Hi all,

I did a quick forum search and found threads on undercoating and how it's a must but not on any recommendations as far as what brand and product to use. I looked up 3m's undercoating products and was amazed at how many different rubberized undercoating sprays they sell. The descriptions on amazon are pretty much the same for all of them but the price varies greatly (some are $10 a can, some are $20).

Here's a few links for examples:



and so on

Which one would you guys recommend? Also, how many cans do you think I should get?

Thanks!

 

I heard of a story where a man drove his jeep through freshly poured concrete and the splatter to the undercarriage was enough to cover and keep it protected and lasted even after the rig rusted out... Just something to think about...


But if that's too extreme and manly for you, I've seen many good thing about the dealership under coating. Don't know about the ones you posted though

 

haha. that's some jeep lore if i ever heard any. reminds me of a post i found about a guy who was looking at a j10 and asked the seller why the bottom was covered in what appeared to be vasoline or a similarly thick, petroleum based product. the seller said it's the only way to keep those old jeeps from rusting out lol.

 

I've been using this Chassis Saver. You paint it right onto rust, and it seals it and stops it for good! It is a very tough coating, and doesn't require any stripping, so it's easy and you won't have to worry about rust! Plus, you can paint right over it to get the color you want! Check your local NAPA store, they should carry it.

http://www.magnetpaints.com/underbody.asp

 

If you believe that enough to repeat it, and you're not on drugs I have some swamp land in florida I need to dump, prime location too...

btw, iirc chassis savor and products similar require 'rust' to be present and is not recommended over coatings...

personally I've never used an undercoating (rubberized like the factory one) so my opinion is only that, so go with the one that you feel is better suited for your application... whether you're going over existing, or you're starting from scratch...

 

This is what i used on my 65 mustang after i restored it. works great and looks even better. I purchased a bed liner spray gun to make it look professional.

Dupli-Color® - Bed Armor™ Truck Bed Liner with Kevlar

http://www.bedarmor.com/bedarmor.php

 

Regardless of the final product underneath, definitely get an oil spray done. I think you guys have Krown down there too. Oil spray gets into all the nooks and crannies and prevents standing water/salt from eating things away from the inside. Rubberized is great but consider the inside of the doors, rockers, frame rails, body pillars, etc.

 

I've used a few cans of the Third one that you posted. My local napa carries it for about $16. It works pretty well, real even coverage with just 1 coat. It won't be as tough as something like bead armor but works well for what it is.

 

I wasn't sure if it was just a coating you were looking for or something to stop and coat surface rust. I guess I'm still in rust mode from being in Maine. In that case then, yes. Bed Armor would be a great idea!

 

there's definitely some rust spots under there already but nothing too bad. I'm hoping I can just sand those down and apply some bed armor or something similar. think that'll work or should I look into something to coat the rust and use bed armor on the rest of the spots that aren't rusted?

 

For dealing with surface rust like that you really have to get it to bare metal, prime, and do a product like bed liner or a rubberized undercoating (I prefer rubberized stuff - different from asphalt - because gravel and the like doesn't 'ping' when it bounces off). If you can't get it down to bare metal through sanding or grinding, you can use a rust converter to treat the corrosion. Most of these contain an acid like hydrochloric or phosphoric that reacts with iron oxide and a new material shows up in its place. The resulting treated area is paintable.

 

Surface rust is great for chassis saver as well. clings right to it! No sanding required, plus it stops the rust dead

 

All of my cars have built in chassis oilers. (Factory valve cover gaskets)

Kidding aside, oil is great for undercoating because you don't have to worry about it peeling up like normal undercoating. Here in salt country the rubber and asphalt sprays work great for a few years then when they crack or peel they rust out worse because they trap the salt.

I've seen cars that were deliberately oil sprayed every few years and they looked like new underneath. Dirt circle track guys use baby oil in a garden sprayer so the dirt comes right off after the races.

 

I tend to alternate every other year with fluid film" and husqvarna bar and chain oil. Fluid film is made of lamolin , aka sheeps wool and some kind of " natural" oil. The fluid film is great if you have very heavy salt conditions as it uses the sheeps wool particles and sticks like glue. It goes on very tacky though compared to a usual undercoating.

 

thanks everyone for all the advice. i think i'll go with some chassis saver for the rust spots and probably do some sort of rubber coating although the alternatives to rubber are intriguing and probably cheaper. we do have a good amount of salting done during the winter months especially recently so i have to do something before i make her my daily driver.

if i do go rubber, i could always inspect it every year and spot re-coat cracked areas more rubber coating, correct? i wouldn't have to remove the current coat to reapply, correct?