I have thought about making a long carpenter’s level. Recently I was part of a volunteer group installing vinyl siding on a storage shed. The long carpenter’s level available to us from a tool trailer had two vials for reading plumb and a third to read horizontal level, but one vial for plumb was poorly aligned and inaccurate. We discovered that fairly early and it is not adjustable, still the inaccuracy was a little disconcerting. That experience inspired me to try making a long carpenter’s level now.

Supplies

I am not making my own bubble vials.* Home Depot, for one, offers a package of five vials on-line for levels with snap-in fittings. The vials are 3/8 inch in diameter and 1 3/8 inches long. They are made of plastic and quite durable. I had a line level for hanging from a string, and have had it for years; but, have never used it. I also had a small pocket level once given as an advertising favor. The vial in the line level is plastic and I am able to harvest it. The advertising favor is glass and a leak developed in the vial that rendered it useless. The least expensive option was a small torpedo level made of plastic, but with snap-in vials.

Materials

3/4 inch plywood with seven plies
Two plastic level vials
Steel pipe
Steel tabs
Steel bar 1/8 x 1/2 inch
Wood screws with round heads

Tools

Table saw
Holesaw and electric drill
Twist drills
Rattail file
Reamer
Arc welder
Hammer
Screwdriver
Grinder
Dremel tool

*See Cooking Oil Level by Howtern

Step 1: Overview of the Project

The body of the level will be a piece of 3/4 inch plywood about four inches wide. Two vials will be used. One will indicate horizontal level and the other will indicate vertical level, or plumb. Step 3 discusses making the hardware for mounting the vials.

Step 2: The Level Body

I used some plywood for the level body that I pulled from a scrap pile and had planned to use it for shelving. My homemade tablesaw uses a rip fence four feet long. If I rip something a couple of times I can remove very little material, but also flip it to remove irregularities. The resulting piece is very straight. I decided to make my level 60 inches long.

Step 3: Hardware for Mounting the Vials

The first image was produced in Google Sketch-up. The proportions are not exact. I used a sketch rather than a photo because the exact outcome of this project was still very fluid in its early stages and I did not regularly take photos.. The pipe collar is black iron pipe a tiny bit over 1 7/8 inch in actual diameter. The holesaw I used is exactly 1 7/8 inches. The pipe collars can be turned down on a lathe, or they can be ground on a wheel by hand to fit.

I had to mount the vials lower than center because their length is considerably shorter than the internal diameter of the pipe. Drilling a 3/8 inch hole across a pipe collar like this is prone to skating by the tip of the drill. I started with small diameter holes. As I proceeded I kept trying to aim the hole drilled from one side more directly at the hole drilled from the other side. A rattail file and a reamer helped to transition to the aiming point I needed without the drill skating.

I did use a 3/8 inch steel rod to check for alignment of the holes, as you see in the Sketch-up drawing. The second image shows sawing the pipe to make a collar the width of the level body. The third photo shows steel mounting tabs I welded onto the pipe collars for mounting to the level body. I also drilled a hole in each tab for a mounting screw. You may notice pieces of 1/8 inch rod that cross over the top of the level vial in the third photo. They are welded in place and insure that the vial does not come out of its mounting holes.

Step 4: Mount and Calibrate the Vials

Use a holesaw to make two holes in the body for the vials and their mounts. (First photo) They can be positioned wherever you want them to be. I chose to mount the one indicating horizontal level equidistant from both ends. I mounted the other indicating plumb near to one end of the level body. The holes for the vials and their mounts are equidistant between the two linear edges of the level body. Final fit can be done with a wood rasp that makes the hole a little larger, or by grinding a bit more on the circumference of the pipe.

In the second photo I am aligning a level vial for an accurate reading. It is not necessary to use an exactly level surface. It is important that when the level is flipped over (plumb reading) or turned end for end (horizontal level reading) the bubble comes to rest in exactly the same position with respect to the lines on the vial. I held the level to see where the bubble came to rest and compared a flipped reading. Then I used a large screwdriver and a hammer to move the vial mount by tapping with a hammer. It sounds daunting, but it is really quite easy to get a precise adjustment. Several tries and some patience may be necessary. Compare the last two photos on the plumb reading. The third and fourth photos show readings from the same vial when the level is flipped vertical edge to vertical edge. Notice how the bubble is positioned equally between the index lines. The level is well-calibrated for this vial.

When satisfied, carefully drill for mounting screws and secure the vial mounts to the level body.

Step 5: Finishing Touches

Smooth any rough or sharp edges with a grinding stone in a Dremel tool. Drill another hole in the level body at the end without a vial if you want to hang the level for storage. Paint or seal the level according to your desires.

I thought a great deal about ways to mount the bubble vials so they are adjustable, but there is no welding. I thought of a couple that involved wood pieces and screws, but viewing the bubble would be reduced a little, or the viewing field would be better on one side of the level than the other.

Most commercial levels are not in any way adjustable. My level is adjustable, but hopefully will never need tweaking. I could also make the level body thicker so it is not likely to tip over, but that also makes the level heavier to handle.

Long levels have quite a wide range in prices. You will need to decide if you want to make your own or buy a commercially produced level. I wanted to attempt making my own. Johnson makes a little “T” surface mount level that mounts with two screws and costs less than a Happy Meal, But, this application would place it at 90 degrees to its intended planes.