Painting them would be fine. Beavers do not smell like canines. (They have more of a castor smell). You don't need to worry about scent. The #4's that you have will be ok as long as the pan is setting level.

I second that, CoonDuke!

I just got a dozen new 330's. I degreased them with a product called Greased Lightning. First I hit them real quick with a scrub brush and a greased lightning and warm water solution. Then I sprayed them down with straight greased lightning, let them set for a minute, and then rinsed them off with hot water. I then painted them with flat brown Rustoleum...they look nice anyhow! I asked a similar question a while back, because it is now too cold to get dip to dry any time soon. A few guys said that some beaver will shy away from an untreated trap.

Painting or dipping,while not necessary--speeds up and protects your traps.
Nothing worse than using a rusty 330 and having a fine beaver pelt stained by rust.
Take care of your tools,they perform better and last longer.
Tom

I second what Bogmaster said. Any metal, unless it's aluminum, that is exposed to the elements should be painted or something. It doesn't take long for the paint smell to go away.

I think a trap with a little paint odor would be better than a rusty trap under water.

I spray paint all my conis. Flat black Wally world spray paint... under a buck a can. Couple of coats and it lasts pretty good. Touch up is easy...and it dries super fast with little residual odor.

My MB 750s I usually dye and wax...mostly because I just throw them in with the other traps when I dye and wax. I've also run them with spray paint and it works....but not as well...IMO.

Poundage setting on the pans.. anything from about 2-5 is workable. Roughly 4 being what I normally set them at.

I spray paint all my beaver traps.