Hey guys, I have a spare Plenum and I would like to paint it, but I am confused as to what paint to use (if my local bunnies or supercheap auto would have it) and whether I should sand it and primer it before applying the first layer of paint? And, what colour would you recommend?
Better off using engine enamel or at least automotive paint rather than regular spray paints. While heat isnt necessarily going to be an issue on the plenum engine enamels tend to be far more resistant to greases/oils/solvents than regular paints are, so will wear down less over time. VHT is my personal preference for brand. Plently of great colours, and at $10-15 a can you cant really complain about the price. As far as sanding and priming, it all depends on the finish you expect. If you paint over the factory cast metal you will see all the casting marks, the grain from the casting sand etc. If you want a real good finish then sanding is the way to go. Priming isnt a must, but definitel does help bond the paint. My biggest tip to painting engine parts is to not do it while they are cold. You want them above 30 degrees, otherwise the paint wont stick as well as it could.
Much better off doing it properly and having it powdercoated. Rattle cans will only chip off and leave it looking nasty.
Seriously man, get it powder coated, i had mine done in an old antique copper look and it came up a treat. pics here
Mines painted with proper engine enamel. No scratches or chips to speak of and its been painted for 3ish years. Engine enamels go quite hard when cured. They arent as hardy as a powdercoat, but for what you pay they are a great option.
I just did this one with paint, thought it came up OK. I used ally paint 'cause that's the look I was after but could just as easily have done satin black or similar. Clean it well. Then sand. Then primer. Then colour. Then clear. Sounds harder than it really is. Make sure you let the primer dry before putting the colour on, and let the colour dry before putting the clear on. In other words follow the directions on the back of the can. Also the longer (days) you leave it without handling the harder the paint will be when you go to refit it. Too big for the oven I just let it air-dry for a couple of days and the finish is pretty resilient. Of course powdercoating or 2k would be better (harder) but this cost me $50 in materials (primer, black for the balance tube/IACV/rocker covers, ally for the plenum), powdercoating would have cost $400.
Engine enamel comes up great if done correctly. If you want to reduce the risk of chipping, follow the last post Make sure to use the same engine paint for the primer (very important to prime. Engine enamel sticks to everything without primer but you reduce the risk of chipping and flaking if you do use it? Then go colour and several coats of engine enamel clear. But heres the tricky part. for the paint to cure you need to bake it for an hour at 92 degrees. ... if you dont bake it, it wont harden properly and is way more likely to chip. My plenum and balance tube werent baked, and they chipped slightly (especially around any bolts or nuts) My brake calipers were baked and they stood up well to being thrown around on the concrete. How big is your oven? And are you happy for your kitchen to smell like enamel for a few hours?
Also worth mentioning, you can bake your parts just using the ambient engine bay temperature. No need to put them in the oven if they will get enough heat from the engine
This ^^ If you dont bake. The bolts for the balance tube will destroy the paint there. And if you are painting the throttle bodies the TB bolts will probably ruin the paint there too... Maybe a hair dryer might help a tiny bit if you cant find an oven.. or paint the bulk of it.. put it on the z and touch up around the bolts once its all back together... Thats what I was going to do
Yeh mate, im for real. Heres the back of a VHT can of engine enamel if you dont believe me. "The inherent heat of engine operation will also accomplish curing."
