I had adhesion problems printing PLA on glass. I’ve been printing PLA on glass from the very beginning, and had no adhesion problems at all for about a year, but suddenly it stopped adhering. I have tried everything (increase head temperature, bed temperature, increase or decrease initial gap, hairspray, ABS juice), nothing helped. The deciding factor was switching back to 1% Salicylic acid alcohol solution to wipe the glass instead of Würth degreaser or acetone, now I have several successful prints again. Looks like silver PLA I have now from http://igo3d.com sticks worse than clear from Faberdashery and green from eBay/Poland, these were not sensitive to the glass wipe at all, even window cleaner every now and then worked fine.
I use cheap hardware store glass with Kapton tape and ABS… it works well 98% of the time. I also wipe the surface down with nail polish remover at the start of each print.
Ordinary window glass works for me. I got several pieces so I can quickly swap when a print is done, then leisurely remove my finished print while another is going. I frequently change between PLA and ABS so having seveeral build plates ready is handy.
@Christopher_Benjamin I use a rep 1 regularly at work. We have boro glass, but window glass (like at home depot) will work. Way cheaper. Some people have also reported good results with mirror.
If using glass I recommend skipping tape and the nasty chems. Experiment with hairspray or gluestick (soap and water clean up). Hairspray works well for me.
We, on the Mendel90 forum at http://reprap.org, have tried various glass cleaning methods.
The conclusion that we have come to is that any solvent e.g. Acetone, Methylated Spirit or Isopropanol alcohol can dissolve components out of the cleaning cloth which get left behind as a residue. So instead of making the glass cleaner they can actually cause additional problems.
The technique we have developed is to use a craft knife blade edge to periodically scrape over the bed and remove any tiny plastic residue. Then we wipe the glass with Pure White vinegar (95% distilled water/5% acetic acid) on a plain tissue until it squeaks and no more (beyond which the tissue starts to break apart and leave debris behind).
We print PLA at 185C on a heated bed at 70C and this technique leads to prints that require a moderate amount of effort to remove after the bed has cooled to room temperature and considerably more effort at higher temperature.
@Neil_Darlow have you tried news paper instead of tissue? This is a common window cleaning technique. Tissue breaks down extremely quickly.
With hairspray I print pla on my Rostock glass at 50 to start dropping to 40 after first layer. Never had an issue with adhesion, or getting the print off afterward.
Rep 1 hairspray on glass I print abs at 100 bed temp. Usually no problems, but sometimes it’s more tricky.
I just had a 4x200x200 mm piece glass cut at a local glazier shop. I bought a piece of matted glass. I use the matted side for ABS (with ABS juice) and the glossy one for PLA. I figured the glass is heated pretty evenly so there should be no problems with untempered glass, too.
@Nathan_Ryan , I’ve heard that some newspaper ink is silicone based these days, so a newspaper might contaminate the glass so that ordinary organic solvents won’t be able to clean it. I’d suggest kitchen rolls instead of tissue.