Need help etching enclosure

[nobodysweasel]

I'm trying to etch an enclosure for the first time, and for some reason I can't get the toner to transfer very well to the aluminum.  I have successfully etched many PCBs using the same paper, printer, iron, everything.  I've done some searching in the archives and found a great tutorial by Ruz Guitar Gear, but even when I'm following it as closely as I can it's just not transferring the toner cleanly (there are a few dark spots and everything else is patchy - some grey, lots of spots that should transfer that just plain don't).  Does anyone have any ideas that might help?  Am I missing something in the prep?  I've been sanding it to 220 with a random orbital sander then cleaning with alcohol and a paper towel.  Any ideas?  Thanks in advance.

[bonaventura]

i am no expert and am collecting all resources that i have before etch my first,but first thing that occur to me is that maybe not enough heat introduced?

encloalsures have way alot more mass than pcb and they will sink heat away fast.

just a thought.

[deadastronaut]

not enough toner?....print with best quality, toner save off...

i sand by hand with a block to get a flat surface.., 180 grit paper with warm water and soap....rinse off, dry, tape image to box, (no movement/smudging,

put iron on full and leave it on there to get hot....then criss cross pattern iron for a few mins.. ....

some like to leave to cool then peel, some like to instantly put under cold water to harden the toner..then peel/rub off....toner is pretty durable when its on there..

above all keep everything clean...box/image etc...no fingerprints...good luck.

[nobodysweasel]

Thanks for the ideas.  I guess I'll give it a few more tries and see what happens....