This tonor transfer method is pissing me off!

[Mbira]

Argh!!!I've been happily doing photo resist pcbs for almost 10 years now.  Now I have this piece of brass that is about 1/8" thick-one of those "push plates" that you see on restaurant doors, etc.  i'm wanting to etch a logo for my business into it.  I've been trying various "toner transfer" methods and nothing has kept enough toner on the brass for me to actually even try to get a good etch.  Is there a way to "paint" on the photo resist and develop the board that way?  Any other ideas?  The problem is I need these done like now!

 

[mitsos]

If you can find the paint-on photo-sensitive etch resist(same stuff as what's on those pre-coated PCBs, but in liquid form), you could just paint some on and then etch the same way as making PCBs.

Or you could have a silk-screener put the image on a screen, then apply etch-resist paint to your panel through it and etch.

 

[Mbira]

Do you know what paint would be an etch resist paint?  I can probably get our t-shirt silk screener to do this faster than any other way...

 

[PRR]

> brass that is about 1/8" thick

You need a hot-plate that can hold that heavy metal about 200 degrees F. Then an iron can bring it up the last few dozen degrees to melt toner.

Dang near any paint will stop standard copper echants. Be sure you know how to get the paint off. T-shirt silk-screen may be fine, just get a cup of what they use to clean-up.

 

[VacuumVoodoo]

Why not use spray-on photoresist? Google will tell you where to buy a small can for <$10

 

[Nora]

I did some experiments with press n peel film on a 1mm alu panel with no decent results.
Anything thicker than a standard pcb copper layer will need more heat than a clothes iron can supply I guess.

 

[mitsos]

Do you know what paint would be an etch resist paint?  I can probably get our t-shirt silk screener to do this faster than any other way...

I have some paint that is specifically etch resistant, it's a grayish color paint. It is the same brand as the silk-screen supplies, so I guess you just have to find a silk screen supplier who handles etching stuff.  Like PRR said, make sure you know how to get the paint off the screen (and brass of course) so you can re-paint if it doesn't come out right, or if you want to make more.

 

[Mbira]

Talked to the nice guys at MG Chemicals today.  They have a positive resist sheet that comes 12" x 5'.  You cut it and put it on your piece and then run it through a laminator.  Then you can do the development like a normal board (except it's a positive resist instead of negative).  I ordered a roll ($20) and it'll be here on Monday.  The guy seemed to think there should be no problem with what I'm working with...

 

[JohnRoberts]

Good luck. That sounds vaguely like the stuff we used to make silkscreens with.

One time  (as a tech back in the '70s) I made a simple rush circuit board, by hand painting the pattern onto copper clad with  blue (dychem?) toolmaker's ink. Ugly, but it worked. Of course back in the '70s you could actually see the parts on PCBs.  

JR

 

[Ptownkid]

Part number...can't see to find it on their site.

 

[Mbira]

Yeah-if it could be ugly, I'd just whip out a sharpie and be done with it...Curious to see how iut'll work.  Will keep folks posted.

 

[Mbira]

Part number...can't see to find it on their site.

http://www.mgchemicals.com/products/416dfr.html

 

[kato]

Nail polish makes a durable etch-resist.