In prototyping the Q, I had to take some matters into my own hands. One of these was anodizing aluminum, and not just little things since you know the Q is quite large. There used to be some great info on the web but most of it has gone commercial and so is limited by necessity (baby's gotta eat). I've researched and experimented with anodizing for about 10 years now, and while it is easy to get some "wow" results on the cheap, the processes did not scale up to any real-real-world sized objects. That said, I'm beginning this thread to show everyone how you can produce excellent results on a hobby budget. I'd say from experience that the 3 major mistakes any novice makes with anodizing are:
Lack of process control: Temps, acidity, time and # of amps all play critical roles in the successful growing of a thick, dye taking, durable layer. Proper quick sealing of the anodic layer is also critical. That said, depending on a number of factors, good results can still be had over a fairly wide range, but consistently finished results require tight process control!
Lack of amps: You can't cheap-out on the PS, it's gotta have the "ass" to do the job. I use the biggest battery charger available at a reasonable price ($130-200 HF, Northern etc). It has 200 amps and variable voltage up to 24v.
Lack of quality chemicals: Good acid and real dye are absolutely necessary. If you use RIT, you get SH*T. If you buy commercial chemicals, try to avoid the "quick sealing compounds" (deadly toxic fluoride, not disclosed by "resellers" so don't be fooled!). A great seal can had cheaply by the use of steam, which is far easier to produce over the material surface area than 50+ gallons of boiling water is.
Pic post next (trying to stay awake).
Full Version: DIY Anodizing
Many samples were made and tested. Only one of these was "perfect" (leftmost).
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A big charger going to 24v:
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Lots of high quality acid from the local auto store:
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Be safe! Keep lots of base mixed up in case of splashes or spills:
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Numerous layers of 6mil poly are placed under the acid container to avoid spills:
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A bad pic of the acid container with cathodes being placed:
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ANYTHING IN THE ACID TANK MUST BE ONLY ALUM OR LEAD...In my case, I chose alum because well, lead doesn't thrill me. This also means that all anode attachments must be alum (screws etc) or you will ruin the piece by burning out the non lead/alum pieces. Also, having the cathode surface area larger than the anodic (workpiece) is recommended, but by no means should your cathode be more than ~30% larger. If it is, you are wasting energy and possibly "shorting" the energy transfer between the pieces. It is easy to conclude then, that your cathode should be close to and opposing the areas you want anodized (the closeness reduces energy losses to heat in the electrolyte ((but not too close!)), and after all, there's no point anodizing the "back" of a piece that will never see the light of day. Careful planning is required for something as large as the Q sides. A cathode "jig" held together by alum screws is one option for making a close fitting cathodic jig, but in my case, I wanted a better connection. Screws are known to fail in the electrolyte, so I welded my cathodic jig together. Naturally when I went to do this, the TIG welder died (go China), so out came the alum sticks....widely believed to be impossible to use. As you can see, I'm non-plussed:
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MMM smells so good!
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A big charger going to 24v:
Click to view attachment
Lots of high quality acid from the local auto store:
Click to view attachment
Be safe! Keep lots of base mixed up in case of splashes or spills:
Click to view attachment
Numerous layers of 6mil poly are placed under the acid container to avoid spills:
Click to view attachment
A bad pic of the acid container with cathodes being placed:
Click to view attachment
ANYTHING IN THE ACID TANK MUST BE ONLY ALUM OR LEAD...In my case, I chose alum because well, lead doesn't thrill me. This also means that all anode attachments must be alum (screws etc) or you will ruin the piece by burning out the non lead/alum pieces. Also, having the cathode surface area larger than the anodic (workpiece) is recommended, but by no means should your cathode be more than ~30% larger. If it is, you are wasting energy and possibly "shorting" the energy transfer between the pieces. It is easy to conclude then, that your cathode should be close to and opposing the areas you want anodized (the closeness reduces energy losses to heat in the electrolyte ((but not too close!)), and after all, there's no point anodizing the "back" of a piece that will never see the light of day. Careful planning is required for something as large as the Q sides. A cathode "jig" held together by alum screws is one option for making a close fitting cathodic jig, but in my case, I wanted a better connection. Screws are known to fail in the electrolyte, so I welded my cathodic jig together. Naturally when I went to do this, the TIG welder died (go China), so out came the alum sticks....widely believed to be impossible to use. As you can see, I'm non-plussed:
Click to view attachment
MMM smells so good!
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For "impossible" alum welding, nonsense! Impossible for those who give up maybe (which is everybody nearly). While sloppy and more dangerous, good welds can be made with stick welding alum on a DC machine:
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Phew, cathodes done....
Next is to prepare the "work" by applying your surface finish and then scrupulously cleaning the piece with degreaser, then alcohol. This should all be done very soon before your pieces go into the acid tank for anodizing. There are those who like to "desmut" with lye or nitric acid; I'm not one of them. If you thoroughly clean the pieces and can see no blemishes, finger prints etc, it is good enough. When the pieces go into the tank, a wire/s must carry the current to the pieces. The wire must be alum, and anywhere the wire touches a piece will not anodize. Careful planning is needed to insure your pieces are both excellently connected and not impinged by the wires. Leaving a "sprue" as a part of the piece that is not necessary and can be cut away after the operation is sometimes possible.
After the juice has been put to the pieces, they will get rinsed instantly and thoroughly to avoid contaminating the dye with acid. It is important to keep everything wet constantly. I don't use a big tank of water, just a garden sprayer and a big ol' plastic tub as a "sink".
Next is to dye the pieces. It is especially true that black is a difficult (non) color to get right. Buy your dye from a reputable anodizer and you will never regret the very small expense. The dye bath should be held at the temp specified by the dye, with most being around 140f. Any more and the capillary pores of the aluminum oxide will start to "hydrate", which is the same phenomena that hardens concrete. If the pores hydrate before the dyes are allowed to seep in thoroughly, you've just wasted lots of time and money!!! If you've ever tried to remove alum oxide (with alum oxide sandpaper) you'll note the futility of such an exercise! The anodic layer even munches away at your lathe/mill/router tools....it is sapphire after all! PROCESS CONTROLS, ADHERE TO TEMPS BOTH MAX AND MIN. (You could strip the anodic layer with caustic or strong acids, bleh.)
After the dye bath, the anodic layer must be sealed. In another of nature's little tricks, if you let the piece dry out AT ALL during the transfer from dye bath-to-rinse-to-seal stage, you're toast again! You will have a beautifully made and dyed splotchy POS. (PS, every stage requires rinsing to avoid contaminating the next stage with the previous). PROCESS CONTROLS: ALL THINGS MUST BE READY AT THE RIGHT TIMES.
Click to view attachment
Phew, cathodes done....
Next is to prepare the "work" by applying your surface finish and then scrupulously cleaning the piece with degreaser, then alcohol. This should all be done very soon before your pieces go into the acid tank for anodizing. There are those who like to "desmut" with lye or nitric acid; I'm not one of them. If you thoroughly clean the pieces and can see no blemishes, finger prints etc, it is good enough. When the pieces go into the tank, a wire/s must carry the current to the pieces. The wire must be alum, and anywhere the wire touches a piece will not anodize. Careful planning is needed to insure your pieces are both excellently connected and not impinged by the wires. Leaving a "sprue" as a part of the piece that is not necessary and can be cut away after the operation is sometimes possible.
After the juice has been put to the pieces, they will get rinsed instantly and thoroughly to avoid contaminating the dye with acid. It is important to keep everything wet constantly. I don't use a big tank of water, just a garden sprayer and a big ol' plastic tub as a "sink".
Next is to dye the pieces. It is especially true that black is a difficult (non) color to get right. Buy your dye from a reputable anodizer and you will never regret the very small expense. The dye bath should be held at the temp specified by the dye, with most being around 140f. Any more and the capillary pores of the aluminum oxide will start to "hydrate", which is the same phenomena that hardens concrete. If the pores hydrate before the dyes are allowed to seep in thoroughly, you've just wasted lots of time and money!!! If you've ever tried to remove alum oxide (with alum oxide sandpaper) you'll note the futility of such an exercise! The anodic layer even munches away at your lathe/mill/router tools....it is sapphire after all! PROCESS CONTROLS, ADHERE TO TEMPS BOTH MAX AND MIN. (You could strip the anodic layer with caustic or strong acids, bleh.)
After the dye bath, the anodic layer must be sealed. In another of nature's little tricks, if you let the piece dry out AT ALL during the transfer from dye bath-to-rinse-to-seal stage, you're toast again! You will have a beautifully made and dyed splotchy POS. (PS, every stage requires rinsing to avoid contaminating the next stage with the previous). PROCESS CONTROLS: ALL THINGS MUST BE READY AT THE RIGHT TIMES.
Tired...I'll try some more tomorrow!
Anodizing!Its good to see you explaining the process Brainchild.With proper safety and >exact< procedures.I can't believe it sometimes!
lonewolf
lonewolf
To my knowledge, there are only three ways to seal an anodic layer:
Hydration (via boiling or steaming)
Chemical sealants (Nickel Acetate/Nickel Flouride)
Mechanical abrasion ("buffing over")
Clearly #2 and 3 have issues, and neither actually work as well as Hydration.
When working with big pieces on a prototyping level, boiling is not so feasible since it would require big tanks, is dangerous, and needs too much energy. Instead, I choose to steam the pieces, which works great and is comparatively very easy. In order to get the 4' length I required, I combined two electric skillets with a DIY "hood". The gap between the skillets was bridged with alum and insulated underneath. The hood was made from foil backed foam board (celotek) and aluminum tape. A thermal probe and digital readout are affixed at the workpiece level to be certain the temps stay above 180f for the required time, ~15 minutes. It is important to use enough water to last for the entire preheating and steaming phase. Too much water takes too long to heat. Ive found that 1/2" of water was plenty, and heated fast. This method could be expanded upon for even larger pieces, but if you do this, bear in mind the capacity of the circuit. Typically only one skillet per circuit, so get out the heavy duty extension cords, or tap two 120 feeds off a 240 outlet. Also note that a space about as large as the skillet can be left between skillets so long as bridged over and insulated with celotek underneath. This means one skillet can steam two skillet's worth of space, saving YOU money on skillets.
Click to view attachment
The box with probe. Note 212 temp on right hand temp readout! The hole is for safely venting the steam, keep your face and hands away (unless you're going for the melted flesh look).
Click to view attachment
One of my favorite people, and Lumenlab's chief engineer Robin Turner:
Click to view attachment
Inside the steamer are those wire racks your mom cools cookies on. The pieces to be steamed rest on the racks. Note that the pieces can be "face up" on the racks since the hole in the top of the box is not large enough to pass all of the steam, resulting in a slight positive pressure inside. This means steam touches all surfaces before it can exit.
Notes on safety, temperature, amperage and acidity (PH) (a work in progress).
SAFETY: Doh! Acid burns!!!!! Remember the "THREE A's": Always Add Acid to water, never the other way around!!!! Short circuits can cause fires. Wear heavy rubber gloves and always wear a face shield plus protective eyewear. Acid causes blindness. Always protect your clothing by wearing a heavy apron, preferably rubber (you'll look like a butcher too!).
TEMPS: You have to keep the acid-tank temps down during anodizing. Room temp or less is best. The process of dumping amps into an electrolyte makes heat! Have a few of those reusable hard plastic ice-replacers on hand to add to the acid to control the heat. Start with a couple already in the acid.
Click to view attachment
AMPS: I've read everything from 8-20 amps per sq ft to be anodized. You could break out your slide rule, but you'd probably find that whatever you tried to start with does not work! It's best to get some experience for your set-up and materials. Remember that you must always start the current at the lowest setting to avoid blowing out your connections. Using the built in ammeter run the current up until it read just under 20a and you see good bubbling on the surface of the workpiece. After the bubbling slows down a bit (15-20 minutes) increase the amps once more and run it for another few minutes, then turn it off. If you leave the work in the acid too long, the acid will start to eat at the oxide, so be sure to have the dye bath (or steam sealer if not dyeing) ready to go. Remove the pieces to your "sink" and wash all of the acid off before the next step.
PH: If using battery acid with a specific gravity of 1.265, I've found that a 50/50 mix of battery acid and distilled water to be most effective (equals about 20% sulfuric acid total).
It is important to mention that all water used in the process, including washing, should be distilled.
Hydration (via boiling or steaming)
Chemical sealants (Nickel Acetate/Nickel Flouride)
Mechanical abrasion ("buffing over")
Clearly #2 and 3 have issues, and neither actually work as well as Hydration.
When working with big pieces on a prototyping level, boiling is not so feasible since it would require big tanks, is dangerous, and needs too much energy. Instead, I choose to steam the pieces, which works great and is comparatively very easy. In order to get the 4' length I required, I combined two electric skillets with a DIY "hood". The gap between the skillets was bridged with alum and insulated underneath. The hood was made from foil backed foam board (celotek) and aluminum tape. A thermal probe and digital readout are affixed at the workpiece level to be certain the temps stay above 180f for the required time, ~15 minutes. It is important to use enough water to last for the entire preheating and steaming phase. Too much water takes too long to heat. Ive found that 1/2" of water was plenty, and heated fast. This method could be expanded upon for even larger pieces, but if you do this, bear in mind the capacity of the circuit. Typically only one skillet per circuit, so get out the heavy duty extension cords, or tap two 120 feeds off a 240 outlet. Also note that a space about as large as the skillet can be left between skillets so long as bridged over and insulated with celotek underneath. This means one skillet can steam two skillet's worth of space, saving YOU money on skillets.
Click to view attachment
The box with probe. Note 212 temp on right hand temp readout! The hole is for safely venting the steam, keep your face and hands away (unless you're going for the melted flesh look).
Click to view attachment
One of my favorite people, and Lumenlab's chief engineer Robin Turner:
Click to view attachment
Inside the steamer are those wire racks your mom cools cookies on. The pieces to be steamed rest on the racks. Note that the pieces can be "face up" on the racks since the hole in the top of the box is not large enough to pass all of the steam, resulting in a slight positive pressure inside. This means steam touches all surfaces before it can exit.
Notes on safety, temperature, amperage and acidity (PH) (a work in progress).
SAFETY: Doh! Acid burns!!!!! Remember the "THREE A's": Always Add Acid to water, never the other way around!!!! Short circuits can cause fires. Wear heavy rubber gloves and always wear a face shield plus protective eyewear. Acid causes blindness. Always protect your clothing by wearing a heavy apron, preferably rubber (you'll look like a butcher too!).
TEMPS: You have to keep the acid-tank temps down during anodizing. Room temp or less is best. The process of dumping amps into an electrolyte makes heat! Have a few of those reusable hard plastic ice-replacers on hand to add to the acid to control the heat. Start with a couple already in the acid.
Click to view attachment
AMPS: I've read everything from 8-20 amps per sq ft to be anodized. You could break out your slide rule, but you'd probably find that whatever you tried to start with does not work! It's best to get some experience for your set-up and materials. Remember that you must always start the current at the lowest setting to avoid blowing out your connections. Using the built in ammeter run the current up until it read just under 20a and you see good bubbling on the surface of the workpiece. After the bubbling slows down a bit (15-20 minutes) increase the amps once more and run it for another few minutes, then turn it off. If you leave the work in the acid too long, the acid will start to eat at the oxide, so be sure to have the dye bath (or steam sealer if not dyeing) ready to go. Remove the pieces to your "sink" and wash all of the acid off before the next step.
PH: If using battery acid with a specific gravity of 1.265, I've found that a 50/50 mix of battery acid and distilled water to be most effective (equals about 20% sulfuric acid total).
It is important to mention that all water used in the process, including washing, should be distilled.
Looks like a drug labs cooking there 
(And lol @ ant acid aka formic acid 
)
(And lol @ ant acid aka formic acid )
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