Author Topic: Airless Spray Painting  (Read 3739 times)

Offline chrissss

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Airless Spray Painting
« on: September 02, 2007, 05:18:21 PM »
Hi all

Ive been a pro painter for many years (uk) and for the last few months I have been working on a large old extremely poor condition exterior  and decided to take the plunge and buy a Graco Airless Sprayer which I am using on the fascia, large tongue and groove eves, barge board on the gables and even tried it on a few windows.
The undercoating with oil based paints doesnt seem to be going too bad but glossing up seems a bit more tricky, I seem to have a tendency to over spray areas thinking its not covering and of course it starts to run, just wondering how you guys in America (as u seem more into spraying over there) get on with spraying oil based gloss, the tip I am using is a 411, I would like to do more spraying but wouldnt trust myself on glossing doors up at the moment but am impressed by the time saving and (in the right hands)the standard of finish that can be achieved.

I know its probably a matter of trial and error but any tips much appreciated.


Cheers Chris

Offline 98mustangguy

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Re: Airless Spray Painting
« Reply #1 on: September 02, 2007, 06:32:52 PM »
Ok since I do mostly all exterior painting and spray everything under the sun i'll try giving you a few tips. First of all it is a lot of trial and error on the learning curve just keep practicing. Check your pressure on a scrap of paper first to make sure pressure is properly set  to little you will get trails on the ends, too much will wear tips faster. keep gun about 10-12 inches from the surface and avoid spraying with gun at an angle. If you get closer the trail size will become smaller and you will deposit paint more heavily if you angle gun you will get un even pattern. As the tip first number is smaller ex 4=8inch path  6=12 inch path ect. you will deposit a heavier coat as the same amount of paint will be applied to a smaller surface area, to counter act runs try to speed up your arm motion a little bit so as not to overdeposit and puddle the paint. If you still have trouble go with a bigger first number like i prefer 6-10 or 12"-20" path for exterior, this will distribute the paint over a larger surface area giving a thiner coat with a lower chance of running. Keep practicing and  you will soon get the hang of it and wonder how you ever lived with brushing paint

Offline Chip McCheckellson

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Re: Airless Spray Painting
« Reply #2 on: September 02, 2007, 11:48:28 PM »
Few basic guidelines to remember when spraying. Actually, graco has a .pdf manual on their site somewhere on basics as well. Keep in mind that the pressure and tip size will give you a specific amount of paint per minute outputted in the fan pattern; which is basically a thick line. Its length depends on your distance from the surface, which directly effects the dispersion of paint. If you move your gun away from the surface your line gets larger, but the same amount of paint/minute is being spread out over that larger surface area.

1. With the gun moving, start your full trigger just before the area you intend to paint.
2. Keep the gun aimed at a right angle to the surface, ie, directly at it, as opposed to at the angle as much as possible(...until you become comfortable with measured speed changes)
3. Keep the gun's distance from the surface the same from start to finish. This is important This also helps, because if you look at your last stroke and it looks like it needs twice as much as you just put on, you can quickly go over it the same way, at the same speed. Or much faster if only a little more is needed. The sooner the better as the paint starts forming its texture quickly.
4. Keep your gun speed the same, which gives you an even coat
5. If you have to trigger on, or trigger off with the gun still pointing at the surface your spraying, trigger off or on quickly. (problem with airless gun design, although, supposedly reduced significantly with Graco's newest Fxt and Contractor line guns)
6. On the next stroke, overlap 50%.

Those are the basics, but some others helped me out:
6. Be ready...when spraying something important like a door. Its stressful to have to go fix something/mask something right in the middle of spraying a door. I always carry a tiny wisk broom around for dirt/dust lying at the bottom of the door, you can also spray the dirt away in various ways.
7. Think it through. For example, when doing a door and it's trim, make practice strokes while imagining where the fan pattern is going to be putting the paint. This allows you to avoid second guessing and putting too much paint on.
8. Be a robot (something i heard while spraying autos)

Triangle pieces of cut-out cardboard can be helpful for masking doors open.

I personally spray doors up and down, with the gun turned sideways so i can spray directly at it near the bottom. Corners are supposed to be spray this way as well (aimed directly at the corner).
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Offline rivdog

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Re: Airless Spray Painting
« Reply #3 on: September 16, 2007, 05:00:26 AM »
i agree w/the guys.  Im now spraying an aluminum sided house.  No soak in.  Start your motion in a spot u have masked.  Always having ur gun in motion is key, AND make sure ur tip is in the right direction.  When in doubt, come back later
Git er done!

Vin

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Re: Airless Spray Painting
« Reply #4 on: September 16, 2007, 10:02:42 AM »
When I do doors I stay back sometimes 2-3 FEET. I fog the hell out of it but not close enough for it to build up to fast and too heavy all at once, I  get a nice clean finish doing it this way.


Doing it this way also means a lot more over spray ( waste ) so prep the area fully spreading the prep out quite a distance .

A second coat may be necessary but it's usually just alight one but make sure its even like the guys above mention keep the gun tip the same distance from what your painting all the way across or all the way up and down thats the trick. be a robot I like that i feel like a robot when I'm srayin, so true.

« Last Edit: September 17, 2007, 10:18:24 AM by Vin »