Paint repair with rattle cans (base and clear coat)

fifthofwhisky

During recent fine weather I prepped some panels for a paint repair. I managed to get a few coats of basecoat on over a week ago. I've read various views on when to put the clear coat on and some advice is about an hour after the basecoat dries off, with the rationale that the clear coat will better bond to it and so reduce flaking later. I've also read that after the base coat dries (over a longer period) one option is to flat and key the basecoat, apply another basecoat, and then clear coat soon after. There is a bit of orange peel in the basecoat in places, and I planned to use fine wet and dry (probably dry) to flat that and blend (levels) where the new paint meets the old paint, then apply a clear coat overlap and then super fine wet and dry and buff. 

What would be my best course of action to get the clear coat on?

Thesaltmustflow

Sounds like you pretty much know what you're doing, maybe get on Youtube and have a look at some of the many videos there on prepping, painting, clear coating etc.

I know some people aren't fans of YT on here but I've found some great tips on how to do things on there. I buffed out a whole mess of scratches in the clearcoat on my car door by following advice on one of the videos, using the right cutting compound and buffing wheels AND being careful not to burn the paint/clear coat which I really never knew that could happen, door came up like brand new   

fifthofwhisky

Thanks. If I just dry flat the base coat, what grade wet & dry would be best to leave enough to key the clear coat but not show scratches? I think 400 is needed for basecoat to key/stick. Clear coat?

Thesaltmustflow

There isn't much clear coat to play with unless you are taking all of it off and if you are taking it back to paint then re-clear coating there are good videos showing how best to do that.

In answer to your main question of getting the clear coat on it appears to be applied in layers approx 20-30 mins apart straight over bare paint finish that has been cleaned with a good rubbing alcohol/panel wipe, allowed to dry for at least 24 hrs then any 'orange peel' effect buffed out with different grades of cutting compound and finishing polish.   

From what I've seen on the YT videos there are 3 different types of scratches, 1 only clearcoat scratches, 2 through the clearcoat and scratched paint and 3 down to primer/bare metal and they all require different procedures to rectify.

The 'experts' on there are using 2000-3000 wet and dry for clear coat only scratches and it must be wet. You only go in one direction either up and down or side to side, definitely not circular, then it's on to cutting compound and finally a finishing polish. You really need to watch some of the videos as there are that many I might? not be 100% correct but the ones I watched certainly worked for me.

T.T.D

Every paint manufacturer has a lead in time to apply lacquer over their base coats or window of opportunity to get it painted without further complications, this is because of off gassing or (VOC venting as some call it) and shrinkage. 

I would:
Panel wipe it with alcohol. 

Sand base coat with 1000-1200 wet (using a table spoon of cheap dish soap In the water bucket, in a straight or hatch pattern (your choice) no circles!! Rub the previous base coated area down to key the surface lightly using less pressure on high ridges and panel
lines
the aim is take away the shiny. Using a squeegee pad to wipe away water as you go to see your progress.

once completed, alcohol wipe the whole
area down, this is the time to address any low
spots and burn through a with etch primers high build and sand back to 1200 again.

Warm up base coat can as you prepare the panel in the house getting it to room temp (warm tap water in a bucket and put your can in will do if you forget).

first coat is a light dust over with 20% overlap,  hands width away from panel flash off 20mins and tack cloth it.

second pass is a little heavier keeping same spray overlap. Flash off 20mins tack cloth it.

third pass 50/50 overlap keeping the heaviness of spraying the same as second pass. 

Flash off 20mins and inspect if still stripy fourth coat, and repeat until you’re happy, if metallic paint, dust over from a distance away and allow the flake to drop onto the panel like dust.

flash allow dry fully by lacquer within 24 hours. 

2-3 coats of lacquer and let dry for a week to shrink back and harden, if you need to sand it and flat it you can start with 1200 and make your way up to 2000 then buff with a medium compound cutting liquid, then polish don’t wax or put any sealants or ceramics on for a few weeks let it harden right out and vent.