Help w/Protective Coating, Brass, and CerMark

[Tracey Bakewell]

I just received my first order of Brass and am thinking I made a mistake. I've read through just about every Brass problem engraving thread on this site. I've run this darn thing through the same pattern about 5 times now. First, thinking optimistically, put Cermark on, ran the job, everything just washed right off. Then I noticed on my invoice "w/protective masking", so I ran it through again, again, and again, upping the power and slowing the speed each time. Until I got to 100% power and 25% speed (I'm scarde to go slower?). Once I did that, finally put Cermark on, ran again, still washes right off?

Got this from ID Plates out of texas... www.idplates.com, their item #9045-1, this is how it's listed on their website...

Double Sided Brass
Satin Gold finish with protective masking on both sides. Suitable for sublimation., Satin Gold .040 gauge

Am I still up against the protective coating? How many more times do I need to go over this darn thing until I can use the Cermark and get a nice black finish that does not wash off? I also bought a sheet of bright nickel silver (same problem) and just decided to stick with the brass. Once I figure that out, I'll move back to the silver.

I've checked out the Alumamark products, the only problem is they don't seem to come in a .050 gauge, something heavier duty than .020? These are for horses and need to be pretty tough and heavy duty.

Any ideas on how I can use these sheets of brass? They were fairly pricy!

[Rodne Gold]

If a plate is suitable for sublimating , it will have a laquer type coating on it , a polymer that will absorb the inks.
It will however be totally unuitable for laser engraving cos of this coating. You might be able to get it off with a solvent.
However I would NOT cerdec brass anyway as you need to be down to bare metal to do it , it will mark , but then the problems start cos the unmarked sections will tarnish and if cleaned with brasso or the like , the markings will come off.
You can cerdec and then spray a clear laquer over the brass , but all this will do is delay the tarnish and in fact might make it look worse in time as it tarnishes under the laquer or where the laquer is scratched.
If you do want to cerdec this stuff , try thinners and / or acetone to remove the sublimation coating.

[Tracey Bakewell]

Bummer, anyone want to buy a discounted sheet of Double Sided Brass? I can't do anything with it at this point then???

Am I going to experience the same problem then with theBright NIckel Silver? It had a peel off protective layer, that I pulled off. I haven't run it through more than once yet.

[Joe Pelonio]

It's only going to work on bare metal and most products not sold as laserable are going to have some sort of protective coat. Even the brass should work though, if you engrave through the clear then apply the cermark. I think you were still not running slow enough. On my 45 watt I use 100% power 10% speed.

[Keith Outten]

Tracey,

I have experienced the same problem. I now sandblast everything I intend to engrave with CerMark or TherMark using glass beads in my blast cabinet. This works every time and the engraving will be dark and permanent.

You still have the tarnish problem after engraving to deal with.

.

[Tracey Bakewell]

Ok, I'll slow it down even more then. I'll try more tonight and let everyone know.

So, I'm a little confused on this tarnish issue though??? If the rest of the brass is untouched still with the protective coating, and I'm only removing the protective coating from the exact area I'm lasering, then lasering, and lasering and lasering :) what is left to tarnish? Does the black area (once I get it to stick) eventually turn a different color or come off???

[Rodne Gold]

You will never really remove the coating just lasering , there will always be a residue of sorts resisting the Cerdec . you can use handy andy or a mild detergent abraisive on the playe prior to applying cerdec and re lasering but your re registration has to be spot on.
Brass needs to be etched or engraved via a cutter for best results.
However what you CAN do is use Shiny gold brushed Spectrum lite (I think its a romark product) and laser this and apply it to the brass for a very nice aesthetic look , but a dubious resistance to heavy abuse.
You could also apply a resin coat to the brass and Spectrum , an epoxy bubble (you get kits) and this will be VERY durable as well as look stunning , use the spectrum to cover most of the brass area.
We would supply this rotary engraved , paint filled and uncoated and tell the customer to clean when neccesary with brasso (and then use pledge after to protect and remove the white stuff in the engraved grooves)

[Richard Rumancik]

This might sound too obvious, but are you sure there is no thin plastic film on the plates that you need to peel off first? Sometimes they put .001 film on the metal and it is actually very hard to see it if you didn't know it was there.

[Tracey Bakewell]

Yeah, my husband and I looked this thing over for ever last night looking for some edge to peel off. We even used a paper clip to score the surface to see if we could cause a small tear to show if there was a coating.

[Richard Rumancik]

After looking this over I think Rodne is right. Metal won't absorb the sublimation ink so it is coated first. Even if there was a removable mask on top of that coating you still have to deal with the sublimation coating. Do you have an optical loupe so you can see what has happened after you laser? Good magnification can sometimes tell you a lot.

IF the laser was able to remove the coating, you could use the laser to ablate the coating, apply Cermark, and re-laser. But you would need 100% removal of the sublimation coating AND have a fixture so you could put the plate back in within .001" of the original position. (For small plates .001" isn't that hard but is much more challenging for large sheets.) Requires 2X the laser time or more. I did this on a sample coated with lacquer, and it worked, but I never did any production that way.

But Rodne doesn't think you will be able to laser the sublimation coating off. (I haven't tried that.) So this idea looks doubtful.

I feel for you. I have a few hundred-dollar experiments gone bad . . .

[Bill Cunningham]

It's funny this should come up... I tried something last week, just on a whim..
I had a piece of engravers brass that had being laying around the shop for about 18 years.. Amazingly, the protective paper pealed right off without problem:p
This brass was the stuff I used to make plates from, and engrave them with a diamond point. You could then put some oxidiser on it, and the engraved part would turn black.. I figgured that if I etched the laquer coating off the surface, then it 'should' react to the oxidiser and turn black, which would then give me a thicker plate than I could get with Alumark.. I lasered it at 10% speed, and 100 power 600 dpi, on a 35watt Legend TT ..You could clearly see the etching went right through the laquer coating, and you could read, and feel the text.. I didn't have any oxidiser on hand, I haven't used it for years, but a customer I have in Town did have some, so I dropped the plate off to him over the weekend, and he put the stuff on it Saturday or Sunday..
It did not even touch the surface of the brass, the edge that was cut, turned black, but not where the laser etched off the coating.. This brass was not sublimation brass (sublimation was pretty crude back then), Just ordinary laquer coated engravers brass.. Even with that, I could not get bare metal.. Masking it, and shotblasting would probably work, but thats too much like work to be bothered.. If it wont oxidize, then cermark wont work for sure!! So, Tracey's problem might not be just caused by the the sub coating, because this brass was around long before most sublimation stock was available..

[Rodne Gold]

What we do to chemically etch brass is firstly clean it with a scotchpad , overlay shiny polyester vinyl on it , laser it , blast it with a very fine grit to rid the lasered parts of residue and then spray it with hot ferric chloride. The secret is the blasting.

[Tracey Bakewell]

K, Blasting! My husband will take the ball on that one :)

At least I have some brass around for when I decide to go into sublimation! Not that I know what I would put on brass? Shoot! I'm having serious buyer's remorse !

[Tracey Bakewell]

I think I even forgot to mention, after my several hits with the laser at 100% power 25% speed 1000ppi, and also applied the oxidizer solution, that didn't even turn it black. You can definitely feel a drop on the brass where I've been going over this again and again, the only thing not tried yet is the blasting.

If I could just figure out a good use for this one sheet, I'd feel much better!

[Bill Cunningham]

Most suppliers will send you a material sample for testing 'before' you spend the big bucks..(a little late for that now eh!) :rolleyes: Blasting it off then oxidising, or cermark may then be your best bet.. There are little sand blasters around that are about the size of a airbrush, and don't require a large compressor to operate 3-4 cfm .. This and and a lasered blasting mask may do the trick for you!!

[Tracey Bakewell]

Cool, then maybe a quick trip to Home Depot today for me at lunch! :)

[Bill Cunningham]

I don't know if home depot stocks them!! I have never seen them in their stores here (Canada) anyway.. We have a chain of stores called Princess Auto, That handles all kinds of sandblasting and farm supplies, surplus and buckets of 'junque' :D You may have something similar there.. Check the yellow pages under sandbalsting equipment, or 'art' supplies..

[Mark Winlund]

Hi.... here is a link to an air brush sand blaster:

http://www.paascheairbrush.com/cgi-bin/store/detail.cgi?r=421

Mark

[Tracey Bakewell]

Thanks for the link, at least I know what I'm looking for now. That's an official no on Home Depot and Michaels. I jumped on Ebay and also McMaster-Carr and am now on the right track for a sandblaster. My husband already has a compressor so for all I know when I get home he'll probably already know what I need!

[Tracey Bakewell]

Update: Finally! -- With what I've learned so far I finally got A result. I'm not toally satisfied with it but I think I have enough to understand what to work with. With the coating theory througout this thread and others, I just had my hubby take a sander (since we don't have a sand blaster yet) to the piece of brass I'm working with, sanded the heck out of it! CerMark'd it and voila! Finally my sample name stuck to the brass. It wasn't as crisp as I would like but I think that just may be how rough the surface was and possibly need to run faster, slower, again, not sure, I'll keep playing with it. Best part is, it didn't come off!!!

For those of you out there that responded with take a sand blaster to it, what type of protective tape are you using first, when you laser the tape off the area you want to engrave so? I'm just wondering what is hardy enough to stick to the brass when sand blasting? -- Oh, and where do you get your glass beads? I found several portable sand blasters on Ebay so I'm just shopping for those right now, obviously that's what it seems I need!

Thanks!

[Jim A. Walters]

Harbor Freight has glass beads, and they have some cheap blasters and cabinets. If you wanted a "more professional" grade of glass beads and blasters, there is a mega-supplier to the toolmaking industry at www.mscdirect.com (http://www.mscdirect.com) that would have better selection.

Tool shops and businesses are closing right and left. You might scan your local auctions for a closing business that has an industrial type.

[Tracey Bakewell]

Thanks Jim! I just bought the small hand-held sand blaster and glass beads from Harbor Freight! Thanks for the recommendation! Tracey

[Bill Cunningham]

Let us know how that little blaster works for you Tracey.. I have been tempted to buy one in the past, but just never got a 'Round-Tuit'...
I'll have to make some this week..:D

[Richard Rumancik]

Tracey

I have been a bit concerned about getting proper alignment the second time you laser.

I think your procedure so far is:

Mask metal
laser text to ablate sublimation coating
sandblast through mask to clean up remaining coating down to brass
spray Cermark over lasered areas
re-laser to bond Cermark to brass


Note that the masking is needed to protect adjacent areas from the abrasive blasting but it unfortunately adds another layer of adhesive that you need to get rid of. Some adhesives leave residue. Perhaps a mylar laserable sandblast masking would work. (Razist LazerMask or Innotec?)

Not sure at which point you should remove masking. If you can leave it to the end it will reduce Cermark cleanup.

Getting to the alignment problem - I was thinking about this a bit more and finally recalled what I did in my experiment to alleviate alignment problems.

1. Text was rastered as normal
2. Cermark was applied
3. Text was copied to another layer (Text Pass 2) and outlined in black by .004" to cause it to "grow" by .002" all around. Then the part was re-lasered.

I suggest .004 because above .003 it will raster both the outline and the text fill inside, instead of vector marking the outline. You want to get at least a one-dot border around your text when lasered the second time. At 300 dpi, maybe even .006 would be better. I did not experiment a lot with the fine-tuning of this concept. (Be careful if you decide to convert text to bitmaps before lasering as it shifts images a bit. If you have a graphic to laser you may need to use Photopaint tools to "grow" the bitmap image by a certain number of pixels all around.)

The effect of this was that if the plate was a thou or two off on the second pass, the Cermark would still be "exposed" to the laser. You know Cermark will will not stick to the sublimation coating so the coating acts like an automatic resist. And if the mask is still on at this point, it will act as a resist as well. (In the extreme you could fatten the text up even more and it might not show a shadow at all.)


Just an idea to consider.

Get a good optical loupe so you can look at the text closely after lasering and blasting, and touch the metal with a dental pick or needle so you can see visually that the brass is bare and clean to the edges before proceeding.

[Tracey Bakewell]

Thanks Richard! I will check out those masking suggestions as well, Tracey

[Rodne Gold]

Just write off the coated brass to school fees if its going to prove a huge schlep to engrave , you might end up spending more in terms of time and effort than its worth. Buy engravers brass for your next project , it tarnishes less and cuts far better than "normal (half hard)" brass.
A sand blaster is fantastic combined with a laser , you can use many things as resists , we even use the really cheap paper based transfer tape sold at sign shops as a resist. Masking tape works well too. You want to use a resist that the laser ablates as completely and as fast as possible. Something like polyester sign vinyl (most of mirror gold or mirror silver vinyl is polyester , if the vinyl doesnt stretch , its not pvc and generally laser safe) will withstand seriously deep and long blasting.
The grit is very important when blasting lasered items as it has to clean out some very fine lines , so it has to be small , we use the finest grade aluminium oxide grit as it's "sharp" and will clean out those very inticate ares that have been ablated. Dont skimp on grit , get the best , it makes a huge difference.
Sandblasting is a lot better than lasering on many objects and is often a LOT quicker , often giving far smoother results over large areas.

For example if you wanted to laser something that has big letters and small, you use the laser in raster mode on the small text and vector cut and peel off the big letters , the blasting will take seconds and using vector outlines on big stuff will make the lasering a lot speedier.

You will have no joy trying to engrave metal via sandblasting , it will be almost imposible to get depth , however you can get very nice contrast marks , Stainless will blast a dull darkish grey etc.
Works exceptionally with wood as it expuses grain quite beautifully with ridges and valleys and gives a weathered look and with a mask in place , you can easily colour the blasted wood.

[Tracey Bakewell]

Rodne, thanks so much for this information as well! You're right, in the grand skeme of things, I have definitely learned a lot just from this small purchase :D!

[Tracey Bakewell]

In the meantime, another vendor sent me "RAW" brass material to play with, and wouldn't you know, the cermark sticks like a champ. I'm having some issues with clean edges, but I think that's just me slapping the cermark on with a paint brush and not getting a nice even coat. I'm going to switch to spraying it on to see if that helps. I'm still waiting on my sand blaster to show up as well. So, once I have that, I will still try out engraving out a mask of tape, sand blasting, cermarking, then engraving again.

I'm going to swing by a paint store today to find out what products I can use to polish and re-appy to protect the "RAW" brass so it does not tarnish -- if anyone has any suggestions there, always welcome!

[Dave Jones]

A good paint store should have a "brass lacquer", which is specially made to bond well to brass and copper.