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![]() Ferric Chloride may be safer than Muratic Acid Not even close. http://www.artmondo.net/printworks/articles/ferric.htm Spent ferric chloride can be neutralized with soda as well. Yes, and you wind up with several gallons of the most wonderful brown permanent dye you can imagine. Plus, I THIINK Ferric Chloride is the commonly available de-smuting solution you need to anodize 2000 series aluminum. I'm only going to worry about anodizing 5052, which has very little copper or zinc, so desmutting shouldn't be a problem. For dyeing anodized aluminum, try RIT, or page through this catalog: http://dharmatrading.com/html/eng/2934904-AA.shtml Sealing, I guess you'll have to use clear lacquer. I had thought about RIT, and I've been told that food dye will also do the job. I'll just have to experiment. Jim |
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Jim said:
Ferric Chloride may be safer than Muratic Acid Not even close Can you say more? Let me first say I don't work with either on a regular basis - I'm sure you have LOTS of experience with Ferric Chloride. But if you've etched copper with the Muratic Acid/Hydrogen Peroxide solution you're advocating, it will have lots of copper ions in it, and it's the copper that makes spent Ferric Chloride a Hazardous Waste. http://www.mgchemicals.com/techsupport/ferric_faq.html Make no mistake, I'm not presenting Ferric Chloride as benign - it's clearly not: http://www.jtbaker.com/msds/englishhtml/f1080.htm Neither is Muriatic Acid: http://householdproducts.nlm.nih.gov...ds&id=16009010 Why do you see Muriatic Acid as less trouble? I'm genuinely curious... Highest Regards, |
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![]() Let me first say I don't work with either on a regular basis - I'm sure you have LOTS of experience with Ferric Chloride. Only on a rather steady basis since 1963 or so. But if you've etched copper with the Muratic Acid/Hydrogen Peroxide solution you're advocating, it will have lots of copper ions in it, and it's the copper that makes spent Ferric Chloride a Hazardous Waste. http://www.mgchemicals.com/techsupport/ferric_faq.html That is correct. However, you can toss a pad of steel wool into the muriatic acid when you are done and the copper will plate out onto the wool. Metallic copper is not a hazmat. Steel wool is not a hazmat. Neutralized muriatic acid is not a hazmat. Ferric chloride loaded with copper is and it is NOT easy to precipitate out the copper from a ferric chloride solution. That's why one accepted method of disposal is inside a concrete "septic tank" that is then sealed. Make no mistake, I'm not presenting Ferric Chloride as benign - it's clearly not: http://www.jtbaker.com/msds/englishhtml/f1080.htm Neither is Muriatic Acid: http://householdproducts.nlm.nih.gov...ds&id=16009010 Why do you see Muriatic Acid as less trouble? I'm genuinely curious... Because I have to have a hazmat license to use ferric chloride in the classroom laboratory and I can buy muriatic acid and hydrogen peroxide from the home depot without any permits at all. Jim |
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On 12 Mar 2006 09:31:42 -0800 in sci.electronics.design, "Andrew
Sarangan" wrote, I also used the laser printer toner transfer method for my LED design which I posted a couple of weeks ago. I originally discovered the technique from http://www.fullnet.com/u/tomg/gooteepc.htm The paper came off easily in water and a gentle scrub. One problem I noticed is that the gloss sticks to the ink more than the paper. So when the paper peels off, the gloss stays on the ink. I find it easy to remove the residue by scrubbing the board with a dishwashing brush with soft plastic bristles while the board is wet. |
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Andrew Sarangan wrote:
snip Also, regarding the #70 drill bits, are you sure you got them at Harbor Freight? They did not have anything smaller than 1/16". If you have a product number or a URL that would be helpful. McMaster has numbered sizes to #80. They are good people. I won't do business with Harbor Freight. They have the worst parts and tech help departments I ever dealt with. They still haven't sent me a part I was promised in early December. Dan, U.S. Air Force, retired |
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Andrew Sarangan wrote:
I also used the laser printer toner transfer method for my LED design which I posted a couple of weeks ago. I originally discovered the technique from http://www.fullnet.com/u/tomg/gooteepc.htm The paper came off easily in water and a gentle scrub. One problem I noticed is that the gloss sticks to the ink more than the paper. So when the paper peels off, the gloss stays on the ink. This may not be a problem where the ink is supposed to be, but the gloss also bridges across small openings like drill hole location markers. I tried scratching these areas with a needle to remove the gloss, but it did not come off easily. Also, this is very hard to see because the gloss is transparent. Only after the etch you realize that the location markers are missing. But this was not a big problem for me because the location markers were simply an aid for centering the drill bit.But it could be a problem if the bridging is between closely spaced tracks. Also, regarding the #70 drill bits, are you sure you got them at Harbor Freight? They did not have anything smaller than 1/16". If you have a product number or a URL that would be helpful. wrote: To All: The steady decline in the cost of ultra-bright green LED's (now about two-bits each for a 100-piece baggie) has generated renewed interest in the bug-eyed LED nav lights I described on this Newsgroup a couple of years ago. Unfortunately, that renewed interest has lead to some renewed problems, one having to do with the lay-out of the circuit board, the other with its fabrication. But the most serious problem has to do with the fact that ham radio operators learn to solder shortly after birth, or even before... according to some. Along with the ability to solder is the companion knowledge of how to make a circuit board out of a bit of substrate and a piece of string about... that long. But the main stumbling block for non-hams appears to be how to make all those teenie-tiny holes in the circuit board. MAKING HOLES It's pretty easy. You need a tiny drill -- somewhere between #70 and #75. Then you need to spin it about 12,000 rpm. And you need to keep it perfectly vertical as you make the hole. The drill bits are no problem. Harbor Freight will sell you a selection of solid carbide bits suitable for the task; simply pick a size to suit the components you're using, such as the wire legs of an LED or quarter-watt resister. A Dremel tool (or similar) is the handiest means of chucking the tiny drill, most of which have a shank diameter of 1/8". To hold it perfectly vertical you don't 'hold' it at all -- you make up a 90 degree bracket and clamp, wire or glue the tool to the vertical leg. On the horizontal leg you drill a 1/4" hole to accept a bolt which you then chuck into your DRILL PRESS. There's a few picky-bits to this method, such as using a bracket that is a true 90, and thick enough so as not to deflect as you run the quill of your drill press up & down. You need some method of preventing the quill from rotating of course -- I use a simple wedge between the quill pulley and the frame of the drill press head (big, old Craftsman floor model. Your mileage may vary...) To keep from ruining the chuck in your drill press (which was not designed to grab hold of threaded bolts) you put a barrel-nut on the bolt. Deal with all the tricky bits and the result is a shake-free, carbide-tipped hole-maker that will give you a life-time of accurate service (and already has, in my case... I used it to make the boards for my first computer back in the mid-70's). ELEVATION vs AZIMUTH Azimuth is relative to the horizontal. Elevation means over-head. In laying out the circuit board, asimuth is taken care of by orienting the legs of the LED's. Since the LED's have an average viewing angle of 25 degrees, to provide adequate coverage the azimuth angle starts at 10 degrees and progresses in 20 degree increments. Of course, when you're trying to provide full coverage across a segment of a sphere, your LED's must be accurately oriented in TWO dimensions. The key point here is that I chose to build the aximuth angle into the circuit board. The elevation angle is bent into the legs of the LED's using a simple form-block, accurately printed via DeltaCAD, glued to a bit of plywood and sanded to the line. To keep things simple, I abandoned the variable height arrangement as described in my original post, other than allowing a bit of overlap between one row of LED's to the next so as to keep down the circuit board, which comes out about two by two inches. As a further simplification, I eliminated the left vs right bending angles used in my original (2002) lights. Now all of the LED's get the same set of bends relative to their positive lead. To accommodate the change from left- to right-facing, I re-drew the circuit board. MAKING THE CIRCUIT BOARD The Old Fashioned Way was to start with a drawing then go to litho film, then to a fine-meshed silk screen. Once you had the silk screen you could whip out a hundred circuit boards in an afternoon... after spending a month to arrive at that point. Nowadays I simply print the circuit board mask onto cheap glossy-finished color photo paper using a monochrome laser printer. Here's why it works: Laser printer media is a finely divided thermo-plastic -- a powder so fine it is attracted to the electrostatic charge created by the laser. The thermo-plastic material is transferred to the paper by heat. This lends itself to making circuit boards because once the thermo-plastic material has been transferred to the paper, it may be RE-TRANSFERRED to the clean copper surface of a blank circuit board by the application of ADDITIIONAL heat. In effect, you literally iron-on the mask, solidly gluing the paper to the circuit board. Now the trick is to get rid of the paper, which I'll get to in a minute. But before I do, you should know that while using plain paper is possible, the resulting transfer will show a lot of voids; plain paper simply isn't a very good substrait for the thermo-plastic material. But cheap color copier paper is. Color copier paper is typically coated, giving it a denser, more uniform surface than regular #20 bond. That slicker surface attracts a more uniform layer of the thermo-plastic material; you end up with a dense, dark, void-free pattern. But it's gotta be CHEAP color copier paper because you want the stuff to dissolve in warm, soapy water. High quality color copier paper is some very tough stuff; it doesn't like to come apart. But the paper HAS to come apart if we want to leave ONLY the thermo-plastic material bonded to our circuit board. So use the cheap stuff. And soak it in warm soapy water. Then scrub it with a tooth brush or whatever -- get ALL of the paper off of the thermo-plastic. Now you can etch the board in the usual way. And having etched it, you gotta drill those zillion holes. Once etched & drilled, remove the thermo-plastic, which you can do with MEK or other kidney-killer solvent and a bit of steel wool. The result is a bright copper circuit board, ready to accept components and easy to solder. Once things are soldered and checked and and all the errors corrected, give the thing a coating of clear finger-nail polish (!) and you're all done -- a super bright nav light that will never burn out (at least, not in your life time) that draws about a quarter of an amp, meaning the wiring can be slightly smaller than a starter cable. -R.S.Hoover -(KA6HZF) PS -- Yes, you may have a copy of the circuit boards, if you wish. But you could probably do better yourself -- except for the stern-light, they're just rectangular 5x9 arrays. I don't have a web site and I already get more email than I want so I'll try to find somewhere to hang them. When I do, I post the information here... for all 385 subscribers of r.a.h. to read :-) Don't use drill bits. They break too easily, and don't give you much "mileage". Use dental burs, instead. Far better. http://www.prevent.dentsply.com/cata...hor-Round-5677 Ed |
#8
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Andrew,
Small nit pick: laser printers don't lay down ink, they lay down "toner" which is in fact a type of thermoplastic. When you say that you are transferring the ink from the paper, that is a bit of a misnomer... Dean Andrew Sarangan wrote: I also used the laser printer toner transfer method for my LED design which I posted a couple of weeks ago. I originally discovered the technique from http://www.fullnet.com/u/tomg/gooteepc.htm The paper came off easily in water and a gentle scrub. One problem I noticed is that the gloss sticks to the ink more than the paper. So when the paper peels off, the gloss stays on the ink. This may not be a problem where the ink is supposed to be, but the gloss also bridges across small openings like drill hole location markers. I tried scratching these areas with a needle to remove the gloss, but it did not come off easily. Also, this is very hard to see because the gloss is transparent. Only after the etch you realize that the location markers are missing. But this was not a big problem for me because the location markers were simply an aid for centering the drill bit.But it could be a problem if the bridging is between closely spaced tracks. Also, regarding the #70 drill bits, are you sure you got them at Harbor Freight? They did not have anything smaller than 1/16". If you have a product number or a URL that would be helpful. wrote: To All: The steady decline in the cost of ultra-bright green LED's (now about two-bits each for a 100-piece baggie) has generated renewed interest in the bug-eyed LED nav lights I described on this Newsgroup a couple of years ago. Unfortunately, that renewed interest has lead to some renewed problems, one having to do with the lay-out of the circuit board, the other with its fabrication. But the most serious problem has to do with the fact that ham radio operators learn to solder shortly after birth, or even before... according to some. Along with the ability to solder is the companion knowledge of how to make a circuit board out of a bit of substrate and a piece of string about... that long. But the main stumbling block for non-hams appears to be how to make all those teenie-tiny holes in the circuit board. MAKING HOLES It's pretty easy. You need a tiny drill -- somewhere between #70 and #75. Then you need to spin it about 12,000 rpm. And you need to keep it perfectly vertical as you make the hole. The drill bits are no problem. Harbor Freight will sell you a selection of solid carbide bits suitable for the task; simply pick a size to suit the components you're using, such as the wire legs of an LED or quarter-watt resister. A Dremel tool (or similar) is the handiest means of chucking the tiny drill, most of which have a shank diameter of 1/8". To hold it perfectly vertical you don't 'hold' it at all -- you make up a 90 degree bracket and clamp, wire or glue the tool to the vertical leg. On the horizontal leg you drill a 1/4" hole to accept a bolt which you then chuck into your DRILL PRESS. There's a few picky-bits to this method, such as using a bracket that is a true 90, and thick enough so as not to deflect as you run the quill of your drill press up & down. You need some method of preventing the quill from rotating of course -- I use a simple wedge between the quill pulley and the frame of the drill press head (big, old Craftsman floor model. Your mileage may vary...) To keep from ruining the chuck in your drill press (which was not designed to grab hold of threaded bolts) you put a barrel-nut on the bolt. Deal with all the tricky bits and the result is a shake-free, carbide-tipped hole-maker that will give you a life-time of accurate service (and already has, in my case... I used it to make the boards for my first computer back in the mid-70's). ELEVATION vs AZIMUTH Azimuth is relative to the horizontal. Elevation means over-head. In laying out the circuit board, asimuth is taken care of by orienting the legs of the LED's. Since the LED's have an average viewing angle of 25 degrees, to provide adequate coverage the azimuth angle starts at 10 degrees and progresses in 20 degree increments. Of course, when you're trying to provide full coverage across a segment of a sphere, your LED's must be accurately oriented in TWO dimensions. The key point here is that I chose to build the aximuth angle into the circuit board. The elevation angle is bent into the legs of the LED's using a simple form-block, accurately printed via DeltaCAD, glued to a bit of plywood and sanded to the line. To keep things simple, I abandoned the variable height arrangement as described in my original post, other than allowing a bit of overlap between one row of LED's to the next so as to keep down the circuit board, which comes out about two by two inches. As a further simplification, I eliminated the left vs right bending angles used in my original (2002) lights. Now all of the LED's get the same set of bends relative to their positive lead. To accommodate the change from left- to right-facing, I re-drew the circuit board. MAKING THE CIRCUIT BOARD The Old Fashioned Way was to start with a drawing then go to litho film, then to a fine-meshed silk screen. Once you had the silk screen you could whip out a hundred circuit boards in an afternoon... after spending a month to arrive at that point. Nowadays I simply print the circuit board mask onto cheap glossy-finished color photo paper using a monochrome laser printer. Here's why it works: Laser printer media is a finely divided thermo-plastic -- a powder so fine it is attracted to the electrostatic charge created by the laser. The thermo-plastic material is transferred to the paper by heat. This lends itself to making circuit boards because once the thermo-plastic material has been transferred to the paper, it may be RE-TRANSFERRED to the clean copper surface of a blank circuit board by the application of ADDITIIONAL heat. In effect, you literally iron-on the mask, solidly gluing the paper to the circuit board. Now the trick is to get rid of the paper, which I'll get to in a minute. But before I do, you should know that while using plain paper is possible, the resulting transfer will show a lot of voids; plain paper simply isn't a very good substrait for the thermo-plastic material. But cheap color copier paper is. Color copier paper is typically coated, giving it a denser, more uniform surface than regular #20 bond. That slicker surface attracts a more uniform layer of the thermo-plastic material; you end up with a dense, dark, void-free pattern. But it's gotta be CHEAP color copier paper because you want the stuff to dissolve in warm, soapy water. High quality color copier paper is some very tough stuff; it doesn't like to come apart. But the paper HAS to come apart if we want to leave ONLY the thermo-plastic material bonded to our circuit board. So use the cheap stuff. And soak it in warm soapy water. Then scrub it with a tooth brush or whatever -- get ALL of the paper off of the thermo-plastic. Now you can etch the board in the usual way. And having etched it, you gotta drill those zillion holes. Once etched & drilled, remove the thermo-plastic, which you can do with MEK or other kidney-killer solvent and a bit of steel wool. The result is a bright copper circuit board, ready to accept components and easy to solder. Once things are soldered and checked and and all the errors corrected, give the thing a coating of clear finger-nail polish (!) and you're all done -- a super bright nav light that will never burn out (at least, not in your life time) that draws about a quarter of an amp, meaning the wiring can be slightly smaller than a starter cable. -R.S.Hoover -(KA6HZF) PS -- Yes, you may have a copy of the circuit boards, if you wish. But you could probably do better yourself -- except for the stern-light, they're just rectangular 5x9 arrays. I don't have a web site and I already get more email than I want so I'll try to find somewhere to hang them. When I do, I post the information here... for all 385 subscribers of r.a.h. to read :-) |
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#10
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-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1 Andrew Sarangan wrote: wrote: Andrew, Small nit pick: laser printers don't lay down ink, they lay down "toner" which is in fact a type of thermoplastic. When you say that you are transferring the ink from the paper, that is a bit of a misnomer... De Very true. I have used the terms toner and ink interchangeably, which is not correct. Jut a small nit from one who has used (or attempted to) a laser printer to get good PC board results. Its often hard to get decent thickness of the toner on the paper so the remelt with the iron works properly, therefore, I have have started to use press-n-peel with greater success. You print on this special paper, press onto the copper s normal, then soak in water. Much better results with finer lines. Evan -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQFEHHxhpxCQXwV2bJARAqWfAKCFUfX9hFilGUjsflYfX4 V7QyGOfACdFQfq lLcs2QOQ0p/H5A2F8z0CYzA= =Kwvv -----END PGP SIGNATURE----- |
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Thread | Thread Starter | Forum | Replies | Last Post |
KX-155 LEDs | Steven Barnes | Owning | 21 | July 11th 13 09:04 AM |
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