Undercarriage Cleaning and Painting
 

Well here is part 1 of this post.

Today I started the process of removing 40 years of dirt, grime, and the original tar undercoating. I used a combination of Engine Gunk Degreaser, PB Blaster, and Diesel Fuel in a spray bottle to soak the underside of the car over night. Not sure which of those worked but the next day the hard tar undercoating was soft and started peeling right off with a paint scraper.

I have several more days to go but this is a good start. Probably take about 3 weekends to get most of the gunk off. Then I will wipe it down with some mineral spirits to remove the degreaser, diesel, and any oily residue. And finally I will paint the frame black and find a nice red colored paint that matches the original oxide primer and repaint that.

Here are some before pictures and after the first day of scraping pictures.

http://farm4.staticflickr.com/3683/8...5625ca42_b.jpg

http://farm8.staticflickr.com/7425/8...3da45477_b.jpg

http://farm9.staticflickr.com/8560/8...a9efeaef_b.jpg

http://farm8.staticflickr.com/7430/8...a393cc23_b.jpg

http://farm3.staticflickr.com/2865/8...eb740d63_b.jpg

http://farm8.staticflickr.com/7372/8...d786b598_b.jpg

http://farm4.staticflickr.com/3726/8...f908c94c_b.jpg

http://farm4.staticflickr.com/3670/8...de105d21_b.jpg

http://farm6.staticflickr.com/5325/8...fb0d8a0e_b.jpg

http://farm8.staticflickr.com/7395/8...32dc6945_b.jpg

Sure is nice to see dirt,undercoating & overspray under there........

Cleaning undercoating off is a MUCKY job,but WAY better than welding in floorboards & replacement frame rails...

Did you just spray diesel fuel on the bottom of the car and let it sit over night? Would you be able to power wash it off without using a scraper ? I was gonna doing the same with my car to get it cleaned up.

Looks great I would clean it and leave it alone. If you get a power washer with hot water those work very well. The plastic scrapers is great to use for the larger undercoating and to get the rest I would use the something like a DX 330

PPG DPLF40 is a pretty good match to the factory red oxide.

Chris

EXACTLY!, maybe clear coat it , even a clear enamel in a can, and leave it

Well, seems like that stuff did its job! Looks like you'll have a real nice underneath there.
(was going to say "nice bottom", but I usually reserve that comment for the ladies....) :)

That brings back some memories:)

Yup thats where I started. Now going on 7 years frame off resto. Your car looks pretty clean though. If it is rust free I would try to leave the original paint on the underbody.

No, you need a scrapper. It is gooy and easy to get off in some places but in others it is baked on and needs to be softened with the de-greaser and then scrapped off. Power washer would be very very messy and may mess up the paint on the outside of the car.

I used diesel the first go around but GUNK Heavy Duty Engine Degreaser works the best.

Great! Thank you! Where do I buy this stuff? I did a google search and it did not come up.

Looks good. Nice progress.

I ordered mine from TCP Global, but I found out later that my local paint shop had it in stock along with the activator. You need one can of the activator for one small can of the primer so don't forget to get one if you order from them like I did. :D

Chris

On my last rebuild (79 Camaro) I used easy off oven cleaner to get that old under seal off. It worked quite well.

I used a heat gun on mine and scraped off as much as I could with plastic scrapers, which were upholstery tools from Harbor Freight. While still hot, I cleaned the residue off with wax and grease remover from O'Reilly Auto Parts. I went through a bunch of rags and it was a nasty job, but I'm really happy with the result. The red oxide looks as good as it did coming out of the factory. You can even see the blue over spray.

Very Nice. Today I will start on Day 3 of cleaning. Engine Degreaser works perfect. I am considering using the PPG DP74LF-GL red oxide primer to re-paint to factory red. However, I was reading the instructions for the epoxy primer and it says to sandblast down to bare metal. What happens if I paint over the existing red oxide coating from 40 years ago? Will the PPG DP74LF-GL not stick?

If it was mine I would clean it and leave it alone.

Chris, can you post more Pix of that 70 of yours. Maybe in the Show us thread? Thanks

DP 40 is Gray, the more correct Epoxy is DP74 ( LF ) which is similar to red Oxide

If you like yours now, Eastwood sells 2 part clear now, sprayable, professional grade clear coating

Bruce,
Your correct the red is 74 I was thinking of the catalyst when I wrote that those are 401 and 402. Thanks for the clarification.

Chris