Painting Undercarriage & Avoiding Overspray on Body

Hi, everyone! Before winter arrives in central PA, I want to do a little undercarriage spray painting on some areas of surface rust to make things a bit prettier before I have it sprayed with PFC undercoating by a local shop later this fall.

When you guys do any spray painting under your trucks, do you do anything to prevent overspray drifting out and up onto the body? Or isn’t that a concern? I really don’t want my paint feeling like sandpaper when I’m finished, but I don’t have a way to cover the whole darn truck. Curious how you guys do it.

Do you just let ‘er rip? Do small areas at a time and let it settle? In a garage? Outside? Etc. etc.

 

I usually just grab a big piece of cardboard and use it as a backdrop to whatever area I'm working on. I do mine outside but be mindful of any wind, I fluid filmed my undercarriage and I couldn't believe the places that it oversprayed unintentionally (windshield, side windows, etc.). I'd think inside a garage would be better if you have the space, obviously with some ventilation.

Maybe some plastic sheeting and "tent" the truck along the perimeter if doing it outside, i.e. between the rockers and the ground, then similar in the front and back? Those cheap throwaway paint jumpsuits are helpful as well just to keep yourself clean. I'll be curious what people come up with, I need to fluid film my truck again before winter.

 

I touchup the sliders and frame before every winter. I mask off the body panels up to the midpoint of the door with newspaper and painter's tape. I work in a carport (3-sided garage with no door).

 

I’m not too concerned about overspray under the truck, but I like your idea of using cardboard in certain areas to help block some of it.

Your idea for the plastic sheeting is a great one. I may just do that. Pretty sure Harbor Freight sells that stuff cheap. A pack or two of that and a roll of painter’s tape would protect it and be cheap, quick, and easy! The trifecta!!! Thank you for your input.

Anyone else have any tips or tricks?

 

I used a plastic drop cloth roll from Home Depot (the roll had more than enough to cover my entire truck). I just painter taped it around my rock sliders and up to the top of the doors. I then wrapped the entire front end. Nothing got on the truck.

 

Thank you. I’m thinking this is what I’m going to do. Then, there will be no worries and I can spray away.

 

I also use a piece of cardboard when I touch up my sliders. I just wing it when touching up the hitch receiver. The frame I haven’t worried about (yet).

 

This stuff is great. Painters tape with plastic sheeting built in. I used this to spray my topper and it worked perfectly

$15 ScotchBlue Pre Plastic Painters Tape with Bladed Dispenser, 48 in x 30yd, Tape & Masking Film Combined in One Product, Static Cling to Stay in One Place, No Residue Masking Tape (PTD2093EL-48-S)

https://www.amazon.com/ScotchBlue-Pre-taped-Painters-Plastic-48-Inches/dp/B00AYB8T6W

 

That’s pretty slick.

 

You may also want to stuff between the cab and bed so over spray doesn't blow up and out.

 

Lookin’ sexy! Hopefully this will be good enough. Definitely a pain in the ass, but probably worth it. Once I’m done with this & have it looking a bit fresher underneath, I’m going to make an appoint to have it coated. Hopefully that will protect it & keep it looking good. This is what one local shop uses:

https://www.berkebileoil.com/pfc-undercoating.html

Seems like good stuff. Let me know if you guys know anything, good or bad, about it.

 

Update: It’s going well. Slow, but sure. Just finished one 15 oz. can and have started the 2nd. It looking really nice. I think between the fresh paint and having it under coated, it should stay looking good and be protected for quite awhile. Kinda hoping I don’t have to paint it again and can just have it “winterized” every year or so.

 

What are you using for paint? I use automotive rust reformer

 

The main things I used were a pneumatic die grinder with wire wheel, primer, and Rustoleum Professional Semi-Gloss black paint.

It’s always worked well for me in the past on other projects like tractors & miscellaneous outdoor equipment. I’m hoping that, once I get it under-coated, it will hold up even better.

 

I’m perhaps a little impatient when I paint my sliders. I use a square of cardboard and just work my way along. However, knowing how bad I am at taking the time to properly prep for painting, I do apply a good quality wax to the truck before my annual touch-up painting and find that my little bit of accidental overspray just wipes right off.

if you do have the time to do the proper prep, I encourage that, however, couple it with a good wax job of the body in case some paint finds it’s way behind your tape and sheeting.

 

A good wax or ceramic job prior to painting is a good idea. Luckily, my truck is ceramic coated. However, I don’t think any overspray found it’s way onto the paint. I had it wrapped pretty well in plastic and upon removing it, the body panels were still smooth and slippery.

So, overall, I think it was a success. I’m glad I did it. It was a long day, but it looks great underneath and is ready for “winterization.”

 

Another trick to get the bag to cling to the truck is spray a bit of water to the body. Used to do that in the spray booth . And when undercoating spray the inside of the boxed frame upfront. I made a hose that blows 360 deg. These frames will rust on the inside as bad as the outside.