Yeah dont use your aerosol outside unless there is no wind what so ever. Cover as much of the car up as you can to prevent overspray. Without seeing the damage, usually you sand around the defect aswell as the damage (not by much) to get better blending results and for it to key properly. Mask round the area upto where youve sanded and apply your primer. 10-15 mins between each coat till you think the defect has been covered, Dont worry about getting a little primer on the fresh paint next to where youve sanded to, as you will be sanding over it again when your happy with x amount of coats. Then you need to flat the defect again so it looks flat and feels smooth without seeing the damage.
You will then need to sand past the defect onto the fresh paint to blend it in but dont sand down to primer. Your aim is to take just the clearcoat off till you see signs of colour on your wet and dry. As the milky looking water starts turning clearer then you know you are getting through. Once this is done, give the car a rinse with water and a quick wipe below the damage where the water is running. If this drys, it can be a nightmare as its your clearcoat that is dripping down.
Next is your colour. Again, cover as much of the car as possible to prevent overspray. Mask around the area to where you have sanded to. Add a cm or so around where youve sanded so you have a little fresh paint showing. So alls you will have showing working inside to out will be: Primered defect (say 5x5 inches wide), then a cm or so where you have took the clearcoat off surrounding the primer, then a cm of fresh paint. Everything else should be masked up and out of sight. Then spray your colour onto the area in very light coats giving 20 mins between each one. Dont aim to cover the area in colour after 1 or 2 coats, the thinner the better. By coat 4, you will then be seeing just colour your putting on. Once you cant see primer and your happy, let it dry for 24 hours. If its outside, cover it with a plastic bag and cellotape around the area and not over the painted part!!!
Then when day 2 arrives, remove all the surroundings from the bumper only to view you work. You will then need to lightly sand the area and overlap the area slightly where your painting finishes. this will smooth your painted area and only just break into the clearcoat surrounding it. Then your ready for laquering. Remask the bumper off which leaves the area to spray. Again, widen your masking area a cm or so to view a little fresh paint (technically you are widening the defect which enables you to blend it in). Then use the light coat method again giving 15 mins between coats. Laquer in a tin also comes out faster than paint in tins so be 6-10 inches further away to prevent running. The first coat will look very odd and spotty if its a thin enough coat so dont worry. Your aim is to gradually build the layer up. After 3-4 coats, you will see the finish you are getting. Once your happy with the result, leave it 24 hours in a garage or cover it up again. Dont touch the laquer to see if its dried until the day after.
Day 3 will be removing all the car areas that are covered. You will then need to sand the whole area including a slight overlap onto the fresh paint again. You wont need to a lot of sanding, just until the area turns completely greyish. Make sure you always finish with a very fine grit like 3000 or 4000 grit wet and dry. Then you will need to polish the area with a compound to remove the sanding marks. Once they are all gone, use a final finish and go over it again. Then hopefully you should have a result your looking for. Ive tried to help the best i can but the key is to take your time and always finish every stage using a very fine grit paper. Lew
