I installed a tonneau cover on my Sunday go-to-meeting 2018 F-150 and experienced significant dust in the enclosed truck box after traveling on gravel roads. Installed a tailgate sealer that cut down the amount of dust, but still get quite a bit of dust in the box. I can stand in the box and see daylight along a lot of seams. I can understand the need for water drainage, but the gaps seem to be excessive.

The local Ford dealer says it comes from the factory that way. Anyone else deal with this dust issue and seal up the gaps and maybe leave some seep holes?

Not much you can do about the dust that I know of. We had covers on our truck boxes when the kids played hockey to keep their equipment bags from getting wet and snowy. Nothing I tried eliminated the dust.

A good body shop will be able to seal that with some seam sealer. Kind of surprising to see that though. Cost cutting at it's finest.............

I’ve never noticed gaps in a truck bed other than the tailgate in any of mine. I think I’d just use a tube of silicone and call it a day.

Now days, I just have the beds Rhino or Line-X coated before I drive it off the lot. Seems to help some. I had one of those plastic liners in an older truck and it was absolutely awful for a lot of reasons, but it did cut quite a bit of dust out of the bed with the camper shell on it.

My 2016 had the same "feature" . I wonder if there is some sort of flexible automotive sealant that can be used for that application .

I had/have this problem with a Chevy and a camper shell. I tried to gorilla tape up all the gaps and use a tailgate seal. It works for a while, but the tape ultimately fails and leaves a really hard to remove residue.

I may be able to give you some help with a very common problem. I've experienced the same thing for years on several different pickups. My final solution....1. I had the bed treated to a spray in bed liner to seal all the larger seam openings. 2. Still had some dust problems, so
put in a tail gate seal (Cabelas). 3. Found some small leaks from round holes in the box corner stantions which I can see no rational reason for, so bought several household corks of various sizes, and used silicon sealant to glue then into the holes, then trimmed the ends flush with the surface. 4. After another PD hunt in South Dakota's dusty side roads showed that I was still getting small amounts of dust leakage, I talked to a local body shop about the problem. One of the young body repair specialists gave me a tube (10.5 oz) of a product called "Big Stretch" made by a company called Sashco, in Brighton, Colorado. This is just a non hardening caulk and sealer made for doors, windows, and siding. I later found that several local hardware and "big box" stores carry the product. Doesn't harden or crack, and very easy to apply. Just make sure the surface is as clean as you can get it. (I used Rubbing Alcohol with great results!) Is dry to the touch in 4 or 5 hours, and comes in many colors. After seeking out and sealing 3 or 4 small gaps with the product....no more dust or water leaks.

Now, several of my friends and acquaintances have used only the "Big Stretch" treatment on the boxes of their Chev, Dodge, Ford, and Toyota boxes with good results, they simply calked all the gaps and holes with tubes of the stuff that are close to the body color of the truck, or
clear product that actually dries "clear".

IF, you don't have a good seal on your topper or cap, your are just wasting your time trying to cure the problem of the dust intrusion!

Good Luck
Bill

I have the same exact problem, 2015 F1 50 4 x 4, I have a really nice Ford Tonaeu cover on it, on the way to our hunting spot there is a 2 mile stretch of just diced Stone Road, I have the drain tubes in the front corners of the bed, i’m wondering if the dust is slipping through there or through the gap in the tailgate, all of our stuff was loaded with dust.

I just siliconed the gap on mine and put a tailgate seal in. Makes it better but not perfect.

All the newer aluminum F150 beds are like that. Spray in bed liner will fix a lot of it but the tailgate area has a lot of gaps too.