I'm tack fusing small panels, (4x7 90 coe) the bottom clear glass is 3mm, and I'm stacking a few pieces 1 to 3mm high. So in some parts, it is over 6 mm. I have it at a tack fuse 90 medium speed. (which is what is says on my Evenheat kiln preprogrammed) I usually do a tack fuse 90 fast speed, but since these are a bit thicker, I am using a medium speed. However, it seems it reached a high temp, faster than the "fast" speed would have. I'm hoping this will still be a tack fuse by the time its done. So, my question is, if I use more than 6 mm thickness, how should i tack fuse this? Fast, medium or slow?