Friday, October 3, 2014

Panels in five steps





When we are using solid wood, the panel building is a frequent process in our projects. Apart the difficult of finding boards large enough for our intents, wider pieces have frequently stability problems and risk too much movements in following the humidity changes. 
Building a wood panel is not a particulary difficult job if we have the right tools and follow some precautions.

We can divide the process in five steps:

  

1)    Planing the elements
  2)    Composing the dry panel
  3)    Planing the edges
  4)    Gluing
  5)    Smoothing the panel



In planing the single elements, admitting of using rough wood as start, we can utilize (in order of use) the classical planes as scrub, jack and jointer if we have longer pieces.
Personally, I do not use a smoothing plane in this phase, but I pay particular attention to obtain straight elements and of same thickness (slightly more than the final thickness). In fact, even if a good attention is observed in this phase, is quite improbable to obtain perfect panels: little steps between the elements are frequent and not rarely we will have to relevel the entire panel surface.  
The second phase consists of a dry composition of panel for searching the best aesthetic result. When hand planes are used, is better to orient the elements in the same grain direction in order to favour the next planing steps. For a bigger stability is then better to use well seasoned and/or quarter sawn woods.
If I have to obtain a raised panel, however, I use to orient an external element in the opposite grain direction; in this way, the raising (or moulding) plane can work always with the grain for a better result.
Of course in the successive levelling step this element should be planed in the right grain direction (although this is not always necessary if the wood has straight grain).  
A ideal case occurs when the panel is obtained by resawing a single board in two pieces opened like a book. In addition to the possibility  of using raising planes with favorable grain, the aesthetic result is particulary interesting, mostly if the wood is well figured.








After the wished sequence of elements has been found, mark the panel surface whit a "V" (or a triangle), so we can easily reconstitute the exact sequence.



It is important that edges join perfectly. This is not always easy when the job is done with hand tools. 
A method I use is planing two adjacent panel elements together, a technique I call "book planing" ("tecnica a libro" in Italian), in wich the pieces are picked and closed like a book (see pictures), so the error of plane squareness can be compensated when the elements are opened and joined together.

By planing the elements together, the errors self compensate


the concavity has been exaggerated for drawing clarity
Our attention will be then payed mostly for obtain two straight edges or slightly concave, permitting to the clamps of keeping easy the pieces well joined during the gluing.

What kind of plane is better to utilize for this job?
My advice is to use a longer plane. A Jack plane could be suitable if the work has reduced dimensions (max 50-60 cm long), otherwise, better to use a jointer. It, as its name says, is the plane designed for this specific task.




During planing pay attention to not rock the plane and to obtain a continuous shaving for both coupled elements while we are using little cutting depth.
Pay particular attention in entering and in exiting from the piece (the pressure is on the knob while entering, on the handle when the plane leave the piece).

Marking pieces with a pencil can help in following our job. Continue until all signs are disappeared.


When all edges join together well, we are ready to gluing up following the order indicated by the "V" previously traced.
Prepare all before. For the job we can use some 50x30 mm straight pieces. They keep the panel flat while the clamps push the edges one against the other. Their face in contact with the panel can be overlayed by masking tape in order to avoid their gluing. 

Spread the glue onto both edges by a little brush. If our jointing job has been well done, the glue, with the clamp pressure, squeezes out uniformly along the gluing line.
Eliminate the glue excess with a wet cloth and leave it dries.

 
The finishing step will give to the panel its final appearance, so it is necessary to do it well. The plane type to use depends from the flatness grade achieved during the panel building. Normally a smoother is enough for the job (rarely we will have to use a jack first).
I use to attack the panel with a bigger cutting depth and a diagonal action, so the panel becomes flat rapidly.
In a second step the plane is set for cutting thinner shavings. The action is along the grain. The panel is ready to receive the finishing cycle.



4 comments:

  1. Good write up but you didn't mention if the panel is going to be painted or have a clear finish applied. Knowing that will also dictate how you orient your glued up panel. With a clear finish you don't want your grain "arches" running in opposite directions. If it's painted, it doesn't matter.

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  2. Right Ralph, If a panel has to be painted I would choose the most stable configuration. Putty and paint would cover all planing defects.
    We have an Italian saying (I am quite sure there will be something of similar in English too) : "Occhio non vede....cuore non duole"....translated should be "eye does not see....heart does not hurt".
    Regards
    Giuliano

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  3. Hi Giuliano. . All the very best wishes to you and your family during xmas and into the New Year.

    regards; Stewie Simpson.

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    Replies
    1. Thank you Stewie. A great Xmas and New Year to you and your Family.
      Giuliano

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