Primer Coverage Question


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Old 10-03-20, 01:35 PM
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Primer Coverage Question

In the pic is an outside implement for my BX tractor that I'm repainting. Had most of the factory paint still on it, with scratches and some rust. Sanded the entire thing down, only removed factory paint to blend the scratches in. Prepped the bare metal and applied 2 coats of spray primer. Ending result had some slightly rough finish. Sanded w/400 grit to get what's seen in the picture.

As can be seen some of the factory paint is visible through as the primer coats were light. Where the factory paint remained (most of it) it was solid to the metal. Do I need to have complete blockage of the factory paint in order to ensure the primer has done its job. i.e. solid white everywhere?

 
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Old 10-03-20, 02:56 PM
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Picture shows a pipe/hose??

You do not have to remove all paint primer, in fact original primer and paint is a great base to work with, it was installed in pristine conditions so if its good leave it be!
 
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Old 10-03-20, 03:07 PM
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All of this for an implement???

No, your primer does not need to completely conceal the paint beneath.
 
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Old 10-03-20, 03:53 PM
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More of a restoration. Old post hole digger, connects to the three point. Probably won't have a call to use it again, but I'm practicing on it for future projects. Sorta learning techniques and such before I tackle stuff I want to look pristine. I thought the primer helped adhere between old and new coats, so wasn't sure.

Ok, will topcoat w/spray. I'm using rattle can and on another part of it, whenever I apply the final paint, the end result has a texture feeling (using gloss). When I've used my HVLP on larger objects (either oil or waterbased) the end result is a very smooth finish.

What am I doing wrong with the rattle can? Not applying enough?
 
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Old 10-03-20, 11:44 PM
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What am I doing wrong with the rattle can? Not applying enough?
It's tough getting a food finish with spray cans, the material just doesn't flow out and flatten as well!
 
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Old 10-04-20, 03:38 AM
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Paint in a rattle can is drastically thinned so that it will atomize. This makes it difficult to keep a wet coat because it dries fast. The rough texture is likely from overspray.
 
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Old 10-04-20, 04:32 AM
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Good lighting is important so you can easily see your wet edge. With a spray can I start at one end trying to find that fine line between spraying enough for the paint to wet out smooth and not run, extra difficult on a cylindrical, curved object. I stand upwind and spray downwind so any overspray lands on the area I have not yet painted.
 
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Old 10-04-20, 08:29 AM
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Excellent info from all three of you, thanks! Will try and use that info to figure out how to proceed/revise in my setup.

On to another question, although I probably won't do it for this as its not worth the effort, is it possible to wetsand rattle can w/1000, 2000 to remove the overspray/texture and keep the paint shiny? I have never wet sanded anything and am not sure of end results. Not sure if rattle can leaves enough paint on the surface.
 
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Old 10-04-20, 08:36 AM
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Yes, you can wet sand most spray can paints. As you mentioned, spray can paint thickness is quite thin so you have to sand carefully or put on several coats of paint before sanding. If you work carefully though preventing runs is not too difficult. Vertical causes runs. So, if you are painting a flat sheet of something laying it flat will prevent runs and you can go heavy on the paint. For your auger frame it would be nice if you could hang it horizontally then you don't have as much vertical to pull the paint into runs. I start with the bottom then work up the sides and do the top of the tube last. Just go light on your coats. The bare minimum to get the paint to lay out smooth and without orange peel.
 
 

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