Noxudol and GM factory wax

[akgrown]

[Long post…apologies]

Hey all - short-time lurker but I’ve been reading tons of undercoating threads here since purchasing a new Chevy Silverado a few weeks ago. I only have 175 miles on the truck and looked underneath this weekend to find that there are already imperfections in the factory wax (photos below) and surface rust in spots. Some caused by having winter tires put on the other day, but others must have existed previously. Coming from a 2016 Ram that had very small amount of rust on the edges of the (e-coated) frame, this was surprising to see. I knew I’d have to deal with the wax coating at some point but I didn’t expect it to be within the first year (or month) of ownership. They brine up here in Anchorage on occasion, which is frustrating (they didn’t use to), and of course all of the grocery stores spread salt in their lots instead of plowing and gravel.

I’ve decided to go with Noxudol 300/700 (thanks for the eBay link for the 700, @Trav) over my other contender, Surface Shield, because I like Noxudol’s ability to react with existing rust and the overall durability. I have a couple of questions though, and hoping the resident experts @denwood, @Trav, @mattd, @LeakySeals, and others can assist:

1. @LeakySeals mentioned that Noxudol is compatible with GM frame wax. Assuming this is accepted consensus, is it better to:
   • Coat the frame now, on top of factory wax (this is my gut feeling), and touch up when needed
   • Coat the frame now, but first remove as much factory wax as possible (not sure how I’d clean the insides of the frame)
   • Spot treat trouble spots for now and do the whole frame when the factory coating seems to be giving out
2. If I were to do the frame in the next couple of months, while still winter up here, I outlined a general plan of attack. Please let me know if this makes sense:
   • Heat garage to 70 (RIP heating bill)
   • Thoroughly wash truck, top and bottom (Is it worth rinsing out inner body/door panels? Or better to not introduce additional water?)
   • Optionally spray underneath with some West Marine “Salt Off” and then rinse again
   • Wait until fully dry
   • Clean off and treat any existing surface rust with Ospho
   • Apply 700 to inside of frame, inner door panels, etc and wait for it to cure for several days
   • Apply 300 to the exterior of frame and remaining undercarriage/wheel wells, under bed, etc and let it cure
   • Rejoice

I’d really appreciate any guidance you all can offer, particularly around how this will all work with the factory wax. Nobody around here sprays Noxudol to my knowledge (or Fluid Film for that matter), otherwise I’d be tempted to hire it out. Here are some photos of my 175 mile frame…nothing crazy, just disappointing that it’s already been compromised. Thanks in advance for any assistance!

 

[Donald]

Do you have a lift and a warm place to spray the product? Compressor & undercoating spray gun?

For areas that see a lot of road spray like around wheel wells NH Coatings sells a rust prevention coating that you brush on with a paint brush. It's that thick. Not for the whole undercarriage but just the areas that will see a lot of road spray.

I am not sure any spray can will properly get the cavities. The undercoating spray guns have long wands somes one with straight and one with 360 degree spray pattern.

If you can spray your truck when the frame in warm-ish then I could certainly do areas where you see surface rust and/or missing factory wax.

 

[walterjay]

Welcome to the Forum!

 

[MasterSolenoid]

Welcome to BITOG
An AI search shows Fluid Film will NOT penetrate GM's wax coating, .... but that's ok.
AI search showing compatibility:
https://copilot.microsoft.com/chats/cdhSiruY8Vb1KsHjfaLJ4

Whatever you decide, keep it .. simple .. so you can always 'easily' redo when required.
I like Fluid Film for inside doors, tailgate, and other places where it will NOT wash off .... it does 'creep' .... also for small touch up areas.
Get yourself some aerosol cans (fluid film) and an 'atomizer' hose/nozzle and get into any hard-to-reach areas.
Cosmoline for high wash areas.

Quote: Coat the frame now, but first remove as much factory wax as possible (not sure how I’d clean the insides of the frame)
"Never going to happen .... again, keep it .. simple"

Anything you do will put you in a better position because most people don't do anything.

 

[GW.]

The good thing about Surface Shield and Fluid Film is the self healing. It also creeps inside cavities and the frame for good coverage.

 

[redhat]

Fluid Film WILL melt GM frame wax. I have seen it happen tons of times. Not that it’s a huge worry but it does happen. The solvent in it does that.

Woolwax does NOT melt GM frame wax, but keeps it pliable. I use woolwax on all GMs.

 

[akgrown]

Do you have a lift and a warm place to spray the product? Compressor & undercoating spray gun?

For areas that see a lot of road spray like around wheel wells NH Coatings sells a rust prevention coating that you brush on with a paint brush. It's that thick. Not for the whole undercarriage but just the areas that will see a lot of road spray.

I am not sure any spray can will properly get the cavities. The undercoating spray guns have long wands somes one with straight and one with 360 degree spray pattern.

If you can spray your truck when the frame in warm-ish then I could certainly do areas where you see surface rust and/or missing factory wax.

I don’t have anything fancy like a two-post lift, but I have a QuickJack 7000 and some 6-ton jack stands. Won’t let me stand up underneath but gives me a little space to work in. I have a compressor that can do 6cfm @ 90psi. No spray gun yet but that’s easily solved. Garage is heated. I guess I was mostly concerned with compatibility with GM wax in terms of top-coating it, and whether to spot treat or do the entire undercarriage while it’s relatively “fresh” from the factory.

 

[akgrown]

Welcome to the Forum!

Thank you!

 

[akgrown]

Welcome to BITOG
An AI search shows Fluid Film will NOT penetrate GM's wax coating, .... but that's ok.
AI search showing compatibility:
https://copilot.microsoft.com/chats/cdhSiruY8Vb1KsHjfaLJ4

Whatever you decide, keep it .. simple .. so you can always 'easily' redo when required.
I like Fluid Film for inside doors, tailgate, and other places where it will NOT wash off .... it does 'creep' .... also for small touch up areas.
Get yourself some aerosol cans (fluid film) and an 'atomizer' hose/nozzle and get into any hard-to-reach areas.
Cosmoline for high wash areas.

Quote: Coat the frame now, but first remove as much factory wax as possible (not sure how I’d clean the insides of the frame)
"Never going to happen .... again, keep it .. simple"

Anything you do will put you in a better position because most people don't do anything.

I like the mindset of keeping it simple, and that doing anything puts me ahead of most folks. I tend to dive pretty deep into projects like this and get fixated on the “optimal” solution. But, I tend to keep vehicles for at least 10 years and like to keep them as nice as I can, while others probably wouldn’t think twice about what’s going on underneath.

 

[akgrown]

Fluid Film WILL melt GM frame wax. I have seen it happen tons of times. Not that it’s a huge worry but it does happen. The solvent in it does that.

Woolwax does NOT melt GM frame wax, but keeps it pliable. I use woolwax on all GMs.

I have seen instances of the frame wax coming off with FF, and in corrosion treatments where the product was heated before spraying (which makes sense). Interesting that Woolwax doesn’t have those issues. I’m still pretty sold on the benefits of Noxudol, but I appreciate the intel on Woolwax.

 

[Donald]

I like the mindset of keeping it simple, and that doing anything puts me ahead of most folks. I tend to dive pretty deep into projects like this and get fixated on the “optimal” solution. But, I tend to keep vehicles for at least 10 years and like to keep them as nice as I can, while others probably wouldn’t think twice about what’s going on underneath.

Don't worry you will fit in. People on BITOG members tend to overanalyze everything. You should ask what is the best oil filter cutter and see the responses.

As Groucho said: "I refuse to join any club that would have me as a member"!

 

[MrkofXcellence]

After having numerous GM trucks with crap wax coatings I bought a couple of cans of this stuff and was fastidious about hitting every last frame wax imperfection I could find. A lot are just scrapes and whatnot from the assembly process. Just go over it with a fine tooth comb and hit it with this. This is the GM recommended product. It is by no means a substitute for a proper underbody treatment, but it is an easy quick first step. I even spray the frame after jacking or taking it to the shop. Anyway, just thought I would pass that on as an easy intermediate step to take. Heres the stuff:

 

[akgrown]

After having numerous GM trucks with crap wax coatings I bought a couple of cans of this stuff and was fastidious about hitting every last frame wax imperfection I could find. A lot are just scrapes and whatnot from the assembly process. Just go over it with a fine tooth comb and hit it with this. This is the GM recommended product. It is by no means a substitute for a proper underbody treatment, but it is an easy quick first step. I even spray the frame after jacking or taking it to the shop. Anyway, just thought I would pass that on as an easy intermediate step to take. Heres the stuff:
View attachment 321821

Awesome, thanks. I have a couple cans of that on the way as it was my original plan prior to getting all gung-ho about the Noxudol. Did you use any rust converter on the exposed spots before hitting it with the wax spray? This seems like a good option to get me to spring/summer weather before I do the full undercarriage.

 

[MrkofXcellence]

I just spray it right on the spots. It is a little thinner than you would expect, but it seems to have staying power.

 

[crashz]

I've had a few GM trucks with the wax coating, and in the one I kept for 10 years, I had many application of Fluid Film. I averaged about once every two years. The coating softened and allowed the Fluid Film to wick.

My biggest issues is that any spot you treat will be fine, but areas that you miss will begin to rust, and maybe rust a little worse. So yearly cleaning and re-treating (regardless of product) is needed.

So my advice is to get it in to your shop now, clean what you can (don't worry about the wax, but just get the salt and sand off, maybe even with high pressure air) and coat with your product of choice. Inside of the frame, rockers, cab corners, door bottoms and anything with a plug access is #1 priority. If you are using spray cans, get the long flexible wands for them. They have a head that disperses the spray pretty well, so it will coat the entire inside. Then tackle the underbody. I cover the brakes with paper and the exhaust with towels, pull the tail lights out, remove the spare tire, tape up the brake hoses, and spray like a madman. A few pair of cheap safety glasses and your most disgusting clothes (you'll throw them away after) and you're good. After re-assembly, removing your protective shielding, cleaning up (its all gross), and putting clean clothes on you'll find all the spots you missed. Like inner lip of the hood.

But that's what next year is for. And you might upgrade to the sprayer (makes a even bigger mess, but its more efficient at getting more product on the truck) so you'll be prepared. And in true BITOGer form, you'll start hoarding coating as well as oil. And coming up with unique blends.

 

[MasterSolenoid]

How to spray inside doors, tailgates, and inside frame openings.
Good for any areas that it won't wash-off.

Fluid Film with an 'atomizing hose'.

 

[MasterSolenoid]

I'd also suggest you get some Mudflaps and rubber Floor Mats.

Read the Owner's Manual for any special - engine break-in procedures.