What could be more fun than a low-tech giant toothbrush? Every kid should have one. The only thing better is having a giant empty cardboard box to play in.
This project shows you how to make your own giant toothbrush. They make great accessories for your Halloween costume or award-winning grade-school science fair project. They also make great gifts for the dental professionals in your life.
You can't buy something like this at a reasonable price (call me frugal dad, ok... cheapskate dad) so I started out with some 1x3 wood scraps, scrub brushes, glue and paint to create something big...
This is a great weekend project to do with the kids so they learn some basic woodworking skills, use tools and to watch dad do his magic. Safety first!
And Captain Daydream says, "Brush 'em, brush 'em, woooOOOO!"
Step 1: Layout and Cutting Wood
The pictures show me making four giant toothbrushes but you can make only one or as many as you like.
Begin by buying scrub brushes that look right for a toothbrush. My first one consisted of two scrub brushes cut and placed end to end to get a large enough toothbrush. The bristle color should probably be white for the right effect. The blue bristles make a cool color border that looks like an expensive toothbrush. I found my scrub brushes at a dollar discount store. We are looking for proper proportions so you can easily make a really giant toothbrush with one of those big sweeper broom heads.
Next, get some 1x3 wood stock about 4 feet long. Furring strips will also work if you want to take the extra effort to patch, sand, and round over the edges to make the finish look nice. This time, I found stock that is used for bed slats. It is a bit thicker than the standard 1x3 stock, already has rounded edges and has a little more heft to it due to the species of wood used.
Starting from one end, measure about 2 brushlengths long. This is a creative project so exact measurements are not needed. On the edge, draw about a 30 degree diagonal line from that point. You will then saw the wood through making two pieces. Extend the lines down the wide fronts as saw guidelines. You can use a hand saw or various power saws to cut. A bandsaw would probably be nice for this project but it is not necessary.
Step 2: Shaping Up...
You should now have a short piece with a diagonal cut and a longer piece with a diagonal cut.
On the shorter piece on the side opposite the beveled cut, trace the outline of the scrub brush when it it placed starting at the flat square end. This will be your guide when you glue the pieces together. Glue the pieces so that the longer piece's beveled cut "flows" up to the outline of the edge of the brush. Clamp together and wait for the glue to dry.
When dry, draw lines where the "neck" of the toothbrush is. The toothbrush gets narrower from the bottom of the scrub brush outline and flows to the full width of the brush about 1 and 1/2 brush lengths down. Eyeball this to find the right look.
At the other end of the toothbrush find the center and the point where you will drill a hole. Place a can on the end to help with the semicircular end so you can trace around it. Use a 1/2 inch spade bit. Clamp the toothbrush to some scrap stock when you drill so the hole comes out neat and clean.
Use a jigaw or bandsaw to rough out the toothbrush shape. Use various wood files, scrapers, planes, sanders to fine tune the shape. Use a wood plane to thin out the bump where the bevel cut flows into the bottom or brush piece.
Step 3: Prime and Paint
The final look we are going for is a classic glossy red plastic toothbrush.
Fill any gaps with wood putty and sand smooth. Give it a coat or two of paint primer. Lightly sand between coats. I had some pink paint so I used it as an undercoat for the red. (Nice reminder to give to your favorite charity and raise awareness)
The wood grain on this was pretty spiffy. I may do this project again just to stain and polyurethane the wood. Oak would be cool.
Step 4: The Brush Off
Back to the brushes...
Examine how your scrub brush is constructed. Carefully deconstruct it so that all you have left is the layer with just the bristles. Saw through the brush with a backsaw so you get a straight cut.
Score the areas that will be glued together with a razor knife so that they will adhere better. I used a polyurethane glue to adhere the plastic to the wood. The stuff will make a mess if you are not careful because it does foam a bit when drying and ooze and impossible to clean off your bare fingers.
Align everything and let dry thoroughly. Use a good white latex caulk to cover up the seam between the brush and the wood toothbrush. Use a wet finger to smooth out the joint. Using 100% pure silicone caulk is not necessary and is difficult to work with. If you are a little messy with the caulk, it is OK because it does look like toothpaste lather on the brush when it dries.
Use a metallic paint marker pen to ink in your favorite logo or saying on the toothbrush. There may be some ink-jet paper products that let you print something out to put on as a sticker or decal for the toothbrush if your penmanship is lacking.
Step 5: 1001 Uses for a Toothbrush...
I hope you have fun with making a giant toothbrush.
Just wait till you see our giant horseshoe magnets :)
If anyone is interested, this science fair project was to see what foods stuck to teeth the most so that you would better brush teeth so nothing remains to build up dental plaque. The teeth are made from empty eggshells filled with plaster. Yes, that was one giant omelette that day... It is set in hot glue on a cardboard box shaped like the lower part of the mouth. A giant batch of homemade reddish play-dough was packed around the "teeth" to make the "gums". Half of a popsicle stick pushed into the gums as a label for each of the foods used. A flappy L-shaped diving board giant tongue was attached to the box. The rest of the mouth was drawn and painted on the poster board. The lower jaw is pushed back against the poster board to complete the 3D effect. The display comes apart easily for a kid to haul up the stairs. OK, maybe a kid and a half...