Metal Finishing With Mark Anodising 101

hey you good eyes first wait here thanks for joining me I'm doing another episode today of metal finishing with Mark and this one is called anodizing one I want now why would you want to anodized materials in the home shop well it's a decorative process in my view that's why I do it but there are some other advantages to anodizing it improves the surface corrosion resistance of metals like aluminium magnesium and titanium it also improves the durability of the part it makes the surface tougher and more abrasion resistant but the big advantage is that you can die the part once you've anodized it because the surface becomes porous and the dye can penetrate into that porous layer and look later you can seal the pores over using hot water or boiling water so that makes the color more fade resistant and locks the color into the surface of the metal now these are some parts that I've done at home here this is a dial indicator holder for the metal aid this tracking adjustment mechanism for my metal cutting bandsaw this is one of those multi access by stops all of those were done at home these are probably the more recent parts that I've done I have done lots and lots of parties in this process some of them were absolute failures and it's fair to say I've learned a lot as I've gone along but now I think I'm making more consistent parts and I'm getting more consistent results with this method these are some parts I'm going to do today this is a handle for a jeweler's roll this is the locking knob for a miter fence that goes on the bandsaw this came from and these are two little circular discs that are going to get turned into maker plates also for the bandsaw so that's where we're going with this cart I should add that I'm not going to go into the science of how anodizing works it's far more complex than I've got time to show you here I will point you to a video that is very very good if you want to really get into the nitty-gritty of how it works but what I want to share today is just simply what I do in the home shop and the techniques that I use and you can judge yourself whether it's something that you might be able to work within your shot so let's have a look first of all at some of the materials and equipment you'll need this is probably the single most expensive piece of kit you'll need to buy Canada anodizing home this is a DC power supply brand name is go firt do Phe RT and I'll put the model number on the screen below it I bought this on eBay wasn't terribly expensive I you know from memory I think there's about 50 $60 but I'll check that this one will do up to 32 volts DC and up to 5 amps it's small compact lightweight it's got a little encoder here which allows you to set the voltage and the average and that's selectable by this slide switch so it'll do constant current or constant voltage now if you do any research on anodized sometime you'll see that a lot of people recommend using battery charges or just a 12 volt DC battery and although that works you don't get a lot of control so certainly with a car battery you've got no control over the current power or the voltage for that matter this one allows you to select both of those and I generally operate it around about 15 volts the other thing is that it's just a handy bench power supply it's it's accurate and controllable so if you're doing testing or you just want to run a prototype circuit this is great okay the next thing you'll need is cathodes cathodes used and anodizing can be made of either a mm or LED now when I first got started with this I was using aluminium so these are just the top of strips problem with them though is that they will gradually get consumed by the electrolyte in you are analyzing bath and you see these used to be pristine they're shiny and smooth now they're covered in craters and pits and so on and at one point I was just leaving the cathodes in the tank and it might be six months before I come back and use it I found that one set of cathodes had been completely dissolved nothing left of them and all of that aluminium that was dissolved by the electrolyte ends up in the electrolyte and that can upset the balance of the electrolyte so I've ditched these and now I'm using these LED cathode sphere the advantage with these is that they've got hooks that hang over the side of the tank so you can just simply slip them down into the electrolyte when you finished and for today just lift them out again and wash them clean and store them away lid also doesn't get consumed by the electrolyte so if you really wanted to leave them in the tank indefinitely you could I cast these using a little mold that I made over mmm you can buy lead sheet hardware saw but it's expensive the thickness only needs to be around that one or two millimeters thick that the most these little bit heavier about three millimeters now I've soldered a copper wire to the top of each one of those cathodes there and I've just got a piece of earth wire joining them together and one goes on each side of the tank so there's that cathodes let's have a look the next piece again you will need some sort of bus bar to connect your power supply to the individual parts that your anodizing bus bar can be made of copper this is a medium which works fine and you need some way of connecting the bus bar to your path now I'm using three millimeter aluminium wire this was actually the electrical transmission Y used for taking the power past your house I just unraveled a section of that and I got this any mini wire out of there the downside with a minion wires it actually gets anodized along with the part and there's a curious thing about an anodized surface on aluminium that is that it becomes non conductive and I'll show you that in a minute but it does mean that each time he is one of these hooks you need to clean off the anodized coating or strictly anodized coating before you use it again otherwise it will simply insulate the path from the bus bar now another thing I learned just recently was that you need to be able to clamp this hanger wire to your bus bar now in the past what I was doing was just simply hanging the wire from the bus bar with a hook so I would just simply do that hang that on there and then I'd hang the part in the electrolyte the downside with that is that a lot of the parts you do are quite small it doesn't put a lot of weight on that hook and sometimes you'll find that you get a good electrical connection between the hook and your bus part and unless this is meticulously clean and the same with your wire hook you can hang that part on there put it in the tank come back two hours later and find out that it hasn't anodized at all so what I do now is I've drilled this bus bar with I think they're four millimeter diameter holes and I put the wire into one of those holes and then actually clamp it so come on so I'll tighten that screw down with the screwdriver and actually get the screw to bite into the aiming in and then you can be sure that you've got a you know continuous current going to your part but just hanging out is a bit hidden this for a long time I couldn't figure out why I'd hang five parts on this bus bar and four of them would anodized and one wouldn't and it was simply because it wasn't getting a good electrical connection and it's it's hard to tell at the time when you're doing the anodizing process which parts are working which ones are because the current displayed on your power supply shows a total current for all the parts and unless you lift each one individually and check the current meter you won't really know but this I find now gives me way more consistent results now you will remember I said that an anodized coating on a mm will actually produce an insulating surface on that material and this is a piece of pre anodized aluminium sheet and the back side of this has still got the anodized coating on it and I can demonstrate here with my meter I've got that set as a continuity tester by short out the leads you can see that we get zero resistance but if I place it on the backside of this pre anodized sheet or get nothing absolutely nothing look there we go big way not nothing if I turn it over this side it's been polished to remove that anodized coating and you can see straight away we get back to zero resistance this part here once again already anodized if I check that we get nothing you can scratch through the coding and get the points of the probes through the underlying layout of a man in sea yeah with there we go so that's just some pressing really hard to get through that layer but under normal circumstances that anodized coating is basically an insulator so you need to be a little bit careful if you think about using this as a process for electrical paths for example this part to me was the biggest barrier in getting involved in anodizing home any of the heart two guys that you read will tell you that the correct electrolyte to use for anodizing is soft uric acid now the only problem is that at one point sulfuric acid was very easy to obtain I used to buy it back in the 1980s for cleaning copper when I was making copper boilers with steam engines and you could just go down to your local auto accessories shop and buy a four liter container it's what they used to use for topping up lead acid batteries now when I tried this about four years ago I walked in tried the same spiel and the very first thing they said is what do you want it for I ended up having to pay a fee to get it transported from the central warehouse I had to fill out a declaration to say what I wanted it for and I was treated with suspicion the whole time I was in the shop and I go and see if you start looking around this stuff online or if you make inquiries over the phone you'll end up on a terror watch list somewhere so a bit true but there are the times we live in but what I found out is that this stuff is an alternative now this is sodium bisulfate and it says on the label here it's for lowering pH in swimming pools this is a three kilo tub I bought it down in my local pool supply company and it's cheap it's way cheaper than soft uric acid I can't remember the exact price but I was quite surprised that it was as cheap as it was now my inner dyson tank is 16 liters the correct ratio for the sodium bisulfate is 20% so I ended up using four kilos of sodium bisulfate for 16 litres of water that gives you the correct ratio 20% now mixes very easily with water and you do need to use a demineralized water don't just use tap water because you can't be sure what's in it and the is that it is an acid you do need to pay attention to personal safety when you're doing this so do wear face shield safety glasses wear gloves make sure you get long sleeves on and once you mix this it looks exactly like water so if you have children at home you need to make sure that you either lock the anodizing tank away somewhere or lock the lid down on the tank put a warning label on it it is an acid if you get it on your skin or your eyes little children they're going to stick their hands in it it's going to get serious very quickly so do you use your common sense if you've got this stuff stored anywhere around your house so that's the electrolyte that I'm using in my tank I did start with sulfuric acid but I had a suspicion that it got contaminated in some way as I was having problems with my anodizing so I ended up swapping it out for this sodium bisulfate now if you do have sulfuric acid and you want to get rid of it please be aware that you can't just tip it down the sink you either need to neutralize it or you need to take it to a facility well that will do that for you so some sort of waste disposal facility but certainly don't just tip it out on the lawn or tip it on your sink that's that's gonna get bad alright this is how I got my anodizing bath setup that's actually under the house the reason being that I don't have any more room my workshop is something like this and the other thing is that this is going to give off acid fumes and I don't really want this anywhere near my lathe or my milling machine or my measuring equipment so it lives under here it's it's totally fine there's plenty of ventilation under the house here as well so it's probably the best place for it now I bought this 20 liter top down at the local hardware store came with the lid and it's just it's a convenient size it's made of a good high-quality plastic and remember I said that if you got small children you want to be sure that this is locked in some way so it has a hole in the lid and there's corresponding slot underneath there so you can put a padlock or a chain through that and that would secure that I keep the lid on this all the time just to stop anything dropping in it and get out and it has an air or an aeration system built-in at the bottom of the tank they're just made from PVC pipe now I rarely use it I think with the small batches of parts that I do it's not really necessary the reason you might want to aerate the tank is to make sure that the small air bubbles come up and knock off any bubbles on the part which can cause spotting now like I say I don't normally use it and I haven't noticed any problem with just having the solution uh narrated so you decide whether you think you need it or not I've got the sitting on a stainless steel trolley I've got storage space underneath there where I can put my dyes and other cleaning solutions as well this just sort of rolls away when you're not using it so what we do is we put our bus fire on top there and I've got some 3d printed stops there just to stop that round bus bar from rolling away and then you put your cathodes in there hook up your power supply and you you're ready to rock and roll so let's have a look at that so there we are with the cathodes in place here and they just have drop over the edge of the tank like that so at the end of the day just lift them out rinse them off with water store them somewhere put the lid back on and you're ready to put that back into storage okay this is one aspect of this DIY and a Dyson that gave me the most grief early on and that is being able to hang the parts off the bus bar and ensuring that you're getting a perfect electrical connection now like I say I'm using an iminium wire a better solution is titanium wire and I've ordered some but you know the way things are going at the moment would be the next century before I get it the problem with using any minion wires I said is that it gets anodized and if you don't remove that coating it's electrically insulated what I normally do is either just buff the edge of the wire where it makes contact with a part or clean it in high sodium hydroxide which is caustic soda but either way you've got to get rid of that old anodized coating if you reusing the wire with titanium wire it's like I believe anyway it's more resistant to the anodizing process and you can reuse the wire fairly easily and you need to get a little bit inventive about how you're going to make contact with the part now this one here has a threaded hole in the back so I've doubled the wire over and I've just simply organized that so that it's sort of a tight threaded fit into the the path so you can see there I can twist that and remove it and whereas that wire sort of bites in to the threaded hole so as long as you're getting you know a solid electrical contact you should be good and if if it's not right you can just simply spread that wire apart spread the u-shape of the hook apart but that it's not going to come off there so I'm happy with that one with this one here once again I'll just spread the end of that wire apart a bit and I'll just poke it down inside there and I've cleaned that wire and that'll hang and give me a good electrical contact there now these are a bit more of a challenge of course because they don't have a hole in them and what I've had to do there is make up this sort of a u-shaped hook arrangement here I've filed some notches in the legs of the EU and I'll slid that disc through so it sort of sprung between these two points here and once again that should give me a good electrical contact now got to be a little bit careful anywhere where the wire touches it won't form the oxide coating so a little bit worried about these two points here on the face of this disc we may end up with sort of no anodizing right at those two contact points but that's about the best I can do for now so we'll see how it goes this is probably the most tedious part of the anodizing process and that is getting the metal chemically clean so before this part goes in the anodizing bath I need to make sure I've got all trace of wax and grease and oil and fingerprints off it and you can use a variety of cleaners just a lot of household cleaners will do the job so anything that's slightly alkaline got some turjun and it will work my favorite is just good old Ajax and if you watch my powder-coating video I use the same product on a million parts or powder coating or any parts for that matter and it's just very slightly abrasive I got a little bit of polishing wax on the back of this part here so I'm just scrubbing it off first you do need to wear gloves your fingers will have an oil film on them and that will contaminate surface after you cleaned it so this way your gloves either a really good scrub rinse it and then look for any water breaks that the the water doesn't form beads on the surface you're good to go you can buy commercial cleaners for doing this job I've actually got a tub of it but if you're looking to do this on a budget just use Ajax it works really well that's pretty much done the water isn't bleeding on that surface at all but you do need to be thorough it's nothing worse than spending like an hour to on this process and then finding out when you put it in the dye that a little you know marks and areas where the dye is not taking up and you've got to strip it and start all over again but that's that's one thing that's good about anodized and you can actually strip the anodized coating off fairly easily and just go through the process again now I've already done all the other parts are all the same so I won't bore you with doing them all I've seen people using ultrasonic cleaners to do this but once again this is a gear that you have to invest in that's a really not necessary it's just convenient okay that's looking good by one final step you can use before you put parts in the anodizing bath is to run them through a solution of caustic soda or sodium hydroxide all this does is just strips off any oxide coating that might have formed while you are waiting get the parts all clean and assembled on the rack this step is not absolutely essential I find it sort of just an insurance policy really why that looks a bit grubby it's fine so just give them one last rinse in clean water put it in the caustic soda and we're looking for maybe thirty seconds maybe a minute you should see fine bowls coming up to the surface there and the sodium hydroxide will actually attack the aluminium and etch it so you don't leave it in there too long so come out looking a bit gray and a bit fussy give it another rinse - you see mineralized water here and that's ready to load on to your bus bar and ready to go in the owner dicing bath and you want to do this just before you start the anodizing process so we'll just load this in now and just tighten that screw until it bites down onto though they'll hang a wire that's nice and secure so that part's ready we'll get the other three loaded up and let's start cooking all right so you see here I got all my parts hanging from the bus bar now I've got my lid cathodes in the tank so all ready to power up and set the voltage in the average so I've got the power supply set up here or just switch on first I'll just put my positive on the bus bar negative goes on your cathode and switch on your power supply now I've got this set to 15 volts so if I turn the volt switch either you see that it's showing 15 volts so in reality it drops down lower than that sitting on about 11 at the moment I got my average set to about half a nap now there are various calculators that allow you to work out supposedly exactly the voltage and amperage that you need however in practice I've found that it doesn't really work the problem is that you need to be able to work out the surface area of all your parts that some parts are so convoluted and complex that that would be a difficult task you can model the parts in card and actually query the card program to tell you what the surface area is but even when I've done that I find that the actual amperage being drawn by the parts is nowhere near what the calculator said it should be so what I tend to do is just set the voltage at 15 volts and then just let the part scroll up to say half an hour depending on how many parts you have in there and then as far as the time go I normally leave it for an hour or two the longer you leave it the thick of the anodized coating will be but there's really no downside to leaving it longer rather than shorter and if you're doing everything right you should see fine bubbles coming off your cathodes not sure if we've got enough light here to show you there's some very very fine bubbles coming off from the cathodes the actual armenian part should be showing some fine bubbles as well but not as much as the cathodes okay let's let this go now we'll come back in about an hour and check them ok those parts have been in there now for about an hour and a half just from my experience 40 minutes is about the minimum but if you want a good thick coating more than an hour preferably a hour and a half and what we do now is just disconnect power as we leave that on okay these come out and what you want to do now is just give them a rinse this is just demineralized water and the idea here is to stop any of that electrolyte getting carried over into the next process which is dying and and if you've been successful what you should notice is that the surface of the part now has a slightly gray green look to it and it should be slightly dull like a satin finish if it still looks shiny and like polished aluminium it probably hasn't worked and you need to look at your setup but I reckon these are good so let's get onto the next step which is the dye the exciting part [Music] remember this stuff and when you were a kid good memories oh no oh bad memories oh man then it's so sweet yeah hey the drink - yeah get rid of that yeah thank goodness for a tall beverages oh that's better okay let me clean up this mess okay let's get serious for a minute no that was just my little joke don't go drinking to die now have actually got three different colored dyes here I've got a deep red electric blue and a black the black I'm not so sure about Oh we'll give it a go the red dye is actually heating up at the moment and I bought one of these little immersion heaters from Caswell it's got a thermostat that sits inside the liquid to keep it at a constant temperature so I've got this sitting at about 50 degrees centigrade yellow to adjust room temperature now it'll work at room temperature as long as you're not in freezing conditions that the part will take up the dial up more quickly if it's warmed up the dyes that I'm using from Caswell Caswell Australia they have an online store Caswell is an American company but I get these here in Australia they come in these little four ounce bottles you can also buy as a powder this is just to save on shipping costs you can dilute it when you get at home now some people have had success with this rip fabric dye I haven't I've had some but I haven't actually tried it I figure if you got the real thing that's the way to go anyway let's get the part in here now see how they go now if the anodizing god says smile on you this should happen almost straight away especially if you're using heated die a lot of what you see in there is just the dye on the surface of the pot you really have to rinse that see how well it's taken up I look at my water bottle and we'll just give it a rinse so you can see a lot of that comes off but let's just sit that in there for a few minutes and you do have to monitor that the longer you leave it in the guide that darker will get and if you're trying to color match parts you really need to sort of have them side by side or do them at the same time I did have a problem with the dial indicator holder for my lathe I did the parts on two separate days didn't get it right and you can tell by looking at it but that is pretty much done so you've seen that in real time having sort of cut the video here looks good there's no little bare patches anywhere all right I'm guessing now it's a total of about three minutes in the dye and I don't want that to go any darker something I'll lead that there actually maybe I'll give it a bit more these parts gain the blue dye will take a bit longer these this is room temperature you'll see that there isn't that immediate change so I'm just gonna let them sit there and I will just check then periodically but I will take a lot longer I think I read parts done I'll just rinse that off again the color is a little bit darker than the other parts where I've done but some of the color will leach out when we do the last step in the process which is the ceiling so I'll leave that there now and we'll do the other ones there's a handle in the black once again this is room temperature dyes so it's gonna take a while think it's going to Colorado yeah starting to go once again could take up to half an hour well there's the the blue parts that I've done that's taking a lot longer like an hour and that's the difference between heating the dye or leaving at room temperature but they're pretty much the color I want and what we need in our sprints this and get them into a container of boiling water so this is the final step in the process so they're going to go into a container of boiling water for about 20 minutes and that process seals the paws on the oxidized coating that allows the dye to penetrate and if we don't do this step the dye will eventually leach out and the color won't remain consistent so we do need to do this step but it's pretty straightforward just 20 minutes and in the interest of domestic harmony don't use your wife's best saucepans in this process I've got an old one down the shed here that I use so I'll leave those boil away there and you may notice when you're doing this a small amount of the color coloring the water itself don't be alarmed by that that's quite normal and you may also notice that you go a slightly very slightly lighter shade I'm just rinsing these off in water just so we don't contaminate the other parts the different colored parts suddenly the black one no I likes it there it so didn't kind of jet black it's more like a really dark charcoal gray it still looks okay though so same with that one come back in about 20 minutes well this same pass they cool down now and I've dried them off this little knob here is for the miter gauge she goes on my metal cutting bandsaw and originally this was just a wingnut looked a bit rubbish so I made a nice little a mean one this is the color I was trying to match these are the tracking adjustments for the back of the source I was trying to get the same color this is the handle for my jeweler's roll and like so it's not really black but it's a big improvement of what it was which was just be really mean so I'm happy with that and these little blue disks here what are they for well coming up in the next episode so I'm gonna ask you to join me for that we're going to do a bit of laser etching I've anodized aluminium and some CNC drag and graving so that should be really really cool and then the final episode going to do some zinc plating because this bit of mild steel here just keeps rusting no matter what I do and I hate that so we're going to get that all tarted up and make it look lovely so please join me in the next episode of metal finishing with Mark it's going to be a cracker and yeah and OH kids don't drink the kool-aid so pretty [Music]

Channel: Mark Presling

Views: 106,512

Keywords: aluminium, aluminum, anodizing, anodising, metal finishing, how to, diy, DIY

Id: Z1zT8p7d9Z0

Length: 32min 16sec (1936 seconds)

Published: Tue Apr 28 2020