FUR 564

REPORT

FINISHING AND COATING TECHNOLOGY

By

IZZAH AZIMAH BINTI NOH (2012717865)

Lecturer:

MADAM HAFIZAH BINTI ROSMAN

BACHELOR (HONS) FURNITURE TECHNOLOGY

FACULTY OF APPLIED SCIENCES

UNIVERSITI TEKNOLOGI MARA

2013

TABLE OF CONTENT

CONTENT PAGES

TABLE OF CONTENT 2

ACKNOWLEDGEMENT 3

INTRODUCTION 4

OBJECTIVE 6

METHOD 7

Wood preparation 7

Finishing solvent preparation 7

Finishing application method 7

Sanding wood surface 9

Spraying sealer 9

Top coat application 10

Final product 10

CONCLUSION 11

REFERENCES 12

ACKNOWLEDGEMENT

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Praise to ALLAH the most merciful and the greatest; with permission finished the

report on finishing and coating technology. First and foremost, I would like to express my

sincere appreciation to my subject lecture Mrs Hafizah binti Rosman for guiding and

encourage us in the subject.

Thanks to our advisor Mr. Rosli who willingly supervise our final project, giving

advice and knowledge. Thanks a lot for giving us the knowledge, sharing the experience and

providing guide line finishing the final report. Also, for his willingness to teach the

proceeding to finishing the product, using the machine and its function, also give hand in

helping us, as without him the work does not run smoothly.

A thousands thanks also to all the staff for helping us in conducting the machines and

advice for us. Also for all classmate who gives to give the energy and full cooperation in

making the project work smoothly.

INTRODUCTION

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Finishing/ Wood finishing

The term ‘finish’, when used with reference to furniture or similar wood products. It is

also refers to film forming coatings applied to the surface of the wood to protect it and to

highlight its appearance. It is state as the process of protecting a wooden surface, especially in

the production of furniture. (Richter, Feist, & Knaede, 1995) (Tichy, 1986)

Finishing products can be grouped into manageable categories, based on general

working qualities and the degrees of protection they offer: waxes, oils, varnishes, shellacs,

lacquers and water-based finishes. Different finishes offer varying degrees of protection,

durability, ease of application, repair ability and aesthetics. Unfortunately, no single finish

excels in all of these categories; a finish that excels in one may fail in another. All wood

finishes can be classified as one of two distinctly different types, based on how they dry, or

cure. Evaporative finishes--such as lacquer, shellac and many water-based finishes; dry to a

hard film as the solvents evaporate. (Water is not a solvent; it's a carrier for the finish

emulsion.)

These types of finishes will always dissolve in the solvent used to thin them, long

after they've dried, so they tend to be less durable than reactive finishes. Most reactive

finishes; such as linseed or Tung oil, catalysed lacquers and varnishes; also contain solvents

that evaporate, but they cure by reacting with either air outside the can or a chemical placed in

the can before application. These finishes undergo a chemical change as they cure, and after

that they will not dissolve in the solvent originally used to thin them. Except for the pure oils,

reactive finishes tend to hold up better to heat and chemicals. See Common finish products

compared for a summary of how the finishes stack up against each other. (Jewitt, 2013)

Wood Coating/ Surface coating

All measures that are taken to ensure a long life of wood fall under the definition

wood preservation. Apart from structural wood preservation measures, there are a number of

different preservatives and processes that can extend the life of wood, timber, wood structures

or engineered wood.

Surface coating covers a wide range of categories and emissions. Major surface

coating operations include aerospace, auto refinishing, furniture finishing, metal can coating,

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and paper coating. Surface coating materials are primarily organic polymers dissolved in a

solvent or suspended in an emulsion. The material may be applied to the product by brush or

by spraying. (Rosman, 2013)

OBJECTIVES

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Lesson of finishing and coating technology

In finishing and coating technology subject (FUR564) we have study about the uses,

application, benefits and more about finishing. Finishing is the best way or action by the wood

worker after done do their products. Besides, coating also ads on the product more clear on its

surface and hide the defect of wood finish product.

Objectives of the lesson

- To learn the application method of finishing and coating.

- To identify the best method suitable used for each type wood finishing.

- To learn the use of finishing machine and tools such as spray and brush.

- To apply the theory of finishing and coating technology to the real situation in

workshop.

- To differentiate each part of wood finish stages.

Objectives of wood finishing and coating.

- To keep dirt out of wood.

- To prevent degrade of wood surface as result of abrasion and heat.

- To produce visual and tactile qualities.

- To bring colors into the wood.

- To slow down the moisture exchange with air.

METHODOLOGY

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Wood preparation

One of the most important steps in wood finishing is sanding. A thorough sanding is often

what separates "acceptable" results from "professional looking" results. Start with a medium

grade of sandpaper (e.g. #120) and gradually work your way to a finer grade (e.g. #220). Sand

in the direction of the grain for a smooth, uniform finish and remove all sanding dust using a

spray air gun or vacuum, dry paint brush or cloth. Look out for dried glue, especially in the

joint area. If it's not thoroughly removed by sanding, it will interfere with the staining process.

End-grains (areas where the wood has been cut against the grain), such as the front side of a

table, tend to soak up more stain than surfaces cut with the grain. With additional sanding to

end-grain areas, you can better control the absorption of stain.

Finishing solvent preparation

- Sealer preparation

Thinner 100ml Hardener 100ml AC lacquer 200ml

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The ratio of the sealer solvent is 2:1:1; AC lacquer 200ml, thinner 100ml and hardener 100ml.

AC Lacquer (Acid cured lacquer) is a synthetic, easy-to-use, high quality lacquer. It’s suitable

for indoor wooden furniture. Hard film; good thickness and adhesion; good water, solvent

resistance; no cracking, no blistering. (Thanh, 2011)

Features of AC lacquer:

*    Colour: clear transparent or white

*    Good water, solvent resistance

*    Good adhesion, no blistering and no cracking

*    Fast dried paint film, easy-to-use

*    High solid content of paint film leads to good thickness and gloss

*    Good for all wood species and rich colours development as required.

Finishing application method

Finishing application by using spray gun. It can apply sealer as with any coating, with

a brush, gun, or pad, but that's not always best. After one coat, end grain and spongy areas

may still be insufficiently sealed, while denser flat grain areas are starting to build up too

much coating. There's a way around that. Both more and less absorbent areas would be sated,

but no excess finish would be piled up on top.

While it is not always practical to submerge pieces in a vat of sealer, you can

approximate that by flooding sealer on liberally by hand, then wiping it off. Also can use a

nylon abrasive pad as an applicator, and then wipe off with paper shop towels while it is still

wet. The advantage of this method is that it allows end grain to absorb as much sealer as it

can, but wipes any extra off flat grain surfaces that tend to absorb less. Once the sealer is dry,

the entire piece is uniformly sealed, and the next coat of finish will lay out the same in all

areas. (Dresdner, 2008)

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Sanding wood surface

After the wood dry enough from the sealer stage the surface must be sanding

smoothly.  Sanding sealer is a specific material developed for the lacquer industry, but

somehow the name has spread to things that should, by rights, simply be called sealer. After

sanding stage the wood surface must be clean up by using the dry paint brush or clean towel.

It is because to make sure the surface of the wood product clears from any dirt.

Spraying sealer

The AC lacquer once again must be applied to the product before the top coat has been

applied on the surface. It is because is a clear or coloured wood finish that dries by solvent

evaporation or a curing process that produces a hard, durable finish. This finish can be of any

sheen level from ultra-matte to high gloss, and it can be further polished as required. It is also

used for "lacquer paint", which typically is a paint that dries to a more than usually hard and

smooth surface.

Top coat application

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A high quality medium solids clear acid catalysed lacquers for wood finishing based

on non-yellowing resins. Clear finishing coat for solid and veneered timber. Easy

application, fast drying and good levelling. Dries to a durable finish with good build.

Used coat‐on‐ coat, this product provides a tough, mark resistant surface, very popular

for kitchen furniture and home ware. Ideal for production lines in furniture factories.

Recommended for spray booth application under solvent extraction conditions. Items are

touching dry in about 20 minutes. (speccoats, 1997)

Very light colour – ideal for pale timber.

Pale colour of base allows bright colours.

Available in a range from high gloss to matt.

Excellent resistance to marring, scratches, alcohol and water spills.

Formulated to resist yellowing in the dark or sunlight for applications where

consistency of colour is very important.

Final product

CONCLUSION

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Overall, the stages of the application method of finishing product face the failure but it still

can be hide by using the finishing and coating. It is fact that, as wood worker we must

excellent in hidden the natural defect of wood or artificial defect which is come during the

production session.

During wood preparation, we also face the failure of the wood we use, unknown species

have been choosing from the waste. Most of wood choosing has their own defect such as knot

and tiny hollow along the grain of the wood. Besides, the wood has been sanding to make sure

it is clear from the dirt or rough surface.

Finishing solvent preparation; the solution of the solvent mixture not accurate and it is

not follow the standard that we must follow. But it is still can be used to do the finishing. The

accurately of the finishing solution necessary follow because of the machine we use to apply

the sealer is really sensitive to the viscosity of the solution.

Finishing application method; we use spraying method which is can produce

uniformly and evenly surface of the sealer at the product surface. Using the spray method has

certain disadvantages of application it on the products. It is all about technical problem of

machines (sprayer). And also the solvent of AC lacquer also cause of the gun face failure

during spray on the product. The AC lacquer easily hardens to the spray and make it stuck

during spraying session. It is may cause or effect the production time and also wasting the

sealer solution.

Sanding wood surface; other student roughly sanding the wood surface and its result

that the sealer come out from the wood and need to redo the sealer stage. Sanding wood

surface at this stage must be smoothly and use smooth surface of sanding paper.

REFERENCES

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Dresdner, M. (6 January, 2008). Wood workers journal. Retrieved Friday December, 2013, from Sealers and Pore Filler: http://www.woodworkersjournal.com/Main/Articles/Sealers-and-Pore-Fillers-5129.aspx

Jewitt, J. (13 12, 2013). Fine Wood Working. Retrieved Friday December, 2013, from Fine Wood Working: http://www.finewoodworking.com/toolguide/articles/selecting-a-finish.aspx

Richter, K., Feist, W., & Knaede, M. (1995). The effect of surface roughness on the performance of finishes. Forest Products Journal, 91-97.

Rosman, H. (2013). Component of surface coating. malaysia: uitm.

speccoats. (1997). spec coats. Retrieved 14 December, 2013, from acid catalyzed lacquer: http://www.speccoats.co.za/acid-catalyzed-lacquer.php

Thanh, B. (2011). Btchem. Retrieved Friday Decemer, 2013, from solvent based coating (AC lacquer): http://www.btchem.com.vn/en/product/detail/ac-lacquer-4.htm

Tichy, R. (1986). Interior wood finishing: industrial use guide . Madison, Forest Products Journal, 57-60.

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