A few questions about painting engine compartment

[Dakota]

I'm nearly ready to paint my engine compartment.  The rest of the car (except for the inside of the trunk) has already been painted.  The paint is FC7 basecoat/clearcoat.  The current state of the engine compartment includes scuffed old paint (80% of surface area),?spots with Eastwood Rust Converter (15%) and bare metal (5%).  I'm not building a show car.   The rest of the paint is nice so I'm mostly trying to avoid a big ugly around the engine (340 with a/c, power steering and power brakes, stock exhaust manifolds). 

As my only prior auto painting experience was 10 years ago with single stage paint, this is new territory for me.  I've watched several YouTube videos which are fairly consistent about the use of guide coat and block sanding between coats (except for after metallic basecoat is applied).  The videos are using body panels for test subjects.   As I'm only doing the engine compartment, would you recommend sanding after the primer?  After the sealer? Neither?  Any guidance would be greatly appreciated.  Thanks.

[340challconvert]

I just cleaned up my engine compartment on my A66 Challenger vert
I stripped most of the old paint down to bare metal
I like Eastwood products;
1.  Coated with their Rust Encapsulator (metal was pretty rust free) 2-3 coats
2.  Then sprayed with epoxy primer, several coats then sanded
3.  Sprayed with high build urethane primer, several coats, then sanded
4.  Resprayed and sealed with epoxy primer again; sanded
5. Sprayed single stage Y1 yellow over sanded epoxy

[340challconvert]

Firewall painted w final coat.


Hope this helps!

[RUNCHARGER]

I would wipe it with wax and grease remover about 3 times, scuff it with sandpaper, wipe it again then epoxy prime. Lightly scuff it again, colour, then clear. I wouldn't sand any colour unless there was dirt or a sag etc. That's what I had to do with this one and it came out pretty good.

[kathyscuda]

sounds like your not sure?? have somebody help  you.
pay the $$$. have it done correctly.
start by pulling the motor.

[Claudia]

I agree . . . for me the engine would have to come out first.

I sanded mine with a DA.
Scuffed with Scotch Brite pads.
Primer.
Paint.
Clear.
Done.

[RUNCHARGER]

If you've painted single stage before you can handle this no problem. The engine bay is a good place to practice painting too although it is easy to get a run or get uneven coverage with all the uneven surfaces. Really it's not that hard, I would also consider doing the trunk at the same time if it needs it.

[Dakota]

Thanks for the replies.

The engine is already out.   The "to sand or not question" is one of those "is the view worth the climb?" kind of questions.   Since the car is not mobile right now, there will be work going through the "sand/clean the garage floor cycle" a couple of times between the primer and the sealer, but if that's the right thing to do I'll do it.   On a couple of the car shows that I watch regularly, I've yet to see them spend much time on the engine compartment surfaces compared to the body panels, so that's why I'm asking about this.

[Claudia]

  Ultimately, it's your car and your decision as to what you want in the end.  More time invested into sanding and keeping things clean during the painting process will always yield better results but again, it really just comes down to what you want.  Show car finish . . . daily driver finish . . . somewhere in between???

[JS29]

Sanding is done for two reasons, adhesion and for smoothing or some call it finessing. Epoxy primer does not need to be sanded if you coat it within the time period the instructions tell you. sealer's go on wet on wet, no sanding between sealer and top coat. I etch primer the bare metal, primer surfacer, sand out any flaws repeat if necessary. primer sealer then top coat. NOT necessary to sand etch before primer, just give it time to dry, you DO want to sand the high solids primer before the sealer go's on,once the sealer is flashed off and it looks good and smooth continue with the finish.       

[Dakota]

I would also consider doing the trunk at the same time if it needs it.

Sheldon - I certainly considered doing both areas at once.   I'd like to see how I do on the engine compartment going all the way to clear so that if there's a problem I can adjust when i do the trunk.   

[Dakota]

it really just comes down to what you want.  Show car finish . . . daily driver finish . . . somewhere in between???

Claudia - it may sound weird, but this thread actually helped me decide the answer to your question.   Realistically, I don't have the skills for a show car finish, but I do want to finish it to the best of my abilities.   The "somewhere in between" option will probably be the reality.

[Dakota]

Sanding is done for two reasons, adhesion and for smoothing or some call it finessing. Epoxy primer does not need to be sanded if you coat it within the time period the instructions tell you. sealer's go on wet on wet, no sanding between sealer and top coat. I etch primer the bare metal, primer surfacer, sand out any flaws repeat if necessary. primer sealer then top coat. NOT necessary to sand etch before primer, just give it time to dry, you DO want to sand the high solids primer before the sealer go's on,once the sealer is flashed off and it looks good and smooth continue with the finish.     

I like this plan.  I'll post the pics of the outcome on my build thread.