How To Spray Automotive Primer
Our car repairs expert explains how to get the perfect finish with primer after making a repair to your vehicle. Remember to carry this out in a well ventilated area which is warm enough for the primer to dry quickly inbetween coats.
We’ve done the repairs on the vehicle. The filler work’s all gone on and been finished off. We use a grey scotch bright, they do different colours of this, there’s a red one which is much courser. If you look in there, there’s a slightly different colour and the reason why is because it’s still shiny. So these Scotch Brites will get into those other little crevices to take the shine off, so that the primer sticks. If you’re spraying the wheel arch it’s likely that the spray will go on the wheel, on the headlight and any other nearby areas so it’s essential these areas are covered. Besides this if you are spraying outside you would need to mask out further as if there’s a slight breeze you’ll paint areas that you didn’t want to. You can use an old rug to cover the tire and then mask the vehicle up with some tape, I’m using an inch thick tape, get it to a suitable length and then feed it round. I’m using it on the headlight. You’ll spend more time removing the overspray than you will on the actual job, if you don’t cover the surrounding areas correctly. Now the paper that we use, we use an 18 inch roll of brown paper. If you haven’t got that you can use newspaper or just spare bits of paper. Most cars are metallic; you don’t want to get loads of overspray anywhere. So I’m going to mask on this line here to keep the overspray nice and low and mask it this way round and lift it up, what this allows is a rollback. The other way creates a definite edge which isn’t good. When your paper is the correct way around just add a couple of bits of tape to prevent it from moving around. Always try and make it as neat as possible. Generally if it looks good it is good and if it looks shabby, it’s going to be shabby. Now this areas ready for priming and the car is all masked up. What were going to use today is we’re going to use cellulose. There are other products on the market but cellulose is perhaps more for the DIY person. We do also use isocyanate or two pack primers but again you need to have special areas that you’re painting. And you need to have it properly ventilated and use special breathing apparatus. So I’m going to talk you through the cellulose one, in general you will get away with it and to be honest with you, we’ve used it for about ten years before we then changed over to the isocyanate 2 pack system. So when you’ve got your cellulose primer, the same as with all paints, give it a really good mix up, because the additive or material that’s at the bottom of it is what gives it the build. You will get away with using aerosol but you will not get the bill from the material that you would from spraying it with a spray gun. Obviously with a spray gun you will need a compressor an airline and a spray gun. So the mixing ratio when it comes out, you can see how thick that is, but it needs to be fairly thick to cover up all the impurities on the vehicle and get a nice finish. This always needs to be done in a well ventilated area, you can see the mixing ratio there, it’s about 2 to 1, two parts primer, one part thinners. Same thing when you’re mixing up your topcoat colour, give it a really good mix-up, because the heavier material will lie on the bottom and you need the same consistency within your mixture from top to bottom. So that’s that done, now we can put it in our spray gun. When we’ve finished with our spray gun we always clean out the gun back into the pot with a little bit of thinners, just to keep it all soft and moist. Now the cars prepared, it’s all masked up, we’ve mixed up our primer and put it in the spray gun. You’ll want to start with a little tester on the paper, just to check everything’s working as it should be. So I have my gloves and overalls on, I’ll also be wearing a facemask. It needs to be well ventilated and it needs to be warm and you’ll be fine. Pull the trigger in and air comes out, no volume, no material, just air and when you go past that stage, that is when the material starts coming out.