How To Put A Satin Finish On New Large Dials?

The caustic etching should be preceded with a thorough washing to prevent any hand oils or contamination. The lye will of course, dissolve any oils, but that delays the actual etch time start. Rinse well, handle with non powder coated surgical gloves. Post etch, rinse well, and neutralize with baking soda solution and rinse well again. Warm air dry and clear coat immediately.

If you intend to fill the engraving, use something like a Lacquer-Stik. Brownell's has only one color listed, but there are numerous colors available. The etched surface will allow the filler to adhere well, but if you use lacquer, make sure whatever you overcoat with won't lift it. Like no clear lacquer over a Lacquer-Stik. Enamel uses a much cooler solvent carrier and won't generally dissolve the lacquer.

http://www.markal.com/solid-paint-markers/lacquer-stik/


http://www.engraverssolutions.com/PDFs/tips&tricks-color_filling.pdf
 
Tony Wells said:
neutralize with baking soda solution and rinse well again.
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But isn't caustic soda already alkaline?
Surely rinsing in Baking Soda is to neutralize acid and wouldn't have any better effect than rinsing in water at neutralizing caustic.
 
You're right. I was thinking upside down on pH. Baking soda is about 9, so yes, it's still basic. Best bet would be to rinse with copious amounts of water, then rinse with weak acetic acid (vinegar), then more water, preferably distilled or deionized.

Sorry about that. Funny how a few years away from doing something even every day things slip from the mind.
 
I make emblems for hot rods and other things. When finishing aluminum to a satin finish I use a random orbital sander with either 3000 or 5000 grit paper. That leaves a very nice satin finish. For a more burnished finish I use coarser sand paper (1000 to 2500 grit) and an concentric orbital sander for swirls or a sanding block for a horizontal (or vertical) finish. I usually powder coat with a satin clear to keep the aluminum from oxidizing but that is not necessary for the finish (don't use gloss clear!)
 
Bradrock said:
What is your setup for scribing the lines? Is your project already posted here? I'd like large dials for my SB 405 9"er

Thanks, Brad
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Brad, I took videos, but haven't edited them yet. I suck on video. Here's some pics of the setup. Still have to use the lye. Will test before I do, to make sure my lines are still visible. http://imgur.com/a/bpq3M

BTW see Mr Pete 222 on youtube for a great video on how to make this.

 
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my results of using lye, were mixed, my test piece had promise. It didn't remove the paint on the markings. but I had a lot of sludge and mottled appearance that came off with a good wiping.
My dial the paint came off, the finish was mottled.. I had washed the pieces before I started. I was not looking for a heavy satin look. I got to the goal, but didn't appreciate the mottled appearance. I picked up crystal drano as my source of lye. Anyone care to comment on the mottled look? They looked like dark spots, similar to a winshield that hasn't been cleaned after a rain.
 
The type of aluminum can affect the consistency, as can the temperature of the etching solution. Don't suppose you have a magnetic stir plate? Moving the solution will help. And the part must be absolutely clean.

Make sure the lye you are using is 100%. No inert ingredients. Cooler solution will slow down the reaction and afford more control and give you time to remove the piece and give it a good stir. That may help too. If you suspend the part in the solution, best to use a non-reactive material. SS wire, Nylon or Polyester fishing line.....something like that. If you can't keep the solution moving, keep the part moving. If you have a fairly strong solution, this action may only take a minute or two.
 
so the Drano may have been the probem, I kept the solution moving regularly, by swirling it about. I used cold water, but the whole thing got hot over time. The aluminum was hot too. 6061 Al is what I was using. I had cleaned the part first using soap and water, because I had already painted it, I could not acetone drop it again.

I'll have to order lye online, as I can't find anything but Drano.
 
Drain cleaners tend to have Aluminium powder (and other things) in them already to react with the caustic soda when water is added. The vigorous reaction helps to remove the drain blockage.
You want to use straight caustic soda.
 
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