Weed Destroyer Watering Can

Using boiling water to kill the weeds which are growing through the cracks in your patio or driveway is inexpensive, effective and eco-friendly.

Of course, you could pour the water directly out of a kettle onto the weeds, but it is difficult to aim the flow and too much water is wasted.

There are lots of metal watering cans on the market (don’t use a plastic one!) However, they can be expensive and it’s difficult to find one the right size and shape for this purpose.

This is a fairly simple and inexpensive project to make a suitable watering can out of a large ketchup can. It will produce a fine stream of water which can be safely directed exactly where it is needed.

Later, as well as having a weed-free patio, you will have lots of ketchup available for your grilled hamburgers and hot dogs.

WARNING! Boiling water can cause severe burns. You want to scald the weeds, not your toes, not your kid’s fingers, not your dog’s tongue. So for safety’s sake, wear closed-toe shoes, and keep kids and pets away from the area while you are boiling the water, filling the can and treating the weeds. And use caution while filling the watering can from the kettle... steam can burn you too. Do it carefully and wear protective gloves.

Available at the grocery store:

One restaurant-sized can of ketchup (114oz/2.84L) or similar.

Available at hardware and home supply stores, or in your workshop:

Metal Strap for the handle (Duct Anchor/Strap Tie) approx. 18”/46cm long. Use a flat one, not one with a ridge or you will have trouble bending it.

1/4”/6.35mm copper tubing, approx. 24”/61cm long

Pliers

Propane Torch and Solder with flux

Electric Drill, 1/8”/3.2mm & 1/4”/6.35mm drill bits

A bit of Plumber’s putty or pipe sealant

Blind rivet tool and 1/8”/3.2mm rivets, or 4 small bolts with nuts and lock washers

Optional but recommended: foam pipe insulation and vinyl tape to cover the handle

Cut open the can part way (about 1/3) using a top-cutting can opener (not a side cutting one).

Fold back the lid. Be careful, the metal edge will be sharp! Use a butter knife to help pry the lid open if necessary.

Pour the ketchup into a large bowl.

Bend the lid all the way back until it’s flat against the uncut portion.

Rinse out the can.

Remove the paper label from the can.

Scoop the ketchup into medium freezer bags.

Put the bags of ketchup in the freezer to save for later. Be sure to tell your family about the ketchup, so they won’t think you’re starting your own blood bank at home.

Later on when your old bottle of ketchup is empty, thaw one bag from the freezer, snip off a bottom corner and squeeze out the ketchup into the washed empty ketchup bottle.

Bend the metal strap into a curved shape using the can (or something else that’s rounded) as a form, adjusting the curve manually as necessary to fit the can.

Bend the ends slightly with pliers to facilitate flat attachments to the can. You will attach the strap high on the spout side and low on the other.

Drill two 1/8”/3.2mm holes (or whatever size you need) in each end of the strap, if not already pre-drilled.

Using the strap as a template, mark and drill matching holes in the can where the strap will be attached.

Before attaching the handle, apply a layer of plumber’s putty or pipe sealant to the can under where the handle will be attached, to prevent possible leaks.

Fasten the handle to the can using blind rivets or nuts, bolts and lock washers.

Wipe off any excess putty.

Drill a 1/4”/6.35mm hole in the side of the can, close to the bottom seam. Bend the can with the bit to make the hole face slightly upwards.

Bend the copper tubing roughly into the shape desired. Insert the tubing into the hole.

Making sure the end of the tubing is resting close to but not directly on the bottom of the can, hold the tube against the side of the can and fasten temporarily with tape.

If you are new to propane torches and soldering, there are plenty of instructional videos online. Check them out.

Using the propane torch and solder, fasten the copper tube into the hole, ensuring enough solder flow to completely seal the tube to the can. Let cool.

Remove the temporary tape, then tack the tube to the can using the torch and solder, about halfway between the base and the top of the can. Let cool.

Bend the copper tube into the approximate shape you want for watering. You can adjust it more later if needed. Make sure the end of the tube is above the top of the can, or you will have a siphoning problem when the can is full.

While the handle shouldn’t get hot, it will feel nicer in the hand with a little padding. Cover the handle with foam pipe insulation or something similar and wrap with vinyl tape for a softer, more comfortable feel, like a padded steering wheel.

The hot water in the can will cool down fairly quickly, so for optimum results, be ready to start pouring immediately after filling the watering can.

Try to hit the leaves as well as the stems of the weeds.

You will see that most weeds will look like cooked spinach almost immediately, but it might take a couple of days for the leaves to turn brown and shrivel up.

Some weed species, larger weeds, and more established ones could be stubborn and might take a couple of applications to be rid of them. Check them every few days.

Experiment with your application technique until you are happy with the results.

Happy weeding! And remember... Safety First.