some of those holes/gaps are required... otherwise if you don't put a cap/tonneau on it then when it rains it will fill up with water!

So if you have some gaps by design, why go crazy welding all the seams full length?

 

My 2015 has a spray in liner, and it still had huge gaps in it. I used clear silicone and sealed the entire bed. Every crack crevice and hole got filled. I will still get dust in it I am sure, but not nearly as bad as before. I live on a gravel road, so I am on it every day. I have a retrax bed cover, but it doesn't seal all that well.

 

I used 3m seam sealer around the bed before having bedliner sprayed in. Seam sealer is designed to be painted over so no adhesion issues. Did leave the open slit at the front corners of the bed for water to drain out. just my 2 cents

 

Aluminum is a very active metal and it "rusts" very quickly. But, the aluminum oxide forms a very thin tightly bonded layer on the aluminum which protects the aluminum underneath it from further rusting. Most of the time when you are looking at aluminum you're actualy looking at aluminum oxide.

When you add salt into the mix, there's a different reaction going on. I don't remember enough chemistry to tell you what the reaction is, but it doesn't form the protective layer and the aluminum will continue to corrode.

It will be interesting to see how these new trucks hold up in areas where they still put salt on the roads. and where people drive on the beach.

Also I never heard of silicon drawing moisture?? I must have used several hundred tubes of silicon caulk over the last 50 years and never had an issue!

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