michael.t.albers wrote:

Actually a rough surface has more area for adhesion than a smooth surface especially with extruded materials as they are being melted onto that surface.

A liquid would touch more surface, but I have my doubts that the extruded ABS is liquid enough to get down into the pits. After all, the printers can print plastic out into space for overhangs :-).

Its not liquid OR solid. Its right in-between. As in, if you squish it enough (as proof seen with first layer and adjusting Z height) it will deform to what it is being pushed into.

Actually a rough surface has more area for adhesion than a smooth surface especially with extruded materials as they are being melted onto that surface.

A liquid would touch more surface, but I have my doubts that the extruded ABS is liquid enough to get down into the pits. After all, the printers can print plastic out into space for overhangs :-).

Certainly my experience with using 220 grit to grind a tile flat didn't give the impression that a rough surface is better. The tile is too thick to heat well, but the ABS stuck to the original tile (even though it wasn't very flat) much better than it stuck to the flattened, but 220 ground surface tile. I suspect the smoother the surface the better, more contact area for the ABS to stick to rather than a lot of tiny pits under the plastic making no contact.

Actually a rough surface has more area for adhesion than a smooth surface especially with extruded materials as they are being melted onto that surface.  If the extrusion was solid (cold) before it hit the surface then, yes, there would be less surface area in contact with the part.  This is one of the reasons why it is suggest that you sand plastic before painting it.

it didn't work.

I only put a light etc, (enough to slightly "frost" the glass) so longer exposure to the cream may have helped.

on the whole I was happy with using and replacing kapton tape though, I thought that if I could have gotten a surface that I could use and reuse that I'd have been happy to have never had to buy Kapton again.

but given the amount of experimentation required, and the relatively cheap price of buying a wide kapton roll (not precut squares) I though that it was just easier to keep using kapton.

A more aggressive etch might work. -but I doubt it, I think it's the same effect as shot blasting with beads, peening the glass rather than cutting the glass as said above).

I wonder if blasting with sand, and with etching paste (to have softened the glass) would produce a better surface?

or sanding with one of those diamond knife/chisel sharpening blocks, to add very good/deep groves.

Long story short, a textured glass can do wonders...  if you find a source, please post it.  Mine was Goodwill...

On the other hand I've been having great success with kapton tape on the glass bed. Seems to stick better than hairspray on glass and give a much smoother finish