More HVLP Questions

[skypn]

First, I have never sprayed a finish in my life, except rattle cans.

I started making little 4 x 6x 3 ish jewelry boxes and would like to try my hand with spray finishes, as my brush/wipe on skills leave more than a tad to be desired. I can never get gloss to be more than a semi-gloss.

I usually work with cherry, and have been happy with GF seal a cel, and arm r seal finishes.

I have a little 2gal CM oil less pancake compressor.

I plan on trying the HF HVLP purple gun with the regulator. HF HVLP

Will I still need an in line filter?

Will or should I thin these at all before spraying?

Will I be able to spray water based Polycrylic with this set up?

[Bope]

Yes get an inline air filter. HF has a small one that can connect to the inlet of the regulator.

You know you will make a mess of the surrounding area if you spray arm r seal and seal a cell. Be sure to do this outside so you don't breath too much of this and possibly burn your house down.

Yes you can spray waterbourne products. With the 1.4mm N/N you will need to dilute some of them to bring the viscosity down. Check with customer service to see if it is possible to get a 1.8mm or larger N/N preferably a 2.0mm. Get a #4 ford cup to measure the viscosity will help you be more consistent. Jeff has a nice table or viscosity and N/N combinations on homestead finishing products.

With your pancake compressor you probably wont be able to spray things larger than your small boxes. It comes down to how often you will have to wait for the compressor to catch back up.

[skypn]

Thx Bope

[jteneyck]

What Bope said, plus some more thoughts. You won't be able to spray into the boxes very effectively, so if that's what you were hoping for you're going to be disappointed. For boxes that small rattle cans is a good way to go unless you make a bunch and spray them all at once. You can get all kinds of finishes in rattle cans. They are more expensive, sure, but there is no setup or clean up and for small projects like yours they work just as well.

If you do decide to buy the HF gun you will have to thin most anything thicker than Sealcoat shellac, unless you can buy a larger N/N as Bope pointed out. That gun is made for viscosities around 25 seconds #4 Ford cup. The GF water borne finishes I use most range from about 45 seconds to over 65 seconds. That gun will spray EnduroVar and Enduro Clear Poly without thinning, but only very slowly. But now that I think about it, that may be just fine for your little boxes. HP Poly, however, will require thinning as it's around 65 seconds (at least when I measure it).

Arm-R-Seal is a great product, but I would never spray it. The over spray will make a huge mess, the fumes will be even more intense than normal, and the fire risk just isn't worth it.

John

[skypn]

Thank You both, you make very good points.

[BobW]

Following my HVLP post the other day, I ran down to HF to get a couple of the purple HVLP guns. I noticed that they also have a little detail sprayer...perhaps that would be better for your small boxes.

[Bope]

I agree the smaller detail sprayers might be a better fit from a size perspective but watch the N/N size. I usually see the size go down to 1.0mm. Still fine for shellac but will make clears much more difficult. Again check with CS for option to get larger N/N.

[Snipe Hunter]

Whoa... hang on a second. I think you got some bad advice here.

Sorry I saw this thread so late... the "detail" gun would have been the better choice.
The purple gun requires 12 CFM @ 45 PSI. That ain't no pancake compressor. You could get by with less for very short bursts but there's plenty of inexpensive guns that shoot just as well without requiring 12 CFM. You'll drain a pancake compressor in nothing flat with that gun. Pancakes generally only put around 1.0 CFM at 45 psi.

Here's a touch-up gun which would work well for small projects that only requires 3.5 to 6 CFM @ 45 PSI. You'll still need a little bigger compressor that puts out a min of 3.5 CFM @ 45 psi and still be relegated to small projects as it will also drain quickly on any larger projects. But it will drain half as fast as the purple gun.

You might consider using an airbrush with the pancake compressor if you are really shooting small objects. This is a good little airbrush with needle and tip sizes from .3 to .8mm that would work with your compressor. Although airbrushes put out less finish than a spray gun, they atomize better and are typically fine for very small projects like mentioned above. You'll have to get some adapters to connect it to a compressor.

[jteneyck]

A detail gun may be a better choice for the OP application, but the HF purple gun does not require 12 CFM at 45 psi, despite what it says on the box. I run it at about 20 psi gun inlet pressure with shellac and it sprays great. I've never run it above 35 psi and almost never above 28 psi. What's printed on the boxes is misleading/just plain wrong.

I've even sprayed with it in a pinch with my 3 gal nailer compressor and it worked fine. You can't spray continuously, of course, but for a minute or so it's fine. I think if your compressor can put out at least about 5 CFM at 40 psi it will be fine with that gun.

John

[BobW]

jteneyck said:

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but the HF purple gun does not require 12 CFM at 45 psi, despite what it says on the box.


John

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What's printed on the current box is 6 cfm @ 40 psi.