Purple Haze

For 2+ months, I've been unable to make any progress on my main 6B4G based amp cuz the aluminum plate need coating.  Bare aluminum needs a coating so it doesn't oxidize - that white powderish look.  I had first planned to anodize, but the best deal I could find locally was $150.  Too high, although I could have done 6 to 10 panels for that (next time!).  Alodining, I was told, was the next best solution (no pun intended).  I soon found out that stuff contains hexavalent chromium, the toxic stuff that Erin Brokovich exposed.  I wasn't about to use that, but found an non-chromium version online ("Alodine 5700").  It was supposed to take 7 days, but ended up arriving 7 weeks later.

I set up my basement bathroom with the following:

• Heated to 70+ degrees F
• Installed hooks for drying the panel in front of a heat lamp
• Wore a VOC mask and solvent proof gloves
• Worked with all chemicals in the tub in case of spillage. 

Then I did the following:

1. Prepped the panel with an alcohol rinse, vinegar rinse, water rinse, the air dried.
2. Filled the tank (a shallow Rubbermaid box lid) with Alodine 5700.
3. Immersed the panel in the Alodine for 2 minutes.
4. It didn't look done, so I re-immersed for another 2 minutes.
5. Rinsed in RO filtered water.
6. Funneled the Alodine back into the container (it's reusable)
7. Hung and air dried in front of a heat lamp

As it dried, I knew I wasn't going to like the end result.  Purple haze and rather streaky...

... probably from not prepping the surface with the recommended acid bath.

Oh well.  But now what?!  I considered just painting it silver since now it would hold paint - that would look cheesy.



So I scubbied down the Alodine coating with silver polish.  Here it is 1/3rd polished:

It looked pretty good - probably nearly down to bare metal again.  But now I was ready to just chock up the Alodine waste of time as a learning experience and do what I should have done in January, and slap on a clear coat of engine enamel. 

The clear coat did somehow capture some small dust particles while it was drying outside.  But overall, I'm pretty happy with it.

Finally... TIME TO START BUILDING!!!!