Got a chance to get the 07 up on an auto lift so I could do a little TLC on the underside and noticed quite a bit of rust and surface rust especially on the welds and bolts. Who ever had this must have done a lot of winter driving where they used a lot of salt on the roads or was having a great time driving up and down the beachs somewhere.
Are these units prone to rusting and has anyone else seen a lot of rust on the frame and bolts etc.?
I used some Rust-oleum rust reformer and hit the bad spots and this did get rid of some of the surface rust. This was used after I took a small wire brush and got rid of the flaky rust. Now am trying to decide if I should use a black Rust-oleum spray paint or I noticed that they also make a undercoat spray? Just curious what anyone else has done to TLC the bottom of their Hummer.
Thought this would make a good winter project!!!

 

NEW RUSTY!

last sept when i got my NEW 10 home i used up a container if the converter stuff. ive mentioned b4 how the weld seems to prep the metal for quik rust. problem is u cant get inside the frame.
imagine the guys who drive thru muddy water and get that layer of silt in all the nooks and crannies,to forever gather moisture!!

yeah,even the drive shafts had s brown tint,and the u joint clips already were rusting. i lathered it on and did some more in july this year.
prob a good annual thing to do. even in my oversized body i can get under the h3 on the driveway so its just something to do on a warm day. bring it on!
btw it had 9 miles on it just sitting on the lot,no salt roads when i got it!

 

I'm gonna Por 15 the welded seams on mine this spring. Some fo the GM products don't have nearly as good of a finish on the undercarrage as some other manufacturers.

 

What is the name of the product you are using to contain the rust on the under carriage?
Could not make out the product from your threads.
Thanks for the reply.

 

I do agree with the poor finish on the GM products.

 

its not rustoleum!. i cant find the mt container. got it at ace hdwe paint dept. there are a number of "rust converters" that actually do some good. i dont think its permanent , but you might find one better than i did. someone else will be here soon. happy n y.
oh i also had some from jc whitney,DANGEROUS FUMES!!. i guess it was good huh. i sold the car so i dont know.

 

Our 2008 had a TON of surface rust on the undercarriage. Minimal use in winter and no offroading either. I took it to a fellow here in my area of Michigan who does the service work for a local GM dealer and he was shocked at how poorly the factory paint lasted. I had it sanded, base coated and painted black, then clear coated. Not all individual parts were removed, but many were. Any aluminum cast parts were blasted and clear coated. Installed the Magnaflow exhaust and new Bilstein shocks all around. The undercarriage looks great now. Set me back a few $$ but I'm glad I had it done.

 

i had 2 different experiences with factory undercoating.
a ford crestliner had a light colored coating that years old still felt "alive". it just didnt rust.my thinking was that being a delux van they put some good stuff on it so nit wouldnt go quickly.

the probe gt had a black heavy coating that, over years seemed to trap moisture. i got the probe 10 yrs old, too late to save it. i really liked that car. it must have looked good when new,but i scraped off loose layers of coating with rust stuck to it. nothing would stop it. understand that this was the under body,the outside looked new at 20 yrs old. 1990 to 2010,with very little rust showing

the h3 really just has a light coat of paint it doesent look like any coating to me.

 

The '08 we currently have is our 3rd H3 (the past two were '06's). This one had the worst rust problem of the 3 by far. The places that didn't have rust seemed to just have a very light paint or undercarriage coating left from the factory. Disappointing to say the least.

 

Get some OSPHO at Ace hardware..Put some in a spray bottle and do the spots needed. Have used this for 20+ years..Good for old and new steel protection .