How do I get matte blackening on aluminum parts

upTheHill said:
I use this
http://www.lauerweaponry.com/index.cfm?fuseaction=category.display&category_id=794

put the part in a bead blaster using glass beads, clean clean clean
HVLP sprayer, using less harddener for a more matte finish, more hardener for a gloss finish.
and bake in a toaster oven at 250 for 15 minutes,
letting it cure for another week will give a really durable finish.
the duracoat goes on very thin.
Click to expand...

You've got most of that right, except for the part about bead blasting with glass beads. LCW recommends using Aluminum Oxide 120 grit, though I have used 70 grit and it works just as well. The glass beads are great to prep aluminum parts before anodizing, but do not provide the 'toothiness' for proper adhesion of Duracoat. I'm sure it's better than no blasting, but the catalog that ships with the product says specifically not to use bead blasting. I wish they would put that in the FAQ on the site, because all it says there is "...with the proper blast media". Why not just come right out and say "... with 120 grit Aluminum Oxide."?

I never bake my Duracoat, though I might put it in the attic for a few weeks. Duraheat needs to be baked, but not Duracoat. Check the FAQ here for what needs to be done:

http://www.lauerweaponry.com/index.cfm?fuseaction=page.display&page_id=22


Good luck

Tex
 
Hi purplev,

The anodizing process I am doing does not use sulfuric acid but sodium bisulfate which is nothing but ph decreaser for your swimming pool.
There are varying opinions on this process but a lot, like myself, have had great success.
Sodium bisulfate is the type of chemical that can be poured on the ground and it will break down. I am not suggesting this but the government does not consider it as dangerous as sulfuric acid.
Based on time of anodizing the surface can be built up to whatever suits. I have had great success creating flat/matte finishes to gloss finishes.
My total investment would have been much lower if I would have gone to bargain stores for hot plates and pans. The aluminum for anode and cathode connections, distilled water, dye and the acid are really the main expenses.
One thing I use in my process for the prep process is a "metal brightner/etch" which isn't nessacary if it is a new machined part. All you really need to do is clean it good with a degreaser like dish soap.
I am no expert, not by a long shot....trust me. :))
If you haven't see my post "my latest anodizing" or the staff may be making it an article soon.
I hope I gace you some food for thought but on the other hand I may have confused it, I do that. :nuts:

Have a great day!

Ed
 
eac67gt said:
Hi purplev,

The anodizing process I am doing does not use sulfuric acid but sodium bisulfate which is nothing but ph decreaser for your swimming pool.
...
If you haven't see my post "my latest anodizing" or the staff may be making it an article soon.
I hope I gace you some food for thought but on the other hand I may have confused it, I do that. :nuts:

Have a great day!

Ed
Click to expand...

Ed, thanks for posting. I've noticed your other post yesterday and marked it for later reading as this might be more doable in my scale for what I want to do. :)
 
txgunslinger77 said:
Duraheat needs to be baked, but not Duracoat.
Click to expand...

Now I need to correct myself - turns out there are two products for high heat applications: Durabake and Duraheat. Duraheat air cures in 24 hours whereas the Durabake obviously needs an external high heat source to cure. Sorry about that.

Tex
 
Last edited by a moderator:
Thanks for the correction. good to know there are 2 different products there.
 
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