Recommendations on Bivy Sacks? in The Gear Critic Posted June 23, 2004 · Edited June 23, 2004 by Stephen_Ramsey ... BD Lighthouse. Came in the mail today, seam seal tomorrow, try soon. I somewhat discount previous leaking comment experiences when they said they didn't seam seal - why do you think BD makes a point of sending the sealer & syringe??? You can discount any posts you like, but just to be clear, I fully seam-sealed my Firstlight before using it, and yes, I know how to apply it. It just wasn't enough to keep the thing from leaking. YMMV.