Need Help Thinning General Finishes Color and Top Coats

[David Ruhland]

I am having a heck of a time thinning the General Finishes Milk Paint and High Performance Top Coat. I can not get it to layout smooth. Eventually the Color does level out, but the high performance Top Coat does not and shows a slight appearance of orange peel. Remember I am coming from an automotive spraying background, so i expect the finish to lay down flat. Is the slow leveling process something i just need to get used to? I am trying to develop a waterborne system so i can hobby paint in my basement workshop. Perhaps I am using the wrong topcoat? Should I be using the Enduro Pre Cat lacquer? I am spraying with a 1.3 tip.

I have tried the thinning 10 percent using Flotrol...is that my problem?

I have done viscosity readings and come up with 75 secs #4 Ford cup on the High Performance Satin Topcoat- 180 secs on the Driftwood color. I compared this to another topcoat i spray (Old Masters) and it is 17 secs out of the can.

Is there a "general" viscosity/thinning guideline you start with?

Spraying with an Earlex 3 turbine Sprayport.

Thanks...

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[Gary Muto]

General Finishes sells a product called extender which slows drying and thins the material. i suggest using that 5-10%. I use it all the time in CO since it is so dry. GF says you can also use water to thin the material but I've ehard that it will not slow drying. I don't know tht for sure since I always use extender.

[Jim Becker]

Use the GF extender, not Flotrol. You really cannot "thin" water borne products, per se, beyond just a little minor amount, without affecting finish quality. So if you have the proper gun setup and you're still not getting the result you favor, the GF extender is likely going to help. (It reportedly works for "lay down" issues with some other manufacturer's products, too, according to John T)

[Patrick Chase]

I have done viscosity readings and come up with 75 secs #4 Ford cup on the High Performance Satin Topcoat- 180 secs on the Driftwood color. I compared this to another topcoat i spray (Old Masters) and it is 17 secs out of the can.

75 sec Ford #4 is *extremely* high viscosity, particularly for a ~5.5 psi system like the 3-stage Earlex. I only go up to about 30-40 sec with the largest cap set in my 5-stage 9.5 psi Fuji for example. IIRC that's about where most manufacturers' guidelines end, though Earlex doesn't seem to publish any.

[David Ruhland]

75 sec Ford #4 is *extremely* high viscosity, particularly for a ~5.5 psi system like the 3-stage Earlex. I only go up to about 30-40 sec with the largest cap set in my 5-stage 9.5 psi Fuji for example. IIRC that's about where most manufacturers' guidelines end, though Earlex doesn't seem to publish any.

Well this gives me a good "starting point" at least Greatly appreciated....i watched some of the Earlex videos on a single stage and they are saying "160 secs) is their magic number to spray in the unit... I did call Earlex and they are quite helpful..but they say they have a rating of 160secs for the single stage 5500, but "no rating" for the 6003 3 stage like I have. I am just gonna have to continue to experiment. Thanks for this

[Patrick Chase]

Well this gives me a good "starting point" at least Greatly appreciated....i watched some of the Earlex videos on a single stage and they are saying "160 secs) is their magic number to spray in the unit... I did call Earlex and they are quite helpful..but they say they have a rating of 160secs for the single stage 5500, but "no rating" for the 6003 3 stage like I have. I am just gonna have to continue to experiment. Thanks for this

The problem with "ratings" is that in almost every industry the criteria seem to invariably end up being a race to the bottom as makers push for the best feeds and speeds. I'm sure my Fuji could fling globules of a 160 sec fluid in the rough direction of the work, but I don't think the surface would be quite what I try for.

One other thing I noticed re-reading your post just now is the 1.3 mm air cap. IIRC some of the Earlex models come with a 2 mm cap as well. If you have that then it might work better with such a thick coating.

FWIW one set of viscosity guidelines for the guns that I use with my 5-stage turbine are on p. 9 here. Note that the file has funky pagination because it's made to be stapled into a book. In my experience those numbers lead to consistently "safe" results, probably because that gun is also used with 3- and 4-stage turbines so the guidelines are set accordingly. I can push somewhat thicker fluids with the 5-stage.

[John Kee]

David I use a CAT HVLP gravity gun and compressor so a different spray setup, not a fan of turbine guns. Your pic looks like the product is going on too thick with poor atomization. Before I dropped General Finishes as a supplier I used a lot of their pigmented top coat and never found I could spray it properly right out of the can. I typically had to dilute at least 10% with distilled water to get a nice spray. There is a lot of BS out there about diluting with water and how much you can dilution you can use. I've been told by multiple tech reps that most finishes don't show any problems until you start exceeding 20%. You can take that for what it's worth. There is a difference between using an extender and actual dilution. Floetrol is a product developed for typical house paints and IMHO should never be mixed with sprayable lacquer type products.

[John TenEyck]

I usually measure HP Poly around 65 seconds, so your 75 seconds is in the same ballpark. When I had gravity guns I used a 1.8 mm N/N to spray HP Poly, and added 6% H20 to it, and it laid down great. Now that I have a pressure assisted gun I would use a 1.3 mm N/N. I assume your Sprayport has a pressurized cup, yes?, so I'm a little surprised it's not behaving well.

I would not use Floetrol with it. Plain old water should do it, and I'd have no qualms about adding even 10% if needed, but GF's Extender works better and at much lower amounts. I would try adding 5% and see how that works for you.

FWIW, GF's PreCat lacquer is much harder to spray well than HP Poly. If you are looking to change to a different product I would look at GF's Enduro Clear Poly. It has a lower viscosity (around 45 seconds IIRC) and is harder and more chemically durable than HP Poly.

Keep in mind that many WB products will show some orange peel when first sprayed, but it will disappear as the finish really dries and cures. I'm spraying some kitchen cabinet doors right now and was amazed to see how much better they looked after a week.

John

[David Ruhland]

If you are looking to change to a different product I would look at GF's Enduro Clear Poly. It has a lower viscosity (around 45 seconds IIRC) and is harder and more chemically durable than HP Poly.


John

IS this the product your talking about?

Enduro Clear Poly Quart.JPG

Thanks a million for the advice

[David Ruhland]

Your pic looks like the product is going on too thick with poor atomization.

John... I agree with you... i think the problem i am having is i think i am spraying a car (years ago) and need to have a "wet look" covering the whole panel this of course causes me to put it on to thick... and as John T says I am NOT used to seeing a lil orange peel while its curing, I am not giving up on this Waterborne system yet! Thx for the info.

[Jim Becker]

David, while it will cost a few shekels, it may very well be worth just shooting finish on some "scrap" panels for a bit to get a feel for how things work with your particular spraying setup and the finish(s) you want to use. That's been helpful to me as I try a few things I hadn't previously used from my manufacturer of choice as well as some products from others. It's better to blow off a bit of the finish on something that isn't a project first to insure that things will work as you want them to on the real deal. And getting the right combination of gun/sprayer settings and the specific finish product is key to success.

[John TenEyck]

John, I agree that you can add up to 20% water w/o issues on most WB products. Most of them say as much right on the can.

FWIW, GF's Enduro White Poly became so much easier to spray after I started adding about 3% extender to it. Glass smooth now.

To the OP, I've never had any trouble with HP Poly orange peeling when I've put it on too thick, but I still try not to do so. Most WB products do best when you put on just a little less than you think is needed. If it looks like an almost complete film, that's the right amount, because it will flow out in a few minutes into a complete film. If it doesn't then the humidity is too low and you need to add Extender.

John

[John TenEyck]

Yes, that's the one. It's lower viscosity should make it easier to spray with your setup, although I think you will be fine with the HP Poly if you add water and/or Extender to it to make it compatible with your gun.

John

[David Ruhland]

Jim... I’m a practicing.... I scored a whole cart of cabinet doors at my local restore for 20bucks!

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[Patrick Chase]

I usually measure HP Poly around 65 seconds, so your 75 seconds is in the same ballpark. When I had gravity guns I used a 1.8 mm N/N to spray HP Poly, and added 6% H20 to it, and it laid down great. Now that I have a pressure assisted gun I would use a 1.3 mm N/N. I assume your Sprayport has a pressurized cup, yes?, so I'm a little surprised it's not behaving well.

Do you happen to know what viscosity you were hitting after dilution? (asking to fill in my own knowledge. I generally stick to thinner waterbase finishes as noted above).