I did a lot of home anodising a few years ago but now get my parts done at a local shop.

To get expected,repeatable & consistent results you need to follow a system using proven techniques. By far the easiest & cheapest is Caswell's LCD method & the 720 rule, you need to have a constant current power source where you control the amps going in. Don't buy anything/everything from Caswell, it can all be sourced cheaper if you look.

I used to get excellent results but you MUST stick to the method or diagnosis of any problems is very difficult. Caswell's anodizing forum is very helpful & can sort out any problems as long as you are following a proven method & not just 'experimenting'.

For dyeing you need to dip the parts for at least 10mins, I used to dip black for 15mins for repeatable results. If the dye isn't taking then either the part is not anodised or the anodised layer hasn't 'grown' the correct pore size.

Unless you follow a method & unless you can control the amps entering the bath then every attempt is going to be an experiment with variable results which often means failure.

Tip No'1. Use as big an acid bath as you can, helps massively with keeping the temp stable.

Tip No'2. Use titanium to connect the part. Using ally wires was always hit n miss, I ended up screwing in titanium bolts to the part & connecting with titanium wire . . . never had a failed connection.