Hey, mon ami!
As requested by some of you members following this etching how-to, here's how to adapt a facial solarium into a UV-light box for your PCB designs...
Just before that, I'll comment my own build now that it's been used. It works like a charm, but the glass warms when you expose many times in a row. Since time is quite crucial while exposing, and considering there is a chemical (or physical) reaction with the resin, then temperature may impact the reproductibility of the exposing. Therefore I would probably add some venting holes on the sides... The rest is fine to me.
So now, here's what I've done. I found a facial solarium for 4€ at a boot sale. The unit is fairly common (I bought to second-hand others since) and can be easily found. I bet there are plenty of other types that would do the job as well. The mounted tubes in it are Philips "Cleo" UV-A ones, rated at 15W though these are the same size as 8W standard tubes. Standard 15W tubes are 45cm long, which I find too much...
Of course you can use it straight, with a piece of glass scotch-taped to the unit, and hold it horizontally. That would work, though not very eye-protecting nor practical (and nor beautiful... )
So here's what you get out of here:
The timer is unfortunately way too long for our purpose here... You can see that the plastic chassis inside is made for 4 tubes OR for 6 tubes. There are spaces left for an extra ballast, for two extra starters and for extra tube sockets. This decided me to buy another unit to make a 6-tuber (it's just a matter of adding wires and stuff you know)... I kept one of the metal "mirror" sheet in my UV box, the other one would make great Uni-Vibe light-domes...
Now how can this chassis be placed into a box? Is the bottom flat? Well, no, it isn't... You need to cut a little useless piece of plastic.
You can notice that it's not flat on its whole length (on the right). I decided to use a piece of wood to fill in the gap between the chassis and the bottom of the box.
Now you can spot some places where you will screw it to the box (white crosses).
And you can draw a 1:1 plan (mine had trouble when we moved in our new house ...):
You can see the gap-filling piece of wood on the right, and notice a hole in the bottom for starters. This way, if one fails, I can change it from the outside! This is also why the bottom is made out of thicker wood (compared to the sides). You can see the starters-hole below:
The upper part of the box plan shows the hinges (common DIY-store ones) and the aluminium angles that will keep the glass. I used 3mm glass.
I won't detail the making of the box, since it's basic: just glue and time. I bought the pieces (including the glass) cut to size at the DIY store. The glass panel was made to have a little clearance (3mm) with each edge of the box. I cut the aluminium angles myself at 45°... You need to drill one of the side for the mains cord to pass in.
But there's one tricky thing there. I wanted the glass to be removeable easily if broken, and i wanted the aluminium to be bolted. How the hell can I bolt anything with the glass above?
Well, I used bolts for three sides, and T-nuts for one of the side (the left one on the pics).
When everything was installed in (including the mains!) I assembled the three aluminium sides, slided the glass carefully into its place, and brought the last aluminium angle to finish the whole thing.
The top of the box has been made easily. I just needed it to be high enough for the hinges and for the foam I use to fill it in. This foam is "adjusted" with glued cardboard so that it will press gently on the glass. As a test, I put two CDs on the glass, closed the lid, and shook the box: no movement at all!
Nothing too difficult here, really, just tips for making your own. Be sure to wear gloves when working with the glass panel. The glueing requires some time and clamps, but it's easily done. As a timer, I use a switch mounted on the mains cord, and my watch...
I don't think I've spent more than 60 euros in this box (including two other solariums I bought). I think a commercial unit is still more expensive. And I have 6 spare tubes, and ballasts and starters for a lifetime... So it worths the time spent building it...
I hope it could give you ideas to do your own!
ps: now you can call me a designer. Probably the last time you can here!!
Frequently asked question on the subject of designing, creating, producing printed boards, veroboards or perfboads and on point-to-point construction techniques.
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