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Teach me about spraying......


Jack

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Yes I know it could be the blind leading the blind :argh: but.....

 

 

I have just bought a compressor - a tiny one and kit that goes with it, tire thing, the blowie thing and a paraffin spray thing (what the hell would you be spraying with paraffin :confused::confused:) and it comes with a top of the range spray gun made by a company called Snap-On...

 

Don't panic - I am not about to spray the mans truck but I do need to learn to spray.......

 

What do I need to know. Any basic tips?

 

 

Forever yours.

 

Jack.

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Jack,

I'm surprised you have a Snap On spray gun and a tiny compressor? Normally you need a decent sized compressor to run a spray gun. Make sure the nozzle in the gun is matched to the output of the compressor.

 

The paraffin gun is useful for cleaning stuff, try spraying your engine with it, it will come up nice and clean. I spray watered down Marine Clean from Frosts with one, use a stiff brush to get the stubborn bits off and then wash down with a power washer.

 

Spraying paint is faily easy, there are plenty of good guides on the web. Set your fan size etc by spraying some scrap cardboard etc before moving to your part/vehicle. You need to start off the part and finish off the part. Use a steady speed and maintain your distance and make a pass accross the part. Overlap the passes. Try not to put it on too thick, let it dry slightly before putting another pass on top. I always spray any sticky out bits first, make sure they are covered from all angles, then go over the whole lot with the nice steady sweeps.

 

http://www.diy-compressors.com/spraying-basics.htm

 

With a bit of practice you should find it's fairly easy to spray something without getting any runs.

 

Chris

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Second what Chris say's.

A tiny compressor will be no good, won't maintain pressure at the nozzle and It'll give an uneven finish. Especially true with a professional gun. Though I wouldn't necessarily call a snap-on gun professional, more usually over priced and over-rated in my view.

You can change the nozzle (or cap) size in most guns to suit compressor output and paint. Thicker paints, like primer need a bigger nozzle and more air. You can usually get away with smaller nozzles and air requirement for finishing coats.

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I'm not an expert but this is what I have picked up while I've been learning to spraypaint. Make sure you get some safety advice, as some of the chemicals can be quite nasty and you'll need to protect yourself appropriately.

 

Find something gash to practice on first. Everyone gets runs to start with, and you may need to tweak the settings and paint mixture to get a good spray, especially when starting out.

 

Make sure you drain condensation out of the air system as that causes runs, and don't do it on a cold day outside/with workshop door open, as that makes the paint dry in a peculiar fashion / go gloss.

 

Some paints need hardener to be added along with thinner, but if you put hardener in the wrong sort of paint (or paint that doesn't need it) it goes speckled. Different paints need different types of thinner and hardener, so check when you buy it.

 

Its worth getting some degreaser and wiping that over the surface (especially under wheel arches etc.) once you've prepped the surface for painting (wire brush/sanding/whatever). Then you can use primer. If you leave it for a few days between coats you may want to use some degreaser again. Check what gloves you need for the degreaser as it dissolves most. Removing grease should give you good paint adhesion.

 

Build up the paint with many coats. You do not want complete coverage with the first coat as gravity will hit a couple of minutes later and drag the paint down into runs. A few thin coats gives the best finish until you've got the hang of it and can judge what the paint is doing.

 

The key thing is to watch whats going on past the point that you are spraying. Big panels are easy. Small fiddly bits are difficult, and more often than not youll get a good coat on the fiddly bit, and then find the paint has gone wild on the parts just past it and you've got runs everywhere except the bit you were concentrating on.

 

When it's gone wrong, dont fiddle. If its really bad you might be able to brush on some thinner and spread it out a bit, but more often than not, trying to fix it will make it worse. Leave it to dry, give it a light sanding, spray over and see how it looks.

 

When you've finished, clean the spraygun well. Use a clean paintbrush with multiple pots of thinner, slowly working through to the cleanest one, brushing all of the paint off inside and out leaving a clean surface. Then pour fresh thinner into the gun and spray that through until you get clear white clouds. Then leave the spraygun with a thimblefull of thinner inside. If the paint dries inside the spraygun, it's a real pig....

Edited by Lauren Child
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Thanks very much folks that is a great help. The Snap On gun was my attempt to be funny :sweat:I need more pratice by the looks of it :computerrage:

 

 

What about thinners and all that? What do I need?

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'Ere....... you forgot to tell him he will need a pressure reducer for the air supply to the gun.

 

Well........some tips from another amateur. :)

1- Buying a top of the range spray gun will not give you any better finish than you will get with a cheap one.

 

2-Make sure the thinners you use is suitable for the paint you are going to spray. Try some of the thinners on the surface you are going to paint. If it goes all wrinkly or swells up........use something else

 

3-Use a primer that is compatible with the top coats you are going to use...unless you like wrinkly paint.

.

4- Make sure the surface to be painted is well rubbed down, dry and dust free. (Unless you are spraying in the garden...... then it don't make a lot of difference).

 

5- Connect up yer pressure reducer to the airline and then connect your splatter gun to it. Check to see that the air comes through it ok and the little nozzles in the side of the spray jet have air coming out of them. (If you put your tongue in between the flanges of the spray nozzle you can easily detect the airflow and amuse bystanders by blowing up your cheeks):rofl:

 

6- When the air is going through the gun (Blowing air) set up the reducer to give a pressure of about 40 psi (If you are old like me) or set it to about 3 bar if you are a young smart ar*e.

 

7- Now this bit is really important if you are ready to spray........... you will need to put some paint in the spray gun. :-D First mix some with thinners. About 50/50 and give it a good stir (Pick the skin out first :-D ) Dip a flat blade screwdriver in the paint and pull it out. If the paint almost disappears from the corners of the blade; its just about right. It needs to be similar in consistency to milk. Half fill the spray gun with the paint mix. (That's because if you fill it right to the top, this will be the time you discover that the top isn't screwed on properly, or the jet is blocked and the container breather is pointing in your direction :( )

 

8- You will now need a surface to experiment on. On the back of most spray guns is a twiddly knob. This one controls the paint volume and needle travel. On the side of the gun next to the splat...... er sorry spray jet is another twiddly knob. This one flattens the paint spray pattern from a cone to a flat fan shape. Ideally you are looking for a spray pattern about eight inches high.

 

9- At this point make sure you are wearing a face mask unless you like coloured bogies or your nostril hair all stuck together. :-D Try spraying the dustbin or next doors fence before you tackle your pride and joy. Initially all you are trying to do is get a controllable amount of paint to come out of the gun. Hold the spray gun about nine inches away from the surface you are trying to spray. The trigger on the gun should be pulled on the move just before you move on to the area to be painted and shut off just after you go off the other end of the panel. Never pull the trigger when the gun is pointing at the work because the first burst of air from the gun will be at a somewhat higher pressure and will blast a dollop of paint causing a 'run'.

(I won't explain what "runs" are .....you will find out for yourself ) Move the gun fairly swiftly across the panel and overlap the spray pattern to give even coverage. What you are looking for is sufficient paint applied for it to "Flood out' or go shiny a second or two after the gun has passed by.

If you need to cut down the amount of paint, either move faster with the gun or screw the paint adjuster screw in a little.

If the gun appears to splatter a bit ie large drops of wet paint, try thinning it a little more or try increasing the pressure a gnats.

 

10- If you feel you are ready to tackle the real thing and your surface is properly prepared.........give it a go. Your first coat wants to be a "Mist" coat. Don't put too much paint on the first coat, just enough to show the colour. (Semi transparent) When the paint is tacky and doesn't feel wet to the touch (Not like that you Wally........... on the edge........not in the middle of the panel..............now look, you've got a bloo*y great finger print in it......Ooooooooh give me strength. ) When the paint is touch dry, apply a thicker coat to give even coverage. Again when almost dry, you can apply another coat. For the last coat, leave it a lot longer to dry , or else the paint being applied will "Melt" the previous coats and cause runs. (These you should have discovered already)

 

11- Go and fetch the wife and tell her how clever you are. On the way; check that 'drift' from the paint spray hasn't gone all over her washing, and that the neighbours car hasn't got a tint on one side. :shake: If it has, remove all evidence of any spray activity and put the empty paint cans in the neighbours garden on the other side of you.

 

Always wash and flush your spraygun after use and store it with some clean thinners in it.

 

If like me you use enamel paints (The stuff you get from tractor dealers) try using petrol as a thinning agent. It works very well but it's best not to smoke while you are doing it.

 

If you get a bad run in the paint :cry: and it's important that the finish is perfect; stop spraying, leave it for a few days and rub it down then. DO NOT try and rectify it at the time of spraying.

 

If spraying outside, make sure the breeze doesn't blow overspray towards anything important or expensive.

 

If a fly lands on your wet paint :argh: (Which they will) and refuses to die, try gently blowing it off with an airline. If the bas*ard wont come off and wont die spray over the little bu**er until it does. Small flies rub down quite well and often only leave marks where their legs were. Big flies spiders and butterflies have a different technique which we will deal with in next weeks lesson.

 

DO NOT use open gas fires to heat your garage or dry a panel. I've had a serious wing fire once before. :shake:

 

DON'T breathe paint fumes for too long if you don't have no breathing apparatus (If you use petrol as thinners in an enclosed space, you will feel totally rat ar*ed after about ten minutes, and probably die in about fifteen. Best spray in the open if you can or a well ventilated area.) BEWARE SOME PAINT THINNERS EFFECTS ARE ACCUMULATIVE AND CAN CAUSE HARM IN THE LONG TERM IN THE FORM OF LUNG DAMAGE AND SENSITIVITY TO THE AGENTS IN THE PAINT.

 

Make sure the paint is warm before spraying as it will apply better. Try and warm up the panels before spraying as the paint will "Go off" quicker. Too hot and you will get an "Orange peel" effect.

 

If the paint won't come out of the nozzle, DO NOT point it towards you and look into the nozzle while pulling the trigger. Doing this will immediately rectify the blockage. :argh:

 

I hope this description is of some use to you. While it is a lighthearted look at spraying....... it works for me. No one has ever taught me how to spray and I have had some almost perfect finishes on car panels and motorcycles.:)

 

I, OR THE FORUM, ACCEPT NO RESPONSIBILITY FOR ANY ACTS OF STUPIDITY YOU MAY COMMIT WHILE SPRAYING, RUNS ON THE PANELS, OVERSPRAY ON NEXTDOORS PORSCHE OR BREACHES OF HEALTH AND SAFETY REGULATIONS.

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Jack,

 

That all depends on what type of paint you're spraying! I use gunwash to thin down paint, you can buy large quanities fairly cheaply. Of course, if it's water based paint, just use water.

 

Chris

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Use a proper face mask. A mate of mine didn't and wasn't well for a long time. Can realy **** your chest

 

Make sure that the paint pot is properly attached. Makes a mess when it falls off. been there

 

Dont try and spray your tea and dunk a biscuit in the paint :rofl:

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I also recommend the use of one of these..

 

http://cgi.ebay.co.uk/PAINT-MIXING-TOOL-PADDLE-MIXER-STIRRER-BLENDER_W0QQitemZ290281629328QQcmdZViewItemQQptZUK_DIY_Material_Paint_Varnish_MJ?hash=item290281629328&_trksid=p3286.c0.m14&_trkparms=72%3A1683%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

 

Stick it in a drill and turn it slowly to mix up the paint. Put the paint tin in a cardboard box first though, incase you spin it too fast and it throws the paint everywhere!

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Guest catweazle (Banned Member)

i know this is one of those new oportunities you were talking about brought about by the recession,Your creasoting fences and garden sheds,

cant fool us,well not all the time anyway.Dont believe a word they said.

You will get it everwhere,to much air not enough paint,to much paint not enough air.Runs everwhere,you will drop the can whilst fixing the gun to it

that will hit the deck and send a lovely mushroom cloud of paint everwhere.Not to mention the dust and dirt that will make a bea line straight for the finished article.A good job is 90% preperation 10 % paint.:-D

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It's handy to have some excuses lined up. When I accidentally sprayed the toes of my boots to match our desert coloured MT-LB (I was spraying the bottom of the wheels while standing too close), I managed to maintain my cool suave exterior by claiming it was so my toes would be camoflaged if I ever went sunbathing on the beach. I think I got away with it.

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Jack -you'll need to decide which hand to hold the gun in to spray with, as this will dictate which of your other hands you'll need to use to hold the paint brush to smooth out the runs. (think I'm kidding?)

 

And remember to leave a few of your runs to make the finish more authentic - see pic of new Heil tanker below.

Agnes of Milwaukee 1943.jpg

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  • 2 weeks later...
OK chaps - I have had a go....not saying that I am natural at this or anything :whistle:

 

We'll be the judge of that!

Let's see the evidence please.

 

If you're that good I've a Ward La France that needs touching up. :whistle:

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