My tent trailer has a leaky roof. I've been over it, and I'm pretty sure I've found the leak: right on the center roofline, there's a crack in that seam towards the rear. I bought some "Indoor/Outdoor Acrylic latex caulk with Silicone", and that seems to seal it up ok for a few days (this is why I'm pretty sure I know where it's leaking), but the crack simply resurfaces through the caulk and it leaks again. Any suggestions for a better/more suitable product or ???