report of finishing and coating -method of finishing and coating process

1. 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

2. 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
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3. ACKNOWLEDGEMENT
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.
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4. INTRODUCTION
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.
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5. Surface coating covers a wide range of categories and emissions. Major surface
coating operations include aerospace, auto refinishing, furniture finishing, metal can coating,
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)
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6. OBJECTIVES
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.
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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.
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To bring colors into the wood.
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To slow down the moisture exchange with air.
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7. METHODOLOGY
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
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AC lacquer 200ml

8. 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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9. 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.
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10. Top coat application
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
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11. CONCLUSION
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.
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12. REFERENCES
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-Fillers5129.aspx
Jewitt, J. (13 12, 2013). Fine Wood Working. Retrieved Friday December, 2013, from Fine
Wood Working: http://www.finewoodworking.com/toolguide/articles/selecting-afinish.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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