Spray pattern probelm ("tiger striping") with Earlex 5000 spray gun

[Chris Atzinger]

Hi,

So, I started to start spraying some transtint diluted with DNA (1oz dye into 32oz DNA) on some scrap plywood to test out various colors and I noticed that I was getting an odd spray patter, where it was really heavy and wet on the edges, and dry in the middle. I broke down the gun, cleaned, thinking I had a clog in one of the air horns. Filled back up, same problem. I switched to a 1.5 mm needle, and only opened up the fluid control 1 full turn, same problem. I call tech support, he calls it "tiger stripping". He is convinced it is a clogged air cap. I break down clean again. Same problem. Call tech support, and he asks that I spray some thicker material (thinned latex, and then call him back and describe the pattern),

In the mean time, I order some more dye, and ask about this issue, and he says that 1.5 is way too big of a needle for transtint+DNA and that I need go down to the smallest needle I can get, and choke back the fluid as much as possible.

So....what do you guys think? what as worked for you? What needle do you use?

-Chris

[Brad Schmid]

I would agree. You should see much better results with a .8 N/N set
I don't think I can think of anything that could be thinner than DNA/transtint
If you check it with a Ford #4 cup, I bet it's less than 16sec.
Cheers

[Paul Murphy]

Small needle to spray dna&dye. Try spraying a test pattern, should look like a cigar. If it looks like a figure-eight it could be due to too much air pressure, trying to spread the fan pattern too wide. Try adjusting your pattern a little narrower end-to-end, once it looks like a cigar you are closer to the correct setting.

Many of the better sprayguns are sold to folks spraying ngr dye, it's not a very forgiving task. I am no expert at it so I thin the dye enough to do a north-south application, then follow up with an east-west application to help even out the result.

Edit: Realized Earlex may have different controls than my conversion gun. Don't know if my comments apply well to your spray equipment. I still think you should spray a test pattern to see if it needs adjusting.

[Chris Atzinger]

Hi,

Thanks for the replies. The Earlex system doesn't have an adjustment for air flow, just fluid, which I am seeing is now a problem.

I bought a 1 mm needle/nozzle, which is the smallest size available. I have a roll of white paper to practice. The whether here has dropped into the 50s which may be a little cool to spray outside.

Thanks!
Chris

[John Coloccia]

This is why I usually spray color (mostly Transtint, btw) mixed with a little super blonde shellac. I usually spray somewhat less than a 1lb cut mixed with the transtint. It seems to spray better, lay down better, and blotch much less. If you plan to top coat with lacquer, even better. Mix the transtint with lacquer thinned maybe 50%.

[Peter Froh]

If possible buy a small shutoff ball valve and screw it on near the gun then screw on the hose. This is what Fuji did on their older guns to control airflow. It works ok.

[Mark Blum]

This is why I usually spray color (mostly Transtint, btw) mixed with a little super blonde shellac. I usually spray somewhat less than a 1lb cut mixed with the transtint. It seems to spray better, lay down better, and blotch much less. If you plan to top coat with lacquer, even better. Mix the transtint with lacquer thinned maybe 50%.

I'm curious. Does the thin cut of shellac allow the dye to truly soak in and act as a stain, or does it become more of a toner?

I'm about ready to start some finishing and had planned on using the same Transtint/DNA stain as my first step, followed by a coat of shellac and then topcoated with Target's WB lacquer. If the shellac will make the dye step go easier I may give that a try.

[John Coloccia]

I'm curious. Does the thin cut of shellac allow the dye to truly soak in and act as a stain, or does it become more of a toner?

I'm about ready to start some finishing and had planned on using the same Transtint/DNA stain as my first step, followed by a coat of shellac and then topcoated with Target's WB lacquer. If the shellac will make the dye step go easier I may give that a try.

Try it on scrap first to see how you like it. It still acts like a dye, but it's has a bit more body and it's easier to spray. It doesn't soak in quite as much, but it also lays down much smoother and doesn't blotch as much. Like anything, there's always a tradeoff. I've successfully sprayed (and do spray) straight Transtint & alcohol, but I use a Devilbiss EGA touch up gun. Good luck getting that sort of control and atomization out of anything but an airbrush or a high end automotive spray gun. That's not to say you can't get good results with a cheaper gun, but getting really pro results with a lesser gun CAN be challenging with straight transtint, IMHO.

Just to get the terminology right so we're on the same page, a dye is generally in solution and will soak in deeper. A stain is generally in suspension and is more superficial. So dyes generally stain more than "stains" do...LOL. As Victor Borge would say, "Hey, it's your language...I'm just trying to use it."

You may know this already, but if you use shellac under EM6000, use flakes. Sealcoat will sometimes cause the EM6000 to craze. It will look like old cracked porcelain...sometimes.

Anyhow, it's just something to try that's helped me get more consistent results.

[Curt Harms]

If you're experimenting, you could try setting the air horns at 45 degrees. That sprays a circular pattern rather than the cigar shape. I've experimented with transtint a little but used it like John C. to tweak the color of the finish coats.

[Paul Murphy]

This is why I usually spray color (mostly Transtint, btw) mixed with a little super blonde shellac. I usually spray somewhat less than a 1lb cut mixed with the transtint. It seems to spray better, lay down better, and blotch much less. If you plan to top coat with lacquer, even better. Mix the transtint with lacquer thinned maybe 50%.

The best ideas are usually simple ones, mixing DNA/dye/shellac is a great suggestion especially as it would seem to allow better spraying through the 1.0 tip. I would certainly try this, it's an excellent suggestion in my opinion.

[Mark Blum]

Just to get the terminology right so we're on the same page, a dye is generally in solution and will soak in deeper. A stain is generally in suspension and is more superficial. So dyes generally stain more than "stains" do...LOL. As Victor Borge would say, "Hey, it's your language...I'm just trying to use it."

You may know this already, but if you use shellac under EM6000, use flakes. Sealcoat will sometimes cause the EM6000 to craze. It will look like old cracked porcelain...sometimes.

Thanks. Yes, I am familiar with the difference between dyes and stains, and I haven't used a pigment stain in years since I first tried dye stains. As for Sealcoat, I actually do plan on taking my chances. I don't intend on putting on much shellac and most folks who have used it have not experienced the crazing, including Jim Becker on this site who apparently uses it regularly. Mine is freshly purchased, and I'm keeping my fingers crossed that I don't have the problem.

But I think I'll give it a try mixing in some shellac with my dye coat. Thanks for the tip.

[Chris Atzinger]

The local WW store where I bought my transtint actually recommended that I just mix my transtint directly into the shellac. I mixed a small amount (8oz) of shellac with my usual ration of 1oz dye to 32oz solvent (in this case shellac) and sprayed on some scrap. I quickly realized that the shellac wasn't nearly dark enough and the number of coats required was going to be a problem in order to get the wood the right color. I am guessing I could have adjusted my ratio, but to my eye, it would have required drastically more dye. I am pretty sure I understand what is going on, in that I am still making multiple passes with my DNA only mix, thus being the equivalent of a more concentrated mixture as the DNA flashes off, unlike the shellac mix, where it's just tinted layers of "film" building up.

John C.-Do you think I can swap out part of my DNA with shellac and not affect the color. For example, if I am mixing 1 oz TT/32 oz DNA, that I could go 1oz TT/8oz shellac/24oz DNA, and give the mixture a little more viscosity, without lightening it too much?

Thanks!
Chris

[John Coloccia]

The local WW store where I bought my transtint actually recommended that I just mix my transtint directly into the shellac. I mixed a small amount (8oz) of shellac with my usual ration of 1oz dye to 32oz solvent (in this case shellac) and sprayed on some scrap. I quickly realized that the shellac wasn't nearly dark enough and the number of coats required was going to be a problem in order to get the wood the right color. I am guessing I could have adjusted my ratio, but to my eye, it would have required drastically more dye. I am pretty sure I understand what is going on, in that I am still making multiple passes with my DNA only mix, thus being the equivalent of a more concentrated mixture as the DNA flashes off, unlike the shellac mix, where it's just tinted layers of "film" building up.

John C.-Do you think I can swap out part of my DNA with shellac and not affect the color. For example, if I am mixing 1 oz TT/32 oz DNA, that I could go 1oz TT/8oz shellac/24oz DNA, and give the mixture a little more viscosity, without lightening it too much?

Thanks!
Chris

Generally how I do it is I mix up my shellac to the viscosity I want....let's say I want to use a 1/2# cut. Then I mix the transtint directly into that, generally using the same ratio as I would with straight DNA. A 1/2# cut is very little shellac. It's just enough to thicken it a bit and to act as a conditioner. The more shellac you add, the more it behaves like a toner. The nice thing about using shellac is that it flashes off so fast you can pretty much just spray continuously until you get the shade you want (though you should be able to get there in two passes or so). I use the air from the gun to dry it even quicker when I'm doing sunbursts. Traditional finishers would have a fit, but it works fine.

[Chris Atzinger]

Hi Everyone,

Not to resurrect an old thread, but I thought I would post my resolution. I ordered a 1.0mm needle/nozzle set and set the fluid control knob about 3/4 of a turn. There is no air control on the earlex sprayers. This put a good, thin coat of dye, shellac, and water based poly. I hope this helps anyone who may stumble upon this thread looking for help!

As always, thanks for all of your replies.

Thanks!
Chris

[Curt Harms]

There's no air control per se on Earlex but it uses a universal motor. Plug-in router speed controls work with universal motors. And yes, this works with my Earlex. Will it damage the motor if used a lot? I don't know one way or the other. I tried it spraying thinned acrylic paint and the motor needs to run full speed in order to lay down a smooth coat. With very thin material reducing the motor speed might work okay.