HVLP Primer & Paint Tips Needed

[WoodWrangler]

Looks like tomorrow I should be in a position to begin spraying the primer (and maybe paint) on the beds I'm building for my daughter.

I had read that the HVLP turbine systems in like mine (Wagner FineSpray) wouldn't do good with water-based products like paint ... so I went to Harbor Freight yesterday and picked up their HVLP gun (for a steal at $20) and plan to use it with my 26 gallon air compressor.



Now, I don't know a ton about spraying primer or paint ... so I figured I'd look here for tips.

Things that come to mind are:

• Is it safe to assume I can thin it with just water alone?
• What is the ratio for thinning?
• Does the primer work the same as the paint?
• Can I just use a regular primer from the big box stores? Same goes for paint?

Any help is appreciated!

[Tarhead]

Jeremy,
I have one of these and like it a lot. 2 lb shellac is the thickest finish I've used in mine. Based on what I've read you will need a larger nozzle (~2mm) for latex to work well and also remove the internal screen/filter. The old version of that gun was an exact copy of a Porter Cable gun and their nozzle/needle kits fit. Now that the 43430 is made in China the word is they don't fit. HF sells bigger nozzle/needle kits but I'm not sure they fit the new version.
Because of this I'm using a white tinted lacquer on the sewing room cabinets and the kitchen cabinet rehab I'm currently doing.

I found these instructions here: http://purplesagetradingpost.com/sumner/techinfo/HVLPspraygun.html
and they have worked well for me:

Setting up and spraying with the Harbor Freight HVLP gun #38308 and the 43430
________________________________________
Pressure Adjustment: Open your compressor regulator up so there is plenty of air pressure in the line to the gun (I set mine to about 90 psi). Next set the regulator on the gun handle to 50 psi with the trigger pulled and leave it set there. Close the valve at the bottom of the handle (on the gun, not the regulator) and then with the trigger pulled, open it to the point where the air volume starts to stay the same (just listen to it) and leave it there (it should be pretty far open at this point). I never mess with this after this unless I think it has been changed.
Note: On my two year old gun they say the maximum pressure is 60 psi. On my new gun it says 40 psi. Instead of the 50 psi above you might try 40 psi if your gun says 40 psi max.
Fan Adjustment: Next open the fluid volume control about 3 turns for starters (at the back of the gun). Close the fan control down (on the left side of the gun behind the nozzle) so when you spray you only get small round circle. With the gun about 6 to 8 inches from a test surface (I use the garage door or better yet some sheet rock, or masking paper) move the gun across the surface (about 6 to 8 inches from the surface) and pull the trigger. As you are moving turn the fan control until you get the desired fan shape/width (about 5-6 inches wide top to bottom oval shape for overall painting) (remember if you are spraying up and down on a surface you can change the nozzle at the front of the gun 90 deg. so the fan is horizontal).
Fluid Control: Next after getting the fan the right size continue spraying and adjust the fluid volume at the back of the gun for the final adjustment to get the fluid right for the gun speed (how fast you sweep it across the work). You want to be laying on the paint at a pretty good volume, but not causing runs at a normal gun sweep speed.
Changing the pressure to match spec sheets: Now you're ready to paint and with 50 psi at the handle the gun is spraying about 10 psi at the cap. If you want 5 psi at the cap put 25 at the handle regulator (8 psi = 40 psi, 7 psi= 35 psi, etc.). You can't actually see the pressure at the cap which is what the spec sheets are referring to. The gun is internally regulating the pressure down based on the inlet pressure. Some expensive guns have a gauge off the back of the handle that tells you the cap pressure and then they also have a regulator and gauge at the bottom of the handle like this gun that regulates the pressure into the gun.
Painting: Look at what your painting and the way the paint is going on the surface right behind the gun and adjust from there. For instance if you want to spray some small areas/parts you can turn the fan down to a small round size. You will also have to greatly shut the fluid volume down at the back of the gun (clockwise) at the same time to avoid runs. I usually turn the air pressure at the regulator on the handle down to around 25 to 35 psi to do spot work like this.
Proper Pressure: Remember you need a high air pressure (Set as the spec sheet calls for) so that you get proper atomization and so you can turn the volume up. The higher pressure will actually mean fewer runs since the atomization is better. This is not so critical with the primers, but you really need it with the sealer, base, and clear coats so you get good coverage without runs and with little orange peel.

[WoodWrangler]

Thanks for that info ... sounds like I need to pick up that 2.2mm nozzle. Wonder if any brick & mortar stores have it in stock around here ....

[Travis Porter]

I don't think anyone locally carries it. I know Amazon does, but that is about it.

I will be curious to hear how you do. I tried it with the Porter Cable PSH1 and didn't thin the paint at all. Needless to say it didn't work very well. In addition to the water, I have read that Floetrol should be used as well to help. I have some, but haven't tried it yet as the experience mentioned above made me a bit gun shy.

[Tarhead]

If you're wedded to latex you may need to get a new gun with a bigger tip and some Floetrol. The bigger tip for the 43430 is a special order item and may not fit d/t the new design and will cost ~$40. Try Northern Tool for a $39 Vaper gun with a big tip: http://www.northerntool.com/webapp/w...9459_200319459

A few others in the group have Vaper guns and have had good results.

A gallon of tinted lacquer from Sherwin Williams and a $15 box fan from Wallyworld connected to a spraybooth made from a big cardboard box made the most sense to me. (Just turn it on before you start spraying and wait for the air to clear before you turn it off)

[WoodWrangler]

Thanks again, guys! I might just pick up that Vaper gun and return this one.

I was reading last night and it does sound like the Porter Cable 2.3mm tip will fit the new model of the gun, but I'd rather not wait on shipping. Might just head up to Northern Tool this morning and get this other gun instead.

[skysharks]

Jeremy, I too have the "Fine Spray lock n go" system.
I used it for spraying oil based primer and paint. To which it did a great job.
However I was miss led into thinking that I could spray latex with it.
But could not find a viscosity chart for the latex.
I called the tech line and was told that this system would not spray latex.
I was bummed out. They told me that I would have to thin the latex out like water in order for it to spray out of this system. Even then there is something in the latex that would eventually wear out the tip and gun if they were not good metal/ceramic tips.
It sprays all the oil based stuff fine, however oil based paint takes sooo long to get the smell out of it. I was really wanting to spray the latex paint on these items.
So I am kind of in the same boat as you are.
I will be watching to see what the results of this thread are.

[NCPete]

John, Northern Tool opens in Fayetteville on Bragg blvd this week!

[Travis]

Jermey,

Yes you can thin latex with water for HVLP systems. Fuji recomends 10% which has worked for me. I also add about 3 oz. of Flowtrol to a quart and get the water right out of my dehumidfier. I found that when I spray it looks like orange peel but flows out perfectly smooth in a few minutes.

[WoodWrangler]

I went ahead and picked up the Vaper that Mark recommended. Never got time to spray with it today, but plan to this week. I'm going to start out with a KILZ primer, then follow-up with Latex paint. Do you think I'll need to thin it or add the Floetrol conditioner with this gun and the 2.2mm nozzle?

[Travis]

Jermey,

Are you planning on painting it white. I had a severe problem described as "ghosting" by mixing latex Kilz with white paint that nearly drove me insane. There was a mate on this site by the name of Dozer that described the problem perfectly. I changed to Zinser Shelack based primner instead of Kilz and never had another problem.

He wrote:

"I think what you are seeing is what they call ghosting it usually only occurs when using a bright white paint that has any type of sheen to it. Using a no nap foam roller won't cover the ghosting the only thing that will is if you add another coat but it needs to be 1 or 2 shades darker. The ghosting comes from the pigment used to make the kilz and the latex the best way to explain it is that the pigment bases are butting heads. That is why a color a shade or two darker will hide it."

[WoodWrangler]

Thanks for that info, Travis. I guess the Kilz is out! I'll run up to Lowes or the Depot today to see what they have. I'm hoping to spray today.

[WoodWrangler]

Thanks again for the advice & recommendations. As I mentioned earlier I ended up getting that Vaper 2.2mm HVLP gun, some Floetrol ... and with a little trial & error I was able to get the latex to spray fairly well. I ended up with a 10 - 15% thinned (with water) latex paint & Floetrol combination to spray evenly & not clog up the gun.