Westlake Publishing Forums

General Category => Painting & Weathering Techniques => Topic started by: NORCALLOGGER on August 27, 2010, 06:25:47 PM

Title: I've Been Misled
Post by: NORCALLOGGER on August 27, 2010, 06:25:47 PM
Or more than likley I have just misunderstood.

Hi all,
I tried to etch some Pepsi can corrigated roofing today and had no success. As I understood the process you just submerged the aluminum in the etchent and watched it for 15-20 minutes then rinsed it off and buffed it with a brush.

Welllllll,  it didn't seem to work out for me.
Here is the results after nearly 2-1/2 hours in the solution. Not exactly the results I was hoping for.

 Any suggestions?????

Title: Re: I've Been Misled
Post by: JohnP on August 27, 2010, 07:31:22 PM
I've never etched for weathering but have done brass.  Wild guess- does the can have any kind of coating? Maybe it need to be cleaned of first.


Title: Re: I've Been Misled
Post by: Philip Smith on August 27, 2010, 07:46:57 PM
Two things..Maybe to thick of material and most likely coated with a barrier as John suggested.

Try this available at Michaels or direct from amaco/ amer art clay supply.


Title: Re: I've Been Misled
Post by: finescalerr on August 28, 2010, 02:00:00 AM
My suggestion: Use paper. No hassle and, when you put some pastel chalk on it, you can't tell the difference between it and metal. Fiskars makes a corrugator for your scale. You can find it at Michael's craft stores. -- Russ

Title: Re: I've Been Misled
Post by: Franck Tavernier on August 28, 2010, 03:38:10 AM
What type of etchent did you use?

Ferric Chloride works better with aluminium than Ammonium Persulphate...


Title: Re: I've Been Misled
Post by: NORCALLOGGER on August 28, 2010, 11:22:26 AM
Hi guys,
Thanks for the suggestions.

I was using ferric chloride on the aluminum.
I think the problem was, as some suggested, a coating on the can inside.
I scrubbed a couple of pieces with a wire brush and then tried again.
A lot better results but the material is so thin that most of the sheet is eaten completely up before all of it is etched.  Not a good deal.

I had some of that material on hand for making barrels so just dipped one of them.  The heavier material held up much better and etched quickly but I still managed to let it through in a couple of spots. 

I will pick up a couple of roasting pans today and try that material as it will be heavier yet.  If that doesn't work I may just try Russ's paper idea.  That is some nasty chemical solution and I would just as soon not use it very much.

Anyway here is a couple of shots of the barrel I dipped, the first one is just out of the dip and scrubbed off.  The second shot shows a little of the Bragdon Powders smeared on.


Title: Re: I've Been Misled
Post by: chester on August 28, 2010, 10:33:01 PM
Lovely look to the barrel and so quick and easy.
I've always found aluminum dipped in Ferric Chloride worked very fast in a violent reaction. Much too quick for controlled results. I switched to a much less powerful mixture of muriatic acid (70%) and hydrogen peroxide (30%).
   My guess is the same as everyone else on the can material coating. Try using the aluminum seal that comes on food product containers like peanuts and coffee (two major food groups).

Title: Re: I've Been Misled
Post by: NORCALLOGGER on August 29, 2010, 05:41:26 PM
Well, a little success today.
I picked up a couple of disposable aluminum cookie sheets at the grocery store yesterday and gave that material a try this morning. 

I only need 9 pieces for the shovel roof but the pans gave me about 40 pieces total so I cut them all up just to be sure and have enough.

The first thing I learned, just as Chester pointed out, there is a violent chemical reaction with the clean aluminum and it is difficult to control the amount of etching.  I didn't have any trouble with the sheets being eaten up but the color went to a more rusted look then I would really of liked. 

The second thing I learned is that after dipping 10-12 sheets the liquid started turning more to sludge, I assume from the aluminum residue, and I needed to add more etch fluid.

The third thing I learned is that no matter where I stood in relation to the dip bowl the smoke/fumes wanted to come directly towards my face.  Must be some relation to camp fire smoke  :).

The fourth thing I learned is that even though I dipped and rinsed the sheets in clear water after etching I wasn't careful about how I placed some of them to dry before scrubbing.  Where the sheets lapped or overlaid each other it created darkened patterens.  These sheets should work just fine for old building roofing with enough weathering powders on them to hide the distinct lines of the overlaps. 

Well anyway here is a picture of what I ended up with for the Marion Shovel roof.

Thanks for looking

Title: Re: I've Been Misled
Post by: marc_reusser on September 03, 2010, 05:17:03 PM
What you have there looks OK. ..and sorry to jump in a bit late, but a few pointers on the etching.

1. Wear long sleeves, rubber gloves, and a respirator.

2. Do only 1 sheet at a time (as you progress through the sheets the fluid will heat up and the reaction will happen quicker and more violently)

3. Upon pulling the sheet out, immeditely drop it into a jar or bowl filled with water and some dish detergent (this will stop and neutralize any further reaction.)

4. Once you have etched all the sheets and they are floating in the bottom of your soap/water mix bowl, empy the bowl, of liquid and start doing several long repeat rinses of the bowl with the pieces in it with cold water. (leave the pieces floating in a final bowl of clean water)

5. Take a flat bottom tray-like item (I use a white enamel coated artists tray)...take one piece at a time and using a soft slighltly cut-down-bristle toothbrush scrub each side of the metal to remove most of the orangand black oxidation/residue. To do this, hold the metal down flat in the tray with your thumb and fore-finger, dip the brush in some water, and then scrub in the direction of the corrugation...not to hard to flatten the corrucation, but enough to remove the residue and leave you with a nice dull grey, slightly mottled, surface color. When you have done both sides, drop the piece into a a fresh/different bowl/jar of clean water. (removal of this residue will also help in preventing any potential future progressive etching)

6. When all the pieces have been scrubbed and are floating in the clean water bowl...do another thorough water rinse of the bowl/pieces.

7.  Lastly....place each piece seperately on a piece of paper towel to dry (once one side is dry, you will have to flip the piece to get the other to dry).

This is the technique I have been using for years, and I get continuous consistant results.



Title: Re: I've Been Misled
Post by: NORCALLOGGER on September 04, 2010, 02:45:53 PM
Thank you for the SBS on this, just what I needed.  I think I fell down on the rinsing process so ended up with a darker finish than I really wanted.

Will try some more pieces next week.


Title: Re: I've Been Misled
Post by: NORCALLOGGER on September 12, 2010, 04:42:14 PM
Hi guys,
Well I made up another batch today and came out with better results.  Basically I followed Marc's SBS above (thanks Marc) and ended up with the grey color that I was looking for with out the rusted look.

A couple of pictures below.

Title: Re: I've Been Misled
Post by: Malachi Constant on September 12, 2010, 04:57:17 PM
Rick -- New panels look great!

Marc -- Thanks for taking the time to post your notes ... saved for future reference.


Title: Re: I've Been Misled
Post by: MinerFortyNiner on October 26, 2010, 11:53:33 PM
Very interesting, I wish I knew this before vaporizing my share of siding in ferric chloride before figuring out essentially what Marc shared.  I use a slight variation on Marc's technique, I use a baking soda solution to stop the etching action, very effective in shutting down the acid reaction in seconds.

I was a little disappointed that the etchant didn't really give the final finish of rusty roofing I expected...but what it does do is give the material great 'tooth' and a neutral gray which then allows easy weathering with chalks, washes, etc.  Nothing more frustrating than accidentally brushing roofing material with a finger and exposing bright silver.

Here's some etched Sodders roofing material that I then weathered with acrylics and weathering powders: