FAQ Index
Coating Defects
1. Air Entrapment
Air bubbles, trapped in the coating during mixing or application, can result in bubbles or crater like defects in the cured paint film.
Cause: Too much agitation or lack of anti-foam agent.
2. Bernard Cells:
Bernard Cells are hexagonal cells produced by vortex circulation patterns induced by solvent evaporation in thin films.
Cause: Too thick a film: too low a viscosity or too high surface tension.
3. Bloom:
Bloom is the appearance on the coated surface of a hazy deposit or oil or wax-like material which mars appearance by lowering gloss or giving a mottled look.
Cause: Migration to the surface of an oil, plasticizer or non-cross-linked component.
4. Blushing:
Blushing is the whitening of the surface when a coating is applied in high humidity.
Cause: Evaporation of the solvent at surface lowers temperature and causes moisture condensation on the surface.
5. Bumps & Sinks:
Bumps and sinks are high and low spots caused by unwanted flows which occur during curing after the initial leveling.
Cause: Surface tension gradients during curing.
6. Cratering:
Cratering is the formation of small bowl shaped depressions in a film.
Cause: Gel particles, dirt, fibers, undissolved silicone, overspray, oil contamination and substrate contamination.
7. Crawling and Dewetting:
Creeping back of the coating into beads, craters, islands or pinholes.
Cause: Poor wetting of the substrate.
8. Fish Eyes:
Craters distinguished by a center which consists of a uniform flat painted area surrounded by a ridge.
Cause: Contamination by fluid globules, oil or silicone.
9. Floating:
Floating is a mottled, blotchy, or streaked appearance in the paint film.
Cause: Separation or uneven distribution of different pigments in the paint.
10. Flooding:
Flooding denotes a uniform color change occurring after application.
Cause: Differential settling of the pigments.
11. Orange Peel:
Orange peel is a surface bumpiness resembling the skin of an orange.
Cause: High viscosity; too thick a film; or not enough material for flow and leveling.
12. Sagging, Running or Curtaining:
These all describe gravity induced flows on vertical surfaces.
Cause: Too low a viscosity or too thick a wet film.
13. Solvent Popping:
Solvent pop is the formation of defects by eruption of trapped solvent after coating begins to gel.
Cause: Too fast a cure and/or too fast a solvent for conditions.
14. Telegraphing:
Revealing of surface features through the coating after cure.
Cause: Surface tension gradients.
15. Water Spotting:
Change in appearance from water standing on the film.
Cause: Water sensitivity of the coating.
16. Poor Distinctness of Image (DOI)
Poor DOI means poor quality of reflected images from the coating surface.
Cause: Substrate roughness, too low film build, wrong solvent.
17. Dry Spray:
Rough textured surface.
Cause: Too fast a solvent, low spray viscosity.
18. Die Back:
Loss of gloss after application.
Cause: Improper solvent evaporation.
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COATING FILM DEFECTS
1. Color Match:
Colors do not match.
Cause: Improper mixing, variables in spray application, viscosity.
2. Peeling:
Topcoat peels.
Cause: Contaminated substrate, improper preparation, undercoat not cured, case hardening of substrate.
3. Sand Scratches & Bullseyes:
Objectionable sanding pattern showing through film.
Cause: Soft primer, improper sanding techniques and low topcoat film build.
4. Blistering:
Formation of dome-shaped liquid or gas filled projections in film.
Cause: Loss of local adhesion. Undercoat not cured.
5. Chalking:
Formation of a friable powder on surface.
Cause: Weather disintegrating film binding medium.
6. Checking:
Slight breaks in the film which do not penetrate to the substrate.
Cause: Film too brittle for substrate or primer coat.
7. Cracking:
Cracks in the film all the way to the substrate.
Cause: Film too brittle for substrate.
8. Erosion:
Wearing away by water or air borne grit.
Cause: Too severe an application or coating choice.
9. Filiform Corrosion:
Formation of threadlike corrosion under coating film.
Cause: Improper corrosion protection.
10. Flaking:
Detachment of film fragments after cracking, checking or blistering.
Cause: Loss of adhesion.
11. Mildew:
Fungus growth causing discoloration and decomposition of binder.
Cause: Lack of fungus control.
12. Print:
Coating takes on imprint of something placed against it.
Cause: Too soft a film.
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Metal Preparation
The adherence of any coating to a metal substrate is primarily a function of surface preparation. If the surface is properly prepared and bee nom contaminants one can apply a coating with the confidence that it will adhere and give many years of service life. Paying very close attention to preparation is an absolute must.
ALUMINUM SURFACES
1. The bare surface must first be thoroughly cleaned and any corrosion removed. First the surface can be cleaned with naptha, acetone or MEK. If stripped metal, all stripper must be removed.
2. Wet abrade aluminum surface with a commercial phosphoric acid etch tightener ie. Air Tech Alumiprep keeping surface wet 3 - 5 minutes. Rinse with dean water; water must sheet over the entire surface, a water break bee surface must be had. Abrasives containing iron i.e., steel wool are prohibited for cleaning operations as particles may become imbedded in aluminum and be the beginning of corrosion.
3. Apply a chromic acid conversion coating (Alodine) to the surface. Keep surface wet for 5 minutes. Reapply several times to obtain a pale gold or tan color. Rinse thoroughly and air dry. The next primer coat must then be applied within 24 hours!.
4. For severe service such as water immersion or use in situations where high chemical resistance is required the use of a phosphoric acid wash primer is recommended. The next primer coat must be applied within 24 hours!
5. After the conversion coating and/or wash primer application the surface must be coated with Air Tech's two component epoxy/ primer.
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STEEL
1. Surfaces must be cleaned with naphtha acetone, or MEK to removed oil or other contaminants.
2. Any rust or corrosion must be removed by sanding, steel wool or steel wire brush.
3. Surface must be cleaned by wet abrading it with a phosphoric acid etch solution. Surface must be kept wet for 5 minutes minimum.
4. Within 5 hours after surface has been cleaned it must be coated with an Air Tech two component epoxy primer.
Note: Wash or self etching primer is an optional treatment for steel surfaces after acid etch. It must be used on surfaces which will be placed in extreme service ie. long term water immersion etc. It is very good for zinc coated surfaces (galvanized).
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Plywood Painting
To properly finish plywood sheathed components with the Air Tech process use the following procedures:
1. After plywood is installed and sanded smooth all dust must be removed from the surfaces. Close attention to dust removal will greatly improve final finish.
Option: After sanding it is optional to coat wood with Air Tech catalyzed polyurethane varnish. This step is not mandatory but would add protection to the wood in the event of damage and/or delamination and moisture entrapment.
2. Spray one double wet cross coat of Air Tech UA 55 adhesive thinned approximately 1 part adhesive to 4 parts reducer (RA 4000). Viscosity should be such that good penetration is achieved.
3. After flash off of the first coat; spray a second double wet cross coat of the thinned adhesive. These coats are the foundation coats for the fabric.
4. Place the fabric on the surface after 30 minutes dry @ 70F., longer if cooler.
5. Using a lint free cotton cloth and 4/1 thinned adhesive apply adhesive to the perimeter ensuring removal of all entrapped air. Good adhesion is achieved when the fabric becomes translucent.
6. Brush coat another coat of thinned adhesive (3/1) around edges of part to gain an adhesive foundation for overlapping fabric from the other side.
7. After curing overnight fabric may be shrunk using an iron set at 225-250 F or a heat gun if proper control is maintained. The objective is to only shrink the fabric and remove creases and puckers and have the fabric lay against the wood surface. Full tautening at up to 350 F may cause the fabric to pull away from low or depressed areas and is not recommended. To ensure uniform shrinkage pencil lines may be drawn as a grid on the fabric and when shrinking try to keep the grid square as the fabric shrinks.
8. After shrinking use a ling free cotton cloth and 4/1 thinned adhesive wet all fabric out ensuring good adhesion to the plywood and removal of all entrapped air.
9. Spray a final coat of 4/1 thinned adhesive on surface as a foundation for primer coat. Concentrate in open bay areas so as not to reactivate edge adhesive and cause fabric to slip after tautening.
10. Cover other side of part in the same manner. Overlap fabric about 1/2 inch and trim off excess later with an Xacto knife to gain a good seam. This seam can be covered with surface tape.
11. After part is completed prime and paint according to Air Tech Procedure AT 101. Remember with the primer apply only enough to fill the fabric weave. Extra material serves no useful purpose.
Note: In any areas where a deep plywood depression is encountered
fabric may be slit to allow bonding to the surface after which this slit may
be covered by a patch or surface tape.
WARNING:
HEED ALL RECOMMENDED SAFETY PROCEDURES USE OF RUBBER GLOVES AND GOGGLES ARE HIGHLY RECOMMENDED
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Trash in Paint
Trash can come from many sources and as we begin to paint we always feel sure we have covered our bases well in preparation to spray our paint or primer/fillers.
A. We cleaned the floor and wet it down with water.
B. We installed a ground strap on the metal components to stop that static build up.
C. We sprayed our assemblies using "stat free" and allowed it to evaporate.
D. We dressed our self in those lint free throwaway paint suits and taped up the sleeves.
E. We turned on the exhaust fan and let it run for at least 15 minutes.
F. We wiped down the assemblies very carefully as not to transfer the bees-wax from our tack cloth onto the assemblies.
G. We hand feel of the assemblies as we know the hand can feel better than theeye can see.
H. We mix our paint or primer in accordance with the directions and used thereducers to match our ambient air temperature.
I. We strain the paint or primer through the strainers we have-------WOOOO This is where all that preparation work may look like we have wasted ourtime. STRAIN YOUR LIQUIDS USING THE VERY FINEST MESH STRAINERS THAT WILL STILL ALLOW THE LIQUIDS TO FLOW THROUGH. YOU MAY WANT TO TRIPLE UP ON YOUR STRAINERS OR MORE-----BUT MAKE ABSOLUTELY SURE YOU HAVE FILTER STRAINED YOUR LIQUIDS TO THE HIGHEST POSSIBLE DEGREE.
J. We drain our air moisture separator on our air lines and adjust our air pressureand spray gun spray pattern.
K. We apply our first coat and we look for trash----no trash ----keep spraying---got trash---stop and find out where it is coming from.
One of the most overlooked problems for trash is assuming your paint straineris correct, remember you are the professional or you would not be doing this, so act professionally and read the sighs. Paint suppliers supply the strainers at no charge and most of the time this causes the most expensive mistakes. Professional painters ask for a finer mesh paint strainer than what is provided free or they will double, triple or quadruple the supplied strainers to get the desired filter/straining they are looking for.
As you apply your final coat of color to you assemblies and you are satisfied with your spraying results------dump that left over paint----as this is where many paint jobs go bad --- that left over paint is sure hard to dump out but shy away from that desire to use up that left over paint.
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Paint Confusion
Paint that is applied on a fabric covered aircraft is cosmetic only and is not part of any fabric covering process. The FAA considers any STC'd fabric covering process complete when the correct amount of filler/UV application meets the STC holders directions.
Air-Tech is the only true flexible polyurethane color top coat that was specifically designed and manufactured for polyester/dacron fabric as a cosmetic coating. Air-Tech is not an automotive coating with a flex agent added to reduce cracking of the dried paint.
During manufacturing of the Air-Tech colors the flexing agents are blended into the color pigments and does not have to be externally added during application mixing. Extensive testing by Air-Tech using major brand automotive paints with a flexing agent added does help flexing, but it also makes the dried paint very vulnerable to scratching because the surface stays soft like plastic and will chalk up in only a few years.
Air-Tech manufactures all its color coatings, at our plant in Jacksonville, Arkansas, and uses only the highest quality ingredients to give you, the customer, a product and color match you can count on each and every time.
When you have completed your fabric covering job, using the Air-Tech fabric covering process, use only Air-Tech flexible polyurethane colors and you will have that award winning wet shinny look that every one desires. Air-Tech coatings does not support combustion and is highly pigmented to give you quick coloring without having to apply excessive coats.
Keep in mind when you are spraying fabric covering products, no matter who's, one should wear proper protection equipment and adhere to all warnings and cautions on the label.
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Approved Fabrics
Only polyester/dacron fabrics may be used in this process which meet the requirements and are certified under Technical Standard Order TSO C-15d, dated February 26, 1990 entitled Aircraft Fabric.:
What this simply means-- is that-- you can use Ceconite, Stits, or Superflite, of the weight that is suitable for your application. All aircraft major brand polyester/dacron fabric that is FAA/PMA approved has to meet the TSO C-15d, and the Air-Tech Fabric Covering Process is approved for use on all.
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Fabric Weight Questions
A frequently asked question from customers is how much does the coating process weigh. In truth all fabric covering processes weigh less than metal or composite and in fact this is one of the main reasons fabric was chosen in those days when horsepower was not available. AIR TECH weighs less than any other coating system:
COATING WEIGHT COMPARISON
Aprox. coating weight including fabric in oz/sq.ft.
Fabric Weight Air Tech Stits Stits Dope
5 coats - 7 coats - 12 coats - 20 coats
1.8 --- 0.7 --- 0.9 --- 1.4 --- 1.6
2.7 --- 0.8 --- 1.0 --- 1.5 --- 1.7
3.7 --- 0.9 --- 1.1 --- 1.6 --- 1.8
Aircraft
J-3 Cub
750 sq. ft.
2.7 oz fabric --- 37 lbs. --- 46 lbs. --- 69 lbs. --- 78 lbs.
The Air Tech system will weigh about 1/2 that of Dope!!!
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MSDS Information
For more detailed information on chemicals which might be components of our finishes one may consult http://www.msdssearch.com which is a depository of MSDS information on a wide variety of chemicals.
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Available Products
Fabrics
HTC 104 Certified 1.8 oz. Dacron Fabric 70" wide/yd
C 102 Certified 2.7 oz Dacron Fabric 70" wide/yd
(For most certified aircraft ie. Cubs etc.)
C 101 Certified 3.7 oz Dacon Fabric 70" wide/yd
(For working/heavy aircraft ie ag planes)
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Dacron Finishing Tapes - Pinked Edge
STR tapes are 2.7 oz fabric: precision cut with clean edges
STR1 1" pinked edge tape/50 yd roll
STR2 2" pinked edge tape/50 yd roll
STR3 3" pinked edge tape/50 yd roll
STR4 l" pinked edge tape/50 yd roll
STR6 6" pinked edge tape/50 yd roll
STRB2 2" biased pinked tape/25 yd roll
STRB3 3" biased pinked tape/25 yd roll
STRB4 1" biased pinked tape/25 yd roll
STL tapes are 1.8 oz fabric: precision cut with clean edges: some prefer as the lighter tapes lad down and work easier
STL2 2" pinked edge tape/50 yd roll
STL3 3" pinked edge tape/50 yd roll
STL4 4" pinked edge tape/50 yd rolls
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Covering Accessories
Inter Rib Bracing Tape
RC18 Hi Strength Flat rib lacing cord/500 yd roll
Flat cord pulls up tight: lays flat
RTN1/41/4" reinforcing tape/roll NYLON 72 yd
RTN3/83/8" reinforcing tape/roll NYLON 72 yd
RTN1/21/2" reinforcing tape/roll NYLON 72 yd
GRO1 1" plastic drain grommets/100
GRO SP Seaplane Grommets/100
ABL42 Fabric Rivets I/8"xl/8"/350
ABL44 Fabric Rivets 1/8" x 1/4"/350
Air Tech fabric rivets have large flat aluminum heads and stainless steel pulls. They pull up tight and stay- put.
ATIR Inspection Rings
ST 10/12 Straight Needles
Iron Model Iron Teflon Face
Therm Iron Thermometer
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Adhesive Materials
UA 55Q Fabric adhiesive
RA 4000 Adhesive Reducer
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Primer and Preparation Materials
RF4020 Fabric Wash
M9050 Alumiprep-Acid Etch
M9060 Alodine (converison coat)
PW1950 Self Etch Primer
PCU2950 Self Etch Primer Catalyst (mix 1:1)
N19200 Spar Varnish
M9250 Spar Varnish - Water Based
PA1900 Sealer Barrier Coat (apply over dope prior to topcoating with AT color: requires 4 oz. FA 3030/gal)
PE 1700 Epoxy Primer Base (Gray)
PCE 2700 Epoxy Primer Catalyst (Mix 1:1)
PE 1730 Epoxy Primer Base (Yellow)
PCE 27 30 Epoxy- Primer Catalyst
PE 1800 Fiberglass Primer Base
PCA 2800 FG Primer Catalyst (Mix 1:1)8 Oz
M 9586 Paint Stripper
PFU 10 30 Fabric Primer Filler
PCU 2030 Fab. Primer Catalyst (Mix 5:1)8 Oz.
FA 3030 Flex Resin
PFUW 1050 Fabric Primer - Water Based
Color Holdout Additive
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Hard Deck Floor Coatings
Bicep Cleaner Concentrat
Acid Etch
Epoxy Color
Standard Colors
Catalyst
Premium Colors (reds, etc.)
Catalyst gal
Hard Deck Polyurethane Clear Coat
Hard Deck Resin
CCM 5200 Catalyst
Hard Deck Reducer (for epoxy color)
Roller Frames 18 inch
Rollers 1 /4 nap 18 inch
Epoxy Resurfacer 20 lb. kit (makes 2.5 gal)
Traction Improvement Grit 12oz
Glitter (silver or gold)4 oz
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Copyright © 2007 Air-Tech Coatings, Inc. All Rights Reserved.
Air-Tech Coatings Inc. 1 Paradise Park Road Jacksonville, AR 72076
Phone 501-985-1484 | Fax 501-985-1359
