May 232019
 

Shaun from Monaro Timber is a long-time friend and supporter of the Club.

He has hosted several visits to his workshop and timber yard. He judged our 2018 competition and provided constructive feedback particularly in relation to the structural integrity and finish of pieces. The focus of his presentation followed on from his judging experience to provide guidance on building pieces for competitions.

Following are some notes on what Shaun presented to members on the night
.

The main elements that need to be addressed in preparing pieces for a competition are:

  • design
  • material selection
  • preparation
  • joinery
  • assembly
  • finish

Design
The two main elements of design are aesthetics and technical. Shaun’s main focus is on the technical aspects. Everyone has a different idea about what looks good. His attitude is that if the piece does not hold together and do what it is meant to do then it does not matter how good it looks.

A major issue we need to incorporate into design, especially in Canberra, is shrinkage.

Shrinkage is across the width of a board not the length. Imagine a plank is made up of straws filled with water running the length of the plank. As the water dries out the straws compress inwards. Furniture timber from his yard has typical moisture content of around 12-15%. The moisture content of timber inside Canberra houses during winter can fall to 9.25% or less. You must expect and account for 1% shrinkage for every 4 percentage point drop in moisture content. That is the equivalent of 1cm for a table with planking 1m wide. A bevel edged frame around a planked table top will not cope with this amount of shrinkage.

Material Selection
Don’t use Jarrah for drawer sides – it exudes gum that can clog movement. Try Victorian Ash.
Make sure veneer boards have veneer on both faces of core material. The timber in heavy veneers, ie boards using resawn timber for veneering, have the same properties as timber planking in terms of shrinkage for veneers 3mm or more thick.

Avoid boards with twists for planking jobs but if they have nice feature they may be alright for heavy veneers (but don’t expect as many veneer sheets).
Don’t use polyurethane glues with Huon pine – it turns orange.

Preparation
Be aware that dressed timber which has been sitting in racks in timber yards will have knocks and bumps, rounded or uneven edges and other signs of wear. Ash normally sits OK in horizontal racks but many other timbers will need further dressing before undertaking projects.

Joinery and Assembly
Due to time constraints Shaun skipped over joinery and assembly but stressed that throughout preparation and construction it was always important to be aware of the need for accuracy, quality, attention to detail and consistency. Always bear in mind – will it pass the mum or spouse test. In terms of quality and consistency – a bevel edge must be sharp and well defined with consistent sizes throughout the project. To allow for sanding a routed curved edge is better if it starts below the top face. Also be aware that any problems in preparation and construction (eg glue squeeze out that is not cleaned up at the time) will take a lot more time to correct with sanding and finishing.

With regard to accuracy, it is better to use steel rules for accurate final measurement, rather than tape measures, which can be inaccurate.

Finish
A good finish can make a bad job look better. A poor finish will make a good job look bad. Shaun reinforced the importance of sanding and the need to work through the range of grits. Need to get rid of the hills with coarser grit before going to finer grits. Make good use of a random orbital sander – to get a consistently smooth finish use long straight slow sweeps back and forth along the surface (with a 20cm overlap) rather than fast heavy handed swirling motions. For rounded edges use a smooth roll over motion as the sander is runs along the top surface. Do not apply downward pressure to the sander.

He was a major user of Organoil (based on tung oil) but has been increasing his usage of hard wax oils. With tung oil based products the finer the grit the better the finish (he showed examples up to 2000 grit). Don’t go too fine with hard wax oil as the product will not penetrate the surface. Recently he has switched from Osmo to Bona hard wax oils for cost reasons but has not been able to detect any notable difference in quality or performance.

He highlighted the importance of good downlighting, especially as our eyes deteriorate with age. LED downlights help a lot.

Thanks Shaun for a very informative and much appreciated evening.

(Shaun indicated that he and others at Monaro Timber were prepared to provide advice to club members (send an email) even if you don’t end up purchasing the timber from them – but don’t forget they provide a discount to club members!)