Any good tricks for treating INSIDE hoods and deck lids?

[b5blue]

 I'm getting started on my 70's body and now would be a good time to try and clean, derust and seal certain body parts that are a sandwich of layers like the hood and trunk lid. Getting something inside to kill the rust and remove the crap while off the car while I can roll it around and force solutions to slosh into areas you could never get to.
Ideally these would be "Dipped" or "Tanked" somewhere but I've not found any places around the Tampa/St.Pete FL. area that do this. There are plenty of other areas inside the car I'd like to treat like the side cowl area that supports the doors and roof framework above the rear wheel wells where there are layers of stamped parts.
With the interior mostly gutted I have as good of access as I'm ever going to have and can make a mess before welding in new floor board sections. 

[johnnycharger]

I was in the same position when I did my hood. I pressure washed in all the channels and througth the mat holes, etc. Then I poured "Rust Doctor" in it. I used a lot of it. I rolled the hood around, plus I stood it up on end poured at the top and let it flow down. I rotated what side was up to get it throughout.
I really like the Rust Doctor product. I think it is better than Por 15 because you can use it where there is bare metal and paint.

[Silver R/T]

Rust encapsulator by SEM works great also. You can get spray wand for undercoating gun to teach in frame rails/small openings

[dodgechar]

  sand blasting.   my roof was pitted and i took it to a guy who did  headstones and he sand blasted the top .  the pits are still there but not the rust.  then took  dupont metal conditioner and water to rence it with. then sealed with a good sealer.  primer and paint.  then  covered  w vinal.. in your case just build the  primer  and paint  smooth. lots less chemical work this way.

[b5blue]

 Thanks, I'm off this week and working on the roof...much like you describe. I'm fairly pissed as I paid to have it stripped/blasted/treated and epoxy primed. To say the least I was screwed over. All I got for 500.00 was the rust DA'ed smooth and epoxied lightly, it looks like the only things sandblasted were the rear and quarter windows mostly.
Shame as I had known Doug for 7-8 years, not a top notch body shop but decent work....he had said for years he wanted to do my car as it was a classic.     Looks like I'm not getting to the hood or trunk this week.

[bill440rt]

If you're going to dip the parts to de-rust be SURE to have them dipped in primer afterwards. Otherwise, all the inner braces & areas you cant see will remain in bare metal & rust again. Or, use a spray wand to reapply primer to the hidden areas.

Or, if you're not going to dip, use a spray wand to apply POR-15 or Eastwood's Rust Encapsulator inside the hidden areas.

[b5blue]

 I'm getting ready to order some "Rust Encapsulator" for the roof. It's tested well on my Jeep's hood and is workable. I just talked to my supplier about PPG's single stage Omni paint that would be compatible. If it holds up well it would be a good choice for priming and internal coating.