Laying Out The Curve In A Rustic Office Desk Top

A Basic Desk

Simple 90° Desk

This particular desk was pretty easy to design, there was no call for cabinets or drawers underneath. 

In designing this desk, the first thought is to fill the area with a simple 90° structure. This forces the user to sit at the right or left wing.

Desk With 45° Inside Corner

The next consideration would be to fill the inside corner with a triangle to create an angled seating area. This makes great use of the corner and creates a comfortable work station. The computer monitor is tucked into the corner and a person sits with books, papers, and folders arrayed on the right and left wings. This provides easy access to a large area to the right and left as office work tends to spread out. 

Desk With Inside Curve

The next step in the thought process of designing this desk was to fill the inside corner with a curve instead of a diagonal. Curves are a little easier on the eye, they tend to add a little more visual flow. The inside curve on this desk looks appealing and provides a good place to sit between the right and left wings.

The Layout

The desk material is 2" thick and I knew that I wanted to use a template in creating the curve in the desk. 

Scribing the arc.

I started with a piece of 1/2" plywood that was a little oversized of the arc I wanted to create. I mapped out the location of the desk that would be underneath the template. Now I knew where the structure was located.

I have a simple 4' flat metal straightedge that is quite flexible and would span the two points of the arc. But I needed a way to hold it steady while I marked both ends of the arc. I cut a couple of blocks that were 1 1/2" thick with a miter cut on one end.  

Blocks with miter cut allow access for pencil when scribing.

By using 1 1/2" thick material, that made the blocks tall enough to support the height of the straightedge. The angled cut allows me to get my pencil into the corner to mark as accurately as possible. Now keep in mind that accurate is relative here because I am working on a "rustic" style desk. 

After flexing the straightedge to create the desired arc, I scribe it. Then I like to flip the straightedge end-for-end and see how it reconciles with the first mark. There is almost always a little deviation and I scribe the new line. Before cutting I double check to see how the arc looks overall

Detail of scribed arc.

In my shop, as well as most shops, we are not running CNC equipment to layout or cut our arcs, so they are not going to be machine perfect. But you can increase the accuracy by doing a couple of things.

First, insure even pressure in the middle of the straightedge when when bending it to create the arc. Second, make sure the end points are securely and equally anchored, and the last step is to double check the layout by flipping your straightedge end-for-end and lay it out again.  

No matter what you use to create the arc, whether it be a metal straightedge, wood strip, or plywood strip there will be a slight deviation somewhere in the line. If you flip the straightedge and lay it out again, it will usually deviate at the same point in the straightedge. When you scribe the second line, the deviations will be revealed and you will be able to make adjustments accordingly for the actual cut.

Once you get the arc lined out, it is time to cut. But that is for the next installment...

That is all for now. Be sure to spend some time in the shop practicing what you learn.

Your friend in the shop - Todd A. Clippinger

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A Lesson Review

Pop Quiz!

Didn't you just hate the pop quizes back in school? Well I have one for you today.

What did we learn about monitoring wood moisture content?

• Take readings often.

• Take readings from various locations.That includes the middle and ends of the stock (edge or face) and if you have an opportunity, from the inside when it is cut open.

• Observe the relationship of the changing moisture content and the behavior of the wood movement. Also compare these things to the specific grain patterns and the location of movement in a board. For example: where a twist may center itself.

These things are important to observe as you learn to understand a board and what it is telling you.

Yesterday I was working a piece of the doug fir beam. It is a beautiful piece that I am making a desk leg out of.

5"x5" Beam

After I cut the stock into sections, I took meter readings from various locations on the ends of the freshly cut wood.

Normally, if a board is sitting for a long time, I do not take readings from the end. But, if I just cut it open, I will meter the fresh cut end that came exposes the interior of the board.

Here is something that you should take note of. My stock is 4 3/4" square, if I meter the center of the stock, the moisture content will register higher than if I meter closure to the outside edge.

See the difference in the readings of the following pictures. Moisture Reading 8.5 Moisture Reading 5.3

This is not alarming and is normal. The wood obviously dries from the outside face in and from the ends in. What this also means is that when it is milled open, it should have a chance to equalize before putting it into a project to avoid issues of twisting.

The part of the wood that contains a higher moisture content is going to be swelled in comparison to the drier part of the board. It will be necessary to let it settle down.

Pitch - A Sticky Issue

This doug fir stock came from beams that sat outside for about 10 years. Most of the pitch has solidified and no longer runs.

This is a good thing because you should see the amount of pitch that some of this wood has. If this was fresh pitch, it would be running all over the place.

Pitch PocketsMore Pitch Pockets

Even now the pitch has been creating a mess of my tools. After milling out a tenon on the tablesaw...

Tenon cut on tablesaw.

just look at the pitch build up on the throat plate!

Pitch on tablesaw.

The pitch has just enough body to it that it can be easily scraped off and the residue dissolved with solvent.

Pitch scrapes off easily.

Fortunately for me, the design of the project is rustic and the clients are familiar with the nature of the wood.

This allows me some grace so any issues with finish will be minimal. I will need to seal the pitch with shellac to deter problems, but I am not sure that I can outright avoid them.

That is all for now. Be sure to check back regular and see what's new!

Your friend in the shop - Todd A. Clippinger

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The Challenges Of Building A Rustic Office

A Couple Of Challenges

The challenges of working with the material for this project are ever present.

One issue is the maintenance that this material causes and the biggest issue is the dimensional stability.

Maintenance

For the readers that are just joining us for this project, I am using doug fir beams left over from the construction of a timber frame home to construct an office desk and cabinetry for that same home. The beams are about 10 years old and have been laying outside, stickered on the ground, but unprotected.

Any day that involves milling this material to any extent results in cleaning tables, blades, and knives down with solvent. Most of the sap has crystallized over the years and does not bleed out but it leaves a mess none the less.

The table surfaces load up with a sticky wax residue that causes a lot of drag when pushing the material across the tool. This causes a bit of safety issue because a smooth sliding surface is safer than a sticky one when milling and cutting material.

Blades and knives of the tablesaw and planer will load up with the residue. This causes more friction and thus leads to an ever rapidly increasing build up of the pitch. It is a situation that quickly decreases the cutting efficiency of blades and knives. It has occurred  on a regular basis that I have had to clean cutting edges and surfaces twice a day. While I did figure some time in the bid to do this, it has exceeded my estimations - lesson learned.

Cleaning tablesaw and applying TopCote.

I use solvent to strip the sticky residue from the tools and I like to apply a product called TopCote to the tools. This creates a slick tool surface that allows for smooth feed of materials. This product does not cause contamination that leads to adhesion issues or fish eye when applying the finish.

TopCote is sprayed on and then buffed off when dry, similar to waxing a car.

TopCote

Dimensional Stability

Dealing with dimensional stability has been a constant issue, but I will share with you what I have done to be as successful as possible.

Choose The Best Material Possible

I have been dealing with two sources of material, one is the original 10 year old beams and the other is new stock from the lumber yard. I took several moisture meter readings of both batches of material and have been following and observing them closely.

Old beams on bottom, new beams on top.

To be specific, the old beams had a moisture content anywhere from 21% up to 28%, but with most of it in the 21% to 24% moisture content range

The new doug fir stock had moisture content readings from 21% to 25%. the most frequent readings were 21% to 22%

Solutions To Avoiding Dimensional Issues

The first action to reduce dimensional stability issues was to choose the best cuts of material. For the old 10"x10" beams, I had them milled into quarters. The pith of the tree was nearly in the center of every beam and this automatically created quartersawn rough stock. As I continued to refine the stock I have paid close attention to the grain orientation to preserve the integrity of the quartersawn cut.

For the new stock I also picked the best quartersawn material I could find. You might be surprised to know that it is very possible to get really good quartersawn material off the shelf at the lumber suppliers. It will involve some digging but it is do-able.

Quartersawn 4x4's

As I continue to mill it down, I plan the cuts to maintain the quartersawn orientation.

Maintain quartersawn orientation throughout milling process.

Take It Down In Stages

Considering that both materials have different histories and origins, the same principle applies to both. Never mill the material down to the finished dimension right away, take it down in stages, always leaving it oversized. Milling the material open and then letting it relax allows it to acclimate and continue drying in a controlled manner.

Ripping down to the final rough stage.Planed but left a little oversized and time for one last rest.

Monitor Progress

If you are dealing with stock such as this, a moisture meter is a necessity.

You will need to know how to use it and how to accurately read the material. I have extra material cut in anticipation of the higher than normal loss rate. As the wood twists, I will use the bad pieces to cut open and measure on the inside.

If you take a moisture reading on the outside it may be extremely low, but keep in mind the meter will only read to a certain depth. If you have the opportunity to cut the wood open and read the inside at the center then you get a more accurate reading and understanding of what is going on inside the wood.

Meter reading 5.3 on outside face of stock.

You should do this to gain experience of using the meter and an understanding of what the numbers really mean.

Be sure to measure different boards in different locations. Remember that the readings will be low on the outside of the board, and if you cut it open, the readings will be highest near the center and lower near the ends even on the inside of the board.

Taking the readings and observing the behavior is the best experience that you can have to understanding the nature of wood.

Meter reading 8.9 on freshly milled face of wood.Meter reading reveals 9.8 in the center of the board freshly milled open.

Don't be desparaged by differences, you are looking for an overall average. But also compare your readings to the individual characteristics of the board. This is valuable information that you will draw upon as you pick lumber in the future.

Mill & Rest

After cutting and planing this stock down to it's final dimension I need to let it rest one more time. This particular project has required more of this than normal. A low moisture content on one side and a high moisture content on the other will lead to a warped board. Letting it acclimate and dry a little more alleviates the problem.

Always sticker the wood to create space between the layers. Also be sure to leave some space on the sides to create as much air flow as possible. Never blow a fan on it to accelerate the drying and acclimation. You will cause the wood to wick out the ends at a much faster rate than the center can give up and this will cause checking on the ends and twisting. The wood does what the wood wants to do in it's own time.

Stacked and stickered for what should be the final rest.

Do Not Introduce Too Much Moisture

During the glue up for particularly difficult material, do not use a lot of water to wipe away the glue squeeze out. This will have an adverse affect on the panels. Rely on scraping and sanding off the squeeze out to avoid adding moisture.

Sometimes It Can't Be Stopped

Sometimes you can do all the right things and it still doesn't work out in the end. While this is lost time and labor on one hand, use it as a lesson to understand what went wrong and why.

Sometimes you learn through success and sometimes you learn through failure. Even as a pro, the learning never ends.

Warped panels.

That's all for now. Be sure to check back often to see what's new.

Your friend in the shop - Todd A. Clippinger

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