silver ink pen as etch resist

[GGBB]

Anyone ever try using one of those silver ink pens as ferric chloride etch resist?  I ask because I have no idea if they actually have any metallic content in the ink.

[mistahead]

I would think that if you're using it to resist the etching of another metal beneath it you'd NOT want metallic pignment but rather a non-reactive one?

Sorry - am I along the right lines of the goal though?

[GGBB]

I would think that if you're using it to resist the etching of another metal beneath it you'd NOT want metallic pignment but rather a non-reactive one?

Sorry - am I along the right lines of the goal though?

Yes exactly.  My question is really whether or not there is actually metal in the pigment of the "silver ink" pens, or anything else that would be reactive to ferric chloride etchant.

[mistahead]

I would think that if you're using it to resist the etching of another metal beneath it you'd NOT want metallic pignment but rather a non-reactive one?

Sorry - am I along the right lines of the goal though?

Yes exactly.  My question is really whether or not there is actually metal in the pigment of the "silver ink" pens, or anything else that would be reactive to ferric chloride etchant.

I'd try the type which is sold under the name "UniPOSCA" in AUS - its a heavy acrilic paint marker, if toner resists the etch into metal I would favour a guess that acrilic paints will too.

[GGBB]

I'd try the type which is sold under the name "UniPOSCA" in AUS - its a heavy acrilic paint marker, if toner resists the etch into metal I would favour a guess that acrilic paints will too.

I'm sure the acrylic would work, but I would still like to know if the silver ink would work and if anyone has tried them.

[greaser_au]

Maybe I'm missing the point, but for inexpensive alternatives I'd suggest an oil-based sprit pen,  e.g Artline,  Texta, or  Sharpie. Laundry pen.   Anything that is listed as a 'permanent marker' and is not water based.   I have made many PCBs using a 'Mr Texta' felt tip marker pen  as etch-resist...  make sure the  ink lines are solid.

david

[GGBB]

Maybe I'm missing the point, but for inexpensive alternatives I'd suggest an oil-based sprit pen,  e.g Artline,  Texta, or  Sharpie. Laundry pen.   Anything that is listed as a 'permanent marker' and is not water based.   I have made many PCBs using a 'Mr Texta' felt tip marker pen  as etch-resist...  make sure the  ink lines are solid.

david

I guess I haven't made myself clear.  I'm not asking what I should use as an etch resistant pen.  I'm asking if anyone has successfully used the silver ink pens as ferric chloride etch resist.

[Mark Hammer]

Boy oh boy, is this ever a blast from the past! 

For over 30 years, I have been happily, and successfully using Staedtler Lumocolor waterproof/permanent marker pens.  Thankfully, with toner transfer, I don't have to anymore, but when a touch up is needed, that's what I turn to.  These pens can be bought at just about any art or office supply store, and come with very fine tips that are excellent for drawing crisp boundaries.

It is the liquid vehicle for the pigment that resists the etchant, not the pigment itself.  So, you can use a light yellow marker, and it will resist just as well as the blackest black.  Of course, it is easier to tell if the coating laid down is actually suitable for fully resisting, if the pigment is darker, so black is preferred over blue or red, and those colours preferred over yellow.

Which leads to another question: assuming the medium in your pen that carries the silvery pigment (whatever it is) is waterproof, will that silvery coloration let you accurately see if you have laid down enough?

[GGBB]

Thanks Mark.  One of the pens (I have a couple of different ones) is a Pilot Silver Ink permanent marker roller ball pen.  It's one of those "autograph" pens.  The ink comes out liquid at first but dries quite quickly and it is possible to lay down a fairly thick layer with reasonable amount of control.  Even a normal stroke of this pen puts down a much thicker layer of material than would say a Sharpie or other marker type pen.  Very permanent and water resistant.  I like the idea of it just because it covers so well and so easily - almost like paint.  But I wonder if it does have metallic content then would that react with the ferric chloride and cause the ink to fall away or pit.  I'm only thinking touch ups.

I'd just give it a try but I'm not set up for etching right now and I honestly thought this would be a quick and easy question that surely someone would know.  I guess not - I couldn't find anything via Google either, but mainly because "silver" and "etch" in the same search turns up a whole other subject.  I only found one person who uses it successfully but for acid based etching.

Now I am wondering - since you mentioned about the liquid vehicle - if even ordinary roller ball pens would work - they just put down so much more ink than the felt tip types.

EDIT:  I should also add that I tested it with my DMM and found it was not conductive.

[Mark Hammer]

It is the vehicle that needs to be permanent/waterproof.  Unfortunately, the vehicle is clear, so it is hard to tell if the layer applied is there, or has discontinuities in it or not.  It is the pigments that let us know if it is present.

Back in the pre-toner-transfer days, I would prepare my boards for etching using two such pens.  I'd draw the mask pattern on with one, and then go over the pattern with a second.  The second would be a darker colour than the first (e.g., blue over red).  The use of two colours was simply to let me keep track of what had and hadn't already been gone over.  So long as I kept my "finger juice" off the board, it was a pretty good system, if somewhat time-consuming and cumbersome, relative to toner-transfer.

My own advice would be to keep the silver pen for autographs.    They tend to dry a little too easily anyway, so you don't want to keep them uncovered very much.

[R.G.]

As Mark noted, any pen putting down a thickish layer of stuff is mostly likely to work as a resist.

Remember, you can easily get non-etch marks from the oils carried on your finger prints.

It is unlikely that the metallic pigment in the pen is silver. If it is metallic at all, it's almost certain to be aluminum powder, which is commonly used in paints.

As a personal guess, it would probably work fine as an etch resist. This guess is based on the idea that any metal powder is intimately mixed with the liquid binder, and that there are likely to be either no or almost no metal particles exposed to the etch medium. This is a guess.

In any case, any pen that puts down a persistent goo that solidifies is likely to work well as an etch resist pen. Sharpies were the standard back in the Bad Old Days when only three of us on the planet did DIY PCBs for effects. Sharpies put out a version of lacquer. At one time, PCBs were plotted directly on copper with plotter pens that were refillable with ink, and for this use filled with thinned lacquer. A nib-style pen dipped into a well of thinned lacquer or other paint of almost any kind would lay down a resist trail. I suspect that a pen dipped in vegetable oil would work as well, the only problem being that it would not set and remain where it was laid down.

As hard as it is to get copper to etch uniformly, almost **anything** that covers the surface a bit and doesn't immediately dissolve in FeCl would work.

Shoot - if it was possible to put down pure copper as an etch resist, that would work too, as the FeCl would take longer to etch through the top layer where the copper "resist" coated the base copper. Timing might be tricky, but it would be possible. PCBs were in fact once made using plated metals as etch resist by resisting the non-copper areas, plating the desired copper areas with a metal that etchant would not eat, then stripping the resist and etching.

[GGBB]

Thanks guys - good insights.  I *plan* to etch this weekend, so I'll try to test it out then and post back my results.

[armdnrdy]

I "got" your point from the get go......but let me suggest something.

Instead of going through the whole painstaking process of "drawing" a whole circuit onto copper clad board with a "resist" pen that's not proven, use a small piece of copper clad marked with lines of varying widths and etch it to see the results.

This may save you some time!


I have used this type of pen in the past (Geddy Lee signed All The World's A Stage) and I have the agree with Mark....best for autographs.....but as Geddy stated, "It didn't turn out very good"

[GGBB]

Instead of going through the whole painstaking process of "drawing" a whole circuit onto copper clad board with a "resist" pen that's not proven, use a small piece of copper clad marked with lines of varying widths and etch it to see the results.

Thanks.  It would be downright idiotic to do otherwise.    And as I already mentioned I was just thinking of using it for touch ups to the toner transfer - I was never planning to draw an entire circuit this way.

[R.G.]

For toner touch ups, I always used thinned nail polish and a very small artist's brush. Lots of control.

[armdnrdy]

I use a regular sharpie for larger sections (ground planes, wide traces) and a ultra fine point sharpie for smaller, detailed areas. (thin traces, pads)

[Roger Martin]

Why dont u use calendar paper and laser toner printer ?
Iron it, cool it, iron it again. You wont miss a thing.
Using an ink pen is laborious.

[Mark Hammer]

For toner touch ups, I always used thinned nail polish and a very small artist's brush. Lots of control.

I'm guessing you are not a prolific consumer of either caffeine or nicotine.

In "the good old days" before toner-transfer, one of my preferred methods was to use a combination of approaches.  First, I'd tape the photocopy of the layout to the copper board and, with my trusty spring-loaded center-punch, pop a little dimple into the middle of where every pad was located.  After buffing the board shiny, then I'd take a sheet of rub-on dots or pads, and put them on the copper board over the dimples.  (At one point, Radio Shack was getting rid of packages of electronics rub-on transfers, cheap.  I still have a bunch.)  Once the pads were all in place and smoothed down, then I'd use my Lumocolor pens to "connect the dots".  Worked great.

These days, there's no reason NOT to use toner transfer.  My little Samsung laser printer doesn'T seem to like the photo paper I have, and neither dowes the photocopier at work.  So, I print out the PCB masks on the laser printer and stroll over the the copy shop down the block from work and ask them to copy the layouts onto the dollar store photo paper I brought with me.

[tubegeek]

I've been getting decent - decent, not perfect - transfers using hp glossy inkjet paper run through the copier at work. Gonna have to try some other types of photo paper.

Mark: have you bought a Lumocolor pen lately? I went to a well-stocked art supply store this week and didn't see that brand. It's made by Staedtler, right? They had other types from Staedtler, but not those. I wonder if they still make them.

EDIT: never mind - they're all over Amazon, I guess the store I went into is NOT so well-stocked.

[Lurco]

Shoot - if it was possible to put down pure copper as an etch resist, that would work too, as the FeCl would take longer to etch through the top layer where the copper "resist" coated the base copper. Timing might be tricky, but it would be possible. PCBs were in fact once made using plated metals as etch resist by resisting the non-copper areas, plating the desired copper areas with a metal that etchant would not eat, then stripping the resist and etching.

Congratulations for just having reinvented "printing a circuit board": paint some coppertraces onto an isolating board, and you won`t have to etch at all!