Spraying (Epifanes) Varnish

[geoffschultz]

Has anyone had any luck spraying Epifanes varnish? I've been using an HVLP to spray both the high gloss and rubbed effect varnish and am getting an "orange peel" effect. Note that this is an HVLP system with a 4 stage turbine and I'm doing this in the dead of New England winter, so it's very dry.

I suspect that my issue is the viscosity of the varnish. I'm looking for tips from people who have been able to spray varnish and turn out a "factory finish" like Freedom did when they made my boat.

-- Geoff

 

[Tim R.]

I would suspect that thinning could help. I have also heard that surface contamination can also cause orange peel.

How do you like your 40/40? How long have you owned her? They are great boats.

 

[RichH]

Try warming the varnish for viscosity reduction and/or more thinner, etc. What you dont want is a larger spray orfice diameter.

But then again, the best finishes are ALWAYS allowed to cure then flatsanded to remove the orangepeel and other surface distortions, ..... then hand rubbed. For flatsanding use Wet&dry 800-->1000-->1500--->2000 grit. For handrubbing use bare/clean hand and rub with rottenstone and water for gloss or rottenstone and oil for semigloss or rottenstone and fine pumice for satin finish.

Modern polishing compounds that can substitute for rottenstone are 3M Finese-it followed by 3M Perfect-it. Both of these are petro based so they cant get to the ultra-gloss unless you apply then let dry a bit then add a few drops of water, then rub. Bare handed rubbing usually produces the flattest glossiest surface, as when using any cloth the fibers in the fabric usually scratch the surface, even micro-fibers. If you want a 'quick' gloss (subject to gloss 'die-back' after a few months) you can use an autobodyshop variable speed polisher with a knobby sponge rubber bonnet and the 3M polishes ... but you absolutely need to keep the grits and bonnets segregated - never mix grits on a knobby bonnet ... and never clean them together in a washing machine.
One of the benefits of 'hand-rubbing', etc. is that the process causes a lot heat by the friction of rubbing ... which develops the glowing/dazzling irridescent 'patina' of the surface wood cells just below the coating surface.

The only thing you can depend on when spraying or rolling, etc. is an 'even' application, but unless youre working in a HEPA filtered clean room that is absolutely free of dust the best finishes always need to be 'ultra-finished' by hand .... top of the line automobiles, mega-yachts, private jet aircraft, the finest musical instruments, etc. never 'just coated' or sprayed

Hand rubbing is labor intensive so its has disappeared from use, except for those who want the 'finest' finish possible but who dont want the vulnerability of a 'french polish' which is the absolute finest finish possible.

 

[geoffschultz]

My end goal isn't a gloss finish, but a rubbed effect mat finish. I can assure you that my "spray room" isn't HEPA filtered, but that really isn't the issue. I think that it's the viscosity. I've had much better luck spraying water based finishes and have never sprayed varnish before.

-- Gepff

 

[geoffschultz]

How do you like your 40/40? How long have you owned her? They are great boats.

I love my 40/40. I've put over 35,000 miles on her and my web site (http://www.geoffschultz.org/) has extensive logs and photos from my travels.

-- Geoff

 

[geoffschultz]

Based upon some info that I just found, using a viscosity DIN cup with a 4 mm hole, it should take 20-24 seconds to drain. It appears that they're suggesting a 15-20% thinning.

Now, my HVLP suggests that using the viscosity cup provided, which is equivalent to Zahn #2 (which is a 2 mm hole????), it should take 18-24 seconds for the cup to drain to obtain a usable viscosity.

On Wikipedia, I found the following formulas for viscosity:

Zahn Cup #2: ν = 3.5(t - 14)
Zahn Cup #4: ν = 14.8(t - 5)
​

Using an average of 22 seconds for the 4 mm hole, that places the viscosity at 251.6.

Using an average of 21 seconds to achieve the recommended viscosity for the HVLP sprayer, that would place the viscosity at 24.5.

That's basically a factor of 10 apart! I don't know if viscosity is linear or logarithmic, but clearly they're a long way apart, and I don't understand the differences.

Any help in understanding this would be appreciated.

-- Geoff

 

[Maine Sail]

I have sprayed

I have sprayed varnish though not with an HVLP. The problem with a very thick product like Epifanes is that you'll be thinning quite a bit to make it pass through the HVLP without "spitting". Because you are thinning so much you'll require many more coats to build the same mil thickness.

I agree with Rich in that you still need to hand sand in between coats. Applying Epifanes by brush will require less coats to get a thicker finish and quite franlky will be much easier to clean up and prep for. Spraying large projects is generally worth the effort but the taping, over spray preventative measures as well as equipment clean up plus the additional coats is likely not a benefit over a good quality brush.

I would consider gloss for your build coats then one or two final coats of the rubbed effect/satin. Too many coats of a satin type finish tend to make it look cloudy and not as deep. Also gloss is a harder finish and over coating gloss with your desired look of satin/rubbed effect will result in a tougher final finish and one that looks deeper.

While I hope to someday own an HVLP I don't think varnish is an application where I'll use it. I don't really like the over spray with my traditional gun and the HVLP systems greatly reduce that..

 

[Tim R.]

I love my 40/40. I've put over 35,000 miles on her and my web site (http://www.geoffschultz.org/) has extensive logs and photos from my travels.

-- Geoff

I was looking at your logs. We missed each other in NE harbor last sept. by about a week. We had just sailed from Portland in an overnight race labor day weekend. I will check out the rest of your site later when I have more time. I have always liked the 40/40 for a liveaboard extended cruising boat. We love our Ericson but the simplicity of the unstayed rig is a real plus. Sorry for the hijack.

As for the varnish. Maybe you build by brushing, sand and apply the final coat by hvlp.

 

[RichH]

Orange-peel is that the surface of the newly deposited layer has flashed off its solvents and has begun to 'cure' before the deeper layers have fully 'leveled out'. An HVLP puts on a LOT of material and too thick 'shots' of paint seem to orange-peel the most.
So, thin-out your varnish to the max. (recommended) shoot on successive but thin coats while carefully watching for the 'flow-out' to reduce and minimize orange-peel. The successive coats will resolubalize the thin coats underneath ... so you have to be relatively quick and not wait for the surface to cure.

A 'trick' to extend the flow time is to 'build a plastic tent' into which you can place the item immediately after spraying, in the 'tent' you've placed a few rags soaked in the solvent/reducer, and quickly as possible close the tent. The 'tent' has the minimum volume possible. The solvent-reducer vapor emissions from the rags will slow down the evaporation of solvent from the coating, allowing better 'flow-out' time ... but once you get the proper visual flow-out then immediately remove the rags or this process can dull the surface and greatly extend the drying/cure time. The excess solvent vapor in the 'tent' slows down the 'skinning-over' of the top surface and allows better flow-out.

Thinning out the varnish is your 'key'. Get a plate of glass , hold it vertical and adjust your spraying mixture of varnish vs. reducer based on how well the varnish flows-out on the vertical glass plate when sprayed ... keep adding 'drops' of either varnish or reducer to get the best 'flow' ... not sags & runs nor a 'dry' rough surface, ... and a minimum of orange-peel. Wipe the plate off with reducer if you need 'more plate'.

 

[geoffschultz]

Thanks for all of the great suggestions. I'm just confused by the Epifane's suggested 15-20% thinning and the associated viscosity that I calculated and the recommended viscosity of the HVLP manufacturer.

The idea of the glass plate is a good one. I'll try that.

Building a tent would be difficult as I'm spraying a LOT of small pieces of molding which are all suspended by wire.

Oh, and I did do about 6 coats of gloss followed by 2 coats of rubbed effect.

-- Geoff

P.S. Rich, I was just in Worton Creek last year...Great place! http://www.geoffschultz.org/Log_Page.php?id=1206

Are you the same Rich Hampel that used to post in rec.boats.cruising?

 

[RichH]

Glad you enjoyed Worton. Be advised that many of the moorings were removed 'inside' the creek so its now a decent place to anchor in a NW blow on the 'inside'. There is a fairly good restaurant (summer) at Worton Creek Marina ... especially during the 'all you can eat oyster nights'.

Yup, the same. I rarely post there anymore. Was a good site until the idiots from alt.sailing.asa took over.

 

[Rick2413]

Spray Nozzle

Along with the correct viscosity, the size of the spray nozzle is the most important issue when laying down a nice flat(level) coat. This allows a much higher atomizing which basically means the droplets shooting out your nozzle is an extremely fine mist as opposed to rain drops(exaggerated but that is where the orange peel comes from). You should see if you can borrow an auto body basecoat/clearcoat gun.

 

[geoffschultz]

Along with the correct viscosity, the size of the spray nozzle is the most important issue when laying down a nice flat(level) coat. This allows a much higher atomizing which basically means the droplets shooting out your nozzle is an extremely fine mist as opposed to rain drops(exaggerated but that is where the orange peel comes from).

Rick,

Based upon my research, it appears that I'll need a larger nozzle based upon the viscosity. I have a 1.0 mm and based upon the recommendation from the HVLP manufacturer, I should be using a 1.5 mm nozzle.

-- Geoff

 

[Rick2413]

Nozzles

Not being familiar with your equipment and I may be wrong but here is the information I got on the Devlbiss guns I use:
[FONT=Verdana, Arial, Helvetica, sans-serif]Common FINISHLINE 3 HVLP SPRAY GUN Fluid Tip Set-Up Applications:[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif][FONT=Verdana, Arial, Helvetica, sans-serif]• The 1.3mm Fluid Tip is Ideal for the Optimal Atomization of Basecoats, Clearcoats and
[FONT=Verdana, Arial, Helvetica, sans-serif]• [/FONT]other Light Viscosity Materials.
[FONT=Verdana, Arial, Helvetica, sans-serif]• [/FONT]The 1.5mm Fluid Tip works for Topcoats, Basecoats, Clearcoats, Sealers and other
[FONT=Verdana, Arial, Helvetica, sans-serif]• [/FONT]Light to Medium Viscosity Materials.
[FONT=Verdana, Arial, Helvetica, sans-serif]• [/FONT]The 1.8mm Fluid Tip is excellent for Primers, Oil Base, Latex, and other Meduim to
[FONT=Verdana, Arial, Helvetica, sans-serif]• [/FONT]Heavy Viscosity Coatings.
[FONT=Verdana, Arial, Helvetica, sans-serif]• [/FONT]The 2.2mm Fluid Tip will enable you to spray thicker materials such as Extreme High
[FONT=Verdana, Arial, Helvetica, sans-serif]• [/FONT]Build or Polyester Primers, and well as Thick Enamels, Latex Paints, and Gel Coats.
[FONT=Verdana, Arial, Helvetica, sans-serif][FONT=Verdana, Arial, Helvetica, sans-serif]• [/FONT][/FONT](2.2mm Tip not included in this Promo Kit, but is included in our Master Spray Gun Kit)[/FONT][/FONT]

Your manufacturer will know what you need.

 

[Ron20324]

I'm no varnish expert, so this thread made me go look at the varnishes I have. They say to not shake the can, to avoid air bubbles getting trapped in the varish. They only mention brush application. I'm sure you read the Epifanes label, but are you sure it is sprayable? I'm sure someone else would have caught this, though. Just my minus two-cents worth.

 

[geoffschultz]

Here's the info from the Apollo (http://www.hvlp.com/) web site regarding tip sizes:

1.0MM All purpose, thin lacquers, thin enamels,Water based finishes, Automotive, Marine, airplane finishes. VISCOSITY ZAHN #2 16—18 seconds

1.5MM Catalyzed lacquers, Conversion Varnish, Primers, Automotive, Marine, Airplane finishes, Varnish, High Viscosity, Industrial Coatings, Urethanes, Enamels. VISCOSITY ZAHN #2 18—24 seconds

From this I believe that a 1.5mm tip would work best. I'll contact them tomorrow.

-- Geoff

 

[geoffschultz]

I'm no varnish expert, so this thread made me go look at the varnishes I have. They say to not shake the can, to avoid air bubbles getting trapped in the varish. They only mention brush application. I'm sure you read the Epifanes label, but are you sure it is sprayable? I'm sure someone else would have caught this, though. Just my minus two-cents worth.

Yes, it's sprayable. Freedom sprayed all of my interior with it. I'm just trying to replicate it. You can also read the product information at

www.jamestowndistributors.com/userportal/pdfs/MSDS/Epifanes/epifanesclearglossvarnish.pdf

 

[sandpiper10471]

Just a thought - 10% Penetrol additive in Epiphanes makes the varnish lay out and level much better when using roll and tip. I was wondering if it is a good additive when spraying. Anyone tried it?

 

[geoffschultz]

I talked to the "experts" at Apollo (who makes the HVLP sprayer) and they suggested that I go to a 2 mm tip and a different air cap (which directs the air at the liquid exiting the tip). They also suggested that I thin the Epafanes until I got 45 seconds thru their viscosity cup. The parts are on order from CA, so I'll let you know once I get them and try them.

-- Geoff

 

[Scott On Eagles Wings]

I have the Appolo also

The larger tip will make all the difference in the world. Also don't forget the machine heats the air 30 degress above ambiant temp. Spray your iteams while the machine is cold or even put it outside. The cooler air will give the finish more time to flow before it sets.