solved warping problem

Like most, I was having big problems with larger items warping. So: I cut a piece of 3/16 sheet aluminum to replace the glass on my print bed. I used a belt sander with a really course grit belt to remove all the smoothness from the surface, leaving it with scratches everywhere. Now I heat the print bed to about 110 degrees Celsius and rub a hot melt stick around the bed. then using a putty knife I smooth out the hot melt. I turn off the heat to the print bed and let it start cooling. I start my print. The first layer is laid on the sticky hot melt and is glued down. as the layers are printed, the print bed cools and the hot melt gets hard making the print almost impossible to come off. So how to remove your print when you can hit it with a hammer and it won't budge? Simpler than you think. I remove the plate with the printed model still attached. Put it on the range in the kitchen and turn on the heat. Since hot melt melts at a lower tempature than any plastic, In a few minutes, the hot melt melts and you can easily remove your model.
I was printing coffee mugs 4 inches across and 5 inches high. With high temp tape, it warped separating from the tape, getting caught on the print head and turning sideways. With the blue painters tape, the model stayed in place, but warped about 1/2 inch on one side, pulling the tape off the glass. With my aluminum bed and hot melt, there was absolutely no warping at all. The reason for roughing up the surface is so the hot melt would have a better grip. When I am ready to print again, I just go through the same process adding a little more hot melt to the areas where it came off. As for hot melt that stuck to the bottom of my print, I just scrape it off, or in the case of the coffee mugs, used a heat gun to smooth it out. it makes a great bottom for the coffee mug. I use the glass bed and blue painters tape for small items, and the metal bed for larger items. I hope this is food for thought.