lipstick on a pig?

[Spangles]

Hello,
I was thinking about repainting the backhoe. The paint is faded and there are quite a few rusty spots that's bubbling up the paint etc.
Would it really need to be stripped to bare metal all over before priming and top coating ? Or Can the rusty spots be sanded clean, top coat rough sanded and primer applied all over then going over with new layer of top coat?

For primer and top coat I was thinking about : quick drying, non-sand primer undercoat and Enamel Polyurethane

Many thanks

Spangles

 

[CatToy]

I think if you spend a little time with prep, a ok paint job make your equipment look good, which makes you feel better about it. For a lot of my old equipment, I just pressure/hand washed with Dawn (getting the grease off is key to success), sanded the rusty areas and primed those areas with Rust-Oleum Black Rust Converter and wiped down the rest of it with acetone or xylene prior to painting. I have hired a few equipment painters in the past and I do not think they did a better job than I did but cost a whole lot more. Doing a good job of masking off areas not to be painted will make it look sharp.

 

[Spangles]

I think if you spend a little time with prep, a ok paint job make your equipment look good, which makes you feel better about it. For a lot of my old equipment, I just pressure/hand washed with Dawn (getting the grease off is key to success), sanded the rusty areas and primed those areas with Rust-Oleum Black Rust Converter and wiped down the rest of it with acetone or xylene prior to painting. I have hired a few equipment painters in the past and I do not think they did a better job than I did but cost a whole lot more. Doing a good job of masking off areas not to be painted will make it look sharp.

Thank you for the input. Much appreciated. I will spend the time to prep correctly. Does the top coat adheres correctly on the areas you did not prime?

 

[CatToy]

Does the top coat adheres correctly on the areas you did not prime?

I sometimes scuff up the paint with a Scotch-Brite scrubbing pad but even then, I usually just hit the shinny areas unless it is a small piece, then I might go over all of it. I have painted a few after just wiping it down with acetone, nothing else and they looked fine. My oldest paint job is about 10 years old (see attached picture) and I do not have any peeling or flaking but I do have some fading (that was the paint, I used tractor supply branded equipment paint), so it is good enough for me but obviously the paint job will not be as good as if you sanded and primed the whole piece.

 

[Steve Frazier]

One thing I can add is you can treat the rust simply with phosphoric acid. It will neutralize it. I did some research while preparing steel beams to use on a bridge. Home Depot has it by the gallon, I bought a small pump sprayer there too to apply it with. Read the label on how to do the treatment, the ration will depend on how rusted it is. Show us pics of your progress!!

 

[Spangles]

I sometimes scuff up the paint with a Scotch-Brite scrubbing pad but even then, I usually just hit the shinny areas unless it is a small piece, then I might go over all of it. I have painted a few after just wiping it down with acetone, nothing else and they looked fine. My oldest paint job is about 10 years old (see attached picture) and I do not have any peeling or flaking but I do have some fading (that was the paint, I used tractor supply branded equipment paint), so it is good enough for me but obviously the paint job will not be as good as if you sanded and primed the whole piece.

That does look good after 10 years. Well looked after ?
Thank you for the additional information...I was kinda dreading having to slap on primer everywhere. I think fading can't be avoided so it's fine so long the paint protects from rust. I'm also thinking about getting tractor paint, Enamel Polyurethane which should do the job just fine. Honestly, I feel weak at the knees thinking about having to sand it down and prime it all over...not going to sell the old girl just yet so no need for perfect paint finish.

 

[Spangles]

One thing I can add is you can treat the rust simply with phosphoric acid. It will neutralize it. I did some research while preparing steel beams to use on a bridge. Home Depot has it by the gallon, I bought a small pump sprayer there too to apply it with. Read the label on how to do the treatment, the ration will depend on how rusted it is. Show us pics of your progress!!

Angle grinder with wire brush should take care of the rusty spots. Thank you for the tip with phosphoric acid; will be cheaper than getting a whole tin of etch primer. Wipe off with acetone?
Will definitely take pics of the process.