Cutting Acrylic Sheets...Which saw blade and adhesive?

Carbide tipped, as many teeth as possible. A Glass/plastics shop will have the type of adhesive you need.

Max D

GOOGLE this group. This has been discussed in detail over and over and over and over. :)

As far as the adhesive, the chemicals you listed are not going to effect the adhesive. The solvent you use for the chemicals would be more of a deciding factor. Water?

EEk, potassium cyanide. Be careful dude.

Sodium thiosulphate is an antidote for cyanide poisoning...

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

Call Charles at Forrest Blades 800 733 7111 ext 314. they have a blade specifically for this.

Even so, both taste awful! :-)

Seriously though, call the plastic and glue makers and ask them. There are different grades of acrylic and glues for different uses. Easier to check than it is to clean up a mess.

James

If this is a photographic process, it's probably a ferrocyanide rather than a cyanide. Much less dangerous.

Nope. It's the real deal-potassium cyanide. Deadly stuff if not handled properly. It's a fixer for ambrotypes and collodion wetplates.

The chemical you are thinking of is potassium ferrIcyanide which is a pretty benign compound used as a bleach when toning photographs or as a reducer.

Also run from back to front less cracking that way... At least it worked for me taht way...

-- Log

Interesting - How much fume control do you have to provide ? I've often wanted to use sodium/potassium cyanide in electroplating baths, but couldn't face the hassle of setting up the fume control I'd need. Even with a commercial lab fume cupboard to hand, I still needed to provide fume extraction directly above the bath.

What do you use as a stop bath ? Presumably the usual acetic acid stop bath from modern B&W processes is the last thing you'd want just before a cyanide solution.

I'll be doing this outdoors in the field using a portable darkroom which I'm currently building. I plan to have a sort of French easel type arrangement for the darkroom with a safelight window at top and sleeves at the front ala a changing bag to access the the chemicals within and coat and develop the plates. Strictly 19th century.

You're totally right about the acetic or any other acid potentially mixing with the KCN as that would release deadly hydrogen cyanide gas. This process does not use a stop bath though.

The developer however is acidic ferrous sulphate followed by a water rinse, then KCN or sodium thiosulphate as fixer and another wash. (I believe that a brief rinse in sodium thiosulphate would also neutralize the cyanide by forming a thiocyanate compound. Also, I believe the ferrous sulphate would react with the KCN to form potassium ferricyanide which is not very toxic. IIRC, sodium thiosulphate and ferrous sulphate are both used as antidotes for cyanide poisoning because of these reactions. I'll check on that before I actually attempt to do the process. Additionally, the cyanide is required as a fixer only for ambrotypes and I'm planning to start with wetplate negatives which use the benign thiosulphate as a fixer. I've enrolled in a formal workshop to learn this process and the safety requirements I'll need to consider before actually trying it. I'm quite aware of the potential for fatality with this stuff and also realize a great number of photographers went to the "final wash" as a result of cyanide and mercury poisoning in the 1800s. I have a very healthy respect for this stuff.)

As far as ventilation is concerned, I think the worst of it will be from ether fumes. Ether and ethanol (Everclear) are mixed with the collodion as the vehicle for the emulsion. The stuff evaporates so quickly that the entire process of coating, sensitizing, exposing and processing the plate must be done within about a 5-minute timeframe. Otherwise the collodion hardens and becomes impervious to the processing chemistry. Hence the name "wetplate" and the need for a portable darkroom for location work.

As a photographer the wetplate process has always interested me and especially now as film choices are becoming limited due to the popular switch to digital cameras. As a novice woodworker it is giving me the opportunity to expand my skills making the portable darkroom, a camera and plateholder, developing tanks and racks and a bunch of related items like shutter boxes and plate cases, tripod cradles and perhaps even a wooden tripod. I'm enjoying blending the two and making very practical stuff.

Joe