Ask Lost Cause

Well since there isnt an "Ask Lost Cause" section in the paint and body forums (yet), I figured I would ask my question here. Im wanting to smooth all the panels and dash in my tahoe and paint them black, but I dont know what procedure would be best. What grit sandpaper(s) do I use and in what order? Do i use adhesion promoter or primer? Do I use regular rattle can, plastic paint, or have it sprayed with automotive paint? Do I need to get it cleared? I could use your PROFESSIONAL opinion if you dont mind. Thanks!!

Wow Randy I'm honored lol I'm sure there are quite a few different methods out there, but this is how I do it......... I usually start out with 80 or 180 depending on how course and deep the texture (some have just an eggshell texture and some have an excessively rough texture) From there I work my way from 80 to 180, then from 180 I go 220 and sometimes even 320.......... once you have removed all of the texture from the plastic panels clean them with a good wax & grease remover, I usually use  "acrylic-clean" DX330 made by PPG one the panels are thoroughly cleaned, its important that you lay down a couple good coats of an adhesion promoter. Most people just use "bulldog adhesion promoter" it's inexpensive and is available by the gallon, quart, or even rattle can.Then you can lay down 2-3 coats of a good 2k primer (high build primer) I usually use PPG's K38 After that, I use a dry guide coat (which not many do) then dry block the primer beginning with 320. working my way from 320 to 400 and sometimes even 600 (depending on the color) * If things aren't looking perfect by the time you block the primer with 320, then re-prime, And start the last step over beginning again with 320 to 400 ect. (And remember its all in the prep..... you remove every bit of texture from the panels before you prime, you should only have to block and prime once) one you get every thing block out to perfection, I spray a coat of sealer, then base and clear as usual....  I would always recommend using high quality paints and materials, Especially clear coats!  I only use premium automotive urethanes...Mostly PPg products (I'm a very strong believer in "you get what you pay for"... if you buy cheap shit...that's what you get,.. cheap shit) NEVER rattle can anything!!! it's all crap and will have to be striped and removed to ever guarantee a professional quality finish...... well Randy I hope I was able to helpwhen it comes to stuff like this your going to get quite a few different opinions and methods on the proper process and procedure. I'm sure there are plenty of ways to do it. This is just how I personally do things in my own shop. If there is anything else I can possibly help you with feel free to give me a call anytime bro  Thanks Brain "Lost Cause" Walker

Just another way of doin things................. when I painted my ranger/mazda interior I started by using a good plastic scrub, it is a paste that cleans that plastic really good. I used a red scotch brite pad and cleaned the parts twice because I know i buttered them up a few times with armor all before. Rinse them really well with water and you will c a difference in how the water beads off the parts once them chemicals have been removed from the plastic. Then a quick shot with wax-grease remover just to b sure, then i used 80 grit to get rid of the texture because the rangers panels have alot of it then 180,then 320 wet. I like to use a elastic primer meant for bumpers and plastic parts  because it has adhesion promoter in it and it has good flexible qualities.( i like spies-hecker products- i saw a demo where a man painted a soccer ball then let it dry and deflated the ball and twisted it in his hands and the paint didn't flake.) then just like Brian said if it doesn't look smooth after you sand the primer with @400 wet then re prime, the only thing i didn't sand with 80 was the dash because it is somewhat soft compared to the other panels and i was afraid it would just bugger/gum up because of the softness. So i just cleaned that really well with the plastic prep and put 4 good wet coats of the primer on and sanded it smooth. Then follow normal painting steps from there. Good luck and be prepared to spend a lot of time sanding the raw plastic(I have over 120 hr of sanding in my interior) because you want as little paint on the plastic as possible to fill the texture, it will make the paint stay on the plastic a lot better.  I used all black primer since my interior is flat black so if it ever got scratched it wouldn't show a gray primer spot it would still b black. Just my two cents!

low99maz pointed out a very important step I forgot to mention. Thanks bro You need to have clean plastics before you sand into them! Make sure the plastics are completely clean and free of any silicone ("armor all") that may have saturated the surface of the plastic before you start sanding. other wise your just smearing it deeper into the plastic when the silicone coats your sand paper. and nothing will stick to any thing coated in silicone or "armor all" or any other product used to shine up interior plastic  

I was kinda hoping this wouldnt be out of my league but I may be wrong. Do you have any reccomendations if Ive already started sanding and didnt clean the pieces. Ive started with 180 just on a few of the pieces in the back, which I would assume probably didnt get armor-all'd (much).

Edited: 8/29/2009 10:54:11 AM by slammedcivicsi

if you have already started then a hot soap and water, along with come laquer thinners/final wipe cleaners should do the trick to clean them up....However it wont be a by the book technique it should do the job just fine. Duponts Plastic prep spray is basically just isopropanal alcohol, and acetic acic, which is the main part of vinegar. The isopropanol alcohol helps clean, but also reduces static, because plastics create static when sanding them. -Brad

adhesion is the key to any paint process, especially plastic!

i think this section should happen,since there isnt a "Ask Fraser" anymore...make it happen mods,lol. i have ALOT of P&B questions i could ask,since im tryin to get into it and all.

You guys beat me to it but for sure, clean with degreaser BEFORE you start sanding anything or else you run the risk of just grinding contaminants deeper into the surface. I think a LOT of people overlook this very first step. And this step-by-step of repeated sanding and preping explains why the cost of getting something painted can be expensive, not to mention the material costs involved. Hope your project turns out nice.

I like to epoxy prime all plastic once its cleaned cleaned cleaned, sanded, cleaned cleaned cleaned......... epoxy bites into plastic better than anything else ive ever tried and will not delam even in extreme heat. Once its epoxied and cured i sand with 180 and put 2 coats of 2k primer on then block and paint as normal