Will using interior nails on exterior PVC trim cause rusting and unsightly trails, and how can I prevent this without painting over the trim?
Asked by Akshay Suvarna 
4 months ago
Last Updated: July 26, 2024
I’m putting up some new PVC trim around my windows outside using my 16-gauge nail gun. I just realized that the box of nails I have says they’re for interior use. Do you think I’ll have issues with rust and seeing rust trails from the nails? The trim is bright white, and I really don’t want to have to paint over it. Any advice or thoughts on what I should do? Thanks!
You’re going to wind up with rust.
I used to believe they were all galvanized…
Where did you come across them?
Have you checked out the Porter Cable brand at Home Depot?
You could try looking for a small box of galvanized screws. If they have a rental department, they might sell you a small box. Otherwise, you could screw them in with exterior finish screws.
Darn. I have a box of them tucked away somewhere…. lol
Cool. I’m not actively searching for them though… lol
If you seal up the hole, you won’t encounter any issues because it won’t be visible
Make sure it’s galvanized
Watch out for rust
Just make sure to fill your holes and you’ll be all set
I have a feeling you’ll end up swapping out the trim. We had to take down a whole section of clear cedar siding because someone used the incorrect nails. Rust appeared within days. You could attempt to seal the holes with caulk that matches the color, but I wouldn’t bet on it.
Stainless steel nails
You will definitely see the bleed-through, even if you just put a small dab on the nail head.
Many finish gun nails are labeled as galvanized, but they’re often not suitable for outdoor use. Brands like Hitatchi, Bostitch, and Dewalt may claim to be galvanized, but they’re actually meant for indoor projects. Senco nails, on the other hand, are galvanized and approved for exterior use. While stainless nails are an option, they can be pricey and usually only necessary for working with cedar or cypress.
I got a roofing nailer that shoots stainless steel coils because it was more budget-friendly than stainless screws. My grandfather always built with redwood. The nailer sinks the nail 1/16 to 1/8 inch below the surface, depending on the material of the plank. It seems to work well with drywall, especially since they used drywall nails back in the 1960s. The ribbed roofing nails hold up really good. I used stainless screws for the drywall edges and the nailer for the rest. The holes might be too deep and need more mud for the pros, but us beginners prefer using drydex to speed up the process (especially in humid areas).
Plumbers are supposed to paint PVC pipe because it can become brittle when exposed to the sun. I like to use a clear exterior construction adhesive from Locktite along with stainless trim screws. Even though electricians use stabilized PVC conduit, I still recommend painting the pipe. The plumber’s clear primer is said to help the paint adhere better, but it’s pricey. You could try testing acetone to see if it helps the paint stick, as PVC doesn’t have a grain like wood to absorb it. I wish I could use redwood, but it’s either hard to find or too expensive. Home Depot had some wood dyed to look like redwood, but it wasn’t consistent when trimmed. Some Ace Hardwares might carry redwood half-rounds.
Oh yeah, you definitely will. I actually did this a few years back on a deck I was working on. I wrapped it with PVC boards but ended up having issues with rusted nails causing brown stains to run down each nail hole.
Using a two part epoxy paint may provide longer protection for the metal but it’s a hassle to apply. You could consider testors model paint (oil based) with inexpensive 5 cent brushes from Walmart.
There’s also a bathtub touch up paint that comes in two parts.
Does the manufacturer suggest painting or is it necessary?
I think certain types are fine without paint. The priming options for PVC nowadays are way better than they used to be 10 years ago.
That could potentially resolve your issue.
Yes, you should use stainless steel ones for outdoor use