Nuts & Bolts
The racing season is drawing to a close here in the Northeast. This weekend will be the last 944 Cup race for the NE region over at NJMP. Since my car, dyno'd a couple of weeks with a blistering 120 hp at the wheel, did ok at the Delaware Porsche region DE - ie, actually posted some respectable times - I'm going to take the car out to race for one day. Win, lose or just mosey around the track, it should be a nice fall day at the track. Once back, the gutless 2.5 motor is coming out of the car and a 2.7L is going in. But first, I have to actually build the motor....
And as part of that process, I cranked up my new home plating kit. I plan to re-plate most of the hardware that come off the various broken 2.7 motors in the stockpile. Porsche engineers go their own way and specify exactly what bolt they need: "Ze bolt here should be 42 mm, not 40mm or 45 mm, but exactly 42mm and nothing else." So that 8x40 or 8x45 standard metric hardware bolt that costs 29 cents? No can use, you must use the special OEM bolt, available at your favorite Porsche parts store for $8.45. And you need how many? 20? Yikes! So the plan to re-use the hardware, but tart it up a bit.
Here's part of my plating process, the main zinc plating bucket.
First step is off to the wire wheel - or blast cabinet if you got one, I don't.
They cleaned up nice. Now if you were refinishing nice visible pieces, you probably want to bead blast them, followed by a touch up with the wire wheel. Like most jobs, the better the starting point, the better the end result. But in this case, this is for a race motor, and it's only nuts and bolts, so we're good here.
Now we need to wire them up so we can juice them. I'm using brass wire here.
The parts get suspended in the plating bucket from copper pipe, aka the cathode, that is connected to the negative side of the power supply.
Here's the power source, a constant voltage, constant current lab power supply. For these nuts and bolts we only need about 1.5-2 Volts at about 1/2 amp. The power supply is turned on and the parts are in the solution for about 20-30 minutes. The zinc atoms from the positive anode plate migrate through the solution to the negative charged bolts and stick.
Here's the power supply, bought off Ebay.
After 30 mins being plated, here's the result. Everything coated in zinc. If I wanted bright shiny zinc, I could have added a brightener to my plating solution, but we have another step.
A quick water rinse, and then a 30 second dip in my yellow chromate solution - the only really toxic part of this process, gloves, shields and respirator for this step - and the final result.
Not bad for the first time. I'm sure I can get them shinier with more practice. Only 3 hours for 6 bolts, 4 nuts and 6 washers. I think I can improve on that time in the future... Motor Bling, here we come!
And as part of that process, I cranked up my new home plating kit. I plan to re-plate most of the hardware that come off the various broken 2.7 motors in the stockpile. Porsche engineers go their own way and specify exactly what bolt they need: "Ze bolt here should be 42 mm, not 40mm or 45 mm, but exactly 42mm and nothing else." So that 8x40 or 8x45 standard metric hardware bolt that costs 29 cents? No can use, you must use the special OEM bolt, available at your favorite Porsche parts store for $8.45. And you need how many? 20? Yikes! So the plan to re-use the hardware, but tart it up a bit.
Here's part of my plating process, the main zinc plating bucket.
A two gallon bucket with a heater (approx 90 degrees), pump/agitator and that big flat sheet of metal is the zinc anode. Zinc atoms will migrate to my items suspended in the solution when I apply an electrical charge to the system.
More buckets galore: Water rinse, and a degreaser solution heated to 190 degrees.
The reason I'm doing this is to match the yellow cadmium finish you see on fancy bolts. Why bolts are coated with cadmium is because it is a soft metal and it's job is gracefully sacrifice itself and keep the underlying hardware from rusting. Well unfortunately the cadmium is quite hazardous (carcinogenic) and not really something to play around with. It's something only professional plating shops should be messing around with. In fact if you clean your bolts (doesn't everybody?) with a wire wheel, you should be wearing a respirator while doing so. But don't dispare folks, Caswell has this cool kit.It will plate the hardware with a nice zinc finish and then I can apply a yellow zinc dichromate finish which matches the cadmium finish and it can be done safely in the garage. So lets get to work.
Test Subject 1: a pile of rusted, tarnished, corroded bolts and nuts from an oil pump on the 944 engine block
They cleaned up nice. Now if you were refinishing nice visible pieces, you probably want to bead blast them, followed by a touch up with the wire wheel. Like most jobs, the better the starting point, the better the end result. But in this case, this is for a race motor, and it's only nuts and bolts, so we're good here.
Now we need to wire them up so we can juice them. I'm using brass wire here.
The parts get suspended in the plating bucket from copper pipe, aka the cathode, that is connected to the negative side of the power supply.
Here's the power source, a constant voltage, constant current lab power supply. For these nuts and bolts we only need about 1.5-2 Volts at about 1/2 amp. The power supply is turned on and the parts are in the solution for about 20-30 minutes. The zinc atoms from the positive anode plate migrate through the solution to the negative charged bolts and stick.
Here's the power supply, bought off Ebay.
After 30 mins being plated, here's the result. Everything coated in zinc. If I wanted bright shiny zinc, I could have added a brightener to my plating solution, but we have another step.
A quick water rinse, and then a 30 second dip in my yellow chromate solution - the only really toxic part of this process, gloves, shields and respirator for this step - and the final result.
Not bad for the first time. I'm sure I can get them shinier with more practice. Only 3 hours for 6 bolts, 4 nuts and 6 washers. I think I can improve on that time in the future... Motor Bling, here we come!
Wurth.com
ReplyDeleteI second that!
ReplyDeleteSorry, but when it comes to hardware (nuts & bolts and such) your only choices are new ($$$$), reuse old as is (looks like crap), or replated. The cool thing about this is, instead of getting back a box of 2000 bolts and nuts all mixed together from a commercial plater, I can do small batches as I go.
ReplyDelete