Air Cleaner Housing Cleaning and Painting

[Jason Edge]

FIRST: For a background on when I paint, how I paint, and how I avoid pitfalls such as wrinkling, debris in paint, etc, check out this article from our Help Page:

Engine Painting Tips
https://6364cadillac.ning.com/profiles/blogs/engine-painting-tips

This air cleaner housing is one I agreed to clean, prime and paint for a customer.  The air cleaner lid would be similar, however, I do not bead blast the bottom side as they have a rubber seal and instead hand sand. 

Below are the basic of how I prep and paint the air cleaner housing:

Prepare the Air Cleaner Housing
- After bead blasting the air cleaner housing, I go over with 0000 steel wool dipped in Acetone. (Be sure to use appropriate gloves!).

- Next I wet sand with 240, then 320 then 400 grit wet/dry sand paper. I like to use those small storage bins as seen above if working in the winter so I can prefill with warm water. 

- My next step is wash down with a clean cloth dipped in Acetone, then one more quick rinse in Acetone, which dries extremely fast and will leave the surface free of debris and residue.

- From there, I want to make sure the air cleaner housing and primer and paint are reasonably warm by setting them inside an adequately heated room. You can also set-up in front of small electric heaters at appropriate distance.  For this air cleaner housing I actually set on a stool about 3 feet from a small electric heater and let sit overnight. Using the Digital Infrared Thermometer Laser Gun you can quickly verify it is nice and toasty before painting. I generally never paint any metal below 60 degrees F. and prefer 70 to 90 degrees.  
 
- Since I do not have a downdraft paint booth, and have to do my painting outside, I prefer to paint outside during the cooler months without all the pollen and debris in the air! For me the perfect paint time is a cold, crisp dry sunny day, where I can pop out and paint the part, and bring it right back in to a heated space. If it is above 60 degrees, I will let it sit outside to cure a few hours especially if it is a nice sunny low breeze day.  This air cleaner was painted between 1pm and 2pm, February 5, 2017 on a mild, sunny day with limited breeze here in Garner, North Carolina.  Contrary to my younger inclinations, I now really hate trying to paint anything in the middle of the summer as you get gnats, bugs, pollen, humidity, etc., especially here in the southeastern USA!  Not so much in the winter!

Prime and Paint the Air Cleaner Housing
- My "trick" to prime and paint both top and bottom of the air cleaner in one go round, is to use 4" French drain pipe. The drain pipe fits exactly in the air cleaner opening and provides a very snug fit and the holes allow you to have complete control of the tubing.  For the air cleaner I paint the top inside, then flip over and then spray the bottom side. Just make sure all debris has been removed from rough fresh cut drain pipe ends since it can drop into the primer and paint. Having to set the air cleaner up and spray the top then wait a couple days for it to cure to flip over can really prolong the time. The goals is to be able to prime and paint in one shot, and the 4" drain pipe is the perfect solution.
 
- My next trick, which really isn't a trick is just knowing how paint dries and that it will wrinkle if you apply additional layers after 30 to 45 minutes and before it has had time to fully cure. For this project I applied one coat of Rustoleum Engine Primer, then a 2nd coat of primer after 20 minutes, then my first top coat of Rustoleum Engine Gloss Black after 30 minutes, then a 2nd top coast after another 30 minutes.  For more details on curing times, etc, check out the Engine Painting Tips article.

Let it Cure!
- Before installing, or if you need to apply another top coat because you missed the initial window of opportunity, or if you need to sand down and redo a part, or in my case before packing to ship out; let it cure at least 2 days! Everyone says 24 hrs, but it is better to really let the paint completely dry and cure, so for me it is 2 days or more. 
- For my painted air cleaner housing, I left it outside for about 5 hrs, then brought it into my heated garage where I will let it cure for a few days before I attempt to pack and ship.

Bling it On!
- One final step you can do when painting the "glossy" parts in the engine compartment like the air cleaner housing, is to apply a final coat of clear coat. Like the primer and top coat, I like Rustoleum Engine Clear Paint. As noted in the Engine Painting Tips article, I have used many aerosol paints and the Rustoleum paints are my favorite! Easy to apply and hard to really mess up! Just layers on beautifully!

Pictures showing Air Cleaner Housing with 2 Coats of Engine Primer:
(Note 4" French Drain Pipe in center)

Pictures showing Air Cleaner Housing with Final Top Coat Applied:
  

Here are the Rustoleum Engine Primer and Paint I used.
Note, I may add a coat of the engine gloss paint on right if customer wants even more sheet.

[24ro8f5mbs2jc]

Great explanation. Just out of curiosity, how did you know what the weather will be on 5th of March 2017???

Read somewhere that one of the most boring things you can do is watch paint dry. I think it might hold some truth to it.

[Jason Edge]

Never tried watching paint dry... must be a late 60's chem experimental thing!

[Jason Edge]

Date corrected and added a picture of the Rustoleum Engine Paints I use as seen below: