Remove all dirt, oil, rust, sand lightly, I would recommend a primer first and then apply a at least 2 coats and you will be fine.
Yes, you can put polyurethane paint over eggshell in latex or eggshell in oil.
Yes
I make it a habit never to mix water-based with oil-based, way to many problems occure. On the up note they have water-based poly, use that. Good-Luck
No you cant ,you should never ever put water base over anything except oil base primer and any other water base paints.If you put water base paint over anything that is oil based it will never ever stick it will peal.People will tell you you can do it but they are wrong its bad voodoo
Can you put stain in polyurethane to darken the color?
yes but you cannot put latex on top of oil based surfaces You actually are NOT advised to put oil over latex surfaces, which is why you're supposed to prime will an oil-based (alkyd) primer. Latex and Polyurethane should always have a layer of oil-base beneath it.
Absolutly! You just have to check to see if the primer is first an exterior primer and if it will stick to glossy surfaces. You can lightly sand to rough up the surface or just clean the surface and apply the primer. For oil based primers I would recommend Beauti-tone's fast dry oil primer or Zinsser's oil based cover stain primer.
Yes, however clear polyurethane has a yellow cast that will affect the color of the paint. Most water based clears are crystal clear, very durable and can be used in place of an oil-based clear coating.
Yes, you can use latex paint over poly but you have a few steps to do before you can apply it. First, whether the poly is oil or water based, you'll want to sand it to give it a tooth (something to grab onto). Make sure to wear a mask and goggles. Next, prime the surface you want to paint. You can fill any hole or fix imperfections over the primer but you'll have to prime those areas again if you do. After you're priming is done, you can roll out your paint. Quick note: if the poly is oil-based, I would use an oil based primer (Zinsser"s bin 1-2-3 oderless oil primer, white can with yellow flag on it). You can roll latex over this primer.
yes
Yes, as long as the container has no metal on it.
The heat created by metal on metal friction will eventually cause a metal failure and seize up the engine.