Spray paint or undercoat?

[AllBlackBimmer]

I bought my ranger 3 weeks ago.

Previous owner sprayed painted much of the underside of the truck with what I thought was undercoating.

Today when washing my truck (all the salt and crap) and using a car wash high pressure gun, when spraying out the wheel wells it started flaking off in some spots... Which now makes me think it is just rattle can paint and not actual undercoating.

Long story short, once it gets nice out (spring time) I'm going to re do it. Only parts flaking where the wheel wells, but will check out the rest of the underside. I'll try to scrap any loose paint off that I can, then I want to re-coat.

Question is, spray paint - regular rustoeum rattle can black (maybe would get the high temp stuff just cause) or should I use the actual rustoelum undercoating they have?

I want it to last, I don't care what the finished product looks like under the truck and insider he wheel wells. My truck is slightly lifted, but doesn't matter.
I want to protect from salt and rust.

Application will be spray cans of either, for fast easy results. I'll tape and cover areas where I don't think paint should get, like the suspension.

Rattle can paint is like cheaper, but Undercoating is Only a little more,. But is it worth it over spray paint?
I don't really care about the finish, rattle can is good, rubber-y undercoating/bed liner look is just as good.
I want something that is durable.

Thoughts?

 

[alwaysFlOoReD]

The problem I see about either is if you don't prep properly, water gets trapped inbetween the coating and frame and rusts even worse. The best rust preventative I've seen is a leaking motor and trans

 

[Mark_88]

The best rust preventative I've seen is a leaking motor and trans

LOL...my last engine leaked (sprayed sometimes) oil all over the front of the frame...which was in really good shape...but it only reached as far as the transmission...the rear frame just before the rise over the rear end didn't get the same treatment and was rotting...

I want to try to do my new frame with a better rust guard in the spring also...and I want to put hard rubber/plastic liners on top of the undercoating I did last summer...so that might be something to consider...I am going to be using the inner fenders from a 92 Ranger...cut down to fit inside the rear wheel wells on the box...haven't started that project but will have at it hopefully in a couple of months.

 

[AllBlackBimmer]

The problem I see about either is if you don't prep properly, water gets trapped inbetween the coating and frame and rusts even worse. The best rust preventative I've seen is a leaking motor and trans

Yea I get that too.

I'm going to try to get any and all flaking or bad paint off with a wire brush. I hope the good paint on there is on there well enough to serve as a good base.

On another note, I also bought a few cans of fluid film which I will always be using moving forward to help prevent rusting.

 

[Mike Tonon]

Motor oil sprayed from a pesticide sprayer every 6 months.

 

[AllBlackBimmer]

Motor oil sprayed from a pesticide sprayer every 6 months.

Ok ignore the rust protection part..

Spray paint or undercoating? For durability and general protection of bare metal

 

[Bronco638]

I have some type of sprayed-on undercoat in my bed. It's flaking off in certain areas (similar to your issue). For your case, I would use spray paint. If rust does start, you'll have an opportunity to address the issue before it gets too bad. Those spray-on undercoat products can seal in oxidation and you won't know until it's too late.

My truck is originally from northern Florida and is still body color (yellow) on the underside of the cab/bed. A friend with a local auto shop wanted me to undercoat it, badly, to protect it from the salt. At this point, I think that would be very counterproductive. Yeah, it'll help protect from salt but what would I be sealing in? I prefer to wash/rinse regularly and it helps to have a heated garage. Just my $0.02.

 

[AllBlackBimmer]

I have some type of sprayed-on undercoat in my bed. It's flaking off in certain areas (similar to your issue). For your case, I would use spray paint. If rust does start, you'll have an opportunity to address the issue before it gets too bad. Those spray-on undercoat products can seal in oxidation and you won't know until it's too late.

My truck is originally from northern Florida and is still body color (yellow) on the underside of the cab/bed. A friend with a local auto shop wanted me to undercoat it, badly, to protect it from the salt. At this point, I think that would be very counterproductive. Yeah, it'll help protect from salt but what would I be sealing in? I prefer to wash/rinse regularly and it helps to have a heated garage. Just my $0.02.

Yea, I’m honestly not sure if its spray paint or undercoating that is flaking off.
It doesn’t have the “bedliner” texture to it, and it doesn’t appear to be “rubber-y”, which makes me think it’s spray paint, but Im not 100% sure.

In theory you could really wash the undersize of the truck, wire brush all the crap off of it, and let it sit a few days or a week to dry (also could use an air compressor to speed up the process) and then paint or coat your truck.

Then you, in theory, wouldn’t be “sealing anything in” … at least I would hope not.

Since mine is already painted/coated, I figure I’ll re-do the spots that are flaking the way I mentioned above… for you, with a FL truck, I would probably stay away from it as well.

 

[XLTsplash]

I like the paintable under coating. If you have everything clean and dry before you spray it on, it will do a good job of sealing things up. When the under coating is dry you can paint it gloss black. The gloss paint makes the the under coating much easier to keep clean. The sand and salt will wash off instead of getting stuck to undercoating.

 

[Bronco638]

If my truck was new, I would consider the undercoat or "rocker schutz" (as the Germans call it). But, after 14 years, there's no sense in doing all that work to clean the underside just so I can undercoat it. The combination of heated garage and frequent washes/rinses have served me well, in the past.

 

[truckfan]

Whatever you choose, you have to do the prep really well. I would apply penetrating oils twice a year instead since the rig is old.