Seams on SMD tents aren't sealed. We recommend Seam Grip SIL seam sealer for Silnylon products and Seam Sure for Polyester products to achieve complete waterproofness. We do not offer seam sealing service at this time.
But we would like to encourage you to not to be afraid to perform the seam sealing by yourselves. It is not complicated and you can find a lot of videos on youtube as well. The positive thing is that if you do it by yourself it's a best way how to better know your shelter :)
Here are the steps what Six Moon Designs recommend to follow:
Before seam sealing your shelter. You should thoroughly inspect all seams to insure that they have been correctly sewn. You'll want to identify any potential flaws before starting to apply sealant.
Setup and Inspect your Shelter - Setup your tent before sealing it. Get inside and lay down to make sure it fits your needs. Make a through inspection to insure it's properly sewn and all the seams are in good condition. Make sure you are happy with the shelter before proceeding. Tents that are seam sealed by customers are not eligible to return it for a refund.
Seal the Seams -Most of seams on Six Moon Designs shelters are designed using butt seams. These seams keep the threads on the inside where they are less exposed to dirt and grim. Butt seams must be sealed from the outside of the canopy. Applying sealer to the underside of the seam will not seal them. Work in a well ventilated area, pour a small amount into a paper cup, and close the jar to keep rest of sealer from thickening. Use a small brush to apply a thin coat of sealer to all exterior seams. For butt seams, hold them open to allow the sealer to soak into the seam and coat the threads. If sealer thickens while applying, add some more mineral spirits.
Stripe the Floor- For shelters with floors, adding a series of strips sealer to the floor of the tent. This will reduce the tendency of your sleeping pad from sliding around on the silicone nylon floor.
Drying your Shelter- Allow your shelter to cure for at least 8 to 12 hours after sealing. Once cured, the sealer dries to a clear matte finish that is nearly invisible, and will be both durable and flexible. You may find your seams to feel tacky. This will dissipate with shelter usage. If you prefer, it can be eliminated by sprinkling on a light coat of unscented talcum powder.