some results on cast work...

[rclint]

I have been working more on cast receivers, here are some thinsg I have found

First running LCD and calculating the surface area against time does not work, and I have no idea why, my own idea is the amount of copper in the cast causes a lot more conductivity and burns the part if run at the correct settings/time etc

My first part was smut gray, ugly as could be, then I done another this time I polished the smut off the top of the dye after it was sealed this worked ok, but still left much to be desired in the way of looks, and eye (I) appeal

I prob made 30 or more runs on the cast barrel band on a ruger 10/22, what I have come up with is this

Run the part at the correct LCD current density BUT use PAR as to ho wlong to run the part, the time for a receiver was around 84 minutes for a 1 mil coating, if you do this you will get a grey receiver that will not take dye, and will not show dye only a smut layer if it does

Run the part until the volts max out and start a downhill curve, once it drop down about 2 volts then you are finished, and the part will take dye, but the pores are big and the dye will also "boil out" so you want to steam seal only, steam seal for 20 minutes then let this dry for a day and then a spray down with wd 40

My only reason I can come up with on this is the amount of copper, this would mak ethe piece much more conductive and anodize at a faster rate, and the receiver being a cast mix the copper under the aluminum is drawing the current causing the aluminum to burn off, or anodize at a much faster rate depending on time, to much and I think the aluminum just goes away

The result of all of thsi work is this, but remeber this is only for cast work, you may try it with problem pieces you have

[acidrain]

Nice work... cast is a mystery to most, and your efforts are appreciated!

[rclint]

Comparing to the anodize charts that Fibergeek created on different alloys this agrees with none of them or even comes close

using the smut judge (dip in caustic etch) you get a dark dark grey, like 7075 (7075 is blacker) unlike 7075 the caswell pre acid dip for cleaning impurities from aluminum surface will not touch this smut, so i assume I'm dealing with metals other than copper and zink, maybe it's silicon ?

the smut on the receiver is a grainy smut also if that makes sense...

Clint