Alright guys. Any tips for the bottom of the car. My car is pretty much rust free. Few surface area spots that clean up quickly. Currently I have the rear suspension and tank out. I was going to get a decreased and spray/wile repeatedly to clean, then scuff and do a solvent clean then paint. Any recommendations other then jus por15 for this? Special primers? Tip for better prep?

Any tips on what to do with the heat shields, they have a very rough surface. I am putting a 4th Gen plastic tank and might see if 4th Gen heat shields fit.

 

If you can get it on a lift (preferably outdoors) hose it down with diesel and let it soak overnight then power wash with HOT water the next day - everything will come off and you will be left with minimal wiping.

Unless you have heavy rust you need to encapsulate, I would not put the POR15 on it.

 

yep

POR needs a rough surface to adhere well. it can peel right off of a smooth surface.

good epoxy primer and some paint would be a good option

 

The car is in a garage, on jackstands. I have heard of people using some a decreased in a purple bottle at autostores and it worked great, even pulled some factory paint. As for paint anything beyond a self etching primer and a quality satin black rattle can? Or do I need to get into paint supply store stuff. This will mostly be areas that are not easily seen but just want to protect it so it's good for another 30 yrs or so without having to pull everything.

 

There are a myriad of ways available to prep and underbody. The way I took was to clean the underbody in diesel, followed by gasoline, followed by whatever full strength cleaner you have on hand, followed by scuffing the surface and followed by 50% Isopropyl alcohol and 50% water. Be prepared to be saturated in cleaners...

Do not use spray paint or POR 15. POR 15 is great for rusted metal or exposed metal like A arms, K members, actual frames, rear ends etc. If you use POR 15 on smooth surfaces like a rust free underbody it will easily peel off. If you must use something from a spray can then buy some undercoating. If you have access to an air compressor and a spray gun then shoot some epoxy primer, Rust-o-leum or single stage. Rust-o-leum when it's not from a can and a hardener is used is pretty decent stuff. Epoxy primer/paint is the best but it is typically thin requiring multiple coats and is the most expensive path. There is also the ready to spray paints now available at most auto parts chain stores fro 16-25$ per quart. If it's daily driven then undercoating or truck bed liner is the best route. If it's a show car then go whatever route your pocket book and time allow for.

 

The Gunk engine degreaser GEL works fairly well. It'll remove a lot of garbage, including some undercoatings.

I've taken a liking to odorless Mineral Spirits for scrubbing some parts to remove grease, road tar, undercoatings, etc. It'll remove factory overspray, but won't touch the original E-coat.

I'm pretty sure the heat shields are stainless steel. Depending how bad they are, a simple degrease followed by light polishing would probably clean them up alright.

Personally I'd start small, and test whatever you're planning to use on a small area to see how it's going to react with your car. It'll give you a chance to get familiar with the product and might prevent a lot of wasted time spraying on stuff that doesn't remove the specific mess you're dealing with.

I'd recommend not going crazy with spray bombs, and fancy coatings. If the underside is remotely clean and original it'll be primarily E-coat gray with some body color overspray. Spraying over everything in black or rubberized undercoatings just ends up looking like such a hack, like hosing down everything under the hood in chrome rattle can spray paint.

While you're under there, pay close attention to the factory seam sealer. Most of the thirdgens I've been under in the last few years are shedding sealer in huge chunks if they've been driven much at all. Missing sealer gives moisture a way inside joints, and can lead to rust.

 

I do have a small air compressor not ideal for spraying.

I am cool doing a single stage. Exterior of the car is a non original color, door jambs are apinted, but underhood wasn't and obviously not the underside of the car, I have pretty much everything pulled away.

So bascially clean an prep like normal. Have people had good experience with black single stages being rolled or painted on? It is mainly the underside but I may try the underhood. Any suggestions of brands to get or avoid? I may have access to a few Pre-vals, and willing to buy a cheap air gun for a few coates. I kind of want to stick with a black, like satin black. Simple, not a show car but decent. I do single stage touch ups, on small areas, and a brushed single stage can look decent in some areas.

 

I have used POR15 on my rearend,and sort of regret it right now..Not that it doesnt work(it works well,per directions)..but used rubberized undercoat on the rest,when car was on the lift..keeps things flat black,and easily can recoat..my car doesnt see wet days,snow, and onlt goes to car shows at most, so the rubberized undercoat lasts,and looks clean,but allowing parts to get pulled off rather easily...next time my rearend is out, i will probably sandblast and do a tad more proper!

 

 

If you have to go the route of brushing or rolling on I would choose one of the foam rollers.

 

If you are looking for a satin black paint - use one of the grill paints that's available in spray cans at most hardware stores. Will go on easy and will have some heat resistance to it.

 

Definitely a foam roller.... I am not using grill paint, I don't feel like it will work well.

 

I won't try to convince you but you would be surprised how many top restorers, and I mean guys who get the top awards at shows like Amelia Island and MCACN have a can on their shelves.

 

MustagEater82
I used white wall tire cleaner to degrease and pressure washed it all down which was a good combination but that might be difficult for you as you are on jack stands then I scuffed it down with 3M pads and whipped it all down with a pre paint solution. I used Eastwood extreme chassis black satin paint and their extreme chassis epoxy primer. I love how it came out! it says you can use a foam brush or spray it on, I chose to spray as I wanted a better finish and the spray will get into tighter areas better. As far as the heat shields mine were pretty rough as well so I used the same process as above but used Eastwood Aluma Blast to give it a fresh aluminum look.