If you are planning to go camping using a tarp or tent for shelter, it is a good idea to seal the seams to keep out water from rain or snow. The process is simple and effective.
To seal the seams, you need to protect areas where the noseeum mesh connects to the rest of the tarp or tent. That is where water can seep in when it rains or snows.
Seal the seams when the temperature is not more than 60 degrees Fahrenheit and the humidity is not more than 80 percent. Set up your tent or tarp so that you can easily do the job. If you are sealing a tent, smooth out the seams and focus on the ones that run around the perimeter partway up from the ground. That is the area with the heaviest internal stitching.
You can seal the seams of your tarp or tent with McNett Sil-Net, a viscous sealant that can be applied with a syringe or brush, or a sealer called Seam Lock, which has the consistency of water. Seam Lock is easier to apply but can be messier than Sil-Net. Before you begin to seal the seams of your tarp or tent, get a brush and some paper towels.
You want the sealant to soak into the stitching to prevent water from leaking into your shelter. If the stitching is not exposed, you should fill in the small canyon where two pieces of fabric are joined. Capillary action will pull the sealant into the hidden stitching.
Position the tip of the sealer bottle or a syringe full of sealer above the seam or stitching so that it will get sucked into the gaps between the stitches and the rest of the tent or tarp. This will be easier if you use Seal Lock because it is less viscous. If the sealer creates droplets, you can spread them out and into the seams with a brush. Apply a few coats of the sealer and allow it to dry thoroughly. Your tarp or tent should be protected from rain or snow on your next camping trip.