To spray or not to spray

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NY2LA

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Hi, guys. I'm awaiting my skid plates to arrive from Budbuilt, and meanwhile I'm trying to decide if I should bother with an undercoating before putting them on.

Upon inspection of the underbody, I find very little rust. Despite spending most of my time in the Northeast, including on many salty roads, even my KDSS valve is in nearly perfect surface condition. This may be because I always make sure to clean the underbody at the car wash and keep the truck in a warm garage where moisture does not linger. Most of the rust seems to be on the exhaust system, and it's still pretty light there.

I'm also not sure if I should bother with an undercoating, because I end up soaked in mud a lot of the time and have to powerwash it off. Not sure if an undercoating will hold up very long in such conditions. Seems like a PITA if I have to take off skids to re-undercoat all the time.

What do folks think on this?
 
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I live in the Mid Atlantic and spray Woolwax or Corrision Free on mine every year. That probably explains why I don't have rust. I do spray the undercarriage in the winter and after offroad outings. My truck stays outside. Undercoating still appears intact.

I would think the undercoating would repel some of the mud but it usually collects a lot of dust first which adds a layer of protection.

It can be a pain removing the Budbuilt skids. I don't bother with the gas tank skid as it was a PITA to install and our tanks are plastic.

However, I'm always surprised with the amount of crap I find on top of my skids when pulling removing (rocks, wood parts and a pounds of dirt). I do wheel it quite a bit.

I can spray the undercarriage down in less than 30 mins. Maybe add another another 1 hour to remove and install the skids. Taking them off allows me to inspect the skids and their bolts (which I've damaged before) and other parts that I can't visually see when skids are on.
 
prharper said:
Taking them off allows me to inspect the skids and their bolts (which I've damaged before) and other parts that I can't visually see when skids are on.
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How long does it take you these days to remove them? And how to get your truck up? Ramps? Jacks?
 
I am in NH, and I have my truck sprayed annually by a shop very near me with the NHOU sauce. Seems to work well. I always remove the BB skids and drop the spare tire before taking it over to be sprayed, which they tell me is a huge help.

I have a QuickJack to lift the truck about 15", and I made a cradle for the very heavy SS engine skid that fits on my floor jack. This makes it much easier to reinstall.

When I was prepping to install the new suspension I power washed the stuff off only on the parts to be removed so I wouldn't get the stuff all over me. It look a lot of Super Clean degreaser and scrubbing to get it off, so I would say it sticks very well.
 
Update: I just had a call with Bob at Woolwax to discuss some technical questions about that specific product. Got some good learnings, at least from his POV.

He suggested that after the Woolwax is applied, I force a coating of light dirt onto it by driving around a dusty area to make the Woolwax less sticky. Then, when washing the mud off later, to use light pressure. He also noted that if I'm forced to pressure wash, it's okay to spray on another layer of Woolwax afterward without stripping everything down first. If mud gets caught between two layers of Woolwax, that is okay, he said. It won't be pretty, but it will still keep the moisture off from vehicle components and provide protection.
 
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I typically spray inside all body panels and inside the frame during the summer when the heat helps distribute the coating. I then have everything else - the outside of the frame rails, the suspension, etc - professionally sprayed with woolwax in September. This process seems to work well - 8 years old and no rust even with lots of winter salt exposure.
 
Somewhat on topic on as I would like to look into spraying/different options. I live in an area that's dry with no real vendors doing undercoating sprays around.

How long do you think an undercoat would last if I get it done in one of these snow/salt states but drive it mostly in a dry state like AZ/TX?

I have some slight surface rust that I want to neutralize. I also have a roadtrip coming up to the midwest around Thanksgiving. Thinking of getting it sprayed while I'm over there or just doing it myself.


To the OP's original post, I'd say just get it sprayed if you're on the fence. Should do more good than harm.
 
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AZLX570 said:
Somewhat on topic on as I would like to look into spraying/different options. I live in an area that's dry with no real vendors doing undercoating sprays around.

How long do you think an undercoat would last if I get it done in one of these snow/salt states but drive it mostly in a dry state like AZ/TX?

I have some slight surface rust that I want to neutralize. I also have a roadtrip coming up to the midwest around Thanksgiving. Thinking of getting it sprayed while I'm over there or just doing it myself.
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How much surface rust are we talking about?

I would not do an undercoat unless it is truly needed, and it isn’t in Arizona or Texas. Any work you do under the vehicle will be messy, it will need eventual upkeep, and in those dry states won’t really make much difference.
 
bloc said:
How much surface rust are we talking about?

I would not do an undercoat unless it is truly needed, and it isn’t in Arizona or Texas. Any work you do under the vehicle will be messy, it will need eventual upkeep, and in those dry states won’t really make much difference.
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This is an interesting perspective, for sure. Would love more takes on this from people in this camp.

I don't have much surface rust. For example, my KDSS valve, which seems to be a common rust issue for people, has no rust at all, after 40,000 miles spent mostly in the northeast. I see only light superficial rust mainly on some exposed bolts and in a scattering of places around the exhaust system and some other bits.
 
NY2LA said:
This is an interesting perspective, for sure. Would love more takes on this from people in this camp.

I don't have much surface rust. For example, my KDSS valve, which seems to be a common rust issue for people, has no rust at all, after 40,000 miles spent mostly in the northeast. I see only light superficial rust mainly on some exposed bolts and in a scattering of places around the exhaust system and some other bits.
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There is a ton of evidence that the KDSS valve in particular is a source of big corrosion problems, and plenty of other rigs have problems with corrosion on the chassis bolts that make maintenance or mods pretty difficult eventually. Whatever you are doing with your rig in your climate is working, so keep doing it. But many aren't so fortunate, or bought used rigs where the damage was already done.

In your case I do wonder if the skids will reduce some of the access that the rinse water has had to certain areas and possibly increase corrosion there. Personally if I lived where salt was a thing I most likely would make the sacrifices for an undercoating to know the vehicle won't dissolve out from under me. It's just that I can't see those sacrifices being worth it in a dry/warm climate.
 
bloc said:
In your case I do wonder if the skids will reduce some of the access that the rinse water has had to certain areas and possibly increase corrosion there. Personally if I lived where salt was a thing I most likely would make the sacrifices for an undercoating to know the vehicle won't dissolve out from under me. It's just that I can't see those sacrifices being worth it in a dry/warm climate.
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Yes, I'm wondering how much skids have been affecting corrosion for people. I've been powerblasting the undercarriage regularly and haven't had skids, so I wonder if that's helped me avoid corrosion.
 
bloc said:
How much surface rust are we talking about?

I would not do an undercoat unless it is truly needed, and it isn’t in Arizona or Texas. Any work you do under the vehicle will be messy, it will need eventual upkeep, and in those dry states won’t really make much difference.
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Good advice. Surface rust isn't bad, just a bit up front from some time it spent in a northern state earlier in its life.

What I'm learning as I go down the rabbit hole of undercoating is that what I believe I need is more of a rust "stopper" undercoat (DIY part I was mentioning). Not a yearly undercoat that eventually wears off.
 
AZLX570 said:
Good advice. Surface rust isn't bad, just a bit up front from some time it spent in a northern state earlier in its life.

What I'm learning as I go down the rabbit hole of undercoating is that what I believe I need is more of a rust "stopper" undercoat (DIY part I was mentioning). Not a yearly undercoat that eventually wears off.
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The ‘stopper’ versions like Zie… trap moisture and salt as the layers develop cracks. Actually accelerates rust and destruction. You want a lanolin-based product like wool wax or fluid film as the are self healing and do not trap moisture. You occasionally have to reapply but it is not a big deal. And it works.
 
AZLX570 said:
Somewhat on topic on as I would like to look into spraying/different options. I live in an area that's dry with no real vendors doing undercoating sprays around.

How long do you think an undercoat would last if I get it done in one of these snow/salt states but drive it mostly in a dry state like AZ/TX?

I have some slight surface rust that I want to neutralize. I also have a roadtrip coming up to the midwest around Thanksgiving. Thinking of getting it sprayed while I'm over there or just doing it myself.


To the OP's original post, I'd say just get it sprayed if you're on the fence. Should do more good than harm.
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If there is minor bits of rust put some Corroseal on it, no need for undercoating in dry climate.

Wear old clothes gloces and dropcloths as it turns black when it dries.
 
NY2LA said:
Yes, I'm wondering how much skids have been affecting corrosion for people. I've been powerblasting the undercarriage regularly and haven't had skids, so I wonder if that's helped me avoid corrosion.
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The good thing about salt is it rinses away easily as long as there is some fresh water to do so. Seems like getting creative with how the undercarriage is sprayed could mitigate the risk of the skids changing the game here.

Sand and gravel piled up in the places it is common (like the body mount structure behind the front wheel wells) will continue though.
 
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