Now for the fun part! As I explained in Part Seven I am not able to go through with the complete respray of our project VN at the moment due to a re-occuring back injury but I am hoping that by showing you the basics that I was taught on one panel you will be able to ‘scale it up’ if you are doing a full respray.
Fingers crossed I will be able to hold a spray gun for more than 10 minutes at a time in the near future.
At this stage we should have a nice primered surface ready for the topcoats, the car masked up and the panels wiped down with Wax and Grease Remover or Prepsol.
Time to fire up the compressor and check our pressure setting. When spraying the undercoat I prefer to use anywhere up to about 50psi of air pressure, but when it comes to the topcoat I believe a lower pressure is better as it limits the amount of overspray. There is nothing worse than spraying the roof for example and finding that you have a ugly, rough stripe down the middle where the overspray has mixed with the wet paint. My preference for topcoat is around 30psi, but once again this is only my preference and you should first check the instructions that came with your paint and also experiment a bit first to find the best setting for you. Also be sure to drain any condensation that has built up in the compressor’s tank or in the water trap if you have one.
Next item on the agenda is preparing the paint. Most acrylic paints are thinned at a ratio of one part paint to one and a half parts thinner. I always use Premium Thinners for the top coat instead of the general purpose stuff, it costs a little more but does it make a difference? To be honest I don’t know! I was taught this way and have never tried just using general purpose for thinning the top coat, just a habit I guess.
When I’m ready to paint I usually mix up almost one litre of paint and thinners in an old spray gun pot (using a clean steel ruler for measuring out the two parts), double check the air pressure, half-fill the gun and we’re ready to go.
Just a quick note on air pressure, you will notice that even though you set the pressure at one level, when you pull the trigger on the spray gun the pressure will drop by a few psi. To combat this set your pressure slightly above the pressure that you want to spray at and by the time the paint hits the panel it will be at the desired pressure.
Like when spraying undercoat, the trick is to keep the gun as square to the surface as you can, at the same distance away through the entire stroke and keep an eye on the ‘wet edge’ of the paint to be sure you are getting adequate coverage. A good idea is to have a portable fluro light that you can move around with you as you spray and when set up in the right position it can make following the wet edge a lot easier.
I made the video below to try and show you how following that wet edge of the paint is the best way of ensuring that you don’t go too thick in some areas and that you don’t end up with patchy dry areas of paint ( and to show you my flash new pair of chinese safety boots 🙂 ). Following this edge is vitally important when doing the second and third coats of colour as it is almost impossible (depending on the colour) to see how the coat is being applied. The video is of the second coat being applied, I was hoping to video all three coats but some dufus, that’ll be me, kept standing in front of the camera.
With any luck your three coats of colour have turned out nice and even and have a bit of a shine to them. If the paint has turned out rough or almost sand paper like you have applied it too ‘dry’ and need to focus on laying down ‘heavier’ coats, likewise if the paint has some runs in it or has ‘built up’ areas you need to go a little lighter. The beauty of Acrylic is that once it is completely dry you can then go along and wet sand any areas that you are not happy with. The drying times should be listed on the paint tin.
Although the surface of our front guard turned out pretty good I left it in the sun for a few hours and then wet-sanded it with 1200 paper to give it a nice flat, even look before applying the clear.
As you can see from the photo doing this removes just about all of the gloss the paint had but once the clear is applied the gloss will be back better than ever.
Applying the clearcoat is exactly the same process as with the colour coats. Once again I am doing three coats as I expect to remove a bit with the buffing and polishing process.
That’s where we will leave this part of the never-ending story! I will let the paint dry overnight and put the panel out in the sun for a while tomorrow before going through the final step of cutting and polishing.
Stay Tuned for Part Nine, Cutting and Polishing our new paint job.