Advice on sealing up truck canopy - weatherseal prep and carpet question

[hansolex]

So I've done a lot of reading on here and other forums on the subject, but I'd like some specific advice about prepping the cap so I get a good seal. Background: '98 Tacoma extended cab, located in Western Washington where it's very damp. Truck's new to me, and I've never had a canopy before. Looking to do the bed platform thing and want to stay reasonably dry. Sick of breaking down wet tents! Cap and windows are in good shape, but the old seal is destroyed. All the PO used it for was moving his dog around, so he didn't care. Leaks a small but not insignificant amount. Truck bed rails are professionally Line-x'd.



I'm going to replace it with an EPDM bulb seal like this Ultra Cap Seal. First question: what's the best way to prep the cap side? Lots of old seal residue and unevenness. Do I sand it smooth? Use some Goof-Off like product to clean off the old adhesive and then prep with alcohol? Not sure. Really don't want the seal to unstick itself because of poor prep.



Second question: the canopy liner, a sort of all-weather carpet material, folds over the inner edge of the cap - see below (sorry image is upside down). You can see it in the image above, too, where it's still more attached. Seems like I might be better-served by cutting away the folded-over carpet and adding another compressible layer of weatherstripping along that edge. Anyone have an opinion either way?



Hoping to make it cozy and dry in one shot here. Would hate to have to pull it on and off again due to poor prep trying to chase down a leak. Thanks for the help in advance.

 

[Jsilverado]

I just used a flat foam seal from the hardware store. It has worked fine no leaks even going through a auto car wash. I used black silicone caulk around the body seams and drain holes in the bed. I have a black bed liner so it blended in nicely. I used a bulb type seal around the tailgate. Its stayed warm and dry every time so far.

You could probably trim the old carpet from around the edges. My new topper I recently got has carpet up to the edge and does not tuck under.

 

[Ducky's Dad]

I have factory bulb seals on three trucks, all with SnugTop shells. Trucks are Dodge, GMC, Toyota, all with plastic bed rail caps. Oldest shell is almost 20 years, mid is 12 years, newest has been on the truck for two years, but both truck and shell were bought used from different sources. None of them leaks around the bulb seal, but one (the oldest) leaks around the aluminum rear window frame. For my money, I'd use a factory bulb seal if the shell is from a known, quality manufacturer. I'd also install bed rail caps to provide a better sealing surface than the Line-X. Since you'll probably never get the channel clean and smooth, I'd think about some slow-cure bedding compound in the channel before installing the bulb seal, and then get the shell onto the truck before the bedding compound sets up. We don't get a lot of rain in So Cal, but this winter has been way above normal, with some storms dumping more than 1/2" per hour and blowing sideways. No leaks other than the back window on the oldest truck.

 

[rayra]

I'd lightly block sand the old gasket surface on the fiberglass shell. Just enough to take off the crud without destroying the resin and fraying the glass. I'd wipe it down with acetone or alcohol to clean it as well as possible. Then I'd slather some new resin or epoxy on there. And when that is fully cured I'd put the aforementioned bulb seal on it.