Power Supply Rectification and Smoothing

I'm building a power supply for a 36V, 500W DC motor to drive a small lathe.

I have scrounged a transformer from an old microwave oven and removed the 2000V secondary windings leaving the 240V primary windings intact and undamaged (I will test with a megger before powering up.)

I will wind some 30A automotive flex around the secondary core and test until I have around 36V (the rated voltage of motor and speed controller)

I have found a bridge rectifier to use for the rectification of this secondary 50Hz current. It is rated at 400V and 35A. Will this be suitable? Is there a downside to using too large a BR? This is about the only one that would appear to handle the rated 18A for the motor. Is 35A rating enough for the BR?

Now to smoothing. I have calculated that I will need something like a

I'm not even sure if this will be smooth enough for my motor controller which is a Chinese scooter controller here:

Anyway, I can't find a cap this size in Australia (I'm sure they exist

- they do in Digikey - very expensive but unavailable singly) but I can find 50V electrolytics of 4700 microF for around 75c (US) each. If I strung a dozen or so of these between the DC output terminals, would I have any major problems? Yes, I would prefer 100V caps but the 50s are all that are offered by this surplus goods vendor.

Otherwise, I was thinking of using 3 cheap 12V car batteries across the DC terminals. I've heard these have ginormous capacitance, and hence smoothing effect. They might be short-lived however, and be false economy.

As these caps are so cheap, would it be of advantage to hook several dozen up in series and parallel to increase capacitance and voltage handling?

I'm learning furiously, but as a newbie, some things that are obvious to the experts are rather hard to find out about, especially when you are not quite sure of anything. jack