Keeping water out of the frame rails

[rags]

What is everyone doing to keep water out of the frame rails? On the 72 I just got, it had new rails and floors already installed. I jacked up the car from the rear for the first time and water poured out of the front of the new rails! I'm assuming it got in there when I powerwashed the engine compartment and since the rails are only spot welded water got inside. Can I use seam sealer?

 

Joe

[Metallicar]

I would think it would be better to have drain holes in them than to seal them up, unless you could make them exactly water tight.

[aviatorx]

I don't think that trying to keep your frame rails water tight is the right way to go ..... and I'm sure you'll get more than a few opinions on the subject - but here's mine!

 

You might think about ensuring that whatever water gets in there has a path out, so that there is never any standing water. The rails are open in the front at the radiator support - a good entry point for water off of the road. It's nearly all downhill from there past the firewall to the under-seat supports. A couple of drain holes back there will solve the water retention issue, and if you are paranoid you can even use body drain plugs that you could open every now and again. A couple of 1/2" to 3/4" drains will not sacrifice any rail strength.

 

Stopping rust formation from a draining rail is a easy as providing for a good anticorrosive to the inside of the rail with a spray wand - and to do that you'd need a few access holes that could double as drains.

 

Even if you did make the rails water tight you'd still have condensation occuring in there that would eventually eat through the rails. The best solution isn't always to try to keep the water out, but to manage it.

[Guest TKR514]

Yea, drain holes.

After I finish resoration in about a month, I'm also gonna use a light oil mist through the rails folowing final paint. It may get a bit gritty, but will garantee no rust.