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 (http://www.fujispray.com/User%20Manual%20T-Model%20201602.pdf). 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?

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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).

[John TenEyck]

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).


Around 45 seconds, IIRC.

John

[Patrick Chase]

Around 45 seconds, IIRC.

Thanks. I've been meaning to try edging up a bit from the 30-40 range where I tend to limit myself now, as it would be convenient to use a wider range of less-thinned finishes. I also picked up the new Fuji MPX-30 gun, which should be able to run a little higher (though the guidelines (https://www.fujispray.com/wp-content/uploads/2018/01/MPX-Vixcosity-Chart.pdf) aren't much different).

[John TenEyck]

I don't know much about Fuji except that my friend has a 3 or 4 stage one that runs about 8.5 psi IIRC. With his gun the cup runs at the same pressure as the atomizing air. He can spray Enduro Clear Poly (45 seconds #4 Ford cup) with no trouble w/o thinning it. I've heard others say they can spray Enduro White Poly with a Fuji turbine unit and that stuff is about 100 seconds.

I run my pressure assisted conversion gun at 5 psi to the cup and I can spray White Poly through a 1.3 mm N/N with no issues, same with Clear Poly with a 1.0 mm N/N set.

Something seems amiss about the viscosity recommendations on that Fuji chart you linked to.

John

[Patrick Chase]

I don't know much about Fuji except that my friend has a 3 or 4 stage one that runs about 8.5 psi IIRC. With his gun the cup runs at the same pressure as the atomizing air. He can spray Enduro Clear Poly (45 seconds #4 Ford cup) with no trouble w/o thinning it. I've heard others say they can spray Enduro White Poly with a Fuji turbine unit and that stuff is about 100 seconds.

8.5 psi would be the 4-stage turbine (Mini-Mite 4 or Q4). All Fuji turbine guns pressurize the cup the same as the atomizing air.



I run my pressure assisted conversion gun at 5 psi to the cup and I can spray White Poly through a 1.3 mm N/N with no issues, same with Clear Poly with a 1.0 mm N/N set.

Something seems amiss about the viscosity recommendations on that Fuji chart you linked to.

My experience is that all of Fuji's charts recommend viscosities that yield "no-compromises" atomization and therefore minimal need for self-leveling after application. I'm inexperienced enough that I've stayed within those guidelines so far, but it's obvious even to me that with most finishes I could go higher and get acceptable end results (hence my questions in this thread).

[John TenEyck]

Patrick, most WB finishes are greater than 40 seconds #4 Ford cup. I've found Extender helps the cantankerous ones flow out, but with my pressure assisted gun I haven't had to thin any of them with water, even BM Advance which has a calc. viscosity of 500 seconds. I spray that stuff through a 1.5 mm N/N at 6 psi on the cup. It atomizes fine and flows out great. What I'm saying is, don't be afraid to try higher viscosity materials. They are formulated to flow out under reasonable environmental conditions.

John

[David Ruhland]

Folks,

More testing on some BM ADVANCE today- nothing like watching paint run through a viscosity cup ...Got really nice results at 45 secs (then had to play more) at 28 secs. 1.3 N/N. Is this where the rest of you guys are on this product? First exposure to BM ADVANCE...I like it, but as others have said doing a search on this product, sure takes a long time to dry! I will give it 24 hours and shoot a second coat on it.

D

[Patrick Chase]

Folks,

More testing on some BM ADVANCE today- nothing like watching paint run through a viscosity cup ...Got really nice results at 45 secs (then had to play more) at 28 secs. 1.3 N/N. Is this where the rest of you guys are on this product?

Are you saying you got good results at both 45 and 28? That wouldn't surprise me, though you'd need different flow and maybe air adjustments IMO.

That's about where I'd aim. At that viscosity you should get fine atomization and be able to apply a pretty flat/uniform coat, such that you won't be depending as much on flow-out.

As John has pointed out operator experience and properties of the finish besides viscosity (most notably surface tension and therefore flow-out) are huge variables. I'm inexperienced and aware of it, so I mostly stay in the "kiddie pool" in terms of finish viscosity. IMO 28 sec is a very safe target for this :-).

[David Ruhland]

Are you saying you got good results at both 45 and 28? That wouldn't surprise me, though you'd need different flow and maybe air adjustments IMO.



YUP... I thinned it to 45 secs and got nice atomization, but notice a few "larger" droplets on the outside edges of my fan pattern. I painted my test piece and it looked good. I wanted to see what happened if i thinned it out to 28sec and got favorable results as well. Im a newbie too, but im gonna get this HVLP sprayer figured out! My biggest problem is i think i am painting a car with a siphon feed and move way to fast. Everyone on this thread has been great. Just out of curiosity Patrick where do you "aim" on your GF Milk Finish? I am still all over the board with them anywhere from 28-160 secs yet.

[John TenEyck]

David, how much water did you add to get down to 45 and 28 seconds? If you had to add more than 20% water you are most likely in the danger zone of the finish not forming a contiguous film. I thought I mentioned this somewhere along the way, but I'll say it again in case not. If you have to add more than about 10% water or water + Extender it's time to look at a different spray gun, or at least a different N/N. WB products are formulated to be used as they come from the can. They will tolerate some thinning, but once you exceed a certain amount the product doesn't dry/cure the same, and not in a good way. Don't let your enthusiasm for a perfect finish end up with compromised performance of the final product.

John

[Patrick Chase]

To be clear I don't have direct experience with GF Milk Finish. I mostly shoot shellac, vinyl sealer, stains, and WB clears. The point of my original post was that at your original viscosity atomization will be challenging with *any* finish, and you'll therefore be dependent on the finish to self-level.

GF has a video about spraying (https://generalfinishes.com/videos/how-spray-milk-paint) milk paint as well as aircap size guidelines (https://generalfinishes.com/faq/how-to-spray-water-based-finishes). They state that it's ready to spray from the can with a large (1.8-2 mm) cap, but suggest thinning 10% with water if needed. It looks to me like he's spraying a fairly narrow pattern from close to the work in the video.

[David Ruhland]

David, how much water did you add to get down to 45 and 28 seconds? If you had to add more than 20% water you are most likely in the danger zone of the finish not forming a contiguous film. I thought I mentioned this somewhere along the way, but I'll say it again in case not. If you have to add more than about 10% water or water + Extender it's time to look at a different spray gun, or at least a different N/N. WB products are formulated to be used as they come from the can. They will tolerate some thinning, but once you exceed a certain amount the product doesn't dry/cure the same, and not in a good way. Don't let your enthusiasm for a perfect finish end up with compromised performance of the final product.

John

OOPS.... if I can read my chicken scratch i think i used approx 1.5 oz of water to 14 oz of paint... Im gonna do some remeasuring today and take better notes. Thanks for the remedial reminder..i believe you did tell me about the 20% rule. Hey if a lil is good, a lot is better right? LOL JK

[David Ruhland]

To be clear I don't have direct experience with GF Milk Finish. I mostly shoot shellac, vinyl sealer, stains, and WB clears. The point of my original post was that at your original viscosity atomization will be challenging with *any* finish, and you'll therefore be dependent on the finish to self-level.

GF has a video about spraying (https://generalfinishes.com/videos/how-spray-milk-paint) milk paint as well as aircap size guidelines (https://generalfinishes.com/faq/how-to-spray-water-based-finishes). They state that it's ready to spray from the can with a large (1.8-2 mm) cap, but suggest thinning 10% with water if needed. It looks to me like he's spraying a fairly narrow pattern from close to the work in the video.

I have the next step up in the turbine and gun he is using.. I misunderstood and thought you had a number you try to achieve when spraying it. Your comment about "leveling" is correct... this is where i think i get messed up..i want it to level out as i am spraying... not 5 mins after i am done... Back to the measuring table for me...I have some homework to do Thanks!

[John Kee]

David I don't understand why so many try to spray that BM Advance crap, its thicker than molasses, takes forever to dry, BM recommends brushing or rolling it and BM even states it will yellow with time to a colour you didn't choose. So many superior finishes that are easier/faster to work with and give superior results. If you are using General finishes, John T. is giving you good advice. If you want to BM products you should be looking at their Duralac line. Personally I stick to Sherwin Williams stuff now but the Canadian version differs from the US version. When you were doing car finishing I'm curious did you ever see anyone using a Turbine HVLP to spray or was it compressor driven guns?

[John TenEyck]

OOPS.... if I can read my chicken scratch i think i used approx 1.5 oz of water to 14 oz of paint... Im gonna do some remeasuring today and take better notes. Thanks for the remedial reminder..i believe you did tell me about the 20% rule. Hey if a lil is good, a lot is better right? LOL JK

David, OK that's just about 11%. And you got BM Advance down to 45 or 28 seconds? That seems really hard to believe considering it's about 500 seconds in the can. I had to add 18% water to SW's ProClassic to get it down to around 65 seconds IIRC. Not something I recommend BTW.

John Kee is right; BM carries Lenmar Duralaq, a WB acrylic. BM can tint it to any of the colors, too. It's much lower viscosity and would likely be a better choice with your gun.


John

[David Ruhland]

David, OK that's just about 11%. And you got BM Advance down to 45 or 28 seconds? That seems really hard to believe considering it's about 500 seconds in the can. I had to add 18% water to SW's ProClassic to get it down to around 65 seconds IIRC. Not something I recommend BTW.

John Kee is right; BM carries Lenmar Duralaq, a WB acrylic. BM can tint it to any of the colors, too. It's much lower viscosity and would likely be a better choice with your gun.

John T...

John

I did a lil more EXACT" experimenting and testing yesterday. I used exactly 10% water and got my BM advance to 135 seconds with a 1.3 N/N. It did spray and lay down nice on my test pieces. I continue to test readily available products, but I think as John Kee says I believe I am trying to spray the wrong stuff. My local paint store carries only BM products-that being said I did have them order me some Duralac Waterborne to try. They stock the solvent borne versions and of course tried to steer me in that direction, but I am wanting to stay working in the basement workshop.... I am sure by now you must be thinking I am total donkey, but I do sincerely appreciate all the tips and advice you and others have offered on this thread. Thanks again!

[Wayne Lomman]

David, I haven't said anything prior to this as the product brands being discussed are different to what is available to me. What I do wonder is why you have changed so much from your automotive work? I use the same gravity and suction guns for all my work whether timber, machinery, automotive etc. I am used to them and I know what they can do. Also don't forget that most of your auto finishes work just as well on timber and as you know, they lay down extremely well without all the grief discussed above. Cheers

[John Kee]

David I've been spraying WB finishes for about 12 years now and gone through many trials and tribulations to find what works for me. When I started there weren't many quality WB finishes but thats been changing. The one constant has been that if the stuff is sold off the shelf at a Borg or local paint store its typically what I call house paint, its too thick to be thinned properly and designed to be applied by brush or roller. Its good for drywall and trim but really lacks for high quality cabinet/furniture work. Always read the the TDS info and you've got a good reasonable start if it's recommended for spray only. When using opaques always check for the manufacturer for the appropriate primer designed to work with the product you want to spray. Many primers such as the Zinsser primers a generic in nature, while recommended by many, they may not be the best start. Never spray a hard finish over a soft primer and expect great long term results especially in the durability deptmart.

[Patrick Chase]

I did a lil more EXACT" experimenting and testing yesterday. I used exactly 10% water and got my BM advance to 135 seconds with a 1.3 N/N. It did spray and lay down nice on my test pieces. I continue to test readily available products, but I think as John Kee says I believe I am trying to spray the wrong stuff. My local paint store carries only BM products-that being said I did have them order me some Duralac Waterborne to try. They stock the solvent borne versions and of course tried to steer me in that direction, but I am wanting to stay working in the basement workshop.... I am sure by now you must be thinking I am total donkey, but I do sincerely appreciate all the tips and advice you and others have offered on this thread. Thanks again!

At this point your best bet may be to order a water-base clear that is known to spray well. That will at least give you a reference point for what's possible, so you can decide whether it's worth your time to continue mucking with Advance.

If you want a water-white poly then Target em9000 is what I would personally use (or em6000 if I want a "lacquer look"). I sort of fell into Target's system by reading a few recommendations too many, but there are other equally good options out there.

[David Ruhland]

David, I haven't said anything prior to this as the product brands being discussed are different to what is available to me. What I do wonder is why you have changed so much from your automotive work? I use the same gravity and suction guns for all my work whether timber, machinery, automotive etc. I am used to them and I know what they can do. Also don't forget that most of your auto finishes work just as well on timber and as you know, they lay down extremely well without all the grief discussed above. Cheers

WAyne...

I have been wanting to learn and switch to the HVLP and waterborne for awhile. I still find myself picking up the compressor gun every now and then...

[John Kee]

David not much difference between a conventional compressor gun and and a HVLP compressor gun. The compressor HVLP just allows for a broader range of adjustments but also allows you to be HVLP compliant if needed. Also much easier to spray a broader range of viscosities. Turbine HVLP is a different system because of the limited pressure the turbine can develope.

[Patrick Chase]

David not much difference between a conventional compressor gun and and a HVLP compressor gun. The compressor HVLP just allows for a broader range of adjustments but also allows you to be HVLP compliant if needed. Also much easier to spray a broader range of viscosities. Turbine HVLP is a different system because of the limited pressure the turbine can develope.

HVLP guns (compressor or turbine) typically have different nozzle patterns in the cap than conventional ones, to ensure adequate atomization at lower pressure. In particular the LP guns usually have air nozzles closer to the fluid nozzle on each side.