So I've been reading up on ceramic coatings, and I have a quick question: From what I've skimmed, it seems that ceramic coatings tend to produce greater heat resistance and (more concerningly in some ways) can work as great insulators.

My questions are:

1. Does the heat-resistance apply to the ceramic laquers being considered? If so, does it perhaps offset the heat-dissipating advantage that having an aluminum body/cover would provide? Or does heat resistance in this context mean resistance from damage/deformation, but not insulation?

2. Does the tendency to work as a good insulator apply to the kind of ceramic laquers being considered? And if so, does the effect on electromagnetic properties of the material bode better or worse for the signal quality of the device, especially once we get to the full-body replacements?

1.The latter - they're resistant to heat and wear under heat (the one used up to 490 C). Not very important in our case, as No one is going to use N900 in such circumstances, but if you drop your device into fireplace, you at least should be sure that your backcover won't lose colour

As for heat dissipation, the effect is negligible, and won't affect properties in any measurable way as compared to anodizing. Of course, bare aluminum will always be a tiny, tiny bit more effective at this - but, it won't be bare for long, as it will oxidize on it's own (just in non-uniform layer, so without as much added scratch-resistance as with anodized or lacquered surface). So, for our intents and purposes, no change here.

2. Indeed they're insulators, but not much more than the layer produced during anodizing. After all the latter, is alu-oxide, formed in layer with certain properties (very small pores, that are used as residue for a special after-anodizing dye, BTW) - not great conductor, either.

But, in our application of whole body replacement, it doesn't matter - for the radios, we have a thousands orders of magnitude bigger "problem" with the *conductor* used for body (that is, Alu). Incidentally, conductor act as shield, in this case - even on it's own, but even better when it's grounded (at the very end to battery - not real ground, but still). It is the case for N900's metal parts (border around screen, back of screen...), and will+must be the case for body replacement.

Due to this, in full body replacement, antennas will get "re-delegated" to the outer side. Think N950's antennas, just without N950's poor radio performance (as they have failed with the quasi-coil antennas).

Of course, there is still the port for connecting external antenna for N900 that is a crucial (read: must have) part of body replacement which will allow to get absolutely superior radios performance in special situations - but I'm absolutely sure that performance of internal antennas is no less important, for everyday use. Won't neglect that part, that is for sure.

Side note - I was *very* tempted to create complete new internal fractal antenna, that could get integrated into back part of body replacement. But, designing one that will work well is hell of a task, with much, MUCH testing and trial&error (even if using antenna designing software, like 4nec), so it would delay body replacement part considerably (it could take as long as doing everything else...). So, it's idea that I'll try someday for my own, slowly, and report if I succeed

/Estel

I haven't been active lately and it's been a long time since I looked in this thread.
Since I made a PayPal account and I got a credit card, etc. I want to donate,
when I get a job next week I will donate to certain people after taking care of something else.
Thanks for your work and I'm looking forward to buying the stuff! And it won't be long until I will repair my N900, I got a soldering iron finally...

Don't think I'm going to live that long.... I'm 65 next May....

Hey, don't put my hopes down!
I can relate this project with Half-Life 3 actually.
Only, this project isn't so secretive...
I've only read the last 10 pages of this thread, whether
Estel succeeds or not at least he tried and did his best
to succeed.

Don't get me wrong, I sincerely hope this succeeds, I will be there in the queue to buy at least one case/back for my much also hoped for neo900's, just hope I live long enough!

FYI I thought the covers were going to cost more than $50 for flat, $70 for fat and $200 for the whole package.
I am willing to donate soon and hopefully when these get released I will be able to buy the whole package.
Right now I'm just a 17yo teenager looking for a job and other ways to make money.

Move to the west and you will live longer.
Edit:
answer for the next post:
If you finalize this project maybe you will be moved in the west to live longer.

Stay on target... Stay on target...

The latest proto (the one in photos few pages back) is lacquered and currently sits in the furnace, hardening ceramic coating (undergoing 4 passes of heating up and cooling). My camera awaits impatiently. Alongside old keys and hammer for resistance tests (don't expect it to be a graphene - it certainly will get scratched by those - but the whole thing is how it will look afterwards, as compared to "standard" lacquer used by all device manufacturers out there).

/Estel

And now, the hardening process is complete:



...and with leg extended:


Below, photo of the much older test unit, coated with the same ceramic lacquer, hardened, and given some harsh treatment (scratching with keys, paper-cutting knife, sandpaper):



As you might notice, the tested surface is clearly visible - no surprise here - but coating never got scratched off to the point of showing silvery aluminum surface underneath - unlike regular lacquer used on aluminum bodies of various expensive devices on the market, which tend to show "shiny scratches" all the time. We're really satisfied with the result.

Now, as for flat backcover and it's after-coating usage test, we haven't encountered any major issues, requiring fixing/re-designing. We're going to make hinges with brass instead of aluminum - just like we're doing already with one part of camera-slide-cover mechanism, not because it deforms or whatsnot, but just in case. Those elements are very small, and considering how comfortable it is to use N900 with the new, big kickstand, we suspect that it's usage may experience kind of renaissance. We wouldn't want to get reports about any damage during more heavy-duty use cases (like, writing angry posts on TMO with device sitting on the desk).

After implementing that, we're moving straight to the "fat" backcover, with it's addition of tripod mounting point! Pre-order people - you may already start to prepare your custom text/logos for being engraved on your backcovers
****

Arien Stokowiec