Epoxy fill for aluminum

[rjssigns]

Not sure if this is the right spot. but here goes.

What epoxy or other product do you use to fill in the background on CNC'ed aluminum? I'm trying to duplicate some antique boat badges and they have a black background with polished letters. I'm assuming the original process was cloisonné and their is no budget for that.

I can get the CNC work done I just need an outdoor durable glossy black filler.

 

[artbot]

how deep? depending on the look you have a few options. is the metal polished on the surface or requires polishing? if it requires polishing there will be a lot of black that comes from the polish by leaving this in the crevices, you will get an aged look with dark shadows. like this:
https://www.flickr.com/photos/alldredge/4543893597/in/set-72157627000489887

if you want the "police badge" look, i'd go with a thin coat of gloss oil/enamel based spray paint. then of course you'll need to brush the paint off the high spots and then polish. the paint will take a licking from all the compound. like in the tio right corner: https://www.flickr.com/photos/alldredge/4561675518/in/set-72157626663081411/


filling it with a low viscosity epoxy will be a chore. do you have photos of the cut pieces?

 

[Biker Scout]

Remember that stuff we used to be able to get as kids. There were these cookie cutter metal forms, and we'd take these beads and pour them in, then place the whole thing in the oven. The beads would melt and we'd end up with stained glass looking things that we gave to mom.

 

[Biker Scout]

Found it... they are called "Baking Crystals"

http://www.ebay.com/bhp/baking-crystals

 

[Biker Scout]

I've got this machined aluminum "positive" I made for a company so I could make some silicone molds for their chocolate bars. I may get some of these baking crystals and try it out.

 

[artbot]

it's like powder coat on crack! i'm gonna git me sum!!!!

 

[Biker Scout]

I can see this being a lucrative side business, if you've got clever enough designs and machined work to match!

 

[letterman7]

Yes, but after those crystals cool, will the resulting puddle still stick to the aluminum?

 

[Biker Scout]

When I was a kid the little frames we poured the crystals in was made out of metal. Then they were hung in Windows being exposed to the sun all the time and they never fell out. I'm betting that if they melted down into a mold with a back they'd stick even better.

 

[rjssigns]

Morning guys,

To answer Artbots question the lettering is approximately 0.030" raised from the background.

Biker Scout your idea for the baking crystals is brilliant. Wonder if Hobby Lobby has them...? Also wonder how UV resistant they are although I could use automotive clear over the top.



The pic is what I need to replicate. Mine won't have the sun ray background since I don't think it's necessary.

In case anyone was wondering. I already tried contacting the company that made these way back when. Zero response.

 

[artbot]

also, how big are these to be.

the lack of detail in these gives you quite a bit of options. a super low viscosity epoxy, very retarded and reduced black lacquer would be my options. the baking cystals look cool but would probably need more like .080 or so to create a decent trough.

 

[rjssigns]

also, how big are these to be.

the lack of detail in these gives you quite a bit of options. a super low viscosity epoxy, very retarded and reduced black lacquer would be my options. the baking cystals look cool but would probably need more like .080 or so to create a decent trough.

Size: 2.6" x 1.02" x 0.100". I'm thinking about trying these with 0.125" material to give a bit more fill depth.


Since you are the resident master regarding this style of work what epoxy would you recommend? I like the lacquer idea also, but makes me think about using a single stage automotive finish Like S-W's Genesis polyurethane. Gets super hard once it goes closed cell.

Ideas and decisions...

 

[artbot]

the SW would possibly work. some straight urethanes do not play well on aluminum, some do. you would get better wetting from it than an expoxy. the best wetting would be from a lacquer. in fact, you might just head the hobby store and try the Testors (http://www.walmart.com/ip/32831271?...56832741&wl4=&wl5=pla&wl6=63495709741&veh=sem) gloss black. the wetting will be the issue in the end. will it pour and fill the cracks and not climb? thicker aluminum would definitely be better. will it be basic mill or some kind of specialty prepolished?

 

[rjssigns]

Probably use whatever is laying around for testing purposes. If it turns out well then I will polish some sheet stock before milling.

Good tip on the Testors model paint. Didn't know that some urethanes have issues bonding with aluminum, but then again you know way more about it than me.