cut, I will go around the edges with some 300 grit wet/dry sand paper. Basically I do just enough to round the edges slightly.

 

[JasonC]

Thanks again for the info.

Jason.