Around The Fourth and New Year's, we always have a flurry of orders from people who are buying Class C (1.4G) festival balls, only to belatedly discover that they only got one mortar tube to shoot them out of. We sell 1.75 inch and 2 inch paper mortar tubes to accommodate these unfortunates. Cardboard mortar tubes are notorious for unraveling after they have been used once or twice. The problem is that the potassium nitrate residue left in the mortar tube absorbs water. The dampness causes the glue in the mortar tube to loosen up, and your mortar tube is now history. You can extend your mortar tubes life considerably by waterproofing them.

Put some thinned varnish or polyurethane in a shallow tray that's big enough to accommodate your mortar tube. (I prefer varnish, even though it takes longer to dry. Varnish penetrates the cardboard; but polyurethane coats it and makes the ID slightly smaller.) Then dip the mortar tube, completely coating it inside and out with goo. Hang it up to dry. I use straightened wire coat hangers and decorate my dogwood trees with them for a couple of days.

We don't offer plastic bases for these mortar tubes, because they tip over. You can make a good base by getting a hole saw (adjustable or otherwise) and cutting about a 3/8 to 1/2 inch deep hole in a piece of lumber. Then use white carpenter's (or Elmer's) glue (do NOT use hot melt!) to mount the mortar tubes to this base. Et voila!

To learn more about using your paper mortar tubes read these:

"Festival Ball Mortar Tube Racks"
"Making End Plugs Fit Your Tubes"