Spraying Duratex with HVLP gun - what nozzle size/PSI?

[miked]

Hi all,

I'm getting way ahead of myself as I haven't even built my OTop 112's (and T48s') yet, but I'm working out details in advance. I am planning on spraying Duratex from this HVLP hopper gun I bought. http://www.harborfreight.com/texture-pa ... 66103.html

It comes with 3 nozzle sizes; 3/16", 1/4", 5/16". Which should I use for spraying Duratex?

Also, what PSI should I set the regulator on the compressor to? The (typically horrible) instructions that come with this Harbor Freight doozie say "25 to 90 PSI". That's QUITE a range there. I'm guessing that 25 PSI would get a dribble all over the place and 90 PSI would blast the Duratex right through my garage door. Some of the reviewers say they used 45 PSI with drywall mix or something...but that's not Duratex and I have never sprayed any textured coating before. What PSI should I use? Thanks!

[DJPhatman]

Honestly, take the hopper gun back to Harbor Freight, and roll the Duratex on. Unless you are quite familiar with using a hopper gun, and have at least some experience with it, rolling expensive Duratex gives very easy & satisfying results. That particular hopper gun is a PITA to get consistent results with. Just my 2 cents worth.

[miked]

Is it that bad? I've never used a hopper gun before. I know you can make a huge mess if you don't build a "paint booth" out of hanging plastic dropclothes but I'm willing to do that.
I've rolled Duratex before on the fEARful bass cab I built and the results were satisfying, yet it took awhile. The front baffle in particular was a PITA due to having to get into the corners, etc. And that was just one big cab. I'm going to have four, small cabs...spraying would just be so quick.

[LelandCrooks]

Smallest tip. 35psi. Close the trigger adjustment down on the gun all the way. You should just barely be able to pull the trigger open. I mean barely. Get a piece of scrap and try it. I don't even pull the trigger open as far as that little bit will allow for the first coat. You should be able to get it to spray just like spray paint doing it that way. Spray from 8-12 inches away. Thin first coat just make it black, don't sweat light spots. You definitely do not want it too heavy. You can wipe it off if you're quick and shoot it again.

Always shoot some scrap before you start at any point. You kind of have to get the gun up to speed.

Let that one dry 10-20 minutes depending on temp and humidity. Spray again, this time you can open the trigger just a tad more. Keep the gun just a little farther away from the cab. The gun should sputter this time, but just a little. Fill in your light areas carefully. If you get too heavy now you're screwed.

Let that one dry. Open the trigger a turn, turn and a half. Get 18-24 inches away from the cab and let er rip, moving pretty quickly. This is the spatter texture coat. This creates a nice mild texture. If you want a taller texture do it again, or open the trigger a little farther.

Edit: It can be done in one coat. But you don't want to. Hard to control the film thickness and not get smooth shiny spots. They're not runs, it just blends into a coat like paint.

I've used that harbor gun, it works just fine. I have a better one that I use that has a 1 quart container instead of that ungainly 1 gallon thing. I much prefer the sprayed texture.

[Bruce Weldy]

Honestly, take the hopper gun back to Harbor Freight, and roll the Duratex on.

+1

I'm with the Phatman here. Rolling is quick and easy. I line 'em all up and go from cab to cab. By the time you've made it around, you can start the second coat. I absolutely hate painting, but duratex makes it easy. I don't even pour it into a container - it's so thick that I just dip the roller in the bucket and it never drips.

And when I'm done - no clean up. Chunk the roller and head for the fridge...

[miked]

Thanks for the very detailed instructions, Leland. That's a great written tutorial! I agree that the gallon-size hopper that comes w/the HF gun is just ridiculous. How are you supposed to see what you're spraying?

Bruce, you make a good point about "quick and easy and no cleanup." When I Duratexed my bass cab, I put down all this newspaper like you typically do when painting. After two coats I had two or three little drops of Duratex on the paper...it was the easiest paint job I've ever done. I plan on doing a black foam/speaker cloth over metal grill, so the entire mouth will be hidden, so I wouldn't have to worry about getting into the nooks and crannies with a tiny brush like w/my bass cab. Duratex does not like little 1" brushes at all.

Guess I've got some thinking to do on this one. Thanks again, guys.

[DaveK]

I'm with Leland. I prefer the spray method and I use the same HF gun. What Leland says bears repeating -- use the lightest touch possible.

Here's a few more tips.

* Only put about 1 quart in the hopper at a time so it is easier to handle.

* Cover the hopper with cling wrap so the product does not spill and does not get as much skin on top while you work.

* Watch out for clots. They jam the nozzle, then come out with a big splat.

* Prime all the nooks and crannies first with a brush. The spray pattern is not tight enough to fully cover them without getting too much on the surrounding surfaces and causing a run. The deeper the spot, the more important this is. Titan and Tuba mouths are the worst.

* Don't spray access panels separately. Spray them in position on the cab so their texture is consistent with the rest of the cab.

[Bill Fitzmaurice]

The only thing I don't like about the Harbor Freight gun is that it's a constant bleed, so it can drain your air tank while you're waiting between passes or filling the tank. I put a shut-off valve on my air line at the gun.

[Bruce Weldy]

Here's the list of things to consider when spraying:

* Only put about 1 quart in the hopper at a time so it is easier to handle.

* Cover the hopper with cling wrap so the product does not spill and does not get as much skin on top while you work.

* Watch out for clots. They jam the nozzle, then come out with a big splat.

* Prime all the nooks and crannies first with a brush. The spray pattern is not tight enough to fully cover them without getting too much on the surrounding surfaces and causing a run. The deeper the spot, the more important this is. Titan and Tuba mouths are the worst.

* Don't spray access panels separately. Spray them in position on the cab so their texture is consistent with the rest of the cab.

Here's the things to consider when rolling:


* Don't get on pants.

[DJPhatman]

And yet, no one mentions:

I've never used a hopper gun before.

Do you really want to teach yourself how to spray Duratex for just a few cabs? This will take time, and Duratex (=$$$) to learn. If you were an Authorized Builder, or an experienced sprayer, then go for it. For 4-8 cabs, eventually, just not worth the expense, IMVHO.

+1,000,000 to Leland Crooks for the very detailed instruction!

[LelandCrooks]

You can get a good finish pretty fast. It does not take much practice. To get my finish, well that's a different story. (need an irony icon)

[Bruce Weldy]

If you were an Authorized Builder, or an experienced sprayer, then go for it.

We're on the same page here....

If you are going to build cabinets on a daily or weekly basis and have several to shoot at one time or have a designated place for spraying - fine, shoot 'em.

But, for the majority of us, it's just not worth expense, set up time, overspray, and cleanup time.

And the best part is - you really can't tell the difference when they're done - and that's what makes duratex so wonderful.