What is Duco Paint? How is it applied?

Duco is a brand marketed by Imperial Chemical Industries (ICI now merged with Akzo Nobel) under which it sells its popular Automotive paints. The Duco brand represents a range of products meant for auto painting and refinishing. The topcoat or the finish coat available under the brand Duco is a Nitro Cellulose (NC) Lacquer. Due to its wide spread use and popularity, the name "Duco" has been genericized to refer to Nitro Cellulose (NC) Lacquers.

Duco was vastly popular as an automotive finish before the advent of Polyurethane paints. Now a days Duco has found a new life as a high quality finish for interiors and other architectural projects. 

NC Lacquers typically are a clear or coloured wood/metal finish that dry by solvent evaporation and produce a hard, durable finish.  (Read more about Lacquers in general here)

Duco being an NC Lacquer has the following properties :

• Fast Drying
• High Solid content 
• Excellent Water Barrier
• Excellent Self Leveling properties
• Takes very well to buffing to give a high sheen 
• Smooth and Hard finish

 Areas of Application :

• Automobile body
• Plywood and MDF
• Sheet Metal
• MS angles and flats
• Architectural and Industrial metal structures

The different surfaces require different preparations. Let us look at the application methods for each of the surfaces mentioned above.


Application method for Sheet Metal and MS Structures :
Materials Required

• Compressor capable of delivering 30-40 psi pressure consistently.
• A good quality spray gun - preferably HVLP type.
• Safety Equipment - Mask, Glasses, Gloves and Overalls.
• Degreaser solvent
• Degreaser Cloth
• Duco Oil Primer / MRF Etch Primer
• Tak Cloths - to remove sanding dust.
• Duco Primer Surfacer - Grey / White - depending on the top coat colour you choose. For Lighter coloured top coats, use Primer Surfacer White and for darker topcoats, use Primer Surfacer Grey.
• Duco Soft Cut Putty 
• Water Emery (Latex paper backed) of grits 220 and 320
• Sanding block
• Duco NC Lacquer
• Duco Thinner
• Rubbing Compund - 3M 1Step is highly recommended.
• Cotton Waste

Application

• Scrap off any loose particles, dirt and old paint from the metal surface to bare metal.
• If the base metal is galvanized, an etch primer is recommended.
• For bare sheet metal, a coat of Duco Oil Primer thinned with a General Purpose thinner in the ratio 5:1 must be applied and allowed to dry overnight. The Duco Oil Primer has excellent adhesion, corrosion resistance and is air drying.
• Apply 2 coats of Duco Primer Surfacer (PS) thinned with Duco Thinner in the ratio 1:1.5 with a flash off interval of 15 minutes between coats.
• Rectify any minor dents and scratches using Duco Soft Cut Putty and a putty knife.
• Wet sand with water emery of grit 220 followed by 320 to level any imperfections.
• Apply a coat of Primer Surfacer on the puttied areas.
• Choose a colour!
• Apply 2 coats of Duco NC Lacquer thinned with Duco Thinner in the ratio 1:2 of the selected colour. Allow flash off interval of 15 minutes between coats.
• Leave to dry overnight.
• Wet sand flat (remove gloss) carefully with emery grits 600/800and apply one mist coat thinned 1:3 with Duco Thinner.
• Allow to dry overnight and polish the surface using 3M 1Step Rubbing compound. 
• For a higher gloss polish use 3M Premium Liquid Wax.

Application for wood and MDF surfaces follows the same procedure as above except for priming using Duco Oil Primer. The Duco Primer Surfacer is applied directly onto the wooden surface.

The finish thus obtained is long lasting and durable.

Duco has the following limitations :

• Requires elaborate equipment to apply - compressor and spray guns are the basic requirements.
• Colour stability on exposure to sunlight is average - easily yellows.
• Attention to surface preparation is required before application - needs a skilled workman.
• Duco is sensitive to the atmospheric conditions during application - A change in temperature can affect the finish.
• Being solvent based, it is not environmentally friendly and precautions must be taken against the health hazards during application. At minimum a respirator mask, gloves and glasses are required. Body overalls are highly recommended. An exhaust system must be in place to extract the solvent flashing off the surface.

 A range of Duco Products is available for delivery across India @ paintnhardware.com

Also available at our store :

A Study of Paint Rollers

Introduction to Paint Rollers - A brief history of how the paint roller evolved in India

 

Micro fiber Roller - European Handle

The evolution of the roller has followed the path of evolution of paint in India. Not too closely though. There have been times when the paint technology was far ahead and the roller lagged far behind. As time progressed and paint graduated from lime wash to distempers and emulsions, the transition of brush to roller was a slow one. This was partly due to unavailability of certain roller products and technologies but majorly due to habits of painters and their reluctance to invest in their trade. Painters were usually part time. The finish of emulsions were not up to the mark due to the use of brushes. To counter this, painters began using cheap foam rollers on wet paint after brush application. The finish was better but still not satisfactory and the paint jobs took longer to complete. This system worked for many years until painters began experiencing problems with application of high sheen emulsions. Around the same time, painters also began facing problems with manpower. The modern cloth roller thus began finding acceptance and quickly replaced the brush as a tool of application. This roller not only provided uniform deposition of paint but also reduced the time taken to paint. After some initial resistance - again due to the painters habit and reluctance to invest in trade - the cloth roller is widely used today. 

Variety of Rollers

. Cloth Vs Foam - Cloth rollers are mats of woven or knitted fiber pasted onto plastic tubes and mounted on to handles. The pasting is done in a spiral fashion so as not to leave any marks on the painted surface. Foam rollers are pieces of foam, cut in uniform cylindrical shapes and mounted onto handles.

. A wide variety of sizes are also available. Width x Diameter - 2 " x 1", 4" x 1", 6" x 1", 6" x 2", 7" x 2", 8" x 2", 9" x 2".

Polyester Roller - Cage Handle

. A Wide variety of materials area also available in cloth rollers : Polyester, Acrylic, Micro Fibre, Poly Amide, Natural Hair and Blends of the above. The material is either warp knitted or woven.

Criteria to choosing a roller

With so much variety there is often a confusion as to which roller to choose. The following criteria will make the choice objective :

. Foam Vs Cloth :

 Low density foam rollers pick up a large amount of material and splatter paint onto the surface and are not suitable for application of paint. This leads to a lot of wastage. They can only be used to remove excess paint or smoothen unevenly applied paint. High density foam rollers pick up less material and cause less splatter when placed onto the surface to be painted. They can be used to apply paint. The problem with foam rollers is that they tend to break after usage. They are also very difficult to clean, as the material is absorbed into the entire thickness of the foam.

Cloth rollers on the other hand provide uniform paint deposition and splatter free painting. They are easy to clean as paint is absorbed only into the mat of the material which is on an average only about 0.5" in thickness.

. Pile / Nap of a Cloth Roller :

The roller pile is the length of the fiber. The longer the fiber, the more material it can hold. Also a larger pile will help the roller cover larger surface undulations. But a longer fiber also means a rougher finish. Rollers meant for rough surfaces such as rough plastered exterior walls have a larger pile.

. Material of a Cloth Roller :

Polyester is the cheapest material but has low paint pickup.

Acrylic is a bit more expensive and has better paint pickup.

Micro Fibre is a bit higher in cost and has excellent paint pickup.

Polyamide fibre has equivalent paint pickup and cost to micro fiber but has much longer life.

. Woven Vs Knitted

Woven fibers pickup more material than knitted fibers and also deposit material more uniformly.

. Handles - Cage Style Vs European Style

Cage handles are more expensive than european style handles but have better grip on the roller.

. Lint Free Rollers do not leave behind any fiber on the painted surface. These are generally more expensive.

Considering the finish required, the surface being painted and the paint being used, a suitable roller can be chosen using the above criteria.

A variety of paint rollers available in the Indian market can be bought here..

Happy Painting!!

A Beginner's Guide to Angle Grinders

An Angle Grinder (AG) is another power tool that is very handy to have. A basic AG can be used with a variety of accessories such as grinding wheels, cutting wheels, metal cut-off wheels, buffing pads, rotating wire brushes etc. making them very versatile.

An AG such as the Bosch GWS 6-100 fits the bill perfectly not only for beginners but also for professionals.

Its ergonomic design and powerful 600W motor make it the preferred tool for jobs around the house.

Let us look at a simple application of an AG.. Re-grouting Bathroom Tiles

Materials :
. Bosch GWS 6-100 Angle Grinder - shop here
. Bosch Diamond Saw 105mm - 4" - shop here
. Grouting materials as described here
. Skil Air Blower 8600 - shop here

Procedure :
. Mount the diamond saw onto the AG. To mount the saw, first clamp on the safety cover at an angle such that debris fly away from you. Now remove the top mounting chuck using the spanner and tool provided. Place the saw onto the bottom mounting chuck. Hold on to the rotation stop provided at the top of the AG to arrest the motion of the machine. Tighten the top chuck with the provided spanner. Ensure that at all times during mounting or un-mounting of the saw, the machine is not plugged in and switched on as it can be a serious hazard to your safety.
. Wear gloves and safety glasses.
. Plug the machine in and test for connection.
. Place the diamond wheel directly above the joint you want to re-grout.
. Squeeze the trigger and gently lower the saw into the joint. Moving slowly along the joint, ensure uniform removal of the old grouting material.
. Using the blower, clean out the loose material and dust from the joint.
. The tiles can now be re-grouted using the procedure given here.
. Re-grouting not only enhance the beauty of the bathroom but also stops any leaks.

Note :
The Angle Grinder is vital in this application as the removal of the old grouting material is essential to this procedure. Manually removing the grout can cause the tiles to chip and break. Also the material cannot be removed uniformly manually.

A Beginner's Guide to Drill Guns

Why invest in Power Tools? 
With labor and skilled workmen in shortage, it is increasingly difficult to maintain our property and furniture in an orderly manner. Small jobs are not a priority to professional workmen and even after months of follow ups are not willing to take up odd jobs. In such a situation it is time to take matters into our own hands... literally.

With the wide spread usage and availability of reliable and user friendly and affordable hand held power tools, the time is right to invest in a few power tools that are useful around the house. Some are listed here :
1. Drill Gun
2. Angle Grinder
3. Sander
4. Circular Saw

Drill Guns
Out of the above the most useful and versatile power tool is the drill gun. It can be used to not only drill holes in wood, metal and walls, with the right accessories, it can also be used to tighten and loosen screws and wrench nut and bolts.

A Basic drill gun with a power rating of 450W is sufficient for home and personal use. An impact drill with forward and reverse functions is the most useful. It can drill holes of upto 10mm Diameter in masonry, about 16mm in wood and about 8mm in mild steel. It has more than enough power to screw and unscrew fastners and wrench bolts and nuts.


Accessories
For drilling :
1. Masonry Bits
2. Wood Bits - twist and spade
3. Metal Bits - twist
4. Multi purpose bits - Can be used for any of the above.
Wood bits can generally be used for plastics too.

For fastners : 
A variety of bits with different heads for different headed screws such as 
. Slotted head
. Phillips head
. Pozidrive
. Polydrive
. Hex etc...
A magnetic holder for these bits is usually supplied as an accessory with the gun.

For Bolts and nuts :
A Variety of spcket wrench bits are available for different headed bolts and nuts.

A Basic Application
Lets look at a basic a application for an impact drill. Say you want to put up your favorite picture frame on the wall. Lets look at what we will require :

Materials 
1. A Stool or ladder to reach the spot on the wall.

2. A measurement tape to locate the exact point to mount the frame.
3. An Impact Drill - such as Skil 450W Impact Drill (you can buy it from my store by clicking here)
4. A 6mm Masonry / Multipurpose drill bit.
5. Phillips head #8 Screws (38mm x 8 are ideal).
6. A Phillips drive
7. 6mm Fischers or Rawal plugs.
8. A Hammer
9. An Extension cord for the drill gun.

Procedure
1. Locate the exact spot you want using the measurement tape and your own judgement.
2. In case more than one hole needs to be drilled, always double check the alignment before placing holes in the wall.
3. Fit the drill bit into the drill gun using the key provided.
4. Make sure the drill is in "Impact" mode and rotating clockwise.
5. Place the drill bit in the stationary position on to the spot you want to drill with a steady hand and squeeze the trigger.
6. Drill a hole about 25-30mm in depth.
7. Clean out the dust remaining in the drill hole.
8. Gently hammer the fischer into the hole.
9. Mount the phillips drive onto the holder and fasten the holder onto the drill gun. 
10. Fasten the phillips screw using the gun.
11. Hang the frame onto the screw.

15 minutes well spent!