Leaf Spring Bath Planter

A neighbour upgraded his Land Cruiser suspension and I ended up with the old leaf springs. We'd also had a cast iron bath sitting in the bush since we moved here two decades ago, that I've been meaning to do something with.

I'm not a professional welder, but I reckon I've picked up enough over the years to try a project like this.

I had a vague idea it might become an outdoor bath, but once the frame was done it was clearly too big and awkward, so I never tried. With encouragement from my wife, it is now a large planter, with irrigation pipe routed up through the drain hole.

Leaf springs a pair of old Land Cruiser leaf springs and matching U bolts, other models will probably work fine.

Cast iron bath free standing.

MIG welder.

Angle grinders a big corded one with a cutting wheel and a cordless with a grinding disc for finishing.

Oxy-LPG torch for preheating the spring steel before welding. Skip this and the hardened steel will crack on you, so I've been told.

Tools to pull the spring packs apart.

PPE welding helmet, gloves, face shield, ear protection, goggles, etc.

Pull the spring packs apart. Undo the centre bolt on each and separate the leaves — you'll end up with 16 (8 per pack).

Pull the rubber inserts out of the eyes on the top leaves, and scrape off any leftover rubber around the eye brackets. Saves you the smoke and stink when you heat and weld them later.

Keep the 4 U-bolts — they get reused to clamp the tub down.

Shown here still attached to vehicle as I forgot to take before pics.

Flip the bath upside down on a flat surface.

Take one of the bracketed main leaf springs and lay it across the tub, with the bath's legs sitting inside the footprint of the spring. Centre it front to back.

Grab two of the next-shortest leaves and lay them perpendicular to the first, just outside the cast legs — forming an "H". These are the cross-braces and sit below the main spring.

Clamp it all down and check that it's square, centred, and that the brackets line up with the legs.

My spring lengths happened to suit the leg spacing. If yours don't, cut the non-bracketed leaves to length before clamping.

Note pic shows next step where it is already welded.

Mark reference lines across every overlap joint where springs will be welded .

Take the clamps off and clean the metal back to shiny steel either side of each weld line. I used a grinder wheel.

Clamp it all back in the marked positions and check it's still square.

Now I have been told that the important bit for spring steel is to preheat each joint with an oxy-LPG torch, out to about 10 cm either side, up to around 300°C. I did this and used an IR thermometer to check. Apparently this is what stops it cracking from thermal shock. I didn't get any cracks so maybe.

Once it's hot, tack all the corners to lock it in, then go back and weld each joint fully — keeping it hot as you go.

Pull the clamps, flip the frame over (still hot), and do the same on the underside.

Weight the tub frame down so it can't move while you work.

Clamp one leaf spring to the outer edge of the frame, pointing up. Use something like a milk crate to prop it at the height and angle you want. Then rest a longer leaf on top of it, pointing down — it'll sit against the clamp and hold itself, no need to clamp the top one. Don't worry if the top leaf overhangs too far, you trim it later.

I went with about 900 mm leg height at the outer join, but suit yourself depending on how tall and wide you want it.

Repeat around the tub, eight leaves total, two per corner (one clamped lower, one resting on top)

Then just keep adjusting each leg until you're happy with the look - remember it's going to be turned over.

Weld each leg at the overlap joint, same as before, clean, preheat, tack, weld.

Once one side's done, flip the whole assembly over to get at the underside. It's getting heavy now!

Tack and weld the underside joints the same way.

I also added a small support tab, just a scrap offcut, welded between the lower leg and the frame for a bit more strength.

I removed the overhang so there was no chance of snagging or getting caught up.

Cut the excess off each leg with the grinder, then knock the edges back with a grinding wheel for a rounded, clean finish.

I trimmed the outer tips to follow the arc and soften the profile.

Initially I was going to use this as a bath, but it looked like it needed to be stronger, so I added a central 'skid'.

Take the two largest leaves with the eyelets, these are the sled runners. Lay them curved side down, centred under the frame, about one spring-width apart. I ran a broom handle through the eyelets at each end to keep them straight and square.

Then grab the last leaf, the thick one with a bracket on the end. Sit it between the two runners so the bracketed end lands flat on one of them. Adjust the angle and height until it mates up cleanly.

Once it fits, clamp, mark, grind, preheat and weld like before.

Trim off any excess height on that vertical support so it won't foul the base of the tub. Then flip the frame over and weld the underside.

That's the frame structurally done.

Lift the tub, I used the tractor's front-end loader with lifting straps. You'll want something similar or lots of people, it's heavy.

Lower it slowly onto the frame, lining the bath legs up with the mount points. Make your adjustments while it's still hanging so it sits level and square.

Last bit, use the four original U-bolts to prevent the tub sliding off.

Press each one over the leaf brackets on the frame. They shouldn't need clamping; the spring tension holds them put. Sit each one snug against the side of the bath so it stops any side-to-side movement.

Then prep and weld.

Not shown in the pics, but I also used a small shackle to attach one of the bath's legs onto the frame, just in case.

I would have loved to try out a bath but it never happened. It's now full of rubble, top soil and plants. The watering pipe sneaks up through the drain plug.