Aluminum surface finish from needle scaler

[Dan Dubeau]

Got finished needle scaling my mower deck for some repairs, and thought I'd play around with a block of aluminum before I put it away. I'd done this a long time ago on a machined case cover protector I made for a motorcycle, but always wanted to play around with it again and experiment more. This block is 6061-T6, and it didn't take long to create this finish. The pics in the vise are as scaled, and the one on the table is after a wire wheel treatment at the bench grinder. Wire wheel kind smeared it down a bit and took the high spots off.





Not quite a sand cast finish, but something unique and different. Princess auto has needles for $5, so next time I'm there I'll pick up some spares to play around with various end treatments on the rods. Maybe Try radiusing them, or bringing to more of a point? There's a couple projects in the queue that I want to make a bit more cosmetically appealing than my standard green scotchbright rubown, so I want to play around with some different surface treatments. If I ever get through the "fixing broken shit" projects....

 

[DavidR8]

It looks reminiscent of hammered finish, very cool.

 

[ChazzC]

Looks like heavily rusted steel that has been stripped then polished.

 

[Dan Dubeau]

After sitting in a forklift safety training class (theory and regs) for 7 hours today, and traffic on the way home I couldn't wait to play around a bit when I finally got here......

My needle scaler is just a princess auto cheapy. I stopped on the way home tonight to see if I could pick up some replacement needles (they're only $4.99) but no stores have them in stock. Online only. Oh well....



I busted it open and started reshaping the tips with a roloc wheel. First was pointed roughly 60*.

Same offcuts of Al. A bit different. Most off the tips flattened out....nice metallurgy

.....


Next, I rounded those same tips off to a nice small radius. Not really much change, but I thought it looks a bit more like rough cast aluminum, so I held up a pretty rough casting I did, and it's even rougher than that.....



Lastly I gave them a nice big radius.



IMO this one was the nicest, and closer to something I was looking for. I held my hand loosely around the needles so I could control them a bit better for all tests, otherwise they're pretty unruly. I wasn't pressing very hard in any of these tests, just heavy enough to activate the tool.

Finally I hit them a scotchbright wheel, and a wire wheel to see how that affected them. Scotch on left, wire on right, untouched in middle. pointed


Large radius, same as above (small radius looks identical to pointed really). I like this one the best, the way it catches light from different angles is very nice. Very tough to photgraph though.



So concludes the "test" for now. I want to play around a bit on some mild steel, and copper too. If I can get that same finish on some brass and copper fishing lures, I'd be a very happy (and well fed guy). More to come.....eventually....

Another traffic driving thought, was to anodize them, but sand off the top layer. I wonder what that would look like.....Could try painting one i guess....

 

[Susquatch]

Another traffic driving thought, was to anodize them, but sand off the top layer. I wonder what that would look like.....Could try painting one i guess....

Pretty cool stuff Dan!

I think painting would sow the effect especially with metallic paint the same colour as the anodizing.

Other colours might look even better!

Hard to justify anodizing strictly for appearance with no durability function.

 

[Stuart Samuel]

Hilarious. I did exactly the same thing at work a few months ago.

We provide a cast aluminum table base for an interior design company (we order the castings and finish them, resin top cast by someone else). The original intent was to highlight the sandcast texture. Well, somebody forgot to tell the foundry on the last batch, because they meandered all over the surface with a 60 grit disc.



What’s a guy to do? Supposed to be textured…

Needle scaler to the rescue! Reshaped all the tips on the belt sander, and went to town. Pretty happy with the result. Quick glass bead to give it a bit of a sheen.

 

[toglhot]

Random orbital sanders give a very nice finish on aluminium.

 

[wmetfab]

Great thread!

 

[Dan Dubeau]

Hilarious. I did exactly the same thing at work a few months ago.

We provide a cast aluminum table base for an interior design company (we order the castings and finish them, resin top cast by someone else). The original intent was to highlight the sandcast texture. Well, somebody forgot to tell the foundry on the last batch, because they meandered all over the surface with a 60 grit disc.



What’s a guy to do? Supposed to be textured…

Needle scaler to the rescue! Reshaped all the tips on the belt sander, and went to town. Pretty happy with the result. Quick glass bead to give it a bit of a sheen.

That looks great!. Much more of a sand cast appearance than my attempts. What shape tips did you settle on for that?

 

[Stuart Samuel]

They were just shaped on the sander with, say, an 80 grit belt. Started out with a radius, then decided a bit of variation would be better.

 

[Stuart Samuel]

 

[Stuart Samuel]

Honestly, other than the smooth spaces between punch marks, the biggest giveaway for me is that the texture is all indentation, with no ‘outies’.