Roughly half of what leaves the fabrication bay is this one job, and most weeks somebody sends us a photograph of a home-made version that worries me. So here is the method.
What it is for
An open-top vessel at a working height, with a drain, that costs a fraction of a purpose-built tank. We build them for livestock water, grain and feed, mulch and media, ice, parts washing, aquaponics beds and grain-spawn substrate.
The appeal is dimensional. A tote cut at half height gives you a 48 × 40 inch vessel about 20 inches deep, which is close to ideal for working into from standing, and it already sits on a four-way forkliftable base.
| Cut height | Depth | Approx. capacity | Suits |
|---|---|---|---|
| Quarter cut (~34 in) | ~32 in | ~190 gal | Deep soak, ice, aquaponics |
| Half cut (~24 in) | ~20 in | ~120 gal | Livestock water, general work |
| Low cut (~16 in) | ~12 in | ~70 gal | Feed, mulch, parts washing |
| Tray (~10 in) | ~6 in | ~35 gal | Spill containment, seedling trays |
What a cut-down gives you at each height
How we cut it
- Decide the cut height from the cage, not the bottle. The cut must fall between two horizontal cage rails, leaving the lower rails intact. Cutting through a rail is the mistake that ruins the structure.
- Remove the bottle from the cage first. It cuts cleanly on a bench and it keeps swarf out of the cage. Reassembly takes ten minutes.
- Cut with a fine-tooth blade at low speed. HDPE melts and re-welds behind a fast blade, leaving a ragged bead. Slow and cool gives a clean kerf.
- Roll the edge or fit capping. Either a heat-rolled lip or a slit-tube polymer capping bonded over the edge. This is not optional — see below.
- Fit the drain. We usually retain the original outlet if the cut is above it, or fit a bulkhead bung at the lowest point if not.
- Reseat in the cage and check the lower rails. The retained rails are now carrying a load they were not originally positioned for, so we check geometry under a test fill.
The two dangerous mistakes
Both of these turn up in home-made units and both have real consequences.
- Cutting the cage. People cut the whole unit through with a reciprocating saw, cage and all, because it is faster. The cage is what carries the load. A cut-down tote with a cut cage is a floppy tub that bulges when filled and can split along the cut line. We do not sell those and I would not use one.
- Leaving a raw edge. A cut HDPE edge at roughly 20 inches is exactly forearm height, and under load it has a thin, hard, slightly serrated profile. I have seen the injury this produces. Roll it or cap it, every time, even if the vessel is only holding mulch.
The cage is the structure. The plastic is the lining. Cut the second, never the first.
Donor grade
| Use | Donor grade | Why |
|---|---|---|
| Livestock drinking water | Food grade | Animals drink it |
| Aquaponics or hydroponic media | Food grade | Output is eaten |
| Grain, feed, spawn substrate | Food grade | Direct food-chain contact |
| Ice and produce washing | Food grade | Direct contact |
| Mulch, compost, soil media | Rinsed | No ingestion pathway |
| Parts washing, workshop | As-is | Condition irrelevant |
| Jobsite water, dust control | As-is | Buy the cheapest sound unit |
What grade the donor needs to be
Cost
| Variant | Labour and parts | Lead time |
|---|---|---|
| Open-top conversion, edges rolled | $95 – $165 | 5 – 8 days |
| Cut-down trough with drain bung | $120 – $210 | 5 – 8 days |
| Trough with hinged half-lid | $180 – $290 | 7 – 10 days |
| Twin-chamber with divider | $240 – $380 | 2 weeks |
| Trough on welded stand, working height | $280 – $450 | 2 weeks |
Indicative fabrication cost, plus the donor unit
A rinsed donor at $120 plus a $165 cut-down comes to about $285 for a 48 × 40 vessel with a drain, on a forkliftable base. The nearest purpose-built equivalent is comfortably three times that.
If you are going to do it yourself
Plenty of people will, and I would rather they did it properly. The short version of the method above, for a workshop rather than a fabrication bay.
- Mark the cut line against the cage rails first, with the bottle still in the cage, then lift the bottle out to cut.
- A jigsaw with a fine wood blade at the lowest speed setting is the most forgiving tool. Avoid anything that generates heat.
- Deburr with a scraper, then cap the edge. Slit polyethylene tubing bonded over the lip is the cheapest acceptable finish.
- Test fill outdoors before you trust it, and watch the lower cage rails for splay.
- If the vessel is going to hold anything edible, start from a food-grade donor. You cannot fix that decision afterwards.
What we will not build
Anything that holds pressure. A composite IBC is an atmospheric vessel with a variable blow-moulded wall, and no amount of bracing makes it safe to pressurise. Same for vacuum. If you need either, you need a rated stainless bin and we will quote you one.
Catalogue builds are on upcycled builds; work to your own drawing is custom fabrication.
Written by
Marcus Vreeland
Founder
Started the company in 2009 with a 1998 flatbed and a hand-written ledger. Still reads every decommissioning survey.