2redrovers

I'll go with the epoxy primer then. 
Thanks everyone
Happy new year's eve

Agree with all thats been said.  A good paint supplier can put GOOD quality paint, any colour/brand into an aerosol can. 

Agreed. Do it once and forget about it.

I'm planning on using spray cans since I don't have access to a compressor in my little garage 😂
Maybe I could use this epoxy spray? a bit pricey though: https://vgautopaints.com.au/collections/primers/products/eastwood-2k-aerospray-epoxy-primer-gray-aerosol
 
If I went with the etch primer, how do you "blend" the bare metal to the existing paint since the etch primer cant touch the existing paint? or is a little bit of overspray ok

The only difference I'd say to that is instead of etch, use ppg epoxy (or similar) after you sand the bay. It will permanently seal the old paint and bare metal at the same time and give you a consistent base layer to work up from. The stuff I use was called ppg 408 grey-green but it's had a name change that I can't remember the new code.

TBH i wouldnt strip it completely unless it is really bad. you can just clean up the rust affected areas and key all the other paint if it is sound. Really depends what you want to acheive. certainly stripping to bare metal etch prime, prime, body work, base and clear is the way to go for a restoration but if you are just doing a  tidy up theres no need to bare metal the bay.
 
Ive done both ways and each looks equally as good, one just take 100s of hours more than the other.

Go for it. rub the rust back and prime it and then spray out the whole bay.
 
Dont waste time filling holes or smoothing unless you are going for a show car. Its amazing how much different a clean bay looks.
 
Id just use some 80 grit on an orby or a 120 grit flappy disk on a grinder to clean up that rust and spray it out.

Looking good

Yeah, did the same with my Fairmont. Kept every part in the shed, in case I wanted to put it back to stock

thanks mate. 
 
it certainly turned out to be a bigger build than originally expected, but yes there has been little expense spared. I figured I’ll never be able to afford to buy another one, so build this into the car I want. 
 
best thing is, its all reversible back to 100% stock if i wanted to. 

Wow..!    This is going to be spectacular.  Well done mate, all the good gear, in a sweet little Esky. Will go like stink, and stop on a dime!

This car is going to turn out really nice

better than new!

I spent yesterday afternoon making all the engine bay brake lines
 
not bad for a first timer 
 
 
 

This is where I am up to. Progress has been really slow, because I am now back at work, and we are smashed at work at the moment now that restrictions have been all but lifted. 
 
This is the driver's side strut complete. 
 

 
I had to get the hubs machined down on a lathe, which I knew was the case, to replicate Cortina Mk2/Capri hubs. 
 
Very very little space. I potentially will need to get a tad more off yet. But it does clear and run freely. 
 

 
 

Problem found. 
replaced the fan speed switch  and is now as good as the day it left the factory. 

voltage may still be fine with a dirty switch, but it might not handle the current, just try switch it back and forth 20 times or so. might work, might break it possibly. 

i'd assume XH is same, not 100% sure. same goes for XF 

switch itself could be dirty also.. could spray some CRC/WD40 in it and turn it on/off 50 times and see if it comes good

That's the best way to go and in reality, it doesn't take any extra effort when compared to chasing problems later (paint reactions, bubbles, etc)

Thanks mate. At this stage I think we're heading down to fresh metal and starting over. Thanks!

Id be pulling any filler out to make sure the rust isnt in behind it.

Yeah that's the type, refers to the curly nylon abrasive. I use a large diameter disc without the backing pad. Get them from your local bodyshop / auto paint supplier. It's important to use a variable speed grinder/sander for this type of disc. Don't spin them too fast or they will break apart and fly off at high speed. I usually run at about half speed on mine. That also applies to the type you linked with the backing pad, the glue is often weakened from not being stored properly prior to sale.

Thank you mate, that is really in depth, thanks for spending the time!
Just to confirm, when you mention poly disks, you're talking about this type https://www.supercheapauto.com.au/p/toolpro-toolpro-poly-abrasive-disc-115mm/553770.html?
 
 

The best method is bare metal then prime with ppg 408 epoxy (in grey-green is the best version), then filler if required, reprime with the 408 epoxy to seal the filler, then start the process for painting (hifill, sanding, colour etc). You can do a panel at a time, the epoxy is 2 pak but does take a long time to dry so be aware of that but it's relatively cheap and the best on the market as far as the resto scene is concerned. I'd strip it with a poly disc for most of it, red brush what I couldn't reach, treat any rust with acid then seal it as above with epoxy. It will be good for a couple of years if done correctly like that and weather proof as well.

I use these from supercheap

https://www.supercheapauto.com.au/p/toolpro-toolpro-nylon-filament-wheel-brush/550790.html

Use in the power drill it will take the rust off without biting into the metal like a grinder wheel. It will strip paint, filler, primer, rust and clean up metal for welding. I use them the most along with flap wheels and strip discs. You can do the red brush first or you can get some rainex rust buster acid from bunnings (phosphoric acid) and use a bit of steel wool or a scourer /scotchbrite to scrub any rusty metal. The acid is brilliant and will take off all the rust with a little elbow grease, back to clean metal, scrub on, wipe off, it will only react to bare metal (doesn't work through paint). Give it a sand when you are ready to paint it, as if it was just bare steel, sand with 180# start primer, slap some paint over and all good. Assuming you just want to patch it so it doesn't rust to pieces. If you want to respray the whole thing, strip a panel at a time, wash it down with acid, wash it down with metho or thinners, epoxy prime then start the repair/paint process.