Do you know the Face-Browning sets that are used to get a nice facial tan ? The tubes that are used for it are UV tubes of about 12'' in length . Every set has 4 tubes in it . You need 2 sets in order to mount 6 tubes next to each other . You get all the parts you need by taking the sets apart and remounting the tubes . Now you make a ply-wood box with the frames on the outside . When you have mounted the lights about 1 '' from the bottom of the box ( crate ) you cut a slot on the narrow side of the box and fix slats on the inside of the box . The reason for this is to have a piece of plywood to slide over the light bulbs and cover these completely . Now you see why you want the framing of the box on the outside . This slide could be mounted about 4 '' over the lightbulbs . The reason for this slide is that because it will take some time for these bulbs to turn out full power and change a little during that starting time . By closing the slide you can turn on the bulbs and do your rest of work without being afraid that the photo plates get ruined . After about 5 minutes the light should be at full power . Now go up another 5'' and mount slats all around on the inside of the box . Cut yourself a piece of 1/4 '' glass and mount that in the box . Now make yourself a nice lid that should give about 3/4'' of room between the glass and the top of the lid . Cut yourself a nice piece of foam rubber to fill the space between the glass and the top of the lid . Your photo plate will be kept in place by this foam rubber and put just enough pressure on the plate to keep it in place . All you need now is a timer . Mine is set for 45 seconds , which I determined by running some tests . In order to get the PCB transfer you make a copy at the right size on your computer . You should use semi transparent paper ( draughting paper ) . If the print does not turn up dark enough you make another print and overlay the two . This should give you the right darkness so the UV light will not penetrate . Now put this transfer on the glass ( the right side toward the photo sensitive layer ) and cover the transfer with the photo sensitive plate . Close the lid and start the timer while at the same time you remove the ply-wood slide . When the timer shuts off the plate will be sensitived and could be developed . To develop the plate you can use Caustic Soda . The only thing to do is messure the right amounts of caustic soda to water . Mostly 1 American teaspoon of soda to 1/4 gallon of water should do it . You may want to experiment a little with this by using small pieces of left over photo sensitive plates . Be carefull that when you mix the soda and water that you add the soda to the water and not the other way . Make this brew well ahead of time because the temperature should be at room-yemperature . When first mixed the temperature will go up sharply and ruin your plates when used right away . Now be sure that you do not spot the plates and hang them in your etching solution . Hey ..... you are done Cornelius
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