I recently got a garage that I started moving tools into. I now need a shelving unit on the cheap. This is made completely from 12 2x4x8s (31 dollars home depot). I already had the other hand tools I needed from other projects:
-miter saw box/saw (if you have a sliding compound miter saw more power to you)
-drill - (with 1/8 bit and driving bit)
-2 inch coarse thread screws
-adjustable square or rafters square (also known as a speed square)
-80-120 grit sand paper
- and of course the 12 2x4x8 (96 inches long)
As always if something isn't clear please ask me to clarify any steps. The difficulty level for this project is not bad at all. Someone who is unfamiliar with tools or assembly might find this a good jumping in project
Step 1: Measuring and Marking
I have attached a cut sheet and schematics for the 2x4x8s.
4 x untouched (the total height will be 8 feet, if you need a shorter shelf these would be the pieces to change. Maybe 6ft?
6 x cut down the middle - we need 12 48" pieces
1 x cut into 5 equal parts - 19.2" each
1 x 3 more 19.2" cuts
In total -
4 - 96" pieces
12 - 48" pieces
8 - 19.2" pieces ( .2 inches comes out to roughly 13/64 or 6.5/32)
Using your measuring tape measure out out on the boards where each cut will have to take place.
Then take your square and transfer that cut mark across the board. Check and recheck your measurements and then you can move onto cutting the boards.
Step 2: Making Cuts
Using your miter box, line up the cutting slot with the line you marked. I try and keep the line directly in the center of cutting guide slots but with a project like this, absolute accuracy is not needed. The width of the blade will not make a considerable difference in end assembly.
Once you have the cutting line lined up take two clamps and affix them so the clamp is holding the board down to the miter box and also the bench. The pictures show my setup.
The miter saw is specific to the box and has a fine tooth pattern for a finer edge than a regular wood saw. It allows you to maintain a (relatively) straight cutting edge without having to pay the cost of a large power miter saw.
When you end up cutting the 5 pieces of 19.2" boards you'll notice that the last one you cut is slightly shorter. This is because an 8ft 2x4 is actually 95 and about 7/8" long. Once again this slight difference in length will not make a large difference in final assembly.
Once you are finished making your cuts. Use some sand paper (80 or 120 grit should be fine) to hit the edges of the cuts to get ride of splinters and such.
Step 3: Marking for Shelf Assembly
On each of the 19" pieces measure in 3.5" on either end of the wide side of the board. Using your square again make a full length line.
On each of the 48" pieces measure in 1.5" and use the square to make a line.
Using the waste board 2x4 place it against something known to be square like the legs of a table or a wall. Take two 48" pieces and lay them flat on the ground and square the edges up against the board. They should be parallel and roughly 12 inches apart from edge to edge.
Taking two of the 19" pieces lay them across the two 48" pieces. There should be approximately 3.5 inches of overhang on each side (hence the 3.5 line marking). I have included two videos below that hopefully convey this idea little bit better.
After everything is set up apply glue to the boards and set them back in place. No need for clamping at this point. This will be just enough to hold them together for screws later on. They are going to need at least a few hours to make sure the glue is dry.
Step 4: Screwing Down Shelf Boards
After the glue is dry we can flip the shelf assemblies over without fear of having them slide around. Using your drill and 1/8" drill bit drill two holes into each shelf piece. The holes should be about 2 inches deep. After drilling all holes chuck up a driving bit and drive a 2.5" screw into each hole.
After securing each board with 2 screws, glue the midsection of each lower support board and lay the final 48" pieces to complete the shelf assembly.
After this third piece is done drying complete the same steps above and secure it with 2 screws.
Step 5: Final Assembly
We are going to use the same method as before to make sure each post of the shelf are parallel by squaring the "waste" board and putting each shelf against the board. Mark each post 24 inches in (or whatever the first shelf is going to be for your shelf).
These two 24 inch marks will be used to make sure the shelf we put in between each post is also semi-level.
On each of the backsides of the shelf's 19.2" pieces mark out a 5 point sketch (like a 5 on a die).
Once the sketch is complete, drop a shelf assembly between the two posts near what will be the bottom of the shelf and the top of the shelf to ensure the two posts are parallel. Keep measuring on each of the two posts for the distance between each shelf until all shelves are in between the posts. Each shelf has a tendency want to lean forward so use a scrap piece of wood, pipe, bar, book. Really anything can keep these shelves up.
Once each shelf has been put into place. Use your drill and 1/8" bit to drill a hole through each 5-dot mark on each shelf piece. Drive a screw through the middle hole for right now. You might want to change the height of each shelf so don't drive too many screws at first.
Lay the last two posts on top of the shelf assemblies and start your final drilling and screwing once you are satisfied with shelf placement. Once done screwing in each shelf lift the shelf up onto its legs and into place.
Step 6: Final Thoughts
I made a video of final thoughts on additional addons or modifications that could be done to make this a better shelf for you.