[njsteve]

The reason I used the Purple Stuff and tube method on the long piece was simply, that it was too long to fully submerge in the kiddy pool. You have to have the entire piece submerged otherwise you get uneven stripping and a big parting line in the trim piece.

Once the Purple Stuff did its work I then washed it in cold water and then transfered the straight trim piece to a section of plastic gutter lined with the same 6-ply plastic sheeting. I filled it with some of the same lye and water solution from the kiddy pool. You can see that the 2 chemical method (Purple Stuff followed by lye/water) works well as the lye solution immediately started taking away the remaining anodizing.

[njsteve]

From start to finish it took 12 hours of soaking in the lye solution to remove all of the anodizing. This included the periodic removal of the trim from the solution, the scrubbing of the surface and washing with cold water and then replacing in the solution again. I think if you used a higher concentration than one can per 10 gallons of cold water you would get faster results. One website I found suggested 1/2 cup per gallon of cold water. But since I was trying not to poison everyone in the house I decided to do the conservative method. When I was done, I poured the drain cleaner solution down the slowest sink drain in the house, which cleaned that up a bit as well. As for the trim pieces, I placed them in the shower and hosed them down with cold water for 5 minutes or so to get all the residue off.

One additional thing to remember. You must use proper protection: heavy rubber gloves and safety glasses are a minimum, plus proper ventilation.

Here is the before on the corner piece...and the after...And here are the other pieces, all ready for polishing this weekend.


This was a cautionary reminder I found on one website concerning using this method:

"Fast and easy, maybe. Dangerous, absolutely. Just one more reminder that every year trained professionals wearing protective gear are seriously injured when something goes wrong making up solutions of sodium hydroxide. It has an enormous "heat of solution" / "heat of dilution". This means when sodium hydroxide is mixed with water, it heats up the water. Not a big problem if a small amount is well mixed into a large amount of cold water. But if a small amount of water mixes with a large amount of sodium hydroxide (which can happen even in a large tank with poor mixing), that small amount of water is instantaneously turned into steam and erupts the contents of the tank all over the operator."

http://www.finishing.com/3600-3799/3674.shtml