# New to HVLP, Help?



## SlapHappy Drums (Jan 9, 2013)

Howdy, I have so far not made a mess of anything with my lil' Harbor Freight HVLP sprayer, mostly because it is still in the box.
Please help me keep this streak alive.

I intend to run shellac and thinned tung oil through it to finish some projects.

I have always just used rub on finishes(mostly tung oil) and am a little nervous about messing up my current project, but I'm way in love with the idea of how quick shellac can dry.

Anything I should know going into my first spray on shellacking? 

Also when I give tung oil a shot I've been told I should thin it to spray properly.....how much should I thin it?

Thanks!


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## SlapHappy Drums (Jan 9, 2013)

....and cleaning too, I suspect that cleaning it kinda sucks.
Tips? 
Tricks?
Can I recycle dirty mineral spirits?


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## Steve Neul (Sep 2, 2011)

You may be able to spray shellac without thinning it. I would try it first and if it doesn't spray alright thin it with denatured alcohol with as little as it takes for it to spray. Spraying shellac is like spraying any other finish. You overlap each path of finish over the previous path. Tung oil really should be thin enough to spray without thinning. Just spray it on and let set for a couple of minutes and wipe off the excess. If you clean the sprayer immediately after using it, it is enough most of the time to just spray some lacquer thinner through the gun. If it's something nasty I normally rinse the gun out and then rinse it again with fresh thinner. If you keep a empty gallon thinner can you can pour the used thinner in the can and the gunk will settle to the bottom and the next time you wash the sprayer out the first wash you can use the used thinner for the first wash. If you let the finish set overnight especially with a gravity feed gun you should probably take the gun apart and wash it and then spray some clean thinner through it.


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## JCCLARK (Jan 30, 2007)

What you can spray depends on the tip size of your gun.
The bigger the tip, the thicker the finish you can spray.
Lacquer thinner works best to clean guns with.
Take it apart as soon as you're done using it and clean everything.
that's the most important thing with a spray gun.

HVLP's use a lot of air, most quick disconnects restrict the flow.
If you don't use bigger fittings, run higher pressure and regulate 
it down at the gun. That's what most car painters do.
Typically 60 to 80 psi to the gun.
I use bigger fittings, that made a huge difference from
the normal ones.
And remember, the PSI setting that your gun is recommended to
to be used at is measured at the gun with the trigger pulled.
you need a gage at the gun.


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## cabinetman (Jul 5, 2007)

JCCLARK said:


> What you can spray depends on the tip size of your gun.
> The bigger the tip, the thicker the finish you can spray.
> Lacquer thinner works best to clean guns with.
> Take it apart as soon as you're done using it and clean everything.
> ...


+1. :yes: In addition to a gauge at the handle of the gun, you'll need a regulator. There are small combo units, *like this*. Add to that a *disposable filter*.

If you are using 100% pure Tung oil *(NOT a product labeled Tung Oil Finish)* it works best when wiped on. A general recommendation is to reduce the Tung oil 4 parts of mineral spirits to 1 part Tung oil, for the first few applications to bare wood that has been sanded to 320x. Allow to sit for about 15 minutes and wipe off, without leaving the surface wet. Allow 24 hours for drying. Mixing ratios can be oil increased with subsequent applications.

If used over a stain, the product label will have suggestions on application depending on the stain used.









 







.


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## Deanr (Jul 29, 2011)

Have you opened the box and read the directions.
It may have a chart or instructions on material and thining.
I don't have the HF sprayer but mine came with directions on using 
a ford viscosity cup. Its a type of calibrated plastic funnel that you dip
and measure (in seconds) the time it takes to stop a steady stream.

Kind of a PIA but after a couple times I got the feal for how thin I should be.


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## HowardAcheson (Nov 25, 2011)

Before you start let me suggest you need to practice and learn how to use your equipment. You don't just fill the gun and fire away. Never let your project be your learning curve. Only begin to spray a real item after you are comfortable with your knowledge.

The first thing I would do is by Charron's Spray Finishing. It will tell you about the equipment. It will tell you how to set it up and adjust it. It will tell you how to "read" the spray so you know what adjustments you need to make to have a good outcome. It will give you info about techniques for spraying.

I am a little confused about your earlier reference to spraying tung oil. Tung oil and linseed oil are typically wiped on, not sprayed. Oils and oil based finishes are very problematic for spraying. The overspray is in the form of a liquid mist that is very slow to dry. The mist will spread finish onto every surface in the area leaving an oily surface and/or a crust when it drys. There is little advantage to spraying oils as they must be wiped dry after being on the surface for 15-30 minutes. You can't just apply the oil and not wipe off the excess.


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## Julie Mor (Feb 10, 2013)

Some finishing products companies will tell you what tip size to use with their products. Others tell you to refer to the gun manufacturer. Do a web search for both and use that information in helping you decide tip information. 

You may also get information about thinning and viscosity cup times needed to spray a given finish.

Once you are armed with all this information, get a piece of cardboard and use it to check fan spray, fluid delivery and air volume. I'd also recommend watching some videos on spraying so you can get a feel for technique. Then find some scrap and finish it just like you would your project. This will give you the experience and confidence you need to use the sprayer on your woodworking project.


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## Cliff (Feb 5, 2012)

SlapHappy Drums said:


> but I'm way in love with the idea of how quick shellac can dry.


Then you owe it to yourself to try some General Finishes Enduro Pre Cat 181. Use the sealer too. 

If you like the way Tung oil or BLO pops grain do a wash coat of Shellac and then top coat it with Pre Cat 181.


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