Moto Guzzi: Zinc Plating

as i've been building up the bike where possible i've been replacing old fasteners with new stainless steel items however there are quite a few bespoke fasteners as well as a few other odds and sods that i'm not able to either obtain in stainless steel or sometimes even get new parts many of these parts appear to be zinc plated with the zinc plating having worn off or deteriorated so my intent is to remove the old zinc plating clean up the items and then replate with zinc removing the old zinc plating is relatively easy all i need is some water this is just tap water nothing special and some citric acid and what i have here is a bag of citric acid crystals all i need to do is mix the crystals with water and that will form the acid as you will see i'm not being very scientific here i'm just going to literally add a an amount of the crystals i'm going to stir it so the crystals dissolve one of the real advantages with citric acid is it's benign so it's not actually going to hurt me having said that if i had any open cuts it would sting but i think i'm okay i'll let you know in a minute okay so there we can see the crystals have dissolved and all i'm now going to do is put the items i want the zinc removing from into that solution and i'm feeling i've got a cut there the first item was the gear change pivot bolt this is the rear brake pivot bolt for the linkage these two items are the oil feed adapters on the oil lines that go up to cylinder heads and lastly i'm not sure this is zinc or maybe it's a chrome finish this is the gear change lever that sits on the gear selector shaft at the back of the gearbox what i'll do now is put the camera on to time-lapse for the next 20 minutes and hopefully we'll see all of those items bubbling away as the zinc has been dissolved by the acid right that's been left sat there for 20 minutes as you would have seen on the time lapse it's bubbling away quite nicely or has been claw stinks as well horrible smell [Applause] all we'll do now is clean those off with some water again nothing other than tap water what i'll do is i'll give these a clean up with some first maybe with a wire brush and also some wet and dry and we'll see what they come out like so yeah i won't show that on the video i'll come back with the results of the cleaning up all the parts have now been cleaned they've all been given a good scrubbing with a wire brush to remove any rust and dirt the oil adapters for the oil feeds into the cylinder heads i've also cleaned up using some wet and dry one of them in particular was quite badly pitted i've not attempted to clean up the bolts or the nuts with wet and dry i'm not looking for a smooth finish on these it should be noted that zinc plating will not fill any of these pits the surface finish as is will appear the same after zinc plating it will not hide anything after cleaning with a wire brush i have coated each one in some wd-40 just to stop any rust from forming on them what i'll now do is i'll give them a really good clean up with the greaser and then i will proceed onto the zinc plating for degreasing i'm using this stuff no nonsense heavy duty greaser it does appear to be quite caustic so i will be wearing some gloves and some eye protection it must be quite strong stuff because the instructions say mix five capfuls with five liters of water i've made a much stronger mix here so i put probably a cap full into i don't know what's that quarter of a liter so this should really get the grease off my components i'm just going to use one of them to stir it i'm going to drop the wall in for a few minutes whilst we are waiting for the parts to degrease i'll just talk us through the plating setup what we have here is a container full of zinc electrolyte the electrolyte has been made very simply from white vinegar with zinc and what you can see here is two zinc plates this is zinc plate and this is a zinc plate they're both attached to copper pipes just to suspend them and give some conductivity and i've passed a current between those two zinc plates using an old phone charger quite literally chop the plug off the end connected one side to one plate and the other side to the other plate so positive one plate negative to the other plate and let that run for about 20 minutes in my setup it was pulling about an amp and that process actually dissipates zinc into the solution to aid in that i've also added some salt common table salt in this case i've got some rock salt from the kitchen that was dissolved in the vinegar prior to putting the zinc in and in fact you can see the zinc plates bubbling away as i talk as that acid is working as the white vinegar is working on those zinc plates for the plating itself the two zinc plates will actually be connected together and you hopefully can see that there single wire these plates form the anode and will be attached to the positive side of a power supply the parts that are to be zinc plated will be immersed in the solution via copper wire and they will be connected to the negative of the power supply what we'll do now is we'll rinse off those parts that have been sat in the degreaser i won't plate all the parts in one go i'll just select a couple for now so we'll get those rinsed off wired up and then we'll run through the process i've got a glove on again as i'm sticking my fingers in this degreaser we'll just rinse those parts off in some water so what i'll do is i'll run both the oil feed adapters through the process as an optional step which i'm not able to do the parts can be immersed briefly into some hydrochloric acid that will remove any remaining dirt as well as putting a fine etch on the surface in the uk getting hold of hydrochloric acid is now very difficult as i've toast those in my hands i am going to just drop them very briefly back into the degreaser okay both parts are fully immersed what we now do is connect the power supply so the anode or the positive needs to connect to the zinc plates need to keep that away of course from the cathode which is the parts are being plated okay i now put the power supply on one i'm looking for is i have three 400 milliamps i think anything more than that and i'll run the risk of overplating which could lead to problems later on when i first did this as i mentioned earlier i actually just used an old phone charger i've now bought a specific power supply cheap item off ebay but i can vary the voltage and therefore get the current in the right range as we can see we're not needing very many volts to get the required current so 1.26 volts has given me 350 milliamps i think that'll be good to go we'll let that run for 20 minutes or so and see how the parts look okay that's been in for 20 minutes the current is still the same round about 350 milliamps let's uh switch it off pull them out and see how they're looking so hopefully you can see that's a nice dull gray finish on those parts from my previous experience on this over the past few days that is good so give those a good rinse off in water and then we're going to clean up to clean the parts up i'm going to use the soft mop on the polisher so i'll go and do that and we'll have a look at the results all right i've given both these a quick buff on the polishing wheel not too much because i don't want to pull off what i've just plated on just give it a clean off with some acetone that actually looks pretty damn good do you seem to have picked up some polishing soap it's a bit annoying i will put these through again so i have another round of plating them what i'll do this time is i'll wire them up first then i'll clean them with degreaser and then we'll give them another 20 minutes i've given both these a quick and light buffing with the soft mop on the polisher as you can see they have come up remarkably well i'm very very pleased with that i don't want to polish them too hard because the zinc layer is microns thick so it'll very easily polish off if i get over vigorous what i'll do now is i'll actually clean off the rest of the parts that i'd prepared earlier and put them through the same process all the parts have now gone through the process and all have now been plated only the oil feed adapters have been through the process twice everything else i put through just the once so a couple of observations and pretty much as expected where i've taken the time to get a good surface finish prior to plating that has resulted in a really nice shiny finish on the past after plating for the other components i haven't made any effort to polish them prior to plating and as i said earlier on the video where there was pitching the pitting will show just as much after plating as it does before and we can see on this particular nut it's quite bad i think i'll actually bend that that's that's not a lot of good to me i don't think the nut the other side is is much better two bolts are interesting i i did these twice i went all the way through the process with both of these including stripping off my first attempt at zinc plating it just didn't seem to work right i think there may be some nickel plating or chrome plating on these bolts beforehand so as a part of the stripping and cleaning up process i also dumped them into the uric acid for a good few minutes the gear change lever for the gearbox that's quite a rough finish and that's reflected in the rough finish on the finish part but i think they're all good these are the first parts on the bike i've actually done this i've i've run a few trial operations earlier on but this is the first batch of parts for the bike and the results are i think as expected so we'll push on hopefully this video has been of use you

Channel: Mark's Home Engineering

Views: 57,151

Keywords: Moto Guzzi, Le Mans 3, Le Mans III, Custom Motorcycle, Cafe Racer, Zinc Plating, Electroplating, Home Engineering

Id: 8bQ2rHgs9BU

Length: 15min 10sec (910 seconds)

Published: Sun Jul 26 2020