Hi,
I have a 2009 Dodge Ram 1500 with 29K miles. I am the original owner and it sits in my driveway most of the time. I recently discovered rust all over the underside including the frame. There is a 1" line that appears to be along the weld line. I am having a hardtime finding a way to get this thing safely repaired. I live in northern MD just south of Pa between York and Baltimore. Not sure if anyone has had any experience with this or knows anyone near me that can help.
Thanks,
Jim

Post pictures.

Here are some:

Yikes. I bet you had that stomach sinking feeling when you saw that.

Sodium Chloride Iron Reduction.

Yes, don't know what to do, trying to make sure it's safe first. Then trying some rust converter if I can't get a shop to do it.

Been considering a newer Dodge truck for once (newest ever owned to date is a 2001 durango)
Seeing your pix doesn't help my cause regarding being talked into it)

I had a whole write up written, then lost my online connection and its gone!

From a retired welder that repaired rusty frames in northern IL, you can relax a bit, what you have isn't going to fall apart tomorrow, or anytime real soon, unless you load it to the max, every time you use it.
Most modern frames are sealed pretty well at the bottom. The problem is, there are holes in the frame that water (and salt water) can get in, but then there is no way for it to get out, until the water level reaches the lowest hole in the frame side, usually about 1/2 way up. The frames tend to rust out from the inside outwards. You don't want to cover the outside of the frame until you can seal the inside of the frame.

The good news is, now your frame has a drain hole at the bottom. But to take full advantage of that drain hole, you need to get proactive pretty quickly.

Take a chisel along the rust through line and knock off the loose edges, open the hole until you get to good metal. Once you have a big enough hole, you can start digging out the debris that is sitting on the bottom of the frame rail. You want to dig as much of that carp out, as far and as wide as you can. Use a screwdriver, or similar item to scrape along the edges and rake that junk out. Its likely you are going to see pretty big chunks of what look like frame rail (because it was before the water and salt started breaking down the steel). That frame rail remains is thick, flaky, and breaks pretty easily, dig it all out! You are probably going to be amazed how much crap you will dig out of your frame rail.

Once you have it pretty well cleaned out, get out your garden hose. Find a hole about 2' to 3' in front of the new "drain hole" and insert the hose, pointing the water towards the drain hole and flush the frame until the water comes out clear. You may have to stop and dig more crap out of the drain hole before you get the frame clean. Repeat the flush process to a hole about 2'-3' behind the drain hole. You do not want to try to flush past the frame kickups.
Once the frame is clean inside, let it dry for a couple of days. then you can seal the inside with paint or what ever you choose, just be sure the frame is dry before you coat the inside.
The bad news is if only one side has the rust hole, the other frame rail still has all the crud inside of it.
Once its sealed inside, an annual wash and maybe a new sealing coat will extend the frame life a long time. You may not have to have it patched for years. Gene

Berst rust converter I have found is OSpho. Ace hardware sells it.

Dude you live in Hunt Valley, just go buy a new truck.

Thinking about it, but this recent problem will dramatically affect my trade in value.
My problem is that I live in a valley and there is a lot of moisture and condensation that forms overnight. That coupled with the fact that I have a cement driveway and don't drive it that much.
If I do get a new one, I will need to coat it somehow.

If that were my truck, I would do the following:

Use a pneumatic needle scaler and go to town on the frame. Wire wheel (minimize the wire wheel as it'll burnish the rust which you don't want) and sand the area's that need further attention.
Then get some Corroseal (it's a much better alternative to ospho as it's easier to work with, won't ruin everything it touches) and corroseal the ENTIRE frame, literally everywhere you can brush it on. Make sure to follow the application guide well, most people don't use enough coats and it's too thin. More is better than less.
Then finally I'd use a good paint to protect it from further corrosion. I've moved away from Por15 and use Rust Seal myself.

I live on the gulf coast and things rust, BAD when left outside and not used. staying ahead of the rust is key. I've found the simplest way to do this is to liberally apply a product like Fluid Film to the chassis twice a year. You can use 3M Cavity Wax for inside the body panels.
The previous poster who mentioned the drain holes is correct, you've got to make sure your frame drains properly and doesn't store moisture.