Ok... Stupid Question, What's This Black Tar-like Goop?

[bOLsAK3]

Was looking underneath my new 2011 SLE Sierra scoping out the suspension (assessing lift difficulty) and I noticed that my brand new frame appeared to have a big scratch on it. It initially appeared like a deep scratch, deep enough to expose raw metal. Upon examining the scatch I touched it and realized that there is no paint and what appeared to be black paint covering the frame is instead a heavy tar-like substance. Can someone fill me in on this? I'm a Jeep guy and used to painted frames so this is all new to me. I mean, what's up with this stuff? Is it normal?

[foghorn23]

Not exactly sure what the substance is....wax? But in four Chevy trucks the same "stuff" has been used. I've had no issues from it, but sounds like yours is totally NORMAL.

[MS3DALE]

Its normal,Its a "hot wax" coating GM has been using for years,It usually looks like crap after a few years (IE-It turns a Brown color) but it seems to hold up pretty well.

[ruggedlife]

its all fine until you try to work under your truck and get covered in it, especially if you ever drill into your frame or do any cutting for a lift kit or anything. that stuff is nasty as hell

[bOLsAK3]

Normal then, gotcha!

 

Thanks for the replies. Well, keeping the frame shiny is out, that'll give me more time to focus keeping the paint waxed I guess.

[tyhuck]

Yeah, its just a rust inhibitor. toughter than paint as it wont flake off, but nasty as hell because it will trnasfer onto you at the drop of a hat. I got it on 3 different pairs of jeans and it never came out.

[SCHSIERRA]

I read on these forums a while back that it was "Nox Rust X-121B" from "Daubert Chemical Company" that is used on the frame.

[MS3DALE]

I read on these forums a while back that it was "Nox Rust X-121B" from "Daubert Chemical Company" that is used on the frame.

 

Bingo! Thats exactly what it is,You can actually buy it in 11oz. spray cans from your GM dealer,Part#12346501,Its $12.14 a can.

[BigBlueLB756]

Is that in case we want to screw up our jeans like we've actually been under the truck? JK, JK!

[MS3DALE]

Is that in case we want to screw up our jeans like we've actually been under the truck? JK, JK!

 

Ha,I haven't ruined any jeans,but I have ruined a few t-shirts because of the stuff

I learned years ago to wear old t-shirts when I'm working under my trucks!

[Bob D]

 

 

..its just a rust inhibitor. toughter than paint as it wont flake off...

I've found mine peeling in many spots. I can peel off playing card sized chunks of the stuff. If left in driveway in hot weather, it results in a nasty mess.

[tyhuck]

..its just a rust inhibitor. toughter than paint as it wont flake off...

I've found mine peeling in many spots. I can peel off playing card sized chunks of the stuff. If left in driveway in hot weather, it results in a nasty mess.

 

 

 

Hmmm. Ive never experienced that, but I live in a completely different climate. Maybe its got something to do with the extreme cold or the salt in the winter. Its never done that on me, but it stays relatively warm around here.

[spolleypt]

Sprayed the salt off mine at the car wash today and found large flake of "paint" gone from the frame tube to the bare metal???? It's only 3 wks old, at this rate the frame will be rusted out by next year! Has anyone gotten any answers from dealers?

[foghorn23]

Sprayed the salt off mine at the car wash today and found large flake of "paint" gone from the frame tube to the bare metal???? It's only 3 wks old, at this rate the frame will be rusted out by next year! Has anyone gotten any answers from dealers?

 

On my previous trucks I had always hated the open tubes that are visible in the rear wheel wells. I ran across these plugs on ebay. a few days ago. So I went ahead and ordered. They fit like a glove. They should keep a lot of gunk out and do makes things look better in my opinion.

[pm26]

Yeah, its just a rust inhibitor. toughter than paint as it wont flake off, but nasty as hell because it will trnasfer onto you at the drop of a hat. I got it on 3 different pairs of jeans and it never came out.

 

Try using mineral spirits. It dissolves these types of petroleum base coatings.