And now for something completely different. First of all I spoke to Tom this morning and he had on his full Hiawatha gear, saying he hoped it would rain
Tom earlier today...
But as much as he tried he could not make the clouds open (thank god !) so it was time for me to get painting. Now I was going to just get on with it and then do a "tadaaaa" but I figured that would be kind of selfish. So, here is a mini guide on painting. This time plastics.
Now. There are some things you need to know. There are many types of paints, these include but are not limited to -
Enamel. Oily based and sticky, kinda like the gloss paint of the spray world. Very tough finish though.
Acrylic. Water based, breathe on it and you will scratch it. However, it is kind to our enviroment and does have its uses.
2 Pack. There are a few names for this stuff, but it's basically similar to epoxy. It's called two pack because it consists of two parts. The first part is your paint and the second part of the pack is the hardener. HOWEVER. The Government are steering people away from this stuff because it's incredibly toxic, is a carciogen (causes cancer in California apparently) and very harmful to the enviroment. It's apparently so toxic that in the USA you have to pay a VOC exempt charge when shipping it @ $80 a go, and they will only ship it in small boxes. Imagine my pissedoffness when I came to paint my Tiburon and found out that it had to be sent in two boxes, meaning I paid the same for the shipping as I paid for the bloody paint
And that's why there is that silly pic of me in Mortal Kooling wearing a mask and goggles. Trust me, when using this stuff you want to unless you want to die very early.
OK. So this time we are using Acrylic. It's what I had lying around and I can also spray with it outside without getting fined by the council. I live in a pretty posh area and people here love to rat on each other. There is one problem with Acrylic though - I am spraying plastic. The reason this is bad is because when sanded the plastic warms up. And when it warms up the molecular structure of it changes. This means expanding and contracting. It also means that if it is ABS plastic when you sand it and it gets warm it releases chemicals. Acrylic is water based, and will react with these chemicals. Watch how oil displaces water in a puddle on the street and you can get a good idea of what happens. Basically the chemicals push the water out of the way resulting in Spiderman paint (wrinkles and creases very similar to spider's web).
The way to get around this is to sand it well in advance and leave it to cure and react. I did mine last night, in water (wet and dry) and let it sit over night. So, this morning I was all ready.
Now as Tom and I jokingly discussed this morning it is not a good idea to paint outside. Firstly it can be cold (a recipe for disaster with spray paint) and secondly it can be damp or wet. However, if it's your only choice there are ways to make the odds tip into your favour slightly.
The first thing you need to do when painting, and this is
absolutely essential is put on the coffee machine. If you don't do this in my house? well, I'd be about as offended as if you had screwed my missus. Coffee is the fuel of champions and mine is imported from the USA as over here we are all "Tea drinking pussies" as my friends used to so eloquently put it.
Right. Now after a good whore's breakfast (three coffees and a couple of cigs) we are now ready to start. I always use P800 for plastic as other harsher papers will mark the plastic too bad causing it to 'fuzz' this will then climb through your paint finish wrecking it.
Always sand anything you want to have a nice finish WET. Never EVER EVER sand plastic dry as it will melt from the heat. Sanding wet also allows the swarf to wash away, instead of clumping up and wrecking your plastic.
Right. Now, get your primer and shake it hard for about ten minutes. Also, the first trick of spraying outside is this.
Run a sink full of warm water and sit the can in it for about ten minutes. This will warm up the paint meaning it will be at the right temps if it is not a warm day. Spraying cold paint onto a warm surface is another mistake people make. Wrinkles, cracks, patches ETC.
Take your bits outside (oo er matron !) and set them up on something. DO NOT EVER EVER EVER paint with things on a flat surface. They will stick and you will form a skin that will peel as you pick them up.
The first thing to note is spraying distance... This needs to be 8-10 inches or MORE depending on the weather. If the weather is warm and dry spray closer (which is harder to do) because when the paint hits the air it atomises and will dry before it even hits the surface you are painting. This will result in a horrid powdery paint finish.
Here I am spraying on the 'tack coat' or 'flash coat' depending on which part of the world you reside.
What is a tack coat?
Put simply a tack coat is a semi rough surface of paint. If you spray on too much at the beginning it will pool and run as it hasn't locked with the surface yet. So, you spray from pretty far back letting it sit in cloud shaped patterns. Then STOP. Don't get carried away hammering on the paint now. Leave it to 'flash' or 'tack' for fifteen minutes before touching it again. What happens is this. The paint will begin to go into the pores and keys you created by sanding. It then sticks up like a load of fingers, ready to hold onto the next coat. However, IT WILL NOT do this if you put on too much. You'll form a smooth surface puddle and the paint will peel off later on. TAKE YOUR TIME. The reason this is called a flash coat or tack coat is because in around fifteen minutes it will 'flash' dry and become tacky. This is a good surface for putting more paint onto. Not when it's soaking wet.
Now here goes the first real coat. Note I have moved the can back? that's because it is quite humid today and I don't want runs. Now this is the point where I make it clear that there is no such thing as a cheap half assed paint job. Moving the can in to prevent waste and trying to cover more area with less paint is stupid and will give you a crappy patchwork finish. To do it properly you need to use A LOT of paint and take plenty of time.
Again if it was warmer and dryer today I would be in a bit closer.
Now. Seeing as you are done for now and have a good 45 mins before you'll be using the paint again, do the following.
Tip the can upside down, press the nozzle until all you get is a nice clear hiss. Some paint will still come out, but it won't sound the same as spraying. What this does is clear the nozzle so you can actually use it again. If you don't do this? Well, it's INCREDIBLY likely that when you go to use it again the nozzle will either be completely blocked or WORSE, the nozzle will be partially blocked and will spit and gob paint all over your surface, totally destroying it.
OK, now it's time to carefully make sure the paint has flashed and you're not going to leave marks in it or damage it. Enamels are far easier to mess up because they are horribly sticky and VERY unforgiving if you touch them too early. Acrylic being water based does not stick to your fingers as much, but you'll still wreck it. Any way, bring it inside and it's time for trick number two with spraying outside and or using cans.
It's time for the Vidal Sassoon treatment. Now. I DO NOT reccomend using this on enamel. Enamel dries by curing, not drying. So blasting it with heat will create dry patches and make the paint softer than before. With Acrylic however we want it to dry, as it is water based.
The first thing I will say is this. USE CAUTION AND BE INCREDIBLY CAREFUL. Hair dryers are bloody hot buggers and this is PLASTIC we are dealing with here. Too much heat and it will warp and become soft. This will crack your paint. However, it will dry the paint ten times faster than a natural curing and also warms the surface of the plastic meaning the paint will bond better than if it was cold
As I say though please do be careful here. I remember once I made a model of a Supra (a very expensive Fast and Furious one with NOS bottles ETC) and became impatient waiting for the paint to dry. I took a shoe box, put the chassis of the model in, cut a hole in one end of the shoe box and put a hair dryer in, putting the lid back on the box. I ran the dryer for two minutes and came back to a puddle of molten plastic. $60 down the toilet. I was gutted.
Once you are done drying the paint (you can use cold air out of it if you wish) gently wipe your fingers over the surface. ONLY DO THIS with Acrylic. What it will do is wipe off the overspray (kinda dusty) saving you from sanding it now. However, you will need to sand it later.
Second coat down then.
And repeating all of the above steps (this is the third time around) we are now done.
Now it will need to cure properly and then when cured it needs to be wet sanded back to smoothen it out. Once I am done doing that later I will get some more pics, but depending on the air humidity today it may need to go in the airing cupboard overnight to harden enough to be sanded.
Til next time !