Thanks so much for all you nice comments
Be more that happy to share my painting experiences. I didn't sandblast the housing even though I have a small blaster. Just didn't have a compressor at the time to power it.
Blasting is the way to go. If you can find someone who isn't to expensive. And knows what they are doing. You can warp sheet metal if you don't do it right.
I just used a right angle grinder. Different grit sandpapers and 3m Scotchbrite Surface Conditioning disks. But just sand paper and some good old fashioned elbow grease will do.
I also ground/sanded the off edges off the steel at all the overlapping seam joints. To round the corners. I used automotive Seam sealer or Spot putty to fill in the seams of
those joint. So as to create a more rounded corner or edge. Paint will stay on much longer, on a round edge than a squared corner edge. If you look at the finished photos.
You won't see any gaps or spaces in the paint at the seams on the ends of the blower housing. You can hardly even see the seams.
I think I probably coated any spots that still looked a little rusty after sanding with a Rust Stopper paint/primer. Usually you would coat any bare steel with an Self Etch Primer
before applying a primer but I think I skipped that. (You wouldn't want to do that if you were painting a car).
Everything was then well coated with a Rust-Oleum Red Oxide Primer with Rust Inhibitor. Great stuff. It goes on think and fills in small imperfection like rust pits. Dries fairly quick and can be sanded smooth (if you choose) to give you a nice smooth surface before the top coat. I believe this is an important step. That primer really binds to the steel and also gives the top coat something good to bind to as well. The primer will be dry in 20 to 30 minutes or so depending on air temp. and humdity. But I usually call it a day by then and let it dry overnight.
Before I top coat it, I usually run a green Scotchbrite pad over all the primer to knock of any overspray or little nubs that may be sticking up. Or I might sand any
really rough spots or orange peel smooth. Make sure that your hands are clean and any rags you might use are clean as well. And if you doing this in the summer, even sweat
on your hands can put a slight oil film on the primer that the paint won't want to stick too. Wipe the whole thing down after sanding with a clean rag to remove any dust.
Or use a clean dry paint brush which also help to get dust out of corners and cracks.
For the top coat I use Rust-Oleums Engine Paint. "Chevy Orange" not the "Red Orange Chevy orange" they are two different colors. I've tried quite a few and this paint over
a Red Oxide primer is almost dead on to the Ariens orange. Any chain auto part store carries it.
I usually start by giving the entire part a tack coat. Which is nothing more than a light see through coat. If the part is small let it sit for a couple of minutes, not long. If the part is large like a blower housing. You can finish with the tack coat and go back to where you started and start putting it on thicker to really cover. But go back and forth over a certain spot until it's covered well. Don't just spray it on in one continuous spray.
You might get some runs. Spray to the left come back over the same spot going to the right and back again to the left. It should be completely covered and shiny by the
third trip. Over lapping each motion and moving downward. Watch so that the overspray isn't landing on area that you just painted. I usually work from the top down.
When you think your finished and your happy with what your seeing. Stop and look over things real close. Look for spots where the paint may be a little thin or spots that you missed.
I should clarify something here, I said I usually work from the top down. I do. But I usually, as with the blower will put a coat on the bottom of things first. Places that are going to
be hard to get to with a good coat with out having the blower turned over. So I do the bottom of things fairly well first. Then started from the top down. You don't see the bottom of things anyway. So just getting a good thick coat on the surface is all your trying to do. If the next day you see a spot you really missed. Wait a few days before you give it a
heavy coat. If you try putting on a heavy coat over paint that is still not completely dry. You can soften up the bottom coat and the paint will wrinkle.
That was the long answer. It sounds like a lot to go through but it's really not. You could come close to doing the whole blower in one day. It's just kind of dirty work.
Short answer
Rust-Oleum Rust stopper primer
Rust-Oleum Red Oxide Primer with Rust inhibitors
Rust-Oleum Chevy Orange Engine Paint. (Not Chevy Red Orange)
In the begining
The holes you see were drill so I could plug weld the stainless steel liner in place from the back side.