DIY HHO Generator Materials: What to Buy and Where to Get It

316L Stainless Steel Plates

The most critical component and the most common DIY mistake: buying the wrong steel grade. Sources for certified 316L stainless in sheet form:

• Online metal suppliers: OnlineMetals.com, MetalsByTheFoot.com, metals4U.com — specify 316L grade when ordering, request mill certificate
• Local metal suppliers: Search "metal steel supplier" locally — often cheaper for small quantities
• Amazon/eBay: Convenient but always verify grade from description and ask seller for documentation. Avoid listings that just say "stainless" without specifying grade.

Gasket Material

EPDM (Ethylene Propylene Diene Monomer) rubber is the best gasket choice for HHO cells — excellent chemical resistance to KOH and good temperature resistance to 150°C. Neoprene is acceptable. Avoid natural rubber and standard silicone sheet (silicone tubing is fine, but sheet silicone isn't as chemically resistant). Sources: McMaster-Carr (professional grade), Amazon (search "EPDM sheet gasket material").

Electrolyte (KOH)

Food-grade potassium hydroxide is widely available on Amazon ("KOH potassium hydroxide lye") in 1–5 lb quantities. Alternatively, sodium hydroxide (lye/NaOH) sold for soapmaking works as a secondary electrolyte choice.

Hardware

316 stainless M6 bolts, nuts, and washers from McMaster-Carr or a local fastener supplier. Using zinc-plated or cadmium-plated hardware causes immediate contamination of the electrolyte — stainless only throughout the cell.

Fittings and Tubing

6mm silicone tubing and barbed stainless fittings from McMaster-Carr or Amazon. For gas lines inside the engine bay, only silicone tubing — fuel line and regular rubber tubing degrade from both heat and HHO contact.