Here are some pics of my progress on the underbody and rear end of my 1988 IROC-Z. Sorry, I don't have many "before" pictures ...trust me, it was ugly.

Some "before" shots... cleaned and primed in last pic.

 

definetly subscribing to this thread.... i cant wait till u finish it

 

how bad was it? Like surface rust or rust holes?

 

Actually, it's almost finished, but for some reason I'm having trouble uploading photos and I got distracted by the better half and gave up on it.

The car's in very good shape, only minor surface rust, no holes. But 18 years of surface rust and dirt makes for one big mess. But structurally, the car is like new, so I'm lucky that way. I'm the original owner of the car, so I know exactly what I'm dealing with on her.

I cleaned the underbody by hand, with a toothbrush at times. It took a week of daily work to get everything spotless, and then another week of sanding by hand to get it ready to paint. I followed the same procedure with the rear end but I used a wire brush on an angle grinder to get the surface rust off. If you look closely you can see where I had the axle tubes welded onto the differential housing.

Then I coated everything with a few coats of "Rust Killer", which is a "rust primer" by "Rust Check". After that, I went with several coats of Tremclad flat black auto rust paint.

 

...Then I put on a few clear top-coats of a Tremclad clear-coat designed to protect shiny metals or to be used as a clear top-coat over paint. On the underbody I used a semi-gloss top-coat and on the rear end I used a gloss top-coat. I polished the brake lines and brass fitting for the break lines and coated that with the gloss top-coat as well (to keep them from tarnishing)...

 

I brushed the aluminum differential cover with a wire brush on a hand grinder until it was nice and shiny and then top-coated that as well...

 

me too...keep it coming!

 

I did the fuel lines and heat shields also. I did all the underbody brackets (for the fuel lines and sway bar, etc... the same color as the car (metallic grey). The springs are Jamex 1.5" lowering springs (not sold for 3rd gens anymore). If you look closely at the rear-end you'll see LCA relocation brackets welded on ...that's because the car will be lowered and I don't want wheel-hop.

Incidently, inside the rear-end are 3.42 gears on a posi (I did that last summer).

 

Looking very nice indeed.

 

I've got adjustable lower control arms and sway bar both done in the same red as the rest of the car accents. The panhard bar is polished aluminum ...but I don't have those things on yet -- that's a job for the next nice day. So the car, above and below is done in grey, black and red.

I used all stainless steel bolts and screws for all the brackets on the underbody (and also have stainless steel panhard bar bolts, LCA bolts, etc.)

Incidently, the transmission's painted the same gloss grey as the car and the engine block is black with grey heads. The headers are ceramic coated, the intake manifold is polished aluminum, as is the water pump and alternator. The rocker covers and air-element are chrome.

 

looks sweet, you've put a lot of attention to detail into it. hard work pays off!

 

I removed the ground effects and did under there as well...

I have an aluminum driveshaft, so that won't be ugly either (have to decide on a way to keep it from tarnishing though).

 

Here's a detail that makes me question my own sanity ...I took the brackets for the gas tank off and painted the clips red, then slipped them back on and used stainless steel bolts to hold the straps in place.

Actually, I never planned to do all of this. I simply wanted to take the fuel tank out and replace the stock pump with a higher capacity unit. When I did that I painted the tank. Then I realized I couldn't put a beautiful black tank up in a horribly filthy underbody coated in surface rust ...one thing lead to another and the last thing I was doing was crawling around under the car with a mascara (sp?) brush painting the heads of bolts

 

you did an awesome job! isn't it amazing how one thing leads to another and next thing you know you have the whole car torn down and you're sanding and painting fuel lines?

 

OMFG i thought i was nuts when i painted my fuel neck flat black...

that looks awsome.

 

Good Job.
I want to do the same.
And you did it all on jack stands too.
PS what does SCREECH taste like any way

 

Yes,this qualifies as one of the most extreme cases of "might as well" I have ever seen...seek medical help you poor man...

 

hahaha, screech... ahh you salt water huderites out there

hey, how did you clean/paint up in the spring perch area, and all those funny nooks and crannys ? I couldn't get my hands up into there, nor my paint brush, so it looks really half-assed..?

 

Yes, it's a bitch getting the tank back in without scratching something. I taped a bedsheet around the neck and pulled it off when the tank was in place.

The whole car was more or less a case of "might as well". I happened across a set of Flowtech headers for sale on ebay ...now the block's overbored and I have a steel stroker crank, forged rods and hypereutectic pistons ready to go in ...but first I have to finish radiusing the oil holes in the block and polishing the lifter valley with a die grinder so oil won't hang up there.

In my line of "work" I have access to PROM burners ...that lead to me bringing the chip from my car in to "take a look at it". Now I've got it down to the assembly code and I'm fiddling with artificial intelligence (i.e. a neural network) to control the fueling and spark advance ...I should have never started on this car.

...a dremel with a flexible shaft. I used mascara brushes to paint the hard to reach areas because they're small and have plastic handles that I could bend.

 

ah, interesting.
What bit on the dremel? Steel brush? sanding wheel? nylon brush?

 

I got a kit from Canadian Tire with a bunch of bits, so I used the ones for soft metals to take the rust off ...those bits are useless for iron and they cake up on most aluminums (except the Rochester TBIs though -- they're made out of a harder alloy that ports nicely ...for aluminum). So I used those "expendable" bits for taking off surface rust. I went through them fairly quickly though and it takes awhile to get the job done because they're so small. They cake up with rust also, and they don't do a spectacular job of getting it too clean, but they loosened it up enough for the wire brushes to get the rest ...the nylon ones were useless. Be prepared to spend a long time in one spot before you accomplish much with the dremel ...I ported a set of heads with a dremel a couple of years ago -- I learned to be patient.

I actually hit that rear end with everything. I used a chemical compound that you brush on and it bonds to the rust and "eats" it off ...I forget the name but you can get it at Princess Auto (which I believe are in Alberta also) -- that made the work with the grinders a lot easier. I used an angle grinder with a wire brush (which has a dangerous amount of torque and cut me up a few times ). I used an electric die grinder with a brush. And the dremel with the flexible shaft to get into the tight spots that the other grinders couldn't get at.

 

ah, I know the bits you mean, the weak little green/brown soft grinding rock sorta things? yea, that would take a while... I think i'd use a die grinder and sanding drums, if I can get into that area.

Damn, you have more perserverence than I do, if I couldn't get it clean, I just painted over it.
I used Plasti-kote brand "rust not" in a can, and brushed it on my underbody, along with the rear end housing.
Then some spray undercoating, along with a gallon jug of undercoating.

hmm, i'm trying to think of the chemical compound to dissolve the rust.... Is it like naval jelly? Like a phosphoric acid jelly?
Yep, princess auto here in calgary, I go there lots
Yea, I got a cup style knotted wire brush for my angle grinder, I think crossfire_83 recommended it. I think that's my all time favorite power tool attachment right there, the angle grinder power and speed with the light material removal of the wire brush - It's flat out amazing.
If you have to remove that rubbery goop that GM used to plug the water drain plugs in the body, use this - it's the only tool that will work.

 

That's it. It's in a grey bottle.

The angle grinder did most of the rear end, including most of the the aluminum cover ...then the dremel in the hard to reach places.

I hooked a small electric motor up to a rotary wire brush using a small fan belt -- grinding wheel on one end of the shaft, wire brush on the other. The whole thing is mounted on a bench. That's how I cleaned and polished the brakelines and most of the underbody brackets. I even polished bolt heads with it ...but it did claim the fingernail off my left index finger. Without that setup it would have been impossible to do most of the detail work on the parts.

 

awesome job.. wanna do mine next?

 

Wow, nice job on the cleanup. Wanna work on my 86 bird?