Seam sealing your tent is quickly becoming the post-factory standard for many lightweight and tarp-based designs. Learning to reapply sealant and waterproofing can breathe a significant amount of life back into your tired old tent as well. For Black Diamond tents such as the Mega Light, you’ll want to use a silicone-based sealant.
How to seam seal a new tent:
Set up your tent somewhere dry and preferably with good lighting
Mix up seam sealant (you can buy it premixed or make your own)
Apply sealant to the inside seams of the tent
Apply sealant to the outside of the tent
Let it dry in a well-ventilated place
If you’re reapplying a seam sealer to an older tent, make sure to strip the old, leftover silicone off the tent before applying a fresh coat. Seam sealing takes patience, and you should be sure to test your coat before taking your tent into a potentially wet situation.