The lid on my kiln is rising at the front during firing. What is the cause?
During firing, the firebricks expand, and the kiln actually rises, becoming taller. The lid hinge is designed to allow the lid to float. This compensates for the expansion of the kiln. If the lid is tight at the hinge, the front of the lid will lift up. The lid rises in the front when the hinge is not adjusted properly or is binding. If this happens, please do not put a weight on the lid to hold it down. That will only damage the lid. Instead, check for play at the hinge, or for binding.
Here are instructions for checking Paragon's LiteLid spring counter-balance system. The spring is used on 10- and 12-sided kilns.
1) The lid must have vertical play in the hinge. To check for play, close the lid all the way. Have someone hold a side handle and lift the lid while you watch the back of the lid. You will find a lid bracket attached to each side of the lid. The lid bracket on the side that you lift should go up about 1/8" when someone lifts the side handle. (If you cannot lift the back of the lid, it may be due to a tight hinge bolt. See step 2.)
2) The nut on the lid hinge bolt must not be too tight. Otherwise the lid can bind, causing the lid to rise in the front during firing. If the lid could not lift up in step 1 above, loosen the nut on the hinge bolt. If, after loosening the nut, the lid still cannot lift up, go to step 3.
3) The lid bracket holds the back of the lid to the hinge. The hinge bolt passes through a slotted hole in each lid bracket. That slotted hole is not easy to see, because the LiteLid rear arm covers it. But if you position yourself so the hinge bolt is at eye level, you can see the slotted hole.
With the lid closed, the hinge bolt should be at the top of the slot in the lid bracket. If the bolt is at the bottom of the slotted hole, the lid was installed improperly. If this is the case, please call the factory for additional help.
4) If the lid still rises after all the above checks out okay, insert a screwdriver between each rear lid bracket and rear Litelid arm. Twist the screwdriver to ease possible binding.