Rhino Liner FAILURE on my 77 K5

[ZombieK5]

I finally started to tear down my K5 that I bought last January. Life got in the way....

Removed the tailgate - No significant issues

Tailpan is dust and the tailgate posts are dust. All of that I expected. The K5 came with a full interior Rhino Liner job. I was anticipating having to spend days grinding it out or somehow removing it. Once the tailgate was out I found small section of liner that had pulled back from the edge of the truck bed. I pulled on it and was able to fully lift the liner off the bed surface. I slid a long screwdriver into the gap and pulled upward. I was surprised to have the liner lift off the bed surface along the entire area. While this is a BOOM for me, has any one seen this? I was planning to line it again once I replaced the existing bed and interior. Any thoughts?? What should they have done to prevent this?

 

[nvrenuf]

If the liner didn’t stick to good metal then that should be bad prep.

As far as the rust under the liner, maybe there was a leak allow water to swap underneath somewhere.

 

[Joel Wilson]

I know a guy who does bedliners for a living and I will ask him the next time I see him. Just seems odd that it is only around the outside edges. I would be seriously looking as to where the water is coming from. Some of those pics look like dry rot in a bathroom instead of rust in a pickup.

 

[diesel4me]

Road salt or other de-icing chemicals cause that..

 

[Joel Wilson]

Road salt or other de-icing chemicals cause that..

Didn't know that course Cali doesnt use salt. So is there anything that you can do to the undercarriage to stop that or slow it down? Like rinse your car off or something? Clear coat maybe?

 

[diesel4me]

You can do 100 things and at best it may slow the corrosion down,but I don't know of anything that stops it 100%...

Oil seems to work the best--the only areas on all the 4x4 GM trucks I have owned that remained rust free was around and above the transfer case,which oozed gear lube out and it coated the cab floor ...or any other areas that got soaked by leaks..
Washing the underside helps slow corrosion down,but doesn't provide any protection..

Years ago many service stations around here used to spray the used oils they drained from cars & trucks back onto the underside of the vehicle ,coating the frame rails,underbody,etc..this not only eliminated any expense to "properly" dispose of the oil,the customers cars would last decades longer than those that were rarely or never washed underneath or had anything applied to prevent this from happening..
Some guys use boiled linseed oil ,that go mudding,it prevents the mud from sticking and also resists rust for quite some time,after it dries to a sticky film..

Undercoat does much the same thing as that Rhino Liner in the photo--bubbles pop in it,leaving an opening and let condensation form between it and the metal and a year later you can poke thru it with your finger..
I've owned a few vehicles that looked nice underneath,all undercoated--till I started picking at it and was horrified when it peeled off ,exposing badly rusted metal devoid of any paint.

That Rhino-Liner usually adheres quite well if the surface was prepped right...most liquid bedliner needs the metal to be roughed up,free of any oils,grease or dirt,then washed good with laquer thinner,that lets it bite into the metal..
If you use enamel reducer,mineral spirits or a pressure washer & soap,it'll peel off like saran wrap not too long afterwards,especially if moisture forms between the liner and metal..vehicles often "sweat" in high humidity or when temperature swings from warm to cold rapidly..most shops that apply rhino liner heat up the metal by parking the vehicle in a heated spray booth several hours in advance and leave it in there overnight..it wont stick as well to cold metal..

 

[LeoneSM]

I see two things going on here:

1) Adhesion to the solid, rust free surfaces is extremely poor. Proper surface prep could have caused this but it's hard to say from the photos.

1a) The failure appears to be a separation of paint or primer layers. There's paint on the bottom of the liner - you don't see black polyurea. The liner isn't failing, the base layers beneath are.

I'm guessing the applicator either missed the recoat window on the primer or just shot over an existing coating. I refuse to shoot over someone else's work. The liner is only as good as the substrate beneath.

2) Rust. If there's rust coming from underneath or if it was shot over, nothing is going to stop that. The only way to prevent is to remove the rust prior to application

I'm guessing this was a combination of the PO saying "I don't care, just spray over it and make it look better" and the shop not going the distance and doing it the right way in order to collect a check.

 

[LeoneSM]

That Rhino-Liner usually adheres quite well if the surface was prepped right...most liquid bedliner needs the metal to be roughed up,free of any oils,grease or dirt,then washed good with laquer thinner,that lets it bite into the metal..
If you use enamel reducer,mineral spirits or a pressure washer & soap,it'll peel off like saran wrap not too long afterwards,especially if moisture forms between the liner and metal..vehicles often "sweat" in high humidity or when temperature swings from warm to cold rapidly..most shops that apply rhino liner heat up the metal by parking the vehicle in a heated spray booth several hours in advance and leave it in there overnight..it wont stick as well to cold metal..

Gotta disagree with this. Temperature of the substrate is almost irrelevant unless you're talking significantly below freezing. Moisture on the surface will cause a hybrid polyurea to blister immediately upon application. You can spray a pure polyurea directly on top of a body of water without issues.

As far as mineral spirits, enamel reducer or pressure washer with soap, it's all about proper usage. Mineral spirits are fine as long as you allow the solvent to flash off. If not, the solvents will off gas and immediately cause a blister. Enamel reducer is fine as long as used correctly. Same with washing with soap and water.

These polyurea products are applied at 2000+ psi and around 150*. The ISO and resin combine in the gun and they're typically dry to the touch in less than 30 seconds. No reason to leave in the booth overnight. Pull the tape and bring in the next...

 

[diesel4me]

I admit not being an expert on Rhino Liner application,I'm sure things have changed since I was in the auto body supply trade..

I only saw some shops doing it early in its appearance back in the day..they were refusing to spray any on a vehicle that sat outside in cold winter temps until it was brought inside and allowed to warm up to shop temperature to avoid condensation issues and any adhesion problems..

Back when I mixed auto paints (up to the mid 1990's) Dupont specifically advised not to use "Prep-Sol" alone,or an enamel reducer,or mineral spirits as both left a residue behind after evaporating that prevented paint from properly adhering,they said to use laquer thinner after Perp-Sol to wash off all the residue..whether this also applies to bedliner coatings I cant say for sure,but I'd assume since they are similar that it would..
At any rate poor prep is likely the cause of the original posters issue..the rot was likely caused by calcium chloride or similar road de-icing chemicals..