D.I.Y. Plexi Printwasher Dilemma - Help!

[Randy H]

Another way to cut plexi and/or acrylic sheet with a skill saw or table saw is to use a "paneling blade" and put it in backwards. And use a beeswax or something of that nature on the blade. Doesn't sound right, but it works excellent. A company I worked with for several years used a "LOT" of plexi and acrylics, up to 3/4 inch thick, and that is how we had always cut it. And another way to do a container is use 1/4 inch thick, and shape it. Heat slowly along the line where you want to bend/shape it, and once formed, let it cool, and it is there for good. A hand-held heat-gun will work for short (up to about 12-14 inch) bends. You could form two long sides and bottom from one piece, and just glue in the ends. Just a thought....

[CG]

With most materials that are amenable to gluing, a well made glue joint is FAR stronger than a screwed or bolted joint. It's kind of the wood or plexi equivalent of a welded joint in metal. If you do a destructive load test, a line of fasteners will often rip through the base material at a fairly low loading, wheras a glue line will often remain intact till the base material is rent asunder, all at a much higher loading. This goes double for brittle materials like plexi, where a brittle fracture failure would be expected to occur early.

I often join wood with glue and screws. I am however, using screws as temporary clamps, in places where conventional clamps are hard to position, removing the screws after the joint has fully set up. The screws, left in place, would contribute almost nothing to the final strength of the assembly. So, I recycle them.

Best,

C

[lee\c]

I asked the same question a while ago and a professional told me he cut the plex over sized and then ran the glue joint face thru a router table to smooth the kerf edges and allow for a tighter fit.

lee\c

[ic-racer]

If you are making it 'upright' (vs 'tray-like') just be cognizant of the fact the pressure bursting your seams at the bottom is only related to the height of the water. So a 20" tall thin chamber that only holds one print and 500cc of fluid needs to have a seam at the bottom just as strong as a 20,000 gallon tank with 20" high walls.

My Nova 20x24 upright washer is constructed of some pretty thick plexiglass.

[thomas]

I recently came across some scrap 1/4-inch plexiglass. I am assuming there is no reason why this material would not be appropriate for building a printwasher for 8 x 20 fiber prints.

I would very much appreciate some info from those of you who have worked with this material and have attempted such a project.

1. What sort of glue/solvent is appropriate for assembly?

2. The 1/4-inch thickness would allow screws at some points for added strength. Is this necessary?

Many Thanks in Advance for Help

Robert
Atlanta

I made a 4x5 negative washer based on the usual vertical print-washer design, using Plexiglas, bonded with acetone applied with a syringe. The edges must be very carefully and precisely cut - as with an accurate tablesaw - for the fit to be good enough for the acetone to work. The acetone dissolves and re-fuses the plastic, so the fit of edge to edge must be very good.

The water is poured out of the faucet directly into the main tank where it runs over the 4x5 film s.s. holders, to the bottom of the tank and up around to a smaller "room" in the tank out of which the water exits through a small hole near the top of the device.

Thomas

[andy bessette]

Yo,

has anyone posted plans for a successfully proven printwasher design? Or does each of you just wing it? I am another who would like to build his own (for 16X20) as it is a rather expensive darkroom item,

The Versalab unit has a rather compelling feature--the removable (for cleaning) interior baffle assembly, which is simply through-bolted together using spacers. This design also makes for extraordinarily easy home construction. Anyone with Versalab experience? Does it do a good job?

Regarding the watertight tank, glue jointed plex is fine--no fasteners should be necessary. I'd like the plex thickness to be a bit heavier than 1/4-inch for the tank I have in mind (at least in the long sides)--I have some 1/2-inch polycarbonate (Lexan MR-10) which seems way overkill--the ends can be thinner but there's not much savings unless an inner and outer are used to produce an inlet/outlet chamber, as in the Zone VI.

Any plans?

best, andy

THERE'S MORE TO OPTICS THAN MEETS THE EYE

[Alan Rabe]

Just about everything that versalab uses for their print washer can be purchased at www.usplastic.com. Particularly the tanks and they also sell covers for the tanks which are pretty handy. I am alos considering replace the baffles in my versalb with ones made of perforated pvc, should give a better flow and keep prints from sticking to a baffle.

[andy bessette]

I am alos considering replace the baffles in my versalb with ones made of perforated pvc, should give a better flow and keep prints from sticking to a baffle.

Yo Alan,

I have seen a "textured" clear acrylic sheet (like that used on some shower enclosures) which may be more effective at preventing prints from sticking, but am not sure they would be safe from scratching emulsions.

Any source for the perforated inlet tubes? Someone mentioned aquarium components.

best, andy

THERE'S MORE TO OPTICS THAN MEETS THE EYE

[Robert McClure]

Yes, a good friend has also suggested a tank from usplastics.com. To be perfectly honest (having read all of your great posts!), I plan to shy away from "flying shards," the use of beeswax, syringes, etc. - as much as I appreciate the kind suggestions.

Hell, I'll just buy a plastic tank (maybe 12x12x24 long), make simple wire guides to hold the film, install fill and drain hoses - and be done with it.

Thanks, guys!

Robert

[andy bessette]

Hell, I'll just buy a plastic tank (maybe 12x12x24 long), make simple wire guides to hold the film, install fill and drain hoses - and be done with it.

Robert

Yo Robert,

it looks as if you have over-simplified the design of your print washer.

All the ready-made ones I've seen have had a few more features than seem possible with your list of materials.

A tank, two hoses, and some wire? Can this be all that is really necessary to build an archival print washer?

best, andy

THERE'S MORE TO OPTICS THAN MEETS THE EYE