What's the best undercoating for a DSM?

[DreamChaser7]

I have a little bit of a conundrum that I'm sure could receive some feedback/opinions here. I'm hoping I can get some help making a decision on this. Originally I was thinking I wanted to repaint the undercarriage of my 1G to match whatever color I ultimately decide on repainting the car like it was sprayed at the factory. Then I came across products the likes of POR15. Then I thought well hell black is fine underneath and extra protection would be an added bonus. Now keeping in mind that this is, at least until I retire most likely, going to be a 100% Florida car, I would still like to build this once for whatever the future holds. That being said after doing some research I came across a couple of videos in particular I would like to reference and get other people's hands on experiences for all to benefit from.

Real World Undercoating Test: Fluid Film, NH Oil, Krown and More...​

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Real World Undercoating Test Pt 2: Homemade Solutions, Woolwax, Rust Check, and More...​

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After watching these I'm thoroughly confused as to what product I should ultimately decide on putting on my car. I want something that is going to provide the needed protection we all desire, not have to re-apply yearly, breathe properly apparently, and not rust out my vehicle. Please insert feedback and knowledge here!

And this video here terrifies me about putting the wrong product on. Please watch!

Rubberized Undercoating Will Destroy Your Car!​

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I look forward to everyone's feedback here and hoping to be able to come to the proper decision very soon. Thanks all.

 

[Widgmaster]

Personal I would recommend https://www.krown.com/en/
Not only does this protect but also has rust inhibitors that stop rust in it`s tracks ... Don`t know if there is one close to you or not...

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[DreamChaser7]

So watching that video it seems great and I wish it was all that, I would definitely look into it. But if you watch the first video I referenced at about the 10:45 mark, a real world test shows that particular product performing just about the worst of all of them. I suggest watching both of his videos in their entirety. He seems to have done a really thorough and subjective job. And I am looking for what will stand up to abuse on the undercarriage as well as protect from rust.

 

[RWD4G63]

I went through this same debate last year, and for me personally, factoring in convenience of application and total effectiveness, I decided on Eastwood products. I sent an e-mail to Eastwood asking how to best do an entire undercarriage for maximum protection and this was their response:

The Internal frame coating is a great product for the uses that you have planned for it.

On the rest of the vehicle, after you get the frame down to the bare metal, wipe the frame with Acetone, available at any hardware store, when you wipe it on, wipe the acetone off while it is still wet so that all the oils will be removed at that time. After the acetone has been wiped off and allowed to gas off for about 20 minutes then it would be the time to go to the rust encapsulator.
At that point, you would apply the seam sealer, followed by the rubberized rust encapsulator.

I don't know how much work you were planning on doing to the underside before you applied the product, but if you were considering POR15 I'd imagine you don't have an issue stripping down the car.
You could always use these in conjunction with cosmoline as well. That's triple layer protection haha. I really want to see how cosmoline performs on heim joints/rod ends, as my garage is very moisture prone and they tend to get surface rust on them.


I used the "rubberized" rust encapsulator (this is not the same type of coating as the above video of rubberized undercoating) on the inner fender wheels of my S13. It dries nice and hard and coats very well.

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I think the only thing superior to this would be to put the car on a rotisserie, strip the entire undercarriage down, use the internal frame coating, clean that off where it drips out, then trailer it to a place that applies Line-X and have them shoot the entire bottom side. Line-X is pretty incredible stuff. I got quoted $1500-$2000 for this job from my localish place.

 

[XC92]

I've heard great things about POR15 but haven't tried it myself, mostly because it's pretty nasty and is nearly impossible to get off anything it lands on, and a bit on the expensive side. But I'm about to finish cleaning up and rust-protecting the rear end on my Talon so I might go for it. Still haven't decided though.

 

[RWD4G63]

I've heard great things about POR15 but haven't tried it myself, mostly because it's pretty nasty and is nearly impossible to get off anything it lands on, and a bit on the expensive side. But I'm about to finish cleaning up and rust-protecting the rear end on my Talon so I might go for it. Still haven't decided though.

POR15 is great if the surface prep is perfect, you don't mind a brush finish (it'll self-level on a horizontal surface but not necessarily a vertical one) or you have access to professional spray equipment, and you can do it all in one go (it requires aggressive scuffing to adhere to itself if left for more than half a day). I didn't sand/sandblast the surface of my subframe (just wirewheel) and it peeled off in sheets. That was my bad of course, but it can be difficult to finish uneven surfaces to an adequate level for adhesion sometimes. It also definitely took 3-5 days to come off of my skin in the spots it got on me. It does work great if all the factors align, and is almost as tough as powdercoat. The process just ruled it out for me personally.

 

[XC92]

Then I'd go with some canned spray paint and do the best you can and keep an eye on things from time to time. That's what I've been doing. I mostly used Rustoleum which I've found is so-so for parts that get banged up, like parts that are close to and face the road and get hit by gravel, or ones that get banged up doing work on the car like calipers and control arms.

I recently tried Duplicolor Ceramic Engine Enamel and it seems a lot tougher, plus it dries very quickly. The parts you're working on probably won't get banged up much if at all, so probably anything would work. Eastwood of course is a quality brand so you should be ok if you go with them. Just do the proper prepping, priming, painting and topcoat and you should be good no matter what you go with.

Also, if there are any parts that have rust that are nearly impossible to remove, you might want to try some kind of rust reformer. Good luck and keep us posted.

 

[BLACK'98DSM]

I've always used bedliner instead of undercoating. Undercoating is too soft while bedliner is rock hard.

 

[Dusty Landrum]

Take a quick look through my build on the profile and you will get an idea of what I did with mine. I am currently doing an article writeup actually on this EXACT scenario. Mine is probably over the top for most people , but my car could be next to a freaking nuclear bomb and the frame would still be there when it was over. I am attaching a link as well to a shorten version of how I did things as well. More to come in an article I put out soon, but its a general idea of how I did it.

https://www.dsmtuners.com/threads/rust-proofing-exposed-undercar-parts.535129/#post-153811230

 

[dustyboner]

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[Dusty Landrum]

Good Ol' Boner pulling out some crazy shit as usual hahaha. I bet 90% of those chemicals are either not made anymore or illegal in CA....