Black paint is tough

[DaveB]

One of my first models after not building for 30 years is the Supernatural Impala. With it warming up outside I got started on spraying the body. I did the hood today (Tamiya gloss black rattle can), even though the primer looked good and I sanded that with I think 8000 grit I still got a small section that looks dull/scuffed. Should I sand that again and respray or will the clear (gonna use floor polish) make it disappear?

[Bugatti Fan]

I would just give it another coat of primer and see what it looks like. It doesn't sound as though it is scratched deeply by your description, so another coat might sort it out and level of off. If it looks OK after, then go for the floor polish to finish it off.

[Bainford]

13 hours ago, DaveB said:

One of my first models after not building for 30 years is the Supernatural Impala. With it warming up outside I got started on spraying the body. I did the hood today (Tamiya gloss black rattle can), even though the primer looked good and I sanded that with I think 8000 grit I still got a small section that looks dull/scuffed. Should I sand that again and respray or will the clear (gonna use floor polish) make it disappear?

It's difficult to say for sure without a good photo. Having said that, I would colour sand just enough to smooth it out, then apply another coat. It is possible that a coat or two of clear would sort it out, but if it doesn't, you will be stripping paint. Besides, it's just good form to ensure the paint is sorted out before laying on the clear.

[DaveB]

5 minutes ago, Bainford said:

It's difficult to say for sure without a good photo. Having said that, I would colour sand just enough to smooth it out, then apply another coat. It is possible that a coat or two of clear would sort it out, but if it doesn't, you will be stripping paint. Besides, it's just good form to ensure the paint is sorted out before laying on the clear.

That makes sense. This is the best pic I could get, which makes it look more textured than it actually is. Think I'll wait a couple days for it to fully cure then try a bit of sanding and put another coat of black down.

[Bainford]

I assume the 'white' flecks are just reflecting light. Yeah, definitely needs a little sanding. Probably work it with 3200 or 3600 Micromesh pads, then 4000 and maybe 6000 should sort it out. If, as you say, it is not as bad as it looks, you may be able to start with 4000. I like the idea of waiting a few days before attacking it with sanding pads. A good solid cure is always best for this type of work.

[DaveB]

12 minutes ago, Bainford said:

I assume the 'white' flecks are just reflecting light. Yeah, definitely needs a little sanding. Probably work it with 3200 or 3600 Micromesh pads, then 4000 and maybe 6000 should sort it out. If, as you say, it is not as bad as it looks, you may be able to start with 4000. I like the idea of waiting a few days before attacking it with sanding pads. A good solid cure is always best for this type of work.

Much thanks, and correct on the white flecks. As was said, worst case is strip and start over as a last resort.

[Speedpro]

Usually when one spot like that shows up, it's most likely an area you touched with your finger that had some kind of contaminant on it. You can try sanding but be careful. You may end up with a bigger mess.

[DaveB]

17 minutes ago, Speedpro said:

Usually when one spot like that shows up, it's most likely an area you touched with your finger that had some kind of contaminant on it. You can try sanding but be careful. You may end up with a bigger mess.

I have some Tamiya polishing compound coming (course, fine, and finish), I might try that first before I attack it by sanding.

[Bainford]

2 hours ago, DaveB said:

I have some Tamiya polishing compound coming (course, fine, and finish), I might try that first before I attack it by sanding.

The problem when trying to remove bumps with a polishing compound is you just end up with shiny bumps. It may be worth a try if the offending area is more of a 'texture' and not actually 'bumpy', but often times it is necessary to level the area with an abrasive affixed to a firm surface (such as a polishing pad). This will knock down the high spots to level the surface, then the polishing compounds can be used. The polishing compounds don't work well at knocking down high spots because they work on high spots and low spots alike, whereas the pads just hit the high spots. 

Edited April 10, 2024 by Bainford

[DaveB]

21 minutes ago, Bainford said:

The problem when trying to remove bumps with a polishing compound is you just end up with shiny bumps. It may be worth a try if the offending area is more of a 'texture' and not actually 'bumpy', but often times it is necessary to level the area with an abrasive affixed to a firm surface (such as a polishing pad). This will knock down the high spots to level the surface, then the polishing compounds can be used. The polishing compounds don't work well at knocking down high spots because they work on high spots and low spots alike, whereas the pads just hit the high spots. 

Ahh, ok, makes sense.

[OldNYJim]

I like the Tamiya polishing compounds too, but I find they work best on heavy ‘orange peel’ like this if you start out with some wetsanding; I usually like a 3600 pad (or cloth) or there abouts 

Polish the affected area until it’s uniformly level and satin (with no shiny spots) and then work thru the compounds

[bobss396]

For me, I try to avoid gloss black paint jobs, they are very unforgiving. Tamiya and Model Master Lacquers have nice metallic blacks. Or you can go clear pearl (TS-65) over the gloss black.

Going gloss, the primer has to be as smooth as a baby's backside. Tamiya and Hobby Lobby both have good primers that are exceptionally smooth out of the can.

Black hides nothing, significant scratches will show through a clear coat. I have been trying to lay down a clear coat that does not require a polishing. Which is hit or miss, I have a heavy hand with finishes and clears in general.