Undercarriage Care Suggestions?

[NJshadow93]

After I lifted my truck, I have easier access to the undercarriage. I would like to take care of the minor rust going on down there (skid plates, little bits on frame and rear axle, etc). I have searched, and saw threads about spraying bed liner down there and similar methods. I was thinking of getting one of those rust converter spray paints, but I am not sure what is safe to use down there with the heat. Any suggestions? I would just like to take care of it before it gets worse, and especially before winter. I already wash it once a week in the winter but would prefer to take care of the rust that's down there. Thanks!

 

[rebelbowtie]

My recommendation is to clean the area with a pressure washer to remove salts and contaminations, then apply a rust converter like Ospho and let it sit for 24 hours. Wipe the area clean with solvent and then paint it with an underbody coating.

 

[xxaarraa]

I have heard that "underbody" or "bed liner" type sprays that have a rubberized texture to them are not good to use as they still let moisture through and it is likely to rust from underneath. I have heard people say to just use regular paint (Rustoleum or similar), or if you want to get creative, use gear oil or heated up chainsaw oil.

I have personally not had to deal with too much rust so this is all just what I have heard. Take it for what it's worth:biggrin2:

 

[Runner27]

I sprayed my undercarriage with Rustoleum engine enamel last summer. Still hold up great.

 

[eli_lilly]

On a rusty Cherokee I had really good luck with Eastwood's Rust Encapsulator. Just knock the loose rust off with a wire brush and spray or brush it on. I had really bad rust behind the rear wheel well and even five years after I applied the Eastwood stuff there was still not even a speck of rust.

-E

 

[MikeInNH]

I have heard that "underbody" or "bed liner" type sprays that have a rubberized texture to them are not good to use as they still let moisture through and it is likely to rust from underneath.

Don't know who told you that...but it's totally bogus. They keep out moisture very well. That is exactly what they are designed to do.

The problem people had with using them is that it was applied when it wasn't dry...Thus trapping the moisture in. Also all rust must be removed or properly treated with a rust convertor and let dry for at least 24 hours.

 

[NJshadow93]

Don't know who told you that...but it's totally bogus. They keep out moisture very well. That is exactly what they are designed to do.

The problem people had with using them is that it was applied when it wasn't dry...Thus trapping the moisture in. Also all rust must be removed or properly treated with a rust convertor and let dry for at least 24 hours.

I have heard similar issues with underbody rubberized sprays or bed liner. Not sure how easily this can happen, but I heard little rocks can chip the by bed liner or undercarriage coating; allowing moisture in and keeping it in. This is just what I have heard though, not sure how accurate that is.

 

[rebelbowtie]

I have heard similar issues with underbody rubberized sprays or bed liner. Not sure how easily this can happen, but I heard little rocks can chip the by bed liner or undercarriage coating; allowing moisture in and keeping it in. This is just what I have heard though, not sure how accurate that is.

That happens with ANY coating system, it's called a holiday. It's a break in the coating and it allows moisture and contaminates to contact the substrate and cause corrosion from under the paint.

 

[boondoggle]

Get some POR-15 and dab it on the rusted spots.

SUPER STARTER KIT Stop Rust Permanently with --POR-15 Inc.

Or go crazy and do the whole undercarriage.

Good stuff. I used some on my old Wrangler.

 

[MikeInNH]

How much moisture is going to contact the bed of a pickup when there isn't spary-on bed liner.

The older hard-plastic liners had a problem with trapping moisture. But the new spary-on bed liners while they may rust if scratched....they will keep the bed of a pickup lasting years and years longer then without...especially here in the North East where snow and road salt have great ways of killing truck beds. Before spary-on bed liners...in places like upstate NY...any open bed would last maybe 2-3 years before there were rust holes....now they are lasting 7-10 years.

 

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There has been so much disscussion on this topic and yet we're still beating on dead horse. Bedliner works for flat bottom part of the frame. Spray on rust converter for welds and hard to reach places.