What am I doing wrong with the PNP Blue transfer?

[davent]

The same iron, safe to assume same transfer material, same box manufacturer, same moon phase... anything else that might have been different this time 'round?

I never sorted my own struggles with the process.
dave

[EBK]

The same iron, safe to assume same transfer material, same box manufacturer, same moon phase... anything else that might have been different this time 'round?

I never sorted my own struggles with the process.
dave

The most significant difference I can see affecting things is the holes.  My previous success was with an undrilled enclosure.  Perhaps hot air is pushing up under the film.

You know what? Tonight, I will try a transfer with some relief holes in the film where the drill spots are.  Maybe....

[Rob Strand]

The most significant difference I can see affecting things is the holes.  My previous success was with an undrilled enclosure.  Perhaps hot air is pushing up under the film.

You know what? Tonight, I will try a transfer with some relief holes in the film where the drill spots are.  Maybe

I've got no idea what the problem is.

Another effect is the holes prevent heat from being conducted away via the underlying aluminium so maybe the plastic is shrinking around the holes.

For tricky problems like this I try to look for patterns.   I can see more of a tendency to fail near the edges and less in the large central area.  Maybe a slight tendency for failures near the holes.   It's by no means a clear conclusion as the entire right edge isn't bad.     Overall it looks fairly random and in small regions.

Maybe the problem is elsewhere.  One possibility is it's just not cooked enough, simple as that.    Another is the sheet itself has random surface issues in patches.

I wish you luck.

[slashandburn]

Is there a particular brand of photo paper that works well?  Does it matter if it says "for Inkjet"?

I'm with Rob in that I just use anything that's glossy. Whatever is cheapest!

The pack I have just now is 220gsm and says its for Inkjet, no issues at all with my laser printer (cheap Samsung m2020). £2 for 15 sheets of A4.

220gsm is maybe a little on the thick side, with this stuff I have to set the paper type to "labels" otherwise it's sometimes jams in the printer.

[mwelch55]

Someone mentioned preheating the enclosure before applying PNP.  I agree. 

I think the PNP is not getting hot enough because the sides of the enclosure are cold and acting like a heat sink.  That is taking heat away from the transfer surface.

I few months ago, I discovered that preheating larger circuit boards makes the transfer work better.  I think the same would apply to enclosure transfers.

[EBK]

It's worth a shot.  I have a blue transfer sitting here, so I can easily try preheating. 

Cutting around the holes, by the way, did not improve the result last night:



I'll try the preheating this afternoon.

[KarenColumbo]

I recently had my own misadventures after great success last year and the year before. DOn't really know what changed, I used the same kind of paper, the same printer etc. I will try this weekend - thinking about using a spray substance called "Toner-Verdichter" (roughly translated "Toner Condenser") which I happen to have a can of around from past PCB phototransfer experimental endeavours. Thinking about spraying the condenser directly to the sanded and cleaned surface, applying the print-out and then proceeding as usual - pressing the iron down with force for some minutes, then gentle circular motions with the iron. Will feed back what I learned.

[deadastronaut]

Is there a particular brand of photo paper that works well?  Does it matter if it says "for Inkjet"?

I'm with Rob in that I just use anything that's glossy. Whatever is cheapest!

The pack I have just now is 220gsm and says its for Inkjet, no issues at all with my laser printer (cheap Samsung m2020). £2 for 15 sheets of A4.

220gsm is maybe a little on the thick side, with this stuff I have to set the paper type to "labels" otherwise it's sometimes jams in the printer.

i accidentally bought 220gsm and it got stuck in my printer,it was pretty thick stuff, it was a pain in the ass, as it then took ages to get a clean print out after....had to run loads of standard a4 paper through it to get it clean.....so i stick with cheapo 150gsm max...

[vigilante397]

I never did enclosure etching, but back when I etched PCBs and had trouble with PNP blue a handful of people on here recommended magazine pages, and I had great success with that. Rip a page out of a magazine, run it through the printer, iron it on. Better results than I ever got with PNP.

[davent]

What happens if you use regular printer paper?
dave

[tonyharker]

Inkjet photo paper really shouldnt be used in a laser printer, as the toner fuser (heater) can lift the coating off and get on the rollers etc.  Gyess how I know

[vigilante397]

What happens if you use regular printer paper?
dave

The toner bonds solidly with the paper and doesn't release onto the enclosure. You need something non-porous so the toner sticks but doesn't solidly adhere, so it will release when applied to a heated surface..

[EBK]

Well, preheating was interesting.  As soon as the film touched the hot enclosure, it was stuck, meaning there is only one chance to get it lined up.  Unfortunately, the transfer wasn't any better.  I'd post a pic, but it looks exactly the same as the other attempts.  At least my results are perfectly consistent even if they cannot be consistently perfect.   

[davent]

What happens if you use regular printer paper?
dave

The toner bonds solidly with the paper and doesn't release onto the enclosure. You need something non-porous so the toner sticks but doesn't solidly adhere, so it will release when applied to a heated surface..

Thanks Nathan. I do a no heat wet toner transfers with regular paper in place of decals but that process would never work for etching and doesn't involve the toner releasing from the paper, you soak the paper with water and rub it off.
dave

[EBK]

Photo paper arrived.
Unfortunately, the gloss film on this paper seems to melt more easily than the toner.  I have much better adhesion to my enclosure in the unprinted areas, and worse, the back of the paper sticks very well once heated too.  I had to whack my enclosure with a hammer to get it unstuck from my heat press!

I'm in the process of removing the mess.


I'm just going to take this as a sign that I am not meant to etch enclosures.   

[deadastronaut]

hang on, heat press?..

not using a clothes iron then.



@dave, im sure you mentioned your no heat toner transfer before, with plain paper

how does that work again?...is it with a mix of acetone and .....

[EBK]

hang on, heat press?..

not using a clothes iron then.

Don't get too excited.  This is a small handheld heat press, smaller than a clothes iron.



Bottom view, with 1590B for scale:


About half of my failures in this thread were with my clothes iron, so once again, I got the same results when changing a variable.   

[slashandburn]

Damn, you're not having much luck Eric.

Does anyone know if hexjibber's tutorial is still online somewhere? That's what I followed when I started and I haven't ran into half as many issues.

As an aside (apologies to Eric for derailing this) the no heat toner transfer Rob mentioned reminds me of something I seen a while ago. Just magazine paper and acetone iirc. Put the magazine paper in place, drench it in acetone and give it a rub. Seemed to work fine for the guy in the video but I didn't have any luck with a few small pcbs so I just went back to the clothes iron.

[KarenColumbo]

Experiment with "Toner Condenser" failed. Toner didn't stick at all Well - sand, rinse, repeat

[davent]

@dave, im sure you mentioned your no heat toner transfer before, with plain paper

how does that work again?...is it with a mix of acetone and .....

Hi Rob, i use primarily Golden brand acrylic artists paint for enclosures and they have extensive line uncoloured mediums. The medium i use is GAC200, dries water clear, hard and glossy, it's an adhesion promoter.

All i do is laser print the art reversed onto regular paper, coat the face of the print with the GAC and stick it down and smooth out where you want it, don't get any of the GAC on the back of the paper. Let it dry overnight, next day rough up the paper with some sandpaper, once roughed up use a spray bottle to saturate the paper  with water and rub the paper off with a finger/thumb. Just keep wetting and rubbing and you can get rid of all the paper fibers. Will take some patience and if the paint/medium starts to reabsorb water looking milky let it dry/clear then carry on with the wet removal.

Don't have to use a clear medium you could just use the same paint, different coloured paint that was used for the enclosure.
dave