Coloring Aluminum Engraving?

I am making prototypes of a new product. The case is made of aluminum plate , approximately 4" x 1" x 3/16". I have engraved a test piece and it worked very well, but:

  • Due to the complexity and fine detail of the engraving, I can only go to

  • Doing this on bare aluminum, it has all the detail, but very little contr ast. I would like to color either the whole piece and then etch through to bare aluminum OR color the design after engraving.

  • All I have read about coloring after engraving recommends a minimum depth of .005", preferably .010 - .012". That would not work well for this desig n. I tried rubbing in some acrylic paint, waiting for tit to dry and rubbin g it off, but it also removed most of the paint from the design. I also tri ed squeegeeing off the paint, with similar results.

  • I'm not even sure that black anodizing beforehand would work, as (I think ) the anodize layer is thicker than I am engraving.

So, I started looking at other coloring methods for aluminum. The one that keeps coming up is Birchwood Casey Aluminum Black Metal Finish https://goo. gl/zfC1eo . The reviews are mixed for this. Some say it's great, others say it comes out blotchy and still others say it barely colors the metal. Brow nells also sells it.

I'm thinking that I could either color the entire piece and engrave through it OR spray a coat of paint on the whole piece, engrave through the paint and then use the Birchwood stuff (or something else) to color the logo, and then strip off the paint.

I welcome any suggestions and experiences.

BTW, I'm doing this with a newly acquired Taig cnc mill. Very cool, fits my needs well. From this engraving test, I see no reason why it won't work fi ne for making prototype pc boards. Sp many toys, so little time.

JPB

Reply to
rangerssuck
Loading thread data ...

te, approximately 4" x 1" x 3/16". I have engraved a test piece and it work ed very well, but:

trast. I would like to color either the whole piece and then etch through t o bare aluminum OR color the design after engraving.

th of .005", preferably .010 - .012". That would not work well for this des ign. I tried rubbing in some acrylic paint, waiting for tit to dry and rubb ing it off, but it also removed most of the paint from the design. I also t ried squeegeeing off the paint, with similar results.

nk) the anodize layer is thicker than I am engraving.

t keeps coming up is Birchwood Casey Aluminum Black Metal Finish https://go o.gl/zfC1eo . The reviews are mixed for this. Some say it's great, others s ay it comes out blotchy and still others say it barely colors the metal. Br ownells also sells it.

gh it OR spray a coat of paint on the whole piece, engrave through the pain t and then use the Birchwood stuff (or something else) to color the logo, a nd then strip off the paint.

my needs well. From this engraving test, I see no reason why it won't work fine for making prototype pc boards. Sp many toys, so little time.

Regarding the reviews on the Birchwood stuff, different grades of aluminum respond very differently to anodizing and chemical treatments. That could b e the issue.

Reply to
edhuntress2

I'll leave the colorizing to others. I am curious though as decent colorizing of aluminum could be very handy for me as well.

However, that last bit got my attention. I started in CNC maching with a Taig 2019CR-ER about ten years ago. I still have it although its sitting on a shelf waiting its turn as a weekend project to put it back together and make it better. My relationship with that Taig was like a marriage. Carressing to get better performance. Screaming in frustration. And ultimately an acceptance of what it is and is not. LOL.

So did you get the older design with the 20TPI V-groove leads or the one that just came out with the factory ballscrews. Either way you should join the Taig Owners Club forum. Not a huge amount of traffic. Only a couple posts per day, but all Taig all the time. I can tell you that within its capabilities its a great machine. Mine paid for Christmas a couple times with its work during the recession we are starting to recover from, and it also paid for my KMB1 and its retrofit along with my first CNC Router and another small CNC mill. At one point I considered buying several Taigs and lining them up side by side, but to be honest if I pushed them as hard as I did my first one I'd have spent all my spare time adjusting them to keep them in spec.

FYI: If your control will run udner Mach 4 it might be worth going that way because Mach 4 has built in part serialization capabilities. (I am told)

Reply to
Bob La Londe

late, approximately 4" x 1" x 3/16". I have engraved a test piece and it wo rked very well, but:

ontrast. I would like to color either the whole piece and then etch through to bare aluminum OR color the design after engraving.

epth of .005", preferably .010 - .012". That would not work well for this d esign. I tried rubbing in some acrylic paint, waiting for tit to dry and ru bbing it off, but it also removed most of the paint from the design. I also tried squeegeeing off the paint, with similar results.

hink) the anodize layer is thicker than I am engraving.

hat keeps coming up is Birchwood Casey Aluminum Black Metal Finish https:// goo.gl/zfC1eo . The reviews are mixed for this. Some say it's great, others say it comes out blotchy and still others say it barely colors the metal. Brownells also sells it.

ough it OR spray a coat of paint on the whole piece, engrave through the pa int and then use the Birchwood stuff (or something else) to color the logo, and then strip off the paint.

s my needs well. From this engraving test, I see no reason why it won't wor k fine for making prototype pc boards. Sp many toys, so little time.

m respond very differently to anodizing and chemical treatments. That could be the issue.

The plate I have (left over from another job) is 6061.

Right now, I'm trying a different approach. I flooded the area with india i

sanding it off with 600 grit paper on a flat plate. I just took a peek in t he oven, and it looks very nice, the ink has flattened out, and the recesse d pattern is quite visible. I'll takeit out and let it cool in a few minute s.

I have to say, by the way, that SWMBO is taking this extremely well - suppl ying both the ink and the oven.

Reply to
rangerssuck

I got the leadscrew model, as the ballscrews are a LOT more money. I haven' t spent very much time with the machine yet - it's only been set up for a c ouple of days - but it seems like it will do almost everything I need. Also , the leadscrews allow the option of manual operation, which doesn't work v ery well with ballscrews.

From what I have read, the X, Y & Z nuts are adjustable to remove backlash, and I also have had luck (on the clapped out cross slide of my old Logan) adding a thrust bearing behind the collar and adjusting for zero backlash t hat way.

As it is, there doesn't appear to be much backlash, and what little there i s can be compensated in Mach3 (I will look into mach4).

Thanks for the pointer to the forum. I have just signed up (user 1.21gigawa tts).

Reply to
rangerssuck

ote:

plate, approximately 4" x 1" x 3/16". I have engraved a test piece and it worked very well, but:

contrast. I would like to color either the whole piece and then etch throu gh to bare aluminum OR color the design after engraving.

depth of .005", preferably .010 - .012". That would not work well for this design. I tried rubbing in some acrylic paint, waiting for tit to dry and rubbing it off, but it also removed most of the paint from the design. I al so tried squeegeeing off the paint, with similar results.

think) the anodize layer is thicker than I am engraving.

that keeps coming up is Birchwood Casey Aluminum Black Metal Finish https: //goo.gl/zfC1eo . The reviews are mixed for this. Some say it's great, othe rs say it comes out blotchy and still others say it barely colors the metal . Brownells also sells it.

hrough it OR spray a coat of paint on the whole piece, engrave through the paint and then use the Birchwood stuff (or something else) to color the log o, and then strip off the paint.

its my needs well. From this engraving test, I see no reason why it won't w ork fine for making prototype pc boards. Sp many toys, so little time.

num respond very differently to anodizing and chemical treatments. That cou ld be the issue.

y sanding it off with 600 grit paper on a flat plate. I just took a peek in the oven, and it looks very nice, the ink has flattened out, and the reces sed pattern is quite visible. I'll takeit out and let it cool in a few minu tes.

plying both the ink and the oven.

You're lucky. Years ago I made a bunch of simple tool boxes for my basement shelves (maybe 30 of them) our of some old, badly cupped sugar pine that I bought for $10 for a van load at a local lumberyard, thinking I could easi ly flatten them. Using C-clamps and wooden cauls, I sprung them flat -- hea ting them in our kitchen oven and cranking the C-clamps closed a little bit every 10 minutes or so, for maybe an hour for each batch.

I'd do this while my wife was at work, of course, but she'd come home to th e house smelling like I'd been burning pine on the kitchen floor. This did not go over well...

Reply to
edhuntress2

The plate I have (left over from another job) is 6061.

Right now, I'm trying a different approach. I flooded the area with india

sanding it off with 600 grit paper on a flat plate. I just took a peek in the oven, and it looks very nice, the ink has flattened out, and the recessed pattern is quite visible. I'll takeit out and let it cool in a few minutes.

I have to say, by the way, that SWMBO is taking this extremely well - supplying both the ink and the oven. =====================================================================================================

No direct experience, sorry, but a suggestion. Have you thought about silk screening instead of engraving? It is easy and pretty cheap to do at the one or a few level, and the paint is pretty durable. An old co-worker used to silk screen all the front panels of his prototype electronics projects, and watching him it seemed pretty simple. Also, maybe the paint itself would work better than india ink to fill your engraving, then bake and sand. Just a thought.

----- Regards, Carl Ijames

Reply to
Carl Ijames

I've used a fine tip felt marker to fill similar grooves. It kind of depends on how much you have to do and how permanent it has to be.

Paint pens work too but usually they have a pretty fat tip...

Reply to
Leon Fisk

Try asking in the TekScopes group on Yahoo. Back in the day, TEK had a process for making front panels. Don't know how it worked, but they printed colors on aluminum then somehow sealed it. Maybe someone on Yahoo remembers.

Reply to
mike

try

========================= ========================= ========================= ==

I've done screen printing with epoxy ink on control panels. It worked great and it's tough as nails. Talk to the people at the metal plating/anodizing shop. Maybe they can come up with some ideas.

Reply to
gray_wolf

Wow that is hardly engraving. What are you using to engrave with ? Is it a rotary diamond ? What speed - are you scratching it ? or laser ? or rotary.

Some is etched.

I see the Taig CNC mill - Hope you have a diamond. They cut nicely and can be deeper if wanted.

Mart> I am making prototypes of a new product. The case is made of aluminum plate, approximately 4" x 1" x 3/16". I have engraved a test piece and it worked very well, but:

Reply to
Martin Eastburn

te, approximately 4" x 1" x 3/16". I have engraved a test piece and it work ed very well, but:

Two ideas:

1 anodize color on the whole piece, and then laser-etch your design. 2 etch, then pour dragon's blood (this is a resin available in micro-bead s) over it, and tilt to allow all the resin not trapped to escape. Bake (this will fil l the etched surface with the resin). Now, anodize normally, with whatever color additi ve you like. Finally, dissolve away the dragon's blood.
Reply to
whit3rd

late, approximately 4" x 1" x 3/16". I have engraved a test piece and it wo rked very well, but:

ontrast. I would like to color either the whole piece and then etch through to bare aluminum OR color the design after engraving.

epth of .005", preferably .010 - .012". That would not work well for this d esign. I tried rubbing in some acrylic paint, waiting for tit to dry and ru bbing it off, but it also removed most of the paint from the design. I also tried squeegeeing off the paint, with similar results.

hink) the anodize layer is thicker than I am engraving.

hat keeps coming up is Birchwood Casey Aluminum Black Metal Finish https:// goo.gl/zfC1eo . The reviews are mixed for this. Some say it's great, others say it comes out blotchy and still others say it barely colors the metal. Brownells also sells it.

ough it OR spray a coat of paint on the whole piece, engrave through the pa int and then use the Birchwood stuff (or something else) to color the logo, and then strip off the paint.

s my needs well. From this engraving test, I see no reason why it won't wor k fine for making prototype pc boards. Sp many toys, so little time.

Reply to
rangerssuck

late, approximately 4" x 1" x 3/16". I have engraved a test piece and it wo rked very well, but:

ads) over it,

ill the etched

tive you like.

Dragon's blood, huh? According to Wikipedia, it's good for everything from violin finishes to voodoo. Sorta like a Swiss army knife. I will be checkin g this out.

But for proto purposes, this is a whole lot of steps, including a trip to a plating shop, which I'm hoping to avoid.

Reply to
rangerssuck

te, approximately 4" x 1" x 3/16". I have engraved a test piece and it work ed very well, but:

trast. I would like to color either the whole piece and then etch through t o bare aluminum OR color the design after engraving.

th of .005", preferably .010 - .012". That would not work well for this des ign. I tried rubbing in some acrylic paint, waiting for tit to dry and rubb ing it off, but it also removed most of the paint from the design. I also t ried squeegeeing off the paint, with similar results.

nk) the anodize layer is thicker than I am engraving.

t keeps coming up is Birchwood Casey Aluminum Black Metal Finish https://go o.gl/zfC1eo . The reviews are mixed for this. Some say it's great, others s ay it comes out blotchy and still others say it barely colors the metal. Br ownells also sells it.

gh it OR spray a coat of paint on the whole piece, engrave through the pain t and then use the Birchwood stuff (or something else) to color the logo, a nd then strip off the paint.

my needs well. From this engraving test, I see no reason why it won't work fine for making prototype pc boards. Sp many toys, so little time.

Thanks all for the suggestions. What I'm going to try next, having done som e more trial and error, is the Birchwood Casey Aluminum Black Metal Finish

formatting link
. I ordered from Amazon and if UPS doesn't lose it, i t should be here today.

If that doesn't work well, I think I'll probably simplify the design to all ow deeper engraving. If I can get to 2 or three thousandths deep, I think I 'll have better results with some of the paint filling techniques.

Reply to
rangerssuck

.003 Shows up pretty good. .005-006 looks like petroglyphs hammered out with a rock. Most customers like .005-.006 for logos inside molds etc. Makes it nicely readable on the molded object.

Reply to
Bob La Londe

I'm glad for the half D carbide. That should fly through Al easily. I used them on copper and fiberglass on a cnc PCB design machine. I have a manual engraver that turns fast that uses D's and HSS and Diamond to engrave plastic, brass, bronze, and glass. Don't like glass... :-)

Mart>

Reply to
Martin Eastburn

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.