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Matt Williams 407
04-11-2016, 11:18 AM
Hello, I'm hoping somebody can provide some pictures showing the proper thickness of cermark on metal. I've spent days reading about it on here and other forums and know that since I'm using a glass tube chinese machine I have to deviate from the normal settings and do some power grids, but I would really like to see what it looks like properly applied since I think we've probably been putting it on to thick from the spray can. We've ordered an airbrush to start using that method, but reading descriptions where people talk about the consistency of milk and being able to see the metal through the coating aren't helping us. If someone could post some pictures or a video of how it should look before lasering I would greatly appreciate it.

The machine we're using has a 100 watt glass tube and the speed maxes out at 400 mm/s or 16 ips. We're mainly using this for stainless Yeti Ramblers on a rotor.

Thanks for any help you can give.

Dave Gates
04-11-2016, 11:59 AM
Here's a video from JDS showing the application from the spray can on a flask. https://youtu.be/PVscWOHZ1bQ

We do a bunch of the Yeti style cups and its just a light coating that works for us. If it is not turning out very good, you should probably adjust your laser settings.

Kev Williams
04-11-2016, 2:30 PM
about 1/4 of my gross income is via Cermark...

I've used a lot of spray-can Cermark, no negative results except to the pocketbook. It IS spendy that way...

I've tried the 'the metal almost shows thru' version and when I'm done, metal shows thru. Light coat, yes, but if I see even a HINT of light shining off metal showing thru, I add more Cermark.

I airbrushed the stuff for several years, until I finally broke down and listened to Mike Null and tried a foam brush. Fantastic way to put down Cermark, especially over large areas.

For smaller areas I find the absolute cheapest artist paint brushes you can find, the type with cheap looking, loose bristles. They absorb way more Cermark than nice, tight bristle brushes, and more in the brush means a lot more gets laid down on your work before loading up the brush.

And while airbrushing saves a LOT of Cermark vs their spray cans, I can attest that I use half as much Cermark brushing it on vs airbrushing it on. It's easy to figure this out when covering 80% of a 24" x 31" stainless operator panel. I would use about 1-3/4 airbrush bottles full to spray these panels, I can brush the same panel with less than a full bottle. I haven't touched my airbrush in over a year now.

As for thinning, if you buy the 250g or larger jars of 6000, start with 6 parts of denatured alcohol to 1 part of Cermark. This is pretty close. My mix is best described as somewhere around chocolate milk. When just right, a crappy paint brush will lay down a swath with streaks, which will flow together within a few seconds. If the streaks don't flow together, it's too thick. If it runs freely beyond the edges of the original swath, it's too thin...

The main problem I have with Cermark is keeping the mix just right. Just while applying it, if taking more than a couple of minutes the alky will evaporate out of the container I have it in (like 2oz fry sauce cups), and I have to keep adding alky to thin it. I keep alky in needle-point jars, easy to dispense small amounts. The smalll containers to brush from don't seal all that well either. I keep my pre-mix in old Cermark jars, those DO work well for storage.

Ross Moshinsky
04-11-2016, 3:21 PM
The spray can is awful. It's wasteful and difficult to control and goes bad relatively quickly. You're MUCH better off with buying the bottle, thinning it yourself, and applying with a foam brush. We go pretty thin and find that the thinner the coat, the better. I personally try to use a brush as large as my engraving. So if I'm engraving something 2" x 6", I try to use a 2-2.5" foam brush. The reason is when you do a small overlap, it gets a little thicker at that spot and can result in some inconsistencies.

One last thing, you simply have to ignore the settings provided by Cermark. Your laser is slow. Cermark assumes 100% speed is about 80ips. So when they say run at 100% and 100% speed (for 100w laser) they are saying run at 100W and 80ips. Seeing as your max is 16ips, you should actually run theoretically at 16ips @ 20W. I'm not even sure your laser will really work at 20W so be careful. Also remember, these are theoretical numbers. I'd likely bump the power to 25-30W.

Mike Null
04-11-2016, 5:25 PM
I have an ongoing job that requires a foam brush and I use foam for most one offs. But I actually prefer the airbrush if it works for the job. For example, 100 or more ss tags that I can set up side by side and spray. When $5 below has the foam brushes I load up with 4 or 5 dozen which will last me a year or more.

Bruce Volden
04-11-2016, 5:31 PM
I also am in the foam brush category (it's all I've ever used).
I apply it very thinly, almost see through.
My 25W LMI's would run @ 15 speed / 90 power 300 dpi.
The TT was somewhat faster.
The DNA will eat a foam brush pretty quickly but, immediate rinsing in H2O would pull off a couple more jobs!
I could make several hundred $ on a $.85 foam brush (providing lotsa knives/swords to be engraved). HTH

Bruce

Matt Williams 407
04-12-2016, 12:33 PM
Thanks for the tips so far everyone. I did some power grids on a 30 oz Yeti at max speed and varying the power. One of them was run with the scan gap (since we don't have DPI settings) at .05mm and the second at .025mm. This was applied with the spray can but thinner than we had been. Our airbrush parts were delivered today, and we also picked up some foam brushes to try. http://i.imgur.com/WCjHDBW.jpg

I'll definitely be running more grids to try to narrow down the largest scan gap and associated power setting we can use and still get a good mark since that drastically increased the length of the job.

Tom Evans Milw
04-14-2016, 6:43 PM
Wow. First time back for awhile, and immediately again you solve my question. I had been using spray and will order the jars and foam brush.

Thanks again.

Mark Sipes
04-14-2016, 7:30 PM
I've found if you heat the can up first...in . Boiling water to raise the temp of the can and cermark the spray is finer and lasts longer.. And no the can will not explode! 5 years and never a mishap, If the bottom of the can pops then you have really gone to far. 5 Cans a years is my average.


Heat the water in a microwave to boiling. immerse can in water. Shake and re-immerse until the can is very warm. Also keeps the nozzle from clogging.


Mark

Robert Tepper
04-17-2016, 1:18 AM
I apply a full coat with a brush, run at 100%, that is 80 watts for me and a speed of about 10%.

Don't do a tremendous amount of stainless but I have had good results.

Best of luck,
Robert

Hannu Rinne
04-23-2016, 6:39 PM
I found this brush from my wife makeup bag. I thinked it would be a good try to see how it works with a Thermark. Seemed to be a very good catch.. because it's so soft you can get a very smooth layer with it and it will also hold a lot of liquid inside. A4 size work will be easily brushed with a one fill. The only bad thing was my wife reaction after she noticed her brush was stolen :D:D:D (but my use for the brush is a lot of better comparing to the use where it is ment to be :p)

Bill George
04-23-2016, 7:32 PM
What is the going rate for a Yeti cup? I had a customer ask and I priced it at $10 for the first one, just one side or area and then $6 each for any more of the same pattern. In my spare time I am working on a liquid powder coating process, where you mix a liquid with standard powder coating powder and then laser it. My initial test on a piece of aluminum turned out ok, just like Thermark.

Bert Kemp
04-23-2016, 9:50 PM
Bill would you care elaborate on this method, what liquid what ratio

Brian Lamb
04-23-2016, 10:29 PM
I'd like to know about the powder coat paint also... I had actually been thinking about using laser toner from a laser printer and see how well it would fuse/adhere.

Bill George
04-24-2016, 8:39 AM
Its a product called, well I will post a picture. Special liquid you mix 50-50 or so with powder coating powder like from Harbor Freight or better suppliers. Mix in a blender and either spray on or other, let dry and then you put in a standard oven or powder coating oven and heat. When I used to do the dry powder coating it was around 400 degrees but the laser will fuse it to metal. Not bonded ceramic like Cermark or Thermark but powder coating. I have not really have time to experiment with much. The liquid was around $30-$35 or so shipped. I purchased a glass beaker blender used at a thrift store for $10. Spraying I have not tried yet.

Been pretty busy and then trying to do my rotary project, but the stuff does work. YMMV.

Going to add 3 pictures of some trials I did this afternoon. Put the mixture on with a foam brush rather thick and set out in sun to dry. I have a pretty strong 50 watt laser, this final piece was done at 100% power and 2% speed.
First picture out of machine and wiped clean, second wiped with DNA and a rag #3 I used some ultra fine steel wood medium pressure about 20 swipes



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