What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Prevent future body rust?

wkasak

wkasak

Registered Member
Joined
Jun 28, 2002
Posts
59
Reaction score
0
Location
Elkridge, Maryland
Hello all...I purchased a rust free 1991 GMC Jimmy this week originally from Georgia and then Tennessee. It appears that it must have been undercoated when new or by one of the previous owners which keep the under body rust free. I want to ensure that the body stays rust free...what are your suggestions? More undercoating? Regular annual painting? I'm in MD so we do get salt in the winter months. My current idea/plan is to use like a 3M seam sealer any place where two pieces of metal are lapped over or butted up against each other and spray with a good quality semi-gloss paint. Suggestions are welcome...please. I hate rust and want to preserve this rust free truck.

Thanks in advance...:waytogo:
 
Honestly I would say your best bet is to park it in a garage and buy a beater for the winter. I had a very clean k5 only took 2 winters for the salt to eat the rockers even with undercoating etc.
 
Yea the salt sucks it will ruin any vehicle it no time. If you really wanted to drive it all winter maybe undercoat it once every year or two
 
I second the advice on getting a "winter beater" thats already rotted,and keep the nice truck in the garage...and I'd also spray the underside of it frequently with used engine oil ,some guys I know go as far as "painting" the underside of the cab and bed,frame rails,etc,with chassis grease or 90W gear oil to retard rusting from condensation or salt exposure..it makes it messy to work on,but I'd rather have to wipe grease or oil off my hands,than pick chunks of rusty flakes out of my eyes after working under a truck..

I have tried all the usual stuff to prevent rust or "convert" it.like POR-15,Duro Extend,Rustoleum Rust Reformer,etc..they all do work to some degree,at least temporarily,but the salt and weather always win out in the end..painting them with a high gloss enamel like Rustoleum helps a lot,but that isn't permanent either by any means..

I wish I had followed my own advice and treated all my vehicles with oil when I first got them--then I wouldn't have had to buy a dozen more and watch them all dissapear from salt exposure..

Best way to keep a truck rust free is to move to Arizona...often wish I'd been born there...
 
talking about spraying oil down reminds me. i knew a guy years ago who had an old 50's landrover which were notorious for having the frames rot out from under the body. he plumbed the entire frame with tubing with holes poked in them at various points. he then hooked it to an electric pump attached to an oil tank and every so often would just spray down the frame with oil. mind you this was all in the vehicle as well so he was able to do it whenever it needed it.
 
Well...this Jimmy will kind of be my winter/year round "beater". My totally restored '89 K5 Blazer stays in the garage when it's not being driven. So...I'm looking for a practical solution for this Jimmy. Oil just seems like a nightmare. Undercoating is a mess to and I think it has the possibly of locking in moisture which is worse. Unless there is a better idea that pops up...I'm going with the seam sealer and good coat of paint route.
 
Seam seal. Paint. Then oil.

If you find a truck that has a leaky engine (every engine ever made in these eras it seems) The entire truck may be rotted out, but I bet when you scrape that 1/4" of dirty oily crud off the frame, that it looks perfect underneath.

The oily buildup really is the best.
 
I've been tempted to get an old pool off craigslist,and fill it 2 feet high with drain oil,and park my truck in it,& let it soak..but the EPA would not like that idea much...besides,its too late now,the damage is done..

I had a '79 C10 Bonanza with a 250 six that oozed oil out of every gasket,and had some blowby as well--that truck was a slimy mess under the hood,and underneath,but it was also as rust free as a new one,under the sludge!...my foolish desire to have a "clean" truck by pressure washing it off several times was repaid by the rockers and cab corners and the floors developing holes in about 2 years ...was better off leaving it oiled..:doah:...

I lived near a gas station that did a lot of oil changes--to avoid having to dispose of many gallons of used oil,the mechanic used to use a siphon gun with his air compressor to spray the oil he'd just drained from customers cars back under the chassis ,rear quarters,etc...a few complained it smelled,and left drips on their driveways,but years later when their cars and trucks were still rust free,long after all the others like them had rotted away and been scrapped,they appreciated it!...I know a guy who bought a woman's '66 Impala that had all its service done at that station--its probably the most solid rust free one left in New England now...

I have read that boiled linseed oil makes a decent rust proof coating,some mud boggers use that to let mud wash off more easily,and after it dries on metal parts it stays on quite some time before eventually washing off--maybe that would be a less messy alternative to use?..
 
Deuling said:
Seam seal. Paint. Then oil.
Click to expand...


yup.. and the quality of the paint helps too..

what I do, that isn't an option for many, that works great for salt here in joysey is, I keep a garden hose in my garage hooked to a hot water spicket (like your hot feed to a washing machine) and I wash the undercarriage of Mutt MANY times thruout the winter... especially right after a storm...

sh*t's blazin hot... :haha:
 
buy a 55gal barrel of anti-seize and a paint brush. or move out west like i did. go packers
 
You'll never seal the seams. What will happen is that moisture, salt and dirt will get trapped where the sealant DOES work, and it will make the problem catastrophic by the time you see the rust.

Rinsing the undercarriage every time it's driven will keep rust to a minimum.

I've looked at this problem fairly thoroughly, essentially you'd need a belly pan of sorts that covered the entire underside of the vehicle, which emphasis placed on wheelwells to keep spray down from the tires. But it's a huge job, and it's not going to stop rust from salted roads. Might slow it down, but won't stop it.

These trucks simply have too many nooks and crannies for spray to get into.
 
I myself use a wd40/motor oil mix in a squirt bottle. When it's warm it just mists right on.

Than I use green rust check to get in drain holes and stuff were the squirt bottle won't reach.
 
So I was watching Deadliest Catch the other night and this post popped to mind, hopefully Ryoken can shed some light on this. I was wondering, since boats are constantly exposed to salt water why don't they rust away in a few years? Do they use an industrial type of paint on the hulls that is more impervious to salt than automotive type paint? Or do boats just need yearly sandblasting/repainting?
 
for exteriors, depends on the substrate, under 75' fiberglass stuff is gelcoated.. which is a polyester based product and pretty impervious, other than poor UV protection...

some fiberglass boats are painted, but it is much more uncommon.. Hateras paints their boats with imron... a few express cruiser blue hulls get painted in DuPont urethane like Formulas, etc.. but that # is pretty low overall in glass boats, the majority are gelled..

all that said, what your more talking about is larger 100' or so stuff in metal.... they will use many of the procedures I talk about.... either epoxy base primers, or zinc washes for alum usually, with polyester based paints over the top of that... usually that means Awlgrip...

it's basically like a car paint like imron, etc in the sense that is catalyzed, reduced, etc... the main difference being it is polyester based, not a urethane base..... it is a MUCH harder surface... and NOT scuffed and buffed..

keep in mind....a sealed surface, with no open edges will hold up fine, even to salt... not as good as sitting in your driveway, but ok.. when weather has an opportunity to get under an edge tho, watch out..
 
I took mine in a few times to get sprayed down with this sticky grease. It's like cosmoline or something and they spray it inside the rockers, doors, everywhere. For years it gets on your hands and tools and it runs out of the drain holes on the driveway when the weather gets hot. Stinks, too. But I put this K5 through several Michigan winters (8? 9?), so I know the stuff helped a lot.

Too bad that place is like 3 hours away from me now. There are a lot of commercial rustproofing products you can buy and I've always wondered if there was one like this stuff so I could keep up with it.
 
ryoken said:
it's basically like a car paint like imron, etc in the sense that is catalyzed, reduced, etc... the main difference being it is polyester based, not a urethane base..... it is a MUCH harder surface... and NOT scuffed and buffed..
Click to expand...

Are you implying that wet sanding a polyester paint (or urethane) compromises some of it's protection properties?

I've heard that aviation paint is very durable too, so I'm guessing it's the same type used in the marine industry ... not that an aluminum plane needs protection from or is ever exposed to a salty environment - well, maybe once in it's lifetime. :whistle:
 
wetsanding a polyester, absolutely does... will it automatically fail? absolutely not, but it is not recommended for maximum durability....

being softer, a urethane is designed to be wetsanded.. thus why car paints are urethanes..


Imron was the standard in aviation for many moons, don't know these days.. I'm sure muddysub or 62 fatguy can chime in for more modern coatings..
 
oh, and just to touch on something I'm not sure I've discussed in here.. it's not so much an issue these days, but since I mentioned Imron, I figure I'll bring it up...

modern car paints are polyurethanes... nason, ppg's, glasurit, etc.... 97% of what you'll see is a poly.. even tho I'm often guilty of referring to em as just "urethane" due to laziness and not wanting to type out poly too..... even in the previous post...

BUT Imron, in it's 30+ yr history is actually a straight urethane.. not a poly... a different resin base... but they are so uncommon these days, I don't have an issue referring to poly as uro... just want everyone here to know the difference..

the differences being that one, poly's are usually 3 to 1, 2 to 1 or even 1 to 1 in paint/catalyst mix ratio.. urethanes only need 4 to 1...

poly's are also softer than a urethane.. it's one of the reasons Imron retained good "legs" in the industrial market due to it's toughness... poly's are softer, which makes them much more user-friendly when it comes to adhesion, and especially wetsanding/buffing... buffing 6 month old Imron? not so fun... :haha: doable yes, but a bit more work involved...


so you have the paint hardness range of hardest being a polyester, next is urethane and softest is a polyurethane...
 
You must log in or register to reply here.

Latest Posts

Top Bottom