Spray painting on site, yes or no?

[Bob Gerritsen]

Let me start by saying I have very little experience with spray painting, I have a Wagner W610 and have played with this a bit with pretty reasonable results. Thought it was fun and can imagine getting the hang of it. Then loads of work came along that did not require any spray painting and the Wagner stayed on the shelve. Actually, I did have some paint jobs but as my neighbor at the workshop build a spray booth in his workshop he got to spray those jobs. The first project was a disaster, lots of start up problems to deal with but now he has things sorted and produces very nice finishes.

However, I have a request for an estimate on built ins now that involves loads of spray painting and passing all of that on to someone else seems a bit of a shame. The quality of the work need not be A+, it sort of has to match existing cabinets and those are brush painted. Just saying a top, no flaws finish isn't the goal here. This would be THE chance to get some spray painting done myself and the results I've gotten with the Wagner would surely be good enough. For this job I'm thinking spraying on site would be the way to go. I've seen the youtube vids and those look promising but need to know from experts what the deal is here so I've a couple of questions:

1- How much overspray can there be on site and is this manageable?
2- How precise is spraying on site? I'm thinking about maybe spraying doors while they are fitted to the cabinets, can this be done? Maybe not all coats but only the last coat.
3- Is the Wagner system ok or do I need something else?
4- What kind of paint or lacquer is best used on site? Water based or alkyd?

Eventually I'm sure I have plenty more questions but hoping these will make the smoke clear up a bit. I also realize all answers depend on the system used, I'm not stuck to the Wagner, just trying to get a good idea of the options I have.

From what I remember from playing with the Wagner unit is a couple of things. One can only dial in the amount of paint/lacquer and air, the pressure however is a given. This made it necessary for me to thin the water based paint down so much, it really made the wood fibers rise a lot, not only with the first layer. This means more sanding and more coats needed. Not sure what alkyd based paint would do but an expert I had try the Wagner said  more pressure was needed to be able to use slightly thicker product.

It would be great to have a system that works well on site, without the use for a dedicated booth, it could then also be used in the shop.

Looking forward to answers and suggestions.

Thanks so much, Bob.

 

[Bob Gerritsen]

Just to be sure, the questions might give the wrong impression. Asking rather specific questions might give the impression I already know a thing or two.  [laughing]

I'm basically trying to wrap my head around spray painting without a spray booth. What is good and not good about it, what can be expected and how does it compare to class A jobs done in a pro spray booth by a pro painter. Usually I tend to grab a roller, in this case the sheer volume of the project makes me think twice. Spray painting would surely be a lot faster but what does that mean exactly and what do I need.

I'm willing to invest in proper equipment btw.

Thanks in advance. Bob.

 

[Tim Sproul]

You can do this with water borne finishes.  I would not spray solvent based lacquer on-site.

Mask all areas and you can use zip-wall to contain as well, especially if the built-in goes to the ceiling.  Once you start spraying, move along the floor carefully to minimize the amount of overspray dust you kick up.  Vac it up once the applied coat of finish dries to the touch.  Use a painters canvas drop cloth on the floor - the overspray dust can make many surfaces very slippery.  You can set up some fans but this won't remove all the overspray out of the area.

The amount of overspray is dependent on you and the spray equipment.  I can dial my HVLP sprayers to have massive amounts of overspray, if I so desired.  I can also dial it in to have minimal overspray - but minimal is still quite a lot compared to brushing/rolling.

And keep in mind that spraying vertical surfaces is much more finicky in terms of wet mil thickness - especially water bornes.  A little too thick and you get runs.  A little too thin and you get orange peel.  The first coat is much more forgiving than subsequent coats.  When you practice, practice on vertical surfaces.

 

[AlexThePalex]

1- How much overspray can there be on site and is this manageable?

There can be ZERO overspray of course. One word: masking - Dutch: afplakken. Masking is one of the basic preparation steps for any spray job. You simply can't eliminate overspray so you'll always have to catch it. When you spray something you have to mask every surface you don't want paint on. I mostly use 37,5 cm masking paper (or 60 cm) on an apron taper to do most masking. I also use a lot of 38 mm and 25 mm masking tape.

The 37,5 cm masking paper isn't enough to stop all overspray so I always mask the area around it with clear plastic foil. The ground and furniture around the spraying area get covered with HD-PE foil.

For a professional job you simply can't allow one drop of paint to escape, so I make sure at least 1,5 meter around the object is masked. Preferably more.

2- How precise is spraying on site? I'm thinking about maybe spraying doors while they are fitted to the cabinets, can this be done? Maybe not all coats but only the last coat.

It can be as precise as you want it to be. It depends on the quality and functionality of your spray equipment and on your masking effort.

3- Is the Wagner system ok or do I need something else?

The Wagner W610 is a very low-end system, meant for hobbyist home owners but not for professionals. It is for people who don't charge an hourly rate, because efficiency with a system like that is very low. If you're planning on doing this job as a one time only and don't want to invest in a bit more expensive system then you could use the W610, but be prepared to put more time in than you could reasonably justify charging the client. Being raised in a body shop, I would never ever use something like the W610.

For a woodworker who wants to do spraying from time to time but not that much, HVLP might be an option. This website shows some nice systems. You can choose for the semi-professional brand Earlex and keep your investment well below €1000, or you could go for better but more expensive equipment like Apollo and Graco. We had quite some Graco stuff in the body shop, and it's a great brand, always a joy to work with. There is also a special battery sprayer, the Graco Minimax, and it's really nice. I wish I could afford one at €700, but not right now.

But I myself would always prefer a real compressor driven system with a good separate spray pistol. It is more versatile than HVLP and better controllable, in my opinion. You could get a good Devilbiss pistol for €300 and a €450 compressor and you're set. Only problem is the compressor needs to be pretty bulky, because you need one that can deliver at least 200 liter per minute, but preferably 300, and those can weigh 60-70 kilograms minimum.      
   

4- What kind of paint or lacquer is best used on site? Water based or alkyd?

Makes no difference. Both are equally as good and easy (or difficult) to work with. However, for health reasons water based is prefered indoors. In Holland it is even mandatory for professionals to use only water based paint in homes, with regard to painters disease (OPS). We always sprayed a lot of furniture in the body shop, and used almost exclusively water based paint for that.

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The biggest thing I always worry about when spraying indoors is dust. One thing that is a bit problematic with spraying indoors is the fact that a sprayed surface can attract dust like crazy, because due to the fine atomisation of the paint, it can be electrostatically charged. Therefore it is very important that the room be as dust free as possible. Clean everything with a vac, and open the windows a couple of hours before starting to spray to get clean air in.    

A little tip when spraying: two thin layers is better than one thick layer, to prevent runs (zakkers). I often spray a thin layer on first, not yet covering 100% (opaque - dekkend),  then let it sit there for 15-20 minutes to dry up a bit, and then add another thin layer to cover it fully.
   

 

[Scott B.]

Bob

First, make sure your insurance will cover you if this is considered working "out of trade". It would be a bummer to get a little mist in the house air exchange and send it through the house, where it lands on the grand piano or the gold leaf.

That said, masking and prep are key. You have to mask everything in the vicinity and secure the vicinity. Zip walls can be your best friend. I would have to see your project scenario to tell you exactly how to set up and do it. But, you do learn the most by doing one for yourself. We have bunches of onsite clear and paint grade cabinet spray vids online, and yes, an accomplished spray operator can get the same results onsite as in a shop setting.

I am not familiar with the Wagner model you describe. Here in my country, they have alot diy or consumer grade stuff that can be frustrating.

Thats where it gets interesting though. A good operator can get a good finish with a less than good machine, as long as he still knows his product and figures out the technique he needs to use (distance from target, how to layer, breaking the piece into workable parts, minimizing overspray through trigger engagement, etc).

The three variables are: you, the machine, the product.

Not sure what is available over there for product, but we spray alot of waterborne primer and paints on cab grade because they match trim packages, dry fast, and can be sequenced efficiently. Hope this helps.

 

[Bob Gerritsen]

Thanks Wooden, Alex and Scott, that sure does help!!

So I'm going to get me a better HVLP system if I get this job, maybe even when I don't get it. I've done quite some experimenting with the Wagner but I think I've seen it's limits. As the Wagner lacks the pressure to really handle any decent viscosity I want to be sure I get that right this time. In the end I was able to get nice constant spray patterns with the Wagner so I think I'm up for a better system.

Alex, the Earlex system will be good for most paints/situations right? I like the pricing, a bit hesitant to seriously consider the more expensive Graco or Apollo systems on their site but would like to know what I'll be missing. Could you tell me what the differences are? I can tell you the paints over here are not like in Holland, don't know what it is but I sure miss the good Dutch brands like Sikkens. I'm sure it is a question of getting used to a new product as materials tend to be of high quality over here but so far I've done a lot of cursing when it comes to painting jobs. I really want to make sure I get a system with plenty power to also handle slightly thicker paints as overall I think the paints are thicker here and thinning them to my taste hasn't worked very well, especially on mdf this has caused fibers to constantly rise through the fresh painted surface. Checking all of the units on the site you mentioned does instantly make me consider more/bigger/better units. As I'm not knowing much about this it is hard to judge what I need exactly.

Generally speaking I want a good (semi) pro unit. As I won't be using it weekly or sometimes monthly even, speed isn't the biggest priority. Flexibility with product is important though and I want to be able to really dial in different things like air and product supply and air pressure (are there more variables?). I will be doing clear coats and color coats, latex as used to cover walls with is less likely.

Overall I get the impression the precision that can be achieved with these units is really exciting. When I see clips of painters spraying with minimal masking I get the idea this is really ideal for me. This means I can also do plenty good work with one of these in the shop. Having my neighbor spray in his booth is fine at times but as I'm also depending on his schedule and it isn't cheap, I'm really liking the promises these systems make. I would be willing to install some curtains in the shop to create a dedicated spray area that can be ready within 10 minutes or so.

One more question guys, how many layers get you a good finish using a portable HVLP system with bare mdf? Are we talking three layers (ground, first coat of paint and finish coat)? Maybe an extra filler coat for the sides of mdf panels? Or an extra coat of clear in the end? I'm hoping three layers will get me a nice finish, sanding twice seems alright, three times is a bit much already.

Thanks a bunch! Bob.

 

[Bob Gerritsen]

Alex, a question for you; when looking at the different brands and models of HVLP systems at the link you provided to the verfspuitwinkel.nl, I've noticed the most expensive Apollo unit is the only unit that allows control of the pressure, is that correct? If so, I'm guessing this means controlling the pressure isn't essential for good results, assuming the other units are well capable of laying down a good finish.

So how does this work then? You dial in the amount of product and the amount of air, the pressure with which the air is reaching the gun remains constant. In that sense this is the same as on my Wagner unit . Except the pressure with a decent unit is much higher, they don't even mention the pressure on the Wagner site.  [laughing]

If this is like I assume, the amount of air and product are enough variables to dial in the perfect mix for a certain product. Then, when choosing one of the brands and models, the difference really is in the gun itself right?

Still trying to grasp this. Not really sure yet what to look for, it's just that pressure control seems very usable. Would be great though if I could do without as keeping the investment below 1000,- euros is a nice goal.

Thanks, Bob.