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Spray painting - Disposables

disposables which are very handy to have.



Disposables

There is a great variety of disposables. Some of them you can't do without. Others can be replaced by common household objects. I'll tell you what is out there and which items you can avoid by doing it in another way.

In general the disposables are not very expensive, downside is you sometimes have to buy like a pack of 100. Let's start at the beginning.




Masking material.


If you are going to paint your car you only want paint in the areas which need that paint. Not masking off the rest will leave you with overspray which can be hard to remove afterwards. Especially if you're spraying clear coat or primer with hardener in it. So at least you'll need this.

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And some of this.

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Don't go for the very cheap stuff concerning your masking tape, it may be very hard to remove after you're done, it may even lift off the paint you stick it to. Instead of newspapers you can buy a roll of special masking plastic which is a lot easier to use but has it's downsides as well. I'll be going in further detail on the matter in the chapter "Masking".

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If you want to go with dedicated masking paper including the dispensers which makes it handy to work with, you'll be spending a lot of money on just the masking. Unless you're painting cars for a living I think it's just to expensive to use it for private jobs. It all depends on your situation and how you want to develop things. In general, if you want to keep the costs of living down and not make spray painting the Bermuda triangle which drains your account inexplicably use newspapers, old blankets / sheets, bashes and what have you. If you're planning to make money spraying cars you may consider it.




Paint mixing and filtering.


One doesn't go without the other so I combined these two items in one paragraph. You definitely want to filter your paint or straining it as it is called. In every paint are dust and dirt particles which you want to get out. Sometimes before mixing the paint with hardener and/or thinner, sometimes afterwards. Definitely before you put it in your spray gun! The order in which you do it is not that important as long as you do it. That gives me no specific order in how to present my comments on both items.

Straining or filtering: There are paint strainers available which cost a few cents each, those can be ordered in different gradations of straining. The finest is 125 micron and the other end is somewhat like 240 micron. Using the 125 micron strainer will not work with high build primer before it's deluded and/or mixed with hardener, it will be far to thick for any strainer right out of the can. So primers you want to strain after mixing it.

Here's a strainer which will filter contaminations as fine as 125 microns of out of the paint.

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To keep your strainers clean you may want a dispenser, this is not necessary but recommended. A plastic bag which is properly closed will do the job as well. In all cases, you don't want something which is meant to get dirt out of your paint get dirty! This dispenser was less than 20 bucks so for me worthwhile.

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Let's move on to mixing the paint you're going to use. Paint, being it primer, color or clear coat needs to be mixed to a specific ratio. One with hardener and the other with thinners. For example, I'm using high built primer which has to be mixed with hardener in a ratio of 1 : 4. On top of that I can add 5 to 10% thinner to it depending on the temperature and the flow I want to have. Under normal conditions I don't add thinner to it. Yet I do want to mix it as close as possible to the prescribed volumes. Mixing cups are very cheap and will make it a piece of cake to mix the primer to the exact rate.

Here's a mixing cup. It's got all the ratio's on it from 1:1 up to 1:10, on top of that there is an indication of how much percent of thinner you want to add to the mix right there on the cup. You can buy 10 or a multiple of that at the time. That way you can keep the cost under control. Be aware (unless you get them from your local paint supplier) post and packaging will cost some. That's why I buy a batch of 100 whenever I need to have a new stock of those. Yes, these are cheap as well, I mean really cheap! An order of 100 of those won't blow the budget at around 25 bucks for the lot.

Here's a good example of a mixing cup. Pay special attention to the mixing ratio's indicated and the percentage you can add on top of that. Best seen on the right side of the cup.



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Again, nice to have but not absolutely necessary. There are many household measuring beakers which can be used just as well. Be sure you clean them thoroughly so you won't get debris from one kind of paint into another using the same beaker. The advantage of the dedicated ones is you just throw them away when you're done. Another advantage is they are solvent resistant, they won't dissolve when you put poly-urethane based paint in those.

Household scales can be used as well, if the mixing ratio is 1:4 you can translate that into weight. Be sure you read the technical sheet about the paint you're using, it will tell you how much the paint weighs per volume. Calculate how much the thinner and/or hardener must weigh in relation to the paint and you're good to go. Complicated but not impossible, for about 25 bucks I prefer to buy 100 mixing cups.

Right, we got the proper amount of volumes in the mixing cup and now we want to mix them. You can buy mixing sticks..... Yeah, really! ANY piece of plastic, wood or even aluminum (in England aluminium), steel or whatever ridged material will do as long as it's free of grease, silicones and dirt. A can of inexpensive brake cleaner can take care of that.


Cleaning the surface to be painted.


Now we're almost ready to go! First we want to get the surface we're going to spray paint as clean as possible. You want to use rubbing alcohol on a lint-free cloth to get all possible grease off, everywhere you touched the surface with your bare hands will have grease on it. Do not use anything else because you want to remove grease and wax, soaps are made from oil so that's a no go! Don't use household cleaners like ready to use window cleaners.

Like I said, you don't want greasy finger prints on the surface to paint. at this stage you need to use these!

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Yeah, gloves! As much as I am a hater of gloves it is very necessary to use them. Your bare hands will contaminate the surface and thus compromise the quality of the paint job. It can and will result in what we call "fish-eyes" I'll explain later what they are, how they get there and how to avoid them. As a preliminary measure use gloves!

After you wiped the surface down with rubbing alcohol you want to make sure there is ab-so-lutely no dust on it. There is a special kind of rag for sale which is called a tack-cloth.

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Tack cloths are not statically charged but a tiny bit adhesive, they will elevate all dust just before you're going to spray your paint on a panel, car or part. You want a 100% clean surface to spray on, this will help you to get it done. Sorry, there is no alternative in this case unless you forget about them all together. If you are convinced the surface is absolutely clean just go ahead and start spraying. I did that for many years and it actually never backfired on me.

An impeccable clean surface will pay off getting the best result possible, take your time to make sure.


Never start without this!


Paints are toxic! Using a spray gun will get a very high concentration of those poisonous vapors in the area you're working. Always protect yourself using one of these, your health depends on it. I tell you, smoking is far less dangerous. Paint will harm your health ten times faster. Just one substance which is in modern car paints is isocyanate. I recommend you look it up on the internet because I'm not going to copy text from other sites.

Be sure a paper dust mask will not do the trick, it does exactly what it's called, filter dust. We're talking about gasses here. You really need something to filter the air you're breathing in. Like my Moldex-mask you want filters you can change out for new ones. Price indication? About 40 bucks including 1 set of filters. That's a whole lot less expensive as brain surgery or a lung-transplant.

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Why did I put this in this chapter? Well, the filters are disposable and you should change them in time. Be sure health and safety warnings will come back in many other chapters.

So, don't go for the cheap stuff because you're not doing yourself or your health any favors. On the other hand it's not necessary to go for a full mask which is hooked up to the fresh (filtered) air from your compressor. If you're spray painting on a daily base you may consider to invest in your physical and mental protection just that little bit more (actually, a lot more!). The message is don't underestimate the devastating consequences if you don't protect yourself.

Having said that, let's move on to the next chapter and find out what kind of paints are available, when to use them and why.


Last update : October 25th, 2018