Since the Epilog laser has a learning curve I have ruined more than my fair share of anodized dog tags in the process :D So the question became "what am I to do with all of these flubs?" I stored them in my box of blanks for a while and used these flubs to try new things and to test settings before I put fresh & clean tags into my jig. It was only a matter of time before I amassed enough flubs to force my hand and clean out my little tackle box. With around 40 tags ready to go, I decided to clean them up and powdercoat them before engraving for a second time.
If you think this instruct able is worth winning a contest, vote for me to win the full-spectrum laser contest!
Made it at Tech Shop, Where dreams are built :D
Step 1: Blast, Clean, Dry, Bake (pi?)
I've got a ton of mistakes in the form of anodized tags that have a variety of mistakes that prevented me from sending them to eager customers around the world. So this is the first step in turning this lost capital into trophies for LevelBF.com's 5v5 defuse tournament on the Xbox one. The guys over at LevelBF asked me if I could make something really special for the tourney winners and while I knew it was possible, I also knew that I would be standing in front of the sandblaster for quite some time.
Step one: turn on your oven to ~400 degrees F (its gonna take a while to get to that temp)
Step two (of step one :D): Blast all of your tags clean of all color, dirt and debris then take them over to the sink and use your favorite type of degreaser to clean off the grit and grime of sandblasting gloves and use compressed air to quickly dry your aluminum tags so no dust lands on your parts. In my case I used Purple Power (Simple Green works well too)
Step 2: Coat, Bake, Examine
Head on over to your local Tech Shop's powder coating room and hang your tags from any metallic wire. I used picture hanging wire bent into a chain link fence type pattern (That pattern helped me shoot the face more easily). For the trophies I decided to use the standard gold, silver, bronze of olympic style medals and black for a "event" tag that would be more universal and available for purchase on our website.
For this job I found that the High setting (250Kv) setting was better. I think it was because I have many more points that projected away from the electrified metal grate but I cant be sure since I never measured the voltage across any points in my setup.
Once shot, go ahead and load them into your pre-heated oven and start the timer as soon as it re-reaches your target temp (ie, target temp is 400 so I set it for 425 and when I load my parts the oven will lose ~40 degrees so you must wait for the oven to reach 400 degrees again before starting the cure timer).
Examine your best tags and identify any tags that dont quite pass muster, they will be useful in dialing in your laser settings since if you were like me, you have no experience engraving powder coated items.
Step 3: Identify the Good, the Bad, and the Ugly
This would be the time for you to identify the best possible tags to be made into trophies. I took mine into the paint booth and examined them under lights that were in the 6500k range (which is the more blue looking bulbs) since it was dark outside.
Any full on rejects should be used only for testing settings on your laser or just thrown back into the sandblaster for a second go-round in the finishing process.
Step 4: Tags Done With Laser Beams!
My local techshop has a Epilog 60w laser for us members to use and all settings discussed here will be of reference to that machine only.
Once I had Identified the best of the best I loaded one of each color into my jig and tried different things out to achieve the best results. You may want to run your own tests but I found that since powder coat is a heat type application process, it was a little tricky when I went to burn off the layer after the fact. After many, many tests I have decided on a 2 pass process that burns very little of the surrounding coating and leaves me with great detail
Pass one: This is when I just want to burn the top layer of the powder off and leave crisp edges that aren't burned or melted looking. I run them at 60% speed and only 30% power in the raster settings of the program as well as focusing the laser about 3/16" ABOVE the tags. I was told that our lasers have a 1/8" focus distance and found out through trial and error that the best detail did not lie in the top or bottom of that focus distance but right in the middle.
Pass two: It is in this pass that I crank the power up and keep the speed the same! Second go-round I program the laser to run at 60% speed (same as before) but I increase the power to 80% (check with your Techshop DC's to get the okay on this one because I did!). After this pass the engraved section will be slightly rough like it just came out of the sandblaster and the edges will be crisp and full of detail!
You can repeat the same process with the cardboard packaging by separating the tag cut-outs and outer ring from the artwork. Run your artwork first at the pass one settings for cardboard (60/15/500hz) then turn off the artwork layer and turn on the tag cut out and the outer ring while you repeat pass two (60/60/500hz) settings. This will result in the artwork remaining on one side of your cardboard and not the other.
Thanks for reading and remember, I did this @ Techshop and SO CAN YOU!