flat and polish - what's the trick ?

In the simple old days when just cellulose paint, thinners and any old spray gun and compressor was enough, I painted a couple of cars in solid colour paint that didn't look too bad and had a reasonable shine without needing too much of a polish. Ive recently painted the front bumper on the green Mk1 F with a one coat gloss type rattle can which, though nowhere near a great job is at least smooth and averagely shiny.
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So what on earth is the story with this base coat and laquer stuff, particularly base coat and lacquer rattle cans ?  Is it just me or is it the norm adequate coverage but always a really flat almost matte finish  ?

I wasn't happy with the front wing i painted on the TF the other year in base and clearcoat. It's in colour but no great depth of shine so I thought I'd have a go at improving my technique.  My daughter's old Nissan Micra was sitting around complete with a few dents in 2 panels whch i straightened out and filled.This was a handy thing to practice on so doing everything by the book i gave it several coats of primer with lots of rubbing down with progressively fine paper beteeen coats and then left to harden for a week..
I was then ready for the colour coat which  covered evenly, surprisingly well really given the constraints of rattle cans. Once covered i took some 600 then 800 grade to it and the gave it another base coat to be sure.
The next day I went in with several coats of clear laquer. After a couple of days in the sun to let it harden I proceeded to give this a rub over with 1500, then 2000 and lastly 3000 grade wet and dry. It felt smoother but didnt look remotely shiny. I then went over it with some Farecla G3 compound with a polishing bonnet on a DA. I cleaned that off the repeated. . Lastly i went in with some Simoniz wax polish, polished and wiped that off, stood back and was immediately disappointed. It still looks matte compared to the surrounding paintwork.
Not that the looks on this old Micra really matter too much as its just waiting for my youngest daughter to pass her test and will be a sacrificial first car. 
But, what they hell is the secret with these base coat and laquer ppaints as ive done everything by the book.  Can anyone ever get a shiny finish with these apparently handy base and clear coat pairs of rattle cans or are they just always a load of crap.  

I know its going to be different with a spray gun, I think it was Len who said something about thinning the lacquer when using that method. But we can't do that with rattle cans, I'm doing an area around the near side rear wheel arch with the two can system, not quite ready for the lacquer yet but I'm now hoping that it creates a better result than what you have described. On the F I used the single can method and was quite happy with the result from that, I'm hoping now that I haven't made a mistake by going with the two can route. The other thing is that not all paints are created equal, more's the pity.
Regards Glyn.

I’m with you on paint consistency, you can’t be sure that the paint in two batches from the same supplier can differ. I ended up with several cans of lacquer from I know not where & from a company I had never come across. The results were jolly good until the last one lost pressure & duly discarded. The results from the replacement was poor in comparison & this was clear lacquer; what can you do wrong with clear lacquer.
M

Some years back I had the same problem with the same method, painting (trying to) the doors of the 90. I did a good mess of it.

Thank Goodness I was only painting the edges, to avoid removing the door cards for the scheduled car’s full spray (I had the doors dismantled for the Dynamat soundproofing and some other treats)

I was really puzzled, as Notanumber, getting that pitiful outcome after following the instructions letter by letter 🤷🏽‍♂️

I'd thought maybe my mistake was not flattening it quite enough with the 1500 grade wet and dry but I'm cautious about going right through the laquer. Has anyone found the right combination that works for getting a shine ?

You guys have got me worried as I have also bought a couple of ebay rattle cans to respray the door handles on my TF; they have delaminated.  I have very little experience with spraying but, about 30 years ago, I had moderate success spraying the front valance of my Triumph Acclaim in metallic "cashmere".  I'll probably put the job off for another 6 months now!

Flatten the primer..apply base coat colour and flatten that and if you are happy with the finish apply more colour but do not flatten..then build up the laquer.
G3 will barely polish 1500 grit.
I use Scholl S3 which will polish up 1500 grit then I really polish it with Scholl S40.
If using G3 I would polish with 2000 then 2500 grit.
You will be hard pushed to get 2000 to go thru the laquer but 1500 will do if overdone.

This is what I did with the interior of my  (bare bodyshell) MGB GT last September. After media blasting I applied two coats of epoxy primer about twenty minutes apart, the following day I applied two coats of base coat, again twenty minutes apart followed probably an hour later after cleaning the spray gun and mixing the clear coat I applied two coats, no sanding anywhere. Hopefully by the beginning of next week  I will have the front wings, tailgate and numerous other parts done with base coat and clear. The gloss was good without polishing, anyway no one is going to look under the interior trim!
The method was given to me paint supplier and confirmed online, the theory is that you will get a chemical bond for up to seven days between epoxy primer and base coat and the same applies to base coat and clear if applied within an hour or so. Although you are using rattle cans the same principles should apply,  

Numbers numbers numbers.
Make sure the surface is flat, chemically clean, no dust or insects. Shake the can, point it in the approximate direction of the object to be painted & press the button. Keep it moving! Lightly cover over; up, down, left, right.
If you have an infrared lamp set it up & walk away.
Return at regular & suitable instances & repeat until you’re happy. Let it harden for a day or so & stand back & admire the results.
The biggest problem with amateur painting is it’s usually done outdoors & in between showers; not everyone can build a tent in their garage & follow Len’s example.
I’m no more successful than the next person, I can play guitar really well until you give me one & I’m not even sure how to hold it.
M

We must remember that Notanumber is not a number..but there are reasons numbers came in to it.
Len used 2000grit because he knew that G3 would not polish up from 1500 grit. No real shine.
There are other products with the right pad that will.
If the humidity is high it will blush so a heated garage does help.

I usually use 2 pack so it glosses of the gun well, but the problem we have here in Oz is not so much rain, but every kamikaze insect for miles around quite literally dying to be part of your paint job! the 2 pack paints give a real hard finish which means it's hard to sand, and as such it's hard to get the bastard bugs out!

I was working at an industrial scale cake bakery, and there was a panel shop just over the back fence, the truck came to fill up the flour silo, this is done by pumping the flour though large diameter tubes with air.
The fill tube broke at the top of the silo, resulting in shit loads of flour being pumped into the air, no one noticed as no one was paying attention, so no one really knew how much flour was lost.........however a great deal of it was found in the panel shop, stuck to many cars in various stages of being painted! Those panel beaters were not happy campers!
It cost the bakery a metric shit ton of money to compensate the panel shop in order to repaint all those cars.
I managed to do a very temporary repair using ratchet tie down straps and duct tape to hold and seal the damaged pipe work, until it could be done properly, when my company pulled me out of that bakery due to them not paying their bill some 9 mths later, the silo filling pipework was still held together with ratchet straps and duct tape!

Did they try paying their bill in industrial scale cakes ?