Have a new project to start next week before Christmas. 2007 Kenworth T800 hood to repaint in a Rapid Red type color. Brand new hood that appears to be an ABS type plastic with fiberglass reinforced areas. Right now it’s black which I believe is is the molding color that was used. Sanded a few areas and the black doesn’t go away plus where it was cut out and shaped is black as well. Going to sand it down with 220 or 320 haven’t decided yet then shoot a 2K high build on to lay a nice foundation. Wet sand to 400 then shoot at least 2 coats of red. Going to try a new euro clear on this hood so we’ll see how that goes. Also going to shoot base and clear with Luma III Exodus guns and their Sun Pro light for the first time. Pretty excited about that part. Supposedly just a rebranded Meiji Finer Core (forgive my spelling) so anyone that’s ever sprayed with one might know what I’m talking about. Truck was in a wreck back in October hauling corn when another car pulled out in front of him and totaled the front. Hood alone was 5600 big ones so need to get it right the first time. Wish me luck!

i've done several, i hate all the tight sharp right-angle corners. be sure to block it good most are real wavy.
Jay D.

Jay is there a brand or type of filler you’d recommend on top of a flexible substrate like this plastic hood? These trucks as you probably know shake pretty bad and bouncing over the roads and fields I’m worried about any type of glaze or light filler eventually popping loose and ruining the job. I’m not sure about the heat either since they can get pretty warm under the hood if that’s something I should be concerned about with filler? If you have any brands or types you’ve gotten away with I’d appreciate knowing what those are!

You're right about the flex - they move all over the place. So, the trick is to keep your total paint thickness as low as possible. If you sand then you'll tear up the nice smooth surface which will then mean more primer to smooth it out. That leads to increased DFT and more likelihood of problems later. I'd start with a fairly stiff block 600mm long and use something like P1200. That won't tear up the surface but it should identify any low areas and give you a good indication of how deep the problem spots, if any, are. Then scuff well with red Scotchbrite all over. Then Prepsol thoroughly followed by a wash and then a water/alcohol cleaner.

If the lows were deep or extensive then use a high build epoxy. There are special plastic adhesion primers that can be used under the epoxy, but generally these are only necessary on lower quality mouldings where the surface is porous and there is the risk that the mould release agent may still be in the plastic. This is usually only aftermarket parts - genuine doesn't usually have the problem. Block the epoxy down until the high spots appear, meaning that the lows are filled. Use powder guide coat to help to see these. Then one final coat of epoxy, mixed down as a sealer and put your topcoats straight over this.

Most reds are quite transparent so the colour of your sealer coat can have a big effect on the final colour. Usually the paint manufacturer will recommend a shade - generally off white to light grey for reds. If so, follow that recommendation or you may have to spray out a few test cards to determine what matches best.

Usually two medium wet coats of base. Don't try to get full coverage with the first coat. Then two coats of a quality clear. Remember that more is not always better. Trucks work in some fairly harsh environments and the thicker your total paint thickness is the more likely that it will chip.

All very good points Chris thank you for the inputs. Is there any reason to use a high build epoxy instead of the regular 2K gray primer that I mix for high build? I assumed epoxy was more for bare metal and this plastic would be alright with a normal 2K high build. Does the epoxy provide better adhesion in this situation? I like the idea of using very little to no filler on this project.

I restored this Ford Freightliner that was in very rough condition. Cracks in the hood and many places where the gel coat was deteriorating.



I removed the hood and after cleaning and repairing the damaged areas, I shot it with white Epoxy primer first.
A couple of coats and began block sanding using guide coat.
Sprayed white epoxy as a sealer prior to painting.



The guy wanted the truck in Dodge Destroyer Gray so that was next:



The truck took a lot of work. New front and rear bumpers, grill, visor, exhaust, etc. Redid the interior as well.

DeerePainter wrote:Is there any reason to use a high build epoxy instead of the regular 2K gray primer that I mix for high build? I assumed epoxy was more for bare metal and this plastic would be alright with a normal 2K high build. Does the epoxy provide better adhesion in this situation?

Epoxy will give you better adhesion than high build primer and it remains more elastic, so better in an application where there is flex in the substrate.

That turned out really nice especially for a truck most don’t consider worthy of making look nice. I have no idea how to fix cracks in a hood like that but yours turned out great! This hood im doing is new so im starting with a fresh work surface which is nice. Just don’t want to make the mistake of adding glaze filler to the wavy areas and run the risk of cracking later

That makes sense Chris. I haven’t used epoxy before so wasn’t sure if it was more flexible than regular primers. The adhesion would be another bonus if it so I’ll try to find some local if I can. Appreciate the advice…I’ve painted a few other things for this customer before and his semi is his baby so it needs to be right. Also for my own comfort and experience I’ll feel better if it’s got all the correct things it needs to have the best chance of survival on the farm.

Get a quality automotive Epoxy Primer.

As stated earlier, with a Red paint the undercoat color is important. Most will go with white, so a white epoxy will work the best if you choose to go that route.

I really like Automotive Art's Motobase LV for great coverage and ease of spraying.

This truck only took two coats to achieve full coverage and true color.
No cut and buff done on this project as it was a driver.