Etching Aluminum

Date 02-01-2008 17:09 Edited 02-01-2008 18:16

Here is what I found once:
Aluminum 1g NaOH (NaOH ASTM#2)
100ml H2O

The Lincoln procedure handbook of welding is a good resource and lists many common etchants.

I also put together a list at work for materials I work with in my job:

Attachment: MetallographyEtchants.xls (25k)

By Goose-em (**)

Date 02-06-2008 18:25

2-6% Nital works fine on aluminum. Use 100Ml of methynol or ethynol mixed with 2 - 6 ML of nitric acid. Start with 2% if it doesn't work add a little more nitric. Add to much and the aluminum will oxidize.

By Sean

Date 02-06-2008 20:01

If you are just looking to check penetration try Drano or something similar. It works well to measure penetration...

By Kix

Date 02-06-2008 21:28 Edited 02-06-2008 21:30

Works toilet bowl cleaner with some water in the mix.;-) You can make bombs with the stuff as well. 1 gatorade bottle with aluminum foil all tore up in the bottom of the bottle and a few onces of Works toilet bowl cleaner. Makes for a heck of a boom, but don't breath the fumes afterwards. lol

By hogan

Date 02-06-2008 21:32

kix, i heard the there were changes being made to not allow for hydrogen production from bowl cleaners and al foil.

By Kix

Date 02-07-2008 01:19

Yeah it's been awhile since I made one so this may be true. So is that hydrogen gas that is being made from the reaction? Whatever it was it smelled horrible. So if thats hydrogen gas being given off, if you set one by a fire do ya think we'll get a fire ball? I still have some of the Works toilet bowl cleaner that works so I'll have to try it some time.

By bozaktwo1 (***)

Date 02-07-2008 18:35

Hydrogen sulfide, probably. H2S. Wonderful stuff.

By Kix

Date 02-07-2008 19:31

It sure doesn't smell like hydrogen sulfide. H2S smells like rotten eggs and this stuff smells more like a really strong acid.

By DaveBoyer (*****)

Date 02-08-2008 03:52

Is the active ingredeint in the bowl cleaner hydrogen chloride? that is what is in Snow Bowl.

By Kix

Date 02-08-2008 13:04

Yeah it has 20% hydrogen chloride in the stuff we have here at work. I couldn't get one to make the reaction the other day so I'm wondering if the old stuff had more active ingredients in it. I could have sworn the old stuff had some kind of acid in the ingredients on the back of the bottle. This new bottle doesn't show squat.

By Goose-em (**)

Date 02-08-2008 18:48

see my last post on this subject please. Hydrogen sulfide is incorrect. The gas when liberated does not have a readily detectable smell.

By dbigkahunna (****)

Date 02-07-2008 00:30

Thanks for the sugestions. Much Appreciated
BABRT's

By Goose-em (**)

Date 02-08-2008 18:46

Actually the correct chemical compound is sodium hydroxide. This compound is very usefull when cleaning aluminum but should not be done near an open flame or in an unventilated area. If the aluminum is cleaned using sodium hydroxide (a caustic) it must be nuetralized using an acid rinse (one particular acid works best).

Aluminum placed in a mixture of sodium hydroxide and something else (what, I am not telling) will liberate hydrogen gas. This gas can be captured but I am not recommending this.

I am not giving the percentages of what to mix with what as this can be a dangerous process and should only be undertaken by persons with the proper training and experience.

I will however say this, yes, the hydrogen gas that is liberated is flammable so please do not fool around with it. It can, will and has killed people in the past.

By dbigkahunna (****)

Date 03-03-2008 03:17

Again, thanks to all. I used Drain-O and the weld shined like a diamond in a goats a$$
BABRT's

By Joseph P. Kane (****)

Date 03-03-2008 16:31

"diamond in a goats a$$"

Now that is an aphorism that I haven't heard before.