Spraying a screen...

[wbassett]

Spraying a screen is an option for those with the skills or desire to practice and get the technique down.

Some say spraying is a must. It really isn't, but it does provide a much smoother surface that is definite. Some of the things that will be covered are the various types of sprayers out there and the pros and cons of them. Also there will be some tips and real world experience being relayed as to the prep work such as thinning, spraying, and cleanup.

I'm sure this post will be getting updated by mech and myself as we layout the structure.

• Advantages of Spraying
• Types of Sprayers
• Safety Precautions
• Tips and Techniques

[wbassett]

Spraying... some say it is the only way to go. It definitely has its benefits, but that mindset would preclude other DIY methods that are exceptionally good and proven performers. As much as some will not like seeing this statement, paint is not the only DIY option. It is just one of many, and a good one at that.

Where painting a screen has its biggest advantage is in the flexibility of options and cost factor. We already know from discussions in other threads that color balance is crucial for the best applications, and we also know that we can get very good performance out of non-neutral screen colors.

The bottom line is the better the prep and how well the paint is applied will really make a difference. If a person can't paint a room without roller marks and making a mess of things, rolling, then perhaps a painted screen is not for them. Same goes with spraying. If a person has never in their life been able to spray anything without runs or able to get an even coating, spraying a screen may not be something they can do.

For those that can, it does provide for a virtually texture free surface, and as the 1080p projectors start dropping in price that is going to make a difference. I am not going to say that a rolled screen won't perform exceptionally well for a 1080p projector, not at all... but if the ability to spray is there then it is a viable option.

So as I mentioned, the number one advantage is surface texture. Some applications require dusting, or very thin layers to achieve special reflective qualities, and those will be tested out and discussed later on.

One of the cons is cleanup. As mech mentioned spraying is relatively fast and actually mixing/thinning the paint and then doing the cleanup afterwords takes more time than actually spraying. Over spray could also be considered a con since there is more prepwork required in covering things up to prevent any over spray from damaging things.

Another con is the cost factor. If a person already has a sprayer then they are ahead of the game. For those that don't, it is an added cost. Spraying can range anywhere from under $20 to into the hundreds of dollars depending on the gear used. Each also have their pros and cons and will be discussed in following sections of this thread.

In the big scheme of things though, something like the Wagner Control Spray unit will add around $70 to the cost of the screen, but compared to commercial screens it is still a fraction of the price. It all comes down to what a person feels comfortable with.

I think the goal of all DIY developers is to achieve the best performing screen they can. I've been hearing comments that there are many acceptable methods out there and that certainly is true. I will apply the same mind set to spraying that I have with grays... We know things like Silver Screen will work and is 'acceptable' but if you can get something that is even better balanced and shown to be neutral for D65 without any complex mixing, simply walk into the store and buy it, why not? Acceptable will work, but if there is something even better that's just as easy... well you see my point. Rolling certainly works, and is more than acceptable, but honestly, spraying is better- a bit more work and added cost factor, but there is no denying it lays down a much smoother surface than rolling.

One thing I am going to put to the test later on is combining the best of both, spraying a neutral.

Spraying is not for everyone though. Since there is enough interest in it and many people have gone this route it is an item that needs to be covered. Please note that this thread will not be covering any specific application. There may be references to a specfic DIY paint, but this isn't about any one over another. The goal is to present spraying options and how to do it.

[wbassett]

SAFETY

More than any other DIY application method, spraying can actually be dangerous if the proper safety precautions are not followed. This is no joke or something to skip, it actually put a member of another site down hard and now he definitely advocates safety first!

Covering everything to protect it from over spray is common sense, don't forget to cover the most important thing though... your nose and mouth! Surgical masks are inexpensive and work fine in most cases. If you know you're going to be kicking up an over spray dust storm, then there are even better face masks available, but for most people the standard surgical style that are sold in all paint stores will be fine. Safety goggles or glasses are another good idea to protect your eyes, but the biggest item is the face mask.

Ventilation is also important. You need to have an open area to spray in with plenty of ventilation and if possible even fans to keep clean fresh air circulating. The last thing any one wants to do is asphyxiate themselves. Don't mess around and take chances with your health, it's not worth it... it's just a screen, not something worth ending up in the hospital over.

[wbassett]

This will be a short post.

There are a variety of different sprayers and manufacturers out there. The most commonly used sprayers for screens are HVLP sprayers- High Volume Low Pressure.

The other sprayer that is going to be presented here is a 'disposable' sprayer.

Of the HVLP units, there are airless and compressor based. The airless ones are like the Wagner sprayers, you plug them in and go, no compressor or air tanks needed. The other type requires an air tank or compressor. Price wise the airless wins hands down, but built quality and durability definitely goes to the more expensive compressor based units.

The disposable sprayers are excellent for laying down a base coat, but I haven't tried it with poly, and to be honest I would probably say it wouldn't be the best thing for spraying poly. It will though provide a super smooth base surface to roll the poly on for those that are applying a top coating.

[wbassett]

The Preval Sprayer

Sherwin Williams carries it, and most paint stores do as well. They can also be ordered online, but you don't really want to have to wait for something to be shipped.

The main unit is around $6 and the power units are around $3-4. I tested this out of a curiosity and they do work, but it takes longer than rolling that's for sure, but it dries quicker. For most house paints that don't have a lot of clay, a simple thinning of 3 parts paint to 1 part water works fine. I went with 3 ounces of paint and 1.5 ounces of water to give a finner mist. The reason it took me 2 1/2 power units is because I replaced the power units well before they were dead to eliminate any chance of sputter when the propellant runs out. Is this a replacement for the Wagner? Certainly not, but it's also much cheaper and great for one time projects. I haven't tested it spraying poly yet, but also I have never had the need to apply poly to any of my screens. I suspect it won't do well with poly, it may but the spray pattern doesn't seem to be wide enough for a large area and with poly that could result in an uneven look to the surface, which will result in an uneven image.

Don't be disuaded from my comment that it takes longer than rolling, this will lay down a coating with virtually no detectable texture. There is a very very slight one but you have to get within an inch or so from the surface to see it. Compared to my rolled screen, which is pretty smooth, this looks like a an acrylic with the color impregnated in the material and not something appled after wards.

I rate it for value and end results, for ease of use.



As far as sprayers and spraying, the best way to say it is what Quiggly said about pistols in Quiggly Down Under "never said I didn't know how to use one... said I never found much use for one."

This unit really does work. There was a question as to how I managed to spray a full size screen with this unit. I assure everyone I'm not pulling anything or playing any tricks here. The answer is simple, I just sprayed it.

The first thing I did of course was to thin the paint. After that you pour it into the glass container provided with the complete unit, which costs around $6 and comes with the container and a power unit. I picked up two so I could have two jars and I knew I was going to need more power units, but you can forego getting two complete units, that's really not necessary. The power units were around $4 at Sherwin Williams, but I have seen them as low as $2.99 online. I opted for the convience of getting them right then and there and not having to wait to save a dollar a unit.

The biggest thing to mention is this sprays like an aerosol spray paint can, meaning it has a circular spray pattern. If you can spray with a can, you can use the Preval.

Now back to the actual task of spraying a full size screen. This won't be for the complex mixes that require a perfectly thin and even coating to allow for claimed light reflection purposes. Like I said, just spray. I went over the 4'x8' hard board panel and laid down an initial fogged on coating. The first coating definitely doesn't cover everything, but you're not trying to glob it all on in one shot. The key is to put light coatings on until the entire surface is evenly covered. Since we deal mainly with flat paints for our screens, you don't have to worry about sheen and splotchy areas where part of the surface looks shiny and others don't. The flat paint dries to a nice even finish and the texture is virtually non existant. When you first start spraying it will look like there is going to be a texture pattern, but once the water used to thin the paint evaporates it is very smooth.

The power units lose pressure as they start to get low. If you run it all the way out you will get sputter and splatter, so I swapped units way before they ran out.

These units are perfect for one time usage and won't break the bank. Unlike the other sprayers, this is opposite... it takes a little longer to spray a full size screen than rolling, but cleanup is much easier than with an HVLP sprayer. In fact, there is basically no cleanup to do! If you have a usable power unit that you want to keep for touch ups or even for other projects, all you need to do is rinse the glass jar out with water and then put some clean water in it, reattach the power unit and spray until all your see is clear water coming out. It's actually less cleanup time than rolling too.

Another great thing is it's not a paint hog. Amazingly I sprayed a 4'x8' screen with only 9 ounces of paint! When you add the water for thinning purposes it was actually 13.5 ounces of liquid, but still only 9 ounces of paint. This means for a 98" diagonal screen you can actually get away with just a pint of paint and still have some left over for touch up work if needed.

It can be a bit of a pain though doing a full size screen... literally a bit of a pain! After awhile my arm started getting a good workout but it's nothing bad. Like I mentioned, this is for applying a basic paint application and not some layered method that has a special spraying technique, so you can take breaks. I actually took a break to cook out on the grill and then finished the screen afterwards.

So total cost was $14 for the Preval (base system and two extra power units) $9.50 for the paint, and $8 for the 4'x8' sheet of 1/8th inch hardboard for a total of $31.50 for this:

Tip/Hint: This is definitely a viable option worth checking into- the cost of the unit and a couple of spare power units is probably around the same price as getting a few good quality 1/4" nap rollers! And cleanup is a snap!

[wbassett]

Place Holder

[wbassett]

High Volume Low Pressure

First picture is of my HVLP gun and the second is of it's nozzle.





The general rule behind HVLP is 2/3 of the product lands upon the substrate with 1/3 ending up as overspray or in the air. You will find that the amount of paint used with this set up will be quite a bit less than other methods as it has the least amount of overspray.

You will need at least a 5hp compressor to use this HVLP rig. And these guns generally require somewhere around 20 PSI or even less to operate as opposed to the 40-60 PSI needed for more conventional paint guns.

The last plus is the finish. There's a reason why auto body shops use this type of paint gun - smooth factory finish.

If you already own a compressor this is definitely the way to go.

(Updated entry by mechman)

[wbassett]

- Ensure that the paint will come out of the sprayer/gun cleanly without sputters/spatters.
- Start spraying a couple inches to the side of your screen and move across smoothly to a couple inches beyond the other side.
- Overlap each row. This is my opinion (mech here) - overlap by at least 50% for the HVLPs. Don't forget to overlap the bottom and the top!


(Updated entry by mechman)

[cynical2]

I was thinking about the Preval solution to paint some in-wall speaker grilles black (they're white now), and found the item on Amazon. I wanted to see what other things people have painted with these units.

There were 4 reviews, all gave 5 stars. Here are a couple of interesting reviews (take them for what they're worth, as obviously we don't know who these people are):

This user has used it for poly (Bill hadn't tried that, so it's useful additional data).

This is not going to replace a compressor and spray gun but it does a pretty fine job for what it is. Preval sprayers are infinitely better than can spray paint and varnish. With Preval you can actually put a mirror finish on metal, wood, or fiberglass. I once refinished a complete 1960 era birch wood kitchen, spraying high gloss polyurethane and did a fantastic job- no drips or sags.I used more than a dozen of the power units, but they're only $3. I've done spot repairs and small spot paint blending on my boat,very successfully. But I never did a car.. to big of a single spray. Preval will spray anything, just thin it down as directed on the directions, fill the bottle, screw the power unit on top and spray away. There's plenty of propellant in a power unit and they clean up real easy with a spare bottle of thinner that you spray thru for cleaning. I believe 1 power unit allowed me to get almost 2 coats of varnish on both sides of a door. Preval provides a reasonably nice finish for almost no investment. You'll be surprised with the product. Highly recommended.

Another (not sure which Wagner unit he's referring to...he doesn't say):

Had a couple of odd jobs that desperately required a sprayer. Unfortunately I purchased one of those $80 Wagner POS sprayers before finding these Preval units.Needless to say, the Wagner did a lousy job, with paint sputtering and running all over the vertical metal surface I was painting. However, the Preval sprayer applied a light even coat that allowed me to come back a second time to finish the job. I'm very happy with this little tool.

Based on the reviews, I definitely think I'm going to try it for my speaker grills and for my ceiling HVAC vent.

[Harpmaker]

Hi folks!

This is my first post here and want to say that a breathing mask of some kind is definitely necessary when spraying paint on something as large as most projector screens. I learned the hard way!

I just sprayed, using an HVLP/compressor, a 45x60 inch (75" diagonal) screen with Silver Fire, which has a LOT of metallic/pearl in it, in fact they are most of the mix. This means there is more small mica particles in it than most other DIY paint solutions.

I forgot about breathing protection and sprayed a test panel about 48x12 inches. Everything went fine. The next day I started spraying my real screen. Everything seemed to be going good until after I sprayed on the 3rd or 4th coat. During the approximately 40 minute drying time I started noticing that I was coughing a lot and something didn't feel right in my chest. I had no shortness of breath or anything like that, but when it came time to spray again I found a mask I had bought years ago for doing heavy sanding and used it during the spraying of the rest of the screen!

I'm OK, just had about 8 hours of chest discomfort, but I shudder to think how much of that mica I breathed in until I started wearing the mask!

I can't stress this enough - you NEED to wear a mask when spraying a large object such as a PJ screen. If you wear glasses (like me) you also NEED to get a mask that is airtight when you are wearing glasses; for me, the hospital masks don't work.

[mechman]

Harp brings up an excellent point!! I used a 3M respirator purchased at Home Depot when I sprayed all my panels.



This one does not have the filter cartridges on it, but you get the idea. I also did it in the garage with one garage door open and the service door cracked. I had a fan blowing out the garage door.

mech

[Harpmaker]

I used an older version of the 3M respirator mech used.

Home Depot sells this version:
http://www.homedepot.com/webapp/wcs/...cStoreNum=4138

It's a bit pricey compared to the hospital masks, but how much value do you put on your health? When spraying paint that contains mica and/or aluminum powder you NEED breathing protection. Believe me folks, you DON'T want that stuff in your lungs! The respirator above has the added advantage that it also comes with Organic Vapor Cartridges; these will protect you from the fumes of solvent-based products like nitrocellulose lacquer, a hospital mask won't.

[cynical2]

Welcome to the Shack, harpmaker!

If you'd like, you can introduce yourself here.

Jim