Some Observations on Joining Boards

Wide boards require careful preparation

I often have to join narrower boards (between four and six inches wide) to make wider panels for a variety of needs such as box sides, cabinets and table tops. 

This might sound trivial but I have often found it isn’t so. Joining narrow boards often leads to misalignment and twist, requiring lots of painstaking hand planing to correct. 

The other problem is if the misalignment is very pronounced then planing could lead to a significant reduction in the thickness of the final stock.

There have been occasions when I have had to rip joined boards along their glue lines, correct the problem leading to misalignment and once again glue up. 

These days I take as much care as possible before glue up to ensure that minimal planing is required afterwards.

Before a glue up it is best to check for several potential problems.

Firstly, the boards to be joined should be as flat as possible and of the same thickness. Bowed, twisted or cupped pieces will not do.

Second, the edges of the pieces need to be as straight as possible; a slight concavity at the centre is often recommended by traditional woodworkers to strengthen the joint but this is sometimes difficult to achieve in thicker or longer boards.

I usually choose the pieces to be joined, place them so that their grain runs in the same direction and then mark them clearly. This facilitates later planing if required. 

I also number the boards and indicate the edges to be joined especially when many pieces are involved.

Often two boards that are to be joined have gaps on their ends. I suspect when we straighten or “joint” an edge, there is a tendency to overdo the ends. This leads to boards that are slightly humped. These pieces will never come together well.

The two boards to be joined have a pronounced gap on the right along the glue line

Careful planing can eliminate gaps

The process of jointing edges is achieved easily with a power jointer or a hand plane called a “jointer” or “try” plane 22 or 24 inches long. 

The jointer planes are significantly longer than standard #4 smoothing planes and because of their long soles do a better job of ensuring flatness along the entire edge of a board.

The jointer plane (top) is a more appropriate tool for jointing as compared to the smaller smoothing plane

Some woodworkers believe that the shorter #5 can do as good a job as the longer jointer plane but I feel more comfortable with a really long plane for jointing edges. These longer #7 and #8 or jointer planes are easily available in India.

No matter what size hand plane you use the aim is to get rid of the dips along the edge of the board and make sure it is square to the sides. This is a matter of careful planing, sometimes made tiresome by difficult grain but otherwise quite pleasurable.

If the boards to be joined are relatively small, it is easy to plane a subtle concavity at the centre of the edge. This concavity or dip should be equal to about a couple of shavings or so.

Then comes the question of how much glue to apply; my experience is the less the better. Rub the two edges well so that they are stuck before applying clamps.

Parallel Clamps: Best for joining boards

This kind of F-clamp is not meant for clamping relatively thin boards

Getting appropriate clamps for joining boards is a bit of a problem in Delhi. The best type in my experience are the parallel clamps; F-clamps with slightly inclined heads are the least appropriate (see photograph) while the second best are pipe clamps.

Clamping cauls are also useful and I usually make sure I use them to ensure the boards don’t twist during glue up.

The boards laid flat on the parallel clamps should be tightened gradually, all the while ensuring that none of the boards go out of alignment.

A slight glue squeeze-out would indicate that adequate glue has been applied; zero squeeze out would point to too little glue. 

Excess glue should be wiped off with a slightly moist rag or sponge immediately after glue up to prevent finishing problems later on.

Misalignment of the boards or a slightly angular join could be the result of improper planing. For instance, if the edges are not absolutely square to the sides then they will come together at an angle when joined.

Even after all this, I rarely end up with perfectly flat or immaculately joined boards. Some amount of planing is usually necessary after glue up. A little bit is fine but if I find I have to do major flattening, then it is better to rip the board apart and re-do the whole process.

I would rate a glue up successful if after final planing the glue line between two boards is practically invisible.

Any comments or suggestions on how to make this process easier and less error prone would be appreciated as I cannot claim to have perfected the art of joining boards.

Indranil Banerjie
19 August 2016

Kishore's Tray

Kishore Parihar, a fellow woodworker based in Jodhpur, Rajasthan, has decided to go commercial. He has launched a website called www.kishorewoodstudio.com to sell his wooden creations. Kishore has made the use of scrap wood an art form. He uses pieces of recalimed Sheesham and other timber varieties to create stunning pieces of furniture and other wooden objects. 

This is what he has to say about himself in his website: "My name is Kishore. My hobby is to reclaim used wood. I have a deep passion to design and create beautiful wood objects. This hobby started in 2012 when I designed, created and installed few bird houses which not only attracted and housed large number of birds but also brought appreciation for me. I have been passionate with woodworking since then. I use good used wood and transform it into useful and artistic object, household items, decorative objects including furniture, Kitchen articles and others, all durable, strong and functional. Well wishers and admirers encouraged me to work further. I am here to serve you now. All these wood work are my hand crafted articles. I assure you for keen sense for details and superb quality."

 

Kishore and I have been following each other for a long time in our respective blogs. He has taken the plunge to raise his passion to another level. Good luck, Kishore!

Jewellery Box

I completed a large-ish box for an old friend out of Teak and Rubber wood. It has small trays inside and is meant to be used as a jewellery box. The finishing is of Shellac; I used the old fashioned Ferench Polish method which imparts a high gloss sheen.

Currently working on several small projects for friends and family. Our house is crammed with furntiure and there is absolutely no place for new pieces.

Good night.