Just had a buddy do a trade deal on re skinning on our 32 pickup doors .he cut the whole skin off ,yup split it at the window track and split the whole door skin off right around the top so he could get in to hammer up the new skin from belt line to bottom. That's a lot of un painted metal in there with a long unprotected weld. Has anyone a helpful trick to getting paint in there around the top window area and decent coverage on the bottom thru the small triangle hole in the inner skin. We don't want to use fisholine at present as there is some more small body work to do . It may be a while before the doors are finish painted.
I've heard of guys putting a WD 40 style spray can tip on a spray paint can and then use the wand tube to spray the inside of concealed spaces.
Check out Eastwood, they have lots of unique devices for getting paint and rustproofing into tight spots. KK
Think of it like a gas tank that you want to prep and coat the inside. Tape up the small holes, dump the stuff in and roll the door around to get to prepped, washed and covered.
i have painted stuff then used a blow gun with a length of brake line as a nozzle to push the paint around inside..........a f#!@$ng mess but it works.
Had an crazy idea I could make a rotary nozzel of sorts by using a small diameter copper tube and block the end off and drill a series of small holes 360 degrees around it. ( there is the tricky bit) The nozzel would attach to a flexible tube then to an under seal gun somehow .what ever I do is going to be messy for sure. May be just a hair brained idea and doomed to failure.
i made a nozzle like that. pictures in this thread; http://www.jalopyjournal.com/forum/threads/deck-lids-and-the-men-that-louver-them.750934/
POR agents in NZ have a nozzle that connects to a hose. Cut hose to whatever length you need. I have a 4ft length for chassis tubes. I usually use a paint called "primacon" made by International and used below the waterline on boats as the primer for antifoul.
If you put paint in a shutz gun (undercoating gun) it will blow paint anywhere you want as long as you can get the angle. A 6 inch hose on the end helps, don't go very long with the hose. I was able to shoot paint down the inside of a rocker panel and get full coverage, 6 feet. Took 70 lbs of air at the gun. Laying it on a bench with a foam pad, skin side down, pouring paint in and rocking it back and forth, stand it on edge and roll it over works also. This is 1 place I recommend rustoleum primer, it sticks to anything and seals well, and you'll end up wasting some paint so the price is right. Anywhere it runs out, grind it off before applying real primer.
On a used door for an AD Chevy truck years ago, I thinned down Rusteoleum Rusty Metal Primer and sprayed it with a long wand pump up garden sprayer. Gary
We use rustolium and pour it in the door laying flat then tilt it and flow it all around. It coats everything then drain the excess out of the drain holes in the bottom of the door. Sometimes simple works.
This is the best method to get at places where there's no way you could hit with a spray. I mix DP epoxy primer and do not thin it. Pour in a small amount at a time and get a buddy to help you roll the door every way possible. You will run some out on the floor but this does the best job.
In the good old manual mode, I swabbed POR on the inside of my old 37 sedan's frame rails (where it was double-walled) with a coat hanger opened up to full length and bent into a small loop at one end. I used the loop to hold some old T shirt scraps dipped in POR. Gary
A buddy has suggested a small round garden spray irrigation nozzel also . We have tried the rock n roll method , but on the top of the 32 door there is more hole than door . In saying that nothing is too hard to do. Have been using a Wattyl etch primer but at $60 litre ,$60 a gallon would be better,I don't want to go wasting it. May check out the local rustoleum supplier. Cheap is good.
If you use Rustoleum, make sure it's a spot you won't need to put other paint on top of later. Most automotive finish paints don't like Rustoleum.
Get a cardboard tube from a paper towel roll, spray your paint inside of it pointed at where the paint goes. It works.