Panel coating options?

[johnpinetree]

Hi all, about to get to the phase where I rivet an absurd amount of panels to the car. I've been kicking around the two ideas I've seen in person for finishing the panels. GTBradleys scotchbrite finish and clear coat, or Papa's truckbed liner. I think I'm leaning towards a black finish, but I'm worried the truck bed stuff will have too much texture for an engine bay. I don't want to take stuff out for powder coat mainly because I want to be able to do a panel at a time in my backyard as needed.

So! Thoughts or suggestions???

[ADI]

I sprayed the bedliner on mine. Have to prep the panels really well before spraying.
What worked best for me is sanding it down (50 grid), cleaning with solvent and thin coats of bedliner (RustOleum).
https://thefactoryfiveforum.com/attachment.php?attachmentid=159372&d=1640805235
https://thefactoryfiveforum.com/attachment.php?attachmentid=163946&d=1647303586

[edwardb]

You asked for opinions. And that's what you'll get. Including mine. No right or wrong answers. I do powder coat on my builds. Just depends on what you want to do and how you want it to look. Most of us want the engine compartment to be "presentable" meaning opening the hood for people to see, at shows, cars & coffees, etc. In my experience, most bedliner products will get dirty and be difficult to keep clean. For under hood, that's a no-go for me. If that's Ok with you, then certainly an option. Frankly, that area doesn't need the protection. So not sure of the point to be honest. My comments are for the generally available air dry latex and solvent based products. Like Rust-Oleum, Herculiner, etc. Something that would maybe be more serviceable is UPOL Raptor. It's a 2-part polyurethane. I used it on the underside of the hood (cowl...) on my Coupe (plus some other places) and it's holding up well, doesn't hold dirt and grime, and is easy to keep clean. Especially if sprayed with their higher end gun and a touch of solvent. But if you want to keep it simple (and DIY) then I'd vote for Scotchbrite and either clear or Sharkhide.

[Indy Shu]

Or.... you could leave them bare aluminum. My car is 15 years old and I can still clean up the visible panels (not much) to look new and shiny. Can wipe them down with wd-40, or do an occasional quick polish with Mothers or similar. Very quick and very little effort. I like the old school, racecar look and there is zero deterioration of the aluminum besides light oxidation.
That being said, I am building a Coupe now and am pc'ing everything under the hood. No wrong answer except rough bedliner - too hard to clean.

[J R Jones]

Black epoxy primer is smooth and reasonably tough, and semi-gloss. The only downside is that it is not UV protected, so direct sunlight over time may cause graying.
jim

[Jeff Kleiner]

Black epoxy primer is smooth and reasonably tough, and semi-gloss. The only downside is that it is not UV protected, so direct sunlight over time may cause graying.
jim

I concur. Something like PPG DP90 epoxy is tough and harder than hammered hell but it will chalk up over time.

Jeff

[Cobradavid]

I did rattle-can black bed liner on the panels in the wheel wells (F panels, elephant ears, etc.). I prepped them by cleaning with acetone, light scuffing with a scotch brite wheel on a drill and then clean them again with acetone. The bedliner spray has held up very well in 12years/15k miles.


For my engine compartment, I fabbed some extra panels to clean up the bay. For those panels and other panels which are visible (like the radiator surround panels), I did a random swirl pattern with scotch brite wheel on a hand-held drill and then clear coated them with rattle-can gloss clear. Same prep work as for the panels that got bedliner spray. The clear coat has held up well also.

The first pic shows the engine bay panels. With a flash, the swirl pattern looks more splotchy in the pic than in person. The second pic shows the radiator side panel with the same swirl pattern. That pic is natural light and it shows the true look of the subtle swirl pattern.

https://thefactoryfiveforum.com/attachment.php?attachmentid=16402&d=1364603634
https://thefactoryfiveforum.com/attachment.php?attachmentid=21604&d=1379546788

David

[tonywy]

Another option you don't see a lot is anodizeing. Mine are all done in black except the inner wheel panels that are left bright. They look great and whatever wipes right off them.

[Fman]

I will also give you my opinion, spend the money and go get them professionally powder coated. At the very least just do all the panels in the engine compartment. Regardless if you choose a hammer/vein finish or black they won't chip and will hold up to solvents, grease, grime, etc and will easily clean up. It is very difficult to get a good bond to aluminum, you can rattle can them but you will eventually see why the $7 can is only $7. For the amount of money your spending building the car this is a very small cost in comparison.

[BrewCityCobra]

I will also give you my opinion, spend the money and go get them professionally powder coated. At the very least just do all the panels in the engine compartment. Regardless if you choose a hammer/vein finish or black they won't chip and will hold up to solvents, grease, grime, etc and will easily clean up. It is very difficult to get a good bond to aluminum, you can rattle can them but you will eventually see why the $7 can is only $7. For the amount of money your spending building the car this is a very small cost in comparison.

X2 for the powdercoat in the engine compartment. Durable and looks great. For my build I only did everything from the firewall forward to keep costs down and it turned out just fine. As work continues on the build I do bump things from time to time (far from perfect in that regard) and the coating hasn't so much as shown a scratch. Always good to know you can keep working and not destroy everything you have done to date.

[Mike.Bray]

Another option you don't see a lot is anodizeing. Mine are all done in black except the inner wheel panels that are left bright. They look great and whatever wipes right off them.

I'm considering anodizing as I have a lot of experience with it. Anodizing is not a coating, it is conversion of the surface metal. The panels are 6061 so they could be hard anodized which converts the surface into aluminum oxide, very hard. Standard hard anodizing is kind of an ugly brown and is difficult to get consistent. In my job our standard specification for hard anodizing has a black dye added which is common. Downside to hard anodizing is the surface is basically a grinding wheel so it's extremely difficult to get through. Drilling a hole through a hard anodized part requires a few drill bits.

Standard anodizing I think everyone is familiar with, that's how AN fittings are finished. It's available in a range of colors and has a dull or flat finish.

With the panels being 6061 another option is standard color or clear anodizing and then do a Bright Dip. Bright dip is basically a chemical polishing and instead of the dull finish it turns into a glossy smooth almost painted finish. It's a simple process but not all anodizing shops do bright dip.

If you have stainless parts or fasteners an option for them is electro-polishing. This is a chemical process and makes stainless shiny like polished. Much less expensive than standard polishing.

[racingandfishing]

I know this is a Roadster thread, but I see there are Coupe owners here as well. I love a new challenge and contemplating doing the powder coating myself. I've read up on it and it seems doable. Does anyone know what the approximate size is of the biggest aluminum panel is for the Coupe?

Also if anyone does this them self and has experience, it would be great to hear about it!

[edwardb]

I know this is a Roadster thread, but I see there are Coupe owners here as well. I love a new challenge and contemplating doing the powder coating myself. I've read up on it and it seems doable. Does anyone know what the approximate size is of the biggest aluminum panel is for the Coupe?

Also if anyone does this them self and has experience, it would be great to hear about it!

The biggest pieces are probably the two cockpit floor pieces and the two rear hatch floor pieces. In the neighborhood of 2x4 feet. (estimate without actually measuring...) Some of the engine surround pieces are pretty good size as well. The challenge with home PC is having a big enough oven. Lots of guys do smaller pieces in an old kitchen oven, with very good success. But having something to do these size pieces is almost always only at the pro shops.

[racingandfishing]

Thank you for the information. I've seen a couple of home built options. I also saw a guy took a double oven, cut the bottom out of one and the top out of the other and put them together to make one big oven.

I do almost everything myself when it comes to cars and homes. However, if I can't get a professional result or better, I farm it out.

Either way, I'm done remodeling my home, so just exploring options on just about everything as I have too much time on my hands before my kit is ready!

[JohnK]

Some builders have down their own powder coating at home with very nice results. When deciding whether to do your own PC, there are several other factors to consider besides the size of the oven. I had my frame and all aluminum parts professionally powder coated by a local shop that primarily does industrial coating work. I had a chance to tour their facility and see the powder coating process. They start by media blasting all parts to clean them and roughen the surface so the PC will bind better. They then apply a primer coat and bake it at 400 deg. F. Then they apply the top coat and bake it at 500 deg F, which re-melts the primer so the primer and top coat fuse together properly. In order to get results like this at home, you'd have to have a media blasting setup large enough to blast big parts, as well as an oven that is not only large enough but that can also get to 500 deg F, which most kitchen appliances cannot. so, IMO you can PC at home but you cannot (without significant investment) get true professional results at home.

[racingandfishing]

Again, great information and very informative, thank you.

My double home oven actually goes to 550 in bake mode, but my wife would kill me if I put car parts in it! It is also was expensive and to your point, I'm not likely to find cheap used one that can reach 500 degrees. And for a DIY, that temp is pushing the envelope as it is way hotter than 400.

Either way, I am not convinced I am going to powder coat the panels. I really am leaning towards old school vintage look and thinking of keeping the panels in their natural color and not even putting in carpet. I saw where someone had success clear coating them or something similar to achieve the look while making it easy to up keep.

I would imagine though I would have to get really creative to control heat and noise without the sound deadening that is hidden by the carpet. May end up with a hybrid with some panels exposed and carpet in some areas or maybe removable carpet like a boat. It's hotter than all get out here in Texas and already concerned about the F5 AC keeping up, so that may make it impossible and carpet may be the only option.

As always I am open to any critiquing, thoughts or advise. This forum is helping me learn a ton thanks to all of the great contributors!

[rich grsc]

I have never seen 500* as a recommended temp. All the powder I ever used had a temp range of 350-425*. That 500* must have been some special high temp resistant coating

[Mick40]

Way too hot @ 500. 360 works well, my oven is 4X4 and have done a ton of parts, and panels. Fit the aluminum first which you most likely know.

[racingandfishing]

I found some interesting home built powder coat ovens that can be easily built from readily available items and wouldn't cost much. They seem to be effective at holding temp. and can be built large enough to accommodate the panels and other large items. In particular there is a modular approach that I believe I am going to use. Bolt the walls together when you need it and take it apart for storage when you don't. In addition with that approach, you can set it up various sizes depending on your needs.

Would be interested to hear if others have gone this route and their setups. Thanks.