One of the causes of orange peel is the application of too much fluid and not enough atomization to break the product up into smaller droplets. It's similar to putting your finger over the end of a garden hose. Increase the atomization by using smaller fluid tips or a larger spray unit. See General Finishes comparison chart for generally recommended spray tips. Contact your spray equipment manufacturer's recommendations as well.
Another cause can be temperature. Refinishing furniture in a space that is below or above the 65-75 degrees F range can lead to problems, and a space below 55 degrees F is definitely too cold.
Enduro-Var sprays beautifully if the gun is absolutely clean and does not have any other finish residue. Proper cleaning with acetone followed with hot water should purge the fluid passage. Enduro-Var itself will not cause gun failure.
Another possibility is the power of the gun. Some of the lower quality guns can overheat causing the product to cure in the gun - they need a rest once in a while if you are using them all day.
Also note that Enduro-Var ADHERES WELL only over WATER STAINS, DYE STAINS, and RAW WOOD.
SPRAY APPLICATION OF GENERAL FINISHES WATER-BASED FINISHES:
All General Finishes water-based topcoats and wood stains are ready to spray from the container without additives with the exception of Conversion Varnish. Always strain material through a medium to fine mesh filter before spraying. If necessary, in hot or dry climates, reduce 10 to 15% with General Finishes Extender to extend the open time.
PRE SEALING:
Softwoods such as Pine absorb stain at an uneven rate and may respond better to staining if the wood is pre-sealed. General Finishes Pre-Stain Conditioner Natural can be applied to raw wood to condition the surface for uniform penetration of the stain. Pre-sealing will cause the final stain to be lighter so you may need to use a darker color. Always test your color on a hidden part of the furniture. Allow the Pre-Stain Conditioner to dry 30 minutes before applying your final stain color.
If you are using a sprayer that has been used for oil-based or lacquers, clean the unit thoroughly with acetone followed with hot water to purge the fluid passage. Apply a thin coat first that will dry and harden faster. Sand this first coat down to a smooth base on which to build your finish coats with a 220-320 grade foam sanding pad or #400-grit sandpaper. It is better to spray 2 thin coats rather than 1 heavy coat.
Contact your supplier to verify proper tip sizes for your specific equipment. GF's general recommended fluid tips for Wood Stains and Top Coats are Compressed air - .040 and Airless - .009.
This PDF lists general guidelines for several different types of sprayers with specific General Finishes product recommendations for HVLP listed below.
RECOMMENDED TIPS FOR GENERAL FINISHES PRODUCTS USING HVLP:
Milk Paint: 1.8mm-2.0mm
Brushable White Enamel 1.8mm-2.0mm
Stain Blocker: 1.8mm-2.0mm
Pearl Effects: 1.8mm-2.0mm
Glaze Effects: 1.8mm-2.0mm
High-Performance Topcoat: 1.1mm-1.3mm
Flat Out Flat Top Coat: 1.1mm-1.3mm
Enduro-Var 1.1mm-1.3mm
Water-Based Wood Stain: 1.1mm-1.3mm
Water-Based Dye Stain: 1.1mm-1.3mm
Exterior 450 Topcoat:1.1mm-1.3mm
Exterior 450 Stain: 1.1mm-1.3mm
Enduro Sanding Sealer: 1.3-1.4mm
Enduro White Poly: 1.3mm-1.5mm
Enduro Black Poly: 1.3mm-1.5mm
Enduro White Under Coat 1.5mm-1.8mm
Enduro Clear Poly: 1.1mm-1.3mm
Enduro Pre Cat Lacquer: 1.1mm-1.3mm
Enduro Conversion Varnish: 1.1mm-1.3mm
Air caps should be medium size. Contact your supplier to verify proper tip sizes for your specific equipment.
Break your work into sections such as dresser top or drawer fronts. Spraying too large of an area can result in a textured grainy surface. A correctly sprayed finish should appear even and glossy. It is important to spray enough material to allow proper flow and leveling of the finish.
Spray medium wet films at 3-5 wet ml thickness. Practice makes perfect. If you have never sprayed finishes before, take a large piece of cardboard and practice your technique first. Spray water on the cardboard to learn how the gun works. Check your fluid settings and adjust the controls to get comfortable with the spray angles and to develop your technique.
SPRAYING TOPCOATS:
Keep your gun at a 90* angle, 6-8" from the surface. On large flat areas, use wet, even patterns 6 to 8 wide. For narrow surfaces, reduce the fan pattern to 2-3" to reduce overspray. For topcoats, overlap each pass 25% to conceal lines.
Keep your gun at a 90* angle, 6-8" from the surface. On large flat areas, use wet, even patterns 6 to 8 wide. For narrow surfaces, reduce the fan pattern to 2-3" to reduce overspray. Overlap each pass of stain 50% for even coverage and wipe back the excess with an absorbent cloth. For narrow surfaces, reduce the fan pattern to 2-3" to reduce overspray.
SPRAYING WATER BASED DYE STAINS:
Keep your gun at a 90* angle, 6-8" from the surface. On large flat areas, use wet, even patterns 6 to 8 wide. For narrow surfaces, reduce the fan pattern to 2-3" to reduce overspray. Overlap each pass of stain 50% for even coverage. If coverage is even, there is no need to wipe. If you have issues with uneven coverage, wipe back the excess with an absorbent cloth. For narrow surfaces, reduce the fan pattern to 2-3" to reduce overspray.
Arm-R-Seal can be sprayed successfully, but we prefer hand application methods because it is very easy to spray too much in one area. If you choose to spray, use very thin coats and watch for runs (large drips that run down the side of your project).
If you notice a run, immediately wipe or brush it out. If you correct a run promptly, you will not see a mark. However, dried runs can be difficult to remove.
Wear a mask and work in a well-ventilated spray booth.
Milk Paint is not like a filler-based wall paint. It is engineered for high-use applications such as tabletops and cabinets that require considerably more durability than a wall. The resins that make Milk Paint durable change the properties of it, so you have to handle it differently.
The type of applicator you use will change the thickness of the film and affect the appearance GF Milk Paint.
When refinishing kitchen cabinets, our contractor customers often roll the face frames and spray the doors. If there are any corners or edges that need to be filled in with a brush, they will fill in before spraying or rolling. Then, they will complete the entire section with one type applicator.
With this approach, you will notice a slight difference between the frame and the cabinet door, but the difference is considerably less obvious than it would be if you sprayed and rolled on this same surface.
Secondly, always stir the can well just BEFORE and DURING use. When working with a large project, we recommend continuing to stir during use to keep color properties consistent. If there is any delay, the ingredients will start separating.
Color separation is a condition that the paint industry calls "float". This is very typical with specific colors such as grays because of the large variance in gravities of the pigments required to create the color. In gray for instance, Ti02 (white) is 3.4 and black is 1.62. The lower density will float. This phenomena will not occur in colors that have less variance in densities.
Although we spray product all the time in our workshop, with several sprayers ranging from airless to HVLP, we do not consider ourselves to be spray gun experts for all brands.
Between these two resources, you should get the information you need.
SPRAYERS THAT WE HAVE USED IN THE SHOP
The Earlex Sprayer Station 5500 is an entry-level spray gun with a self-contained pressure system that sprays our paint quite well. It comes with a 2.0 mm tip for paints and a 1.5 mm tip for clears. You can learn more about this product by going here.
The Earlex Spray Station 5500 has been used for the following GF spray demo videos:
The 3M Accuspray HG18 16570 is also easy to use, It filters the material, and the spray head is disposable. This is one of the units we spray within the woodshop. It uses a 1.5-1.8 mm tip for paints and clears. Check out the 3M Accuspray product listing on Amazon here.