Can you help with spray guns?

[bobbin]

Not related to sewing, but I wonder if any of you furniture guys have experience with spray painting using a gun and your compressor?  I've been thinking about buying one and looked at a set (2 guns) from Harbor Freight for about $50.  I've never used one before and I read the comments; seems most of the use was with oil-based paints.  Could I use them with latex paints if I use an appropriate thinner (Flo-trol) to thin the paint?

I'm interested in clear coating ship lap paneling that will be used for a porch ceiling.  The idea is to prefinish the pcs. before we install them.  I would used water-based polyurethane.  I'd also like to use oil based paint to spray some old wicker furniture.

[Mojo]

Bobbin:

Alot of the sprayers take a great deal of CFM. I am not sure what size your compressor is ( I forgot what type you have ). The thing you need to pay attention to is the CFM rating of the gun at a given pressure vs your compressors CFM at a given pressure. If you do not get the right gun your compressor will constantly run and wont be able to stay up with the guns air needs.

There are guns out there that have low CFM / pressure ratings. When I was renovating one of our homes in Bristol, TN I bought an electric sprayer. Since I wasn't doing finish work like that of a car or boat I didn't really care to much as to how the application went on. I believe it was a Wagner that I bought at Lowe's. It worked well but cleaning it was the key. ( I was spraying Latex ).

Typically the best air spray guns are Devilbiss but can be pricey. For spraying paint I suggest you do some careful research online to make sure you get a good match with your compressor. Your also going to want to read up on cutting the paint to get the best viscocity for the gun flow.

Someone else on here may have some better feedback for you.

Chris

[SteveA]

A good compressor is key.  Spraying needs more air than the staple guns require.  You could brush on two or three thin coats, sand back and spray the last coat for a smoother finish. 
However for what you're describing - oil paint and water based poly - I would just go to a paint shop and get the equipment the painters use.  It may not be worth setting up for finishing if you're not intending to finish and refinish furniture on a regular basis.
SA

[bobbin]

I have a Porter Cable, 6 gal.; 150psi, 2.6scm@90psi.  I wrote it all down before posting this. 

I'm not finicky about clear coating the paneling.  But I'm pretty "picky" when it comes to furniture.  I want the finish to look nice.  I'm willing to fuss and fiddle to make sure it looks good and I know the finish must be oil-base. I'm willing to recoat as required to lay on the coats that will deliver the "nice" finish.  I'm patient and will do what's required to make it "look nice". 

Aside:  I have thought about adding a "tank" that would maintain pressure before the compressor had to kick in.  I'm really new to "air" and am feeling my way along with respect to it.  Need your input!

[ajlelectronics]

http://www.mig-welding.co.uk/spray-painting.htm

[sofadoc]

I have a Porter Cable, 6 gal.; 150psi, 2.6scm@90psi.

Actually, I think your compressor will work as long as you stop periodically to let it "catch up". It's probably going to run non-stop. If you're going to be doing a lot of this type work, then now is probably the time to get a bigger one.

For example, in my case, before I would even consider buying the decorative nailer sold at the top of this page, I would need an air compressor with at least 7 SCFM (standard cubic feet per minute). Otherwise, I would have to go slowly to allow my current 5 SCFM compressor to keep up.
And of course the bigger the tank, the less the unit is going to cycle on.

[Mojo]

Bobbin:

You have the same compressor I do ( I think ). Is yours an oiless pancake compressor ?

The problem with some of the smaller compressors is they can overheat and burn up if run continously. This is especially true for the oiless compressors.

I have heard they have come out with new guns which do not use as much air. I have not checked into them myself. The wagner I a mentioned earlier would be out of the question as it would probably not deliver you the finish your looking for. It is OK to paint walls and houses with but for obtaining a fine finish this is not the gun to use.

A bigger tank will not help as the compressor will have to fill that as well. Most auto painters use two stage compressors or two cylinder heads which provide 15 and more cfm. They have large tanks but because they have dual cylinders they can fill large tanks quickly. The dual cylinder heads start at around $ 500 and go up from there and many require 240 volt power. They are NOT portable either as most are pretty big.

If you have a sherwin williams store in your area talk with one of their sales people. They supply the automotive painters and will know what the latest is in guns as well as paints and finishes.

Sorry I cannot help you more. :(

Chris

[forsailbyowner]

Ive done a bit of spray painting in my time. The viscosity is of key importance for a smooth finish. Part of the morning routine involved mixing the paint meticulously with a viscosimeter a stopwatch and a thermometer. Might consider a larger compressor. Even the low cfm hvlp sprayers use around 4 cfm. Playing with your nozzle on a piece of cardboard to get the right pattern is important and NEVER stop the gun motion while spraying!

[brmax]

Bobbin I think this at 25.00 will work for you #43760 especialy with any of the oil base types, its a clone of the binks no. 7 I have had different brands and most all parts can be attainable from the local auto paint mixer/auto parts its likely you will only use 20-40 psi. as thats the norm.  Everyone should have one for glue or primer but I would keep the water base a seperate one so please consider 2, hope this helps

[MinUph]

bobbin,
  I have a 1 hp sear compressor that is an oldy but goody. I painted my shop outside with it. Sprayed pait and it worked fine. Yes it ran often but it did the job. Still using the compressor 20 25 yrs later.
  These cheap guns won't give you an automotive finish but will do for what your talking about.

[bobbin]

Thank you all for your help.  I knew you guys would be able to offer good insight. 

Update:  I have been brushing the latex polyurethane on the panelling.  I have a lot of experience brushing polyurethane on floor cloths.  I know it takes longer, but I have nice brushes and once I'm "in the zone" I can skim right along. 

We were going to use my compressor (3 yrs. old) to fire the pneumatic nailer today for the panelling installation.  I drained it.  It's never really drained freely but I never gave it much thought until today (because I'm a compressor newbie).  I got a lot of nasty water (looked "dirty"... rusty) and when we fired it up it leaked air through the drain valve.  We removed the drain screw entirely and the "O" ring was non-existent.  But a lot more really nasty water drained out!  I think we'll give it a CLR douche (Calcium Lime Rust) and check the drainage.  But I'm not feeling good about it, you guys.  The idea that the tank has been corroding for 3 yrs. from the inside out makes me nervous when I consider that it is under pressure. 

You guys have a lot more experience with compressors than I do and I'd like to know your thoughts.  Chicken that I am my gut thought is to junk the thing and get a new one, but I'm not sure if maybe that's a newbie, knee-jerk reaction?

[MinUph]

Compressors always get water in them. Three years old it should be fine. I have had mine for almost 25 and it is still good to go. You should empty it more often though as the water gets in the tools.

[bobbin]

I'm worried that I've never fully emptied it, Min..  But I'll give it the CLR treatment and empty it more frequently.  How often do you guys drain your compressors?

[Mojo]

It depends on how much I run it and for how long. If I am using it alot I will drain it at the end of the day. I installed a moisture trap on mine ( mounted on the wall ) and drain that as well. As they build up from continual runs they will start to build up moisture.

I put the moisture trap on after I was blowing off some equipment and it started spraying moisture out intermittently. You can pick up a cheap moisture trap at Harbor Freight for less then 10 bucks. I have a combined unit that traps moisture as well as being a regulator. It works well and allows me to regulate the pressure for my air tools while also providing a bypass for increased pressure for things like blowing up the tires on the coach.

For paint applications it is imperative to have a moisture trap. The gunk that comes through with the moisture is typically laden with oil and can really screw up a paint job. Automotive painters have some pretty elaborate moisture separating systems.

If you give the compressor a decent work out then it is fine to drain it at the end of the day. Otherwise if your using it sparingly over a weeks time then drain it at the end of the week. They will build up some rust inside but frequent draining can help keep the rust factor at bay. Draining will NOT prevent rust from occurring. It will only help reduce the amount.

To make you feel better, in all my years I have never heard of a tank exploding. Catastrophic tank failures are not normal. What is typical is that they will thin out in a wall section and start hissing air through pin hole leaks. That is when you need to either replace the tank or the entire unit. When my pancake compressor starts leaking I will probably throw the entire thing out and start over. The NON oil units do not tend to last as long as the ones with an oil reservoir anyways. I am not sure how much a replacement tank is but I am going to assume they make it high enough to where it ends up cheaper to replace the entire unit.

If I had a big two cylinder compressor and the tank went then I would obviously replace the tank. On the small pancake ones like we have I wouldn't.

Hope this helps,

Chris

[MinUph]

I empty mine yearly if I remember. I don't remember like I use to lol