some more observations on cheap pcb transfer

[zjokka]

After some attempts I'm beginning to draw conclusions about using picture paper:

- Inktjet picture paper! With laser paper there will be a thin paper film over the toner which is a pain to rub off. If you use inktjet paper, the paper will come off completely in one go after long enough a soak in hot water (the time to have a cut of tea)
- It will be a great improvement to the quality of the transfer if youpunch holes in the tonerless areas of the transfer. This will allow air to escape from underneath the toner without damaging it. The more punches, the better.
- Any picture paper (laser or inktjet) seems to resist overheating, smeared toner is a result of the transfer sliding over the board when hot and thus releasing toner.


I'm trying to implement this method for enclosure etching, but a whole lot of different factors are at play there: larger tonerarea, softer metal, etc. seems to demand a different approach.

any comments are more than welcome.
zj

[bioroids]

That hole-punching trick seems interesting, I'll try it next time thanks!

I also found useful to put the circuit part inside a frame of black (toner). This way the paper gets sticked at the borders, of course later you have to cut the PCB to eliminate the extra copper frame, but this allows you to have lees mistakes on the transfer process, as the paper is not trying to lift of the PCB. I don't think this would be of any help with etching enclosures.

Luck

Miguel

[zjokka]

That hole-punching trick seems interesting, I'll try it next time thanks!
I also found useful to put the circuit part inside a frame of black (toner). This way the paper gets sticked at the borders,

that's another intelligent trick I hadn't thought of, but I'm thinking, if it's just meant for sticking, couldn't you take it off the toner on the side with acetone or something.

The hole punching trick really occurred to me when etching enclosures, as there's not much space for escaping air in a negative tone image. But it works for pcbs too, even to such an extent that breaking traces is a thing of the past for me now. Even with laser picture paper, punching secured all the traces better than before.

zj

[Seljer]

has anyone tried using overhead transparencies? I've run out of PnP and I figure they're more likely to have transparencies than inkjet photo paper at the photocopy place next to my school

[JimRayden]

has anyone tried using overhead transparencies? I've run out of PnP and I figure they're more likely to have transparencies than inkjet photo paper at the photocopy place next to my school

Worked quite decently for me.

---------
Jimbo

[R.G.]

Overhead transparencies work partially. This was the original material used for toner transfer. It suffers from not releasing the toner well, pulling up slivers in the black areas. I had to touch up all of the transfers I ever did with overhead transparency. There is quite a variation in overhead tranparencies from brand to brand.

The release paper for sticky-labels is very good for releasing.

[KerryF]

RG, You mean wax paper?

[zjokka]

it seems to me like the plastic in transparant sheets might not be as heat resistant as you would like
I even heard somebody on the board to the transfer with ordinary paper.

has anyone tried using overhead transparencies? I've run out of PnP and I figure they're more likely to have transparencies than inkjet photo paper at the photocopy place next to my school

As they only have laser copiers, this might be only normal. Just stop by the supermarket or anyplace they have inktjet paper. Laser picture paper also works, and better than pnp for me, as there is no risk of overheating.

good luck,
zj

[thumposaurus]

I've used label baking sheets with good results. I haven't tried wax paper, but I've had good luck using parchment paper.  I also use a piece of tape to hold the paper to the board on the back side keeps the paper from slipping around and smearing.

[rockgardenlove]

Seems like wax paper would work great, except for the fact that you'd melt the wax and get it everywhere.

[zjokka]

I've had good luck using parchment paper.

What is parchment paper? Is it arty paper that just looks like parchment?

Seems like wax paper would work great, except for the fact that you'd melt the wax and get it everywhere.

Yes, the slippery the surface the better the release, maybe the parchment paper is paper covered with something waxy?

zj

[RedHouse]

...The release paper for sticky-labels is very good for releasing...

That's what I use, Avery labels, I pull off all the labels and use the backing paper.

I still get some traces pulling-off sometimes when releasing though, haven't quite got it figgered out yet, tried pre-heating, avg temp iron, hot iron, all the stuff, I'll try the hole punching thing next. Seems like none of these methods are perfect every time.

[thumposaurus]

Parchment paper is used for lining baking sheets for making cookies and cakes you can find it near the aluminum foil at the grocery store.  It's a heat resistant paper, sometimes it is impregnated with a silicone the only one I've tried though is the regular version.

[tcobretti]

This is a really interesting thread!  I've recently had some very bad experiences with trying to etch.  I didn't destroy the enclosure or anything, but I could not get a good transfer, and I tried 3-4 times.  I was using glossy paper from a magazine, which has worked for me with PCBs.

[Paul Perry (Frostwave)]

I expect the main difficulty in trying to iron onto an enclosure, is that the body of the enclosure acts like a heat sink & never gets hot enough for the toner to stick. I tried once with PnP & never got a good job (though PCBs were OK). Maybe preheat the enclosure with a heat gun?

[zjokka]

I rearranged the videos from the first message a short 2min-something clip which describes process of transfer

Inktjet picture paper pcb transfer clip

It really doesn't matter what you use but the parameters for a good transfer material are clear:

- easy to print on with laser toner
- heat resistant to the iron
- good realease of the support paper from the pcb (leaving toner behind)

I expect the main difficulty in trying to iron onto an enclosure, is that the body of the enclosure acts like a heat sink & never gets hot enough for the toner to stick. I tried once with PnP & never got a good job (though PCBs were OK). Maybe preheat the enclosure with a heat gun?

Wouldn't puttin the tonerimage on a preheated box guarantee smeared toner? I always use the hottest position on the iron but am told that PNP cannot take that heat. Lot of heat and punching:



However, etched for too long and the box wasn't flat flat: some damage to the lettering once more. The smaller or thinner the lettering, the better the result I learned

I still get some traces pulling-off sometimes when releasing though, haven't quite got it figgered out yet, tried pre-heating, avg temp iron, hot iron, all the stuff, I'll try the hole punching thing next. Seems like none of these methods are perfect every time.

Trace are pulling off because not enough heat and pressure was applied to them to adhere, provided you cleaned well. Sometimes is just not possible to apply enough heat and press. because an air bubble is obstructing, no matter how hard to press. Especially between parallel traces, punching assure air can escape from between toner and copperboard. It will work ... every time, I'm sure

This is a really interesting thread!  I've recently had some very bad experiences with trying to etch.  I didn't destroy the enclosure or anything, but I could not get a good transfer, and I tried 3-4 times.  I was using glossy paper from a magazine, which has worked for me with PCBs.

Look at my first transfers! They like came out of a fire !

There's is a lot of toner to transfer, that's why you have to fill up the large cutout holes with paint, or better: punch holes in the tonerless area's. That worked for me -- to get a good transfer.

Mind you also, I'm beginning to see that aluminium is something entirely differnt than copper. If you ever tried drilling hole in a copper enclosure ( ) you would know the difference with hammond boxes. I tend to conclude that alumium needs a much weaker etchant than pcbs.

Etched two boxes myself, and beginning to see that MarkM is right in the etching times. They should be very short. Maybe this has more to do with safeguarding the toner from being eaten by the etchant. Leaving it in to get a nice deep etch just wont work with FeCL or HCL+H2O2 (which I use). Another point I learned the hard way is: SAND till you STRAND (or somethung..er) and make that box as FLAT or flatter than Popeye's Olive. And for sure you will find that's a lot of sanding, because the tops of the hammonds are somewhat concave.

Peter Moore suggested that HCL would be strong enough by itself, which will be my next first experiment. Gotta have a circuit ready for boxing first. Keep your findings posted

zj