A work in progress: Electropolishing

[BradG]

Very much a test of a new process to me, and rather pleased with the first run.

This is Electropolishing of Aluminium. The first picture shows a rather rough piece of machined aluminium. As you can see, machining marks can still be seen on it.

The second picture shows after a 7 minute process. the reflection is as good as chrome, albeit mottled due to the machining marks. Id imagine if pushed for longer, and tweaking the process this would smooth out quite nicely, though most probably more practical to give it a light sanding while still on the lathe so it's at least smooth to begin with, and of course improve the process with better agitation and even cathodes rather than being one sided.

Quite a learning curve with regards to temperature, agitation, current density, and time frame, but looking good!

My next tests will be on an etched piece to see how well it cleans the base layer of the etch

 

[bassethound]

Interesting indeed..

 

[fortress]

It's that good Brad it's stripped the plaster your walls.

 

[BradG]

it strips most things lol. 85% Phosphoric acid heated to 75'C. I've dissolved a heating element and two airstones so far ruling out what won't work

 

[edlea]

Brad do you have an assistant called Igor.

 

[fortress]

The kites the kites!

 

[BradG]

Brad do you have an assistant called Igor.

no he dissolved.

 

[Macaronytony]

Got to love your mind Brad....

 

[Penpal]

Cauldron boil and bubble. Brad another first appreciate your sharing. I have been going through a rough pineapple week or so of experimenting, learning myself.

Peter.

 

[Vic Perrin]

io

 

[Bill Mooney]

I like your experiments Brad. Looking good.

 

[Doug]

Good results so far Brad

 

[wm460]

Very interesting Brad.

 

[Jim]

Good luck with it Brad .. :wink:

 

[Penpal]

Next step from a smooth surface it should be a winner Brad.

Peter.

 

[BradG]

Tonight's test:

The left side has been electropolished, right side mechanically. Note the brightness of the cut lines on the left side. That's exactly what im after.. polishing the hard to reach parts normally the sandpaper skips over.

This still wasn't a perfect run as I only electropolished it for 3 minutes instead of 7. Mainly due to putting my thumb on the 240 degree hotplate! soaked my thumb in a jug of cold water for the three minutes before deciding to stop the process and go get a bag of frozen veg to take the pain away

Made a note not to touch the hot plate again. Stupid man.

I need to build a jig to suspend the piece accurately in the middle, that's tomorrows joy. On a plus side, I made a bubble diffuser out of a section of LDPE pipe which the acid won;t dissolve so im getting much better agitation. Better than dissolving fish tank airstones anyway!

I will persevere

 

[edlea]

There's a big difference ,Brad even I can see it....... looks like you know what your doing .

 

[BradG]

Getting there Ed!

 

[Penpal]

Using timber it shows in the under cut surfaces when you finish so good news on metal mate the effect is magical.

Peter.

 

[Penpal]

Just spent time on your web site mate looking at your now finishing its so exciting and productive.

Peter.