No torch, no sparks, no power
A metal repair you can make with the tank still on the machine.
Welding is the right answer until it is not: fuel in the tank, paint you cannot burn, a seal two inches away, thin sheet that will blow through, or a part you simply cannot get out and onto a bench. Cold weld is the other option — two pastes you mix by hand, press into the damage, and leave overnight. No heat goes into the part, so nothing warps, nothing catches, and nothing has to come apart first.
Mixed one to one
Equal parts by eye — no scales, no gun for the tubes
Firm in 15–20 minutes
At about 20 °C; full strength after a day
Water, oil and corrosion
Cured paste shrugs off all three
Eight sizes and formats
20 g to 100 ml, singles or twin packs
What actually happens
It cures hard, not sticky
This is not a glue that stays flexible. Once the two parts react, you get a hard, dense filler sitting in the damage — closer to a casting than to a rubber. That is why it suits holes, cracks, worn seats and pitted faces rather than joints that have to move. Press it in with a blade rather than laying it on: the paste has to fill the void, not bridge it.
Leave it slightly proud. The cured paste takes a file and abrasive paper happily, so bringing it flush afterwards is easier than mixing a second batch to fill a hollow.
The part nobody tells you
The surface decides whether it holds
A cold weld does not fuse with the metal the way an arc does. It grips mechanically — the cured paste keys into every scratch and pore on the surface. So the repair is only ever as strong as what you gave it to hold on to, and almost every failure traces back to the two minutes before the paste went on.
Roughen the area with coarse paper or a wire brush until it is dull and scratched, then degrease it. Oil is the enemy: a film you cannot see is enough to turn a solid repair into something you can pick off with a fingernail next week. On a part that has lived in oil — a gearbox case, a sump, a hydraulic fitting — clean it twice, and let solvent flash off before you mix.
Temperature matters on both ends. Below about 10 °C the reaction crawls and the cure can stall; warm the part first. And the two formats are not rated the same: the cartridges are marked for −40 °C to +200 °C, the A+B tubes for −60 °C to +150 °C. If the repair lives next to something hot, that difference is the one number that should choose your format.
Eight ways to buy it
Size it to the job, not to the shelf
Mixed paste has minutes, not hours, so a big pack is not a saving if you only need a walnut of it. Buy the size that matches the damage in front of you — and if you do this work regularly, the twin packs exist because the second one is always needed on a day the shops are shut.
Cartridges — 50 ml and 100 ml
Both parts in one body, dispensed together. The higher temperature rating of the two formats, and the tidier option when you are working above your head or in a confined space.
Tubes — 20 g to 100 g, and twin packs
Separate A and B tubes: squeeze what you need, cap them, keep the rest. The 20 g is a one-repair size; the twin packs are for maintenance shelves where running out costs a day.
Straight answers
Three things we would rather you knew now
It is a repair, not a structural weld. It fills, seals and rebuilds a surface. It does not restore the load path of a broken chassis member, a lifting eye or anything that would hurt somebody if it let go. Use it where failure means a leak or a re-do, not an injury.
The two formats have different temperature ratings. Cartridges −40 °C to +200 °C, tubes −60 °C to +150 °C, as marked by the maker. Near an exhaust, a manifold or a boiler, that gap decides which one you should be holding.
Both parts have to be the same amount. Eyeballing two equal beads is fine; guessing is not. Short one side and the mix stays soft indefinitely — there is no second chance to add the missing half once it is on the part.
The specifics
Sizes and ratings
Mix ratio
1:1 by volume, stirred until the colour is even
Set time
Firm in about 15–20 minutes at 20 °C; leave 24 hours before loading or machining
Cartridge rating
−40 °C to +200 °C, as marked on the 50 ml and 100 ml bodies
Tube rating
−60 °C to +150 °C, as marked on the A+B tube packs
Cartridge size
100 ml is about 12 cm tall, 50 ml about 8 cm, both about 4.5 cm across
Resistance
Waterproof, oil resistant and corrosion resistant once cured
Surfaces
Cast iron, steel, aluminium and other metals; also bonds plastic and wood
In the box
Adhesive plus a mixing spatula; twin packs contain two complete units
Questions people ask
Before you order
How hot can the repair actually get?
It depends which format you buy, and the difference is real: the cartridges are marked −40 °C to +200 °C, the A+B tubes −60 °C to +150 °C. Those are the maker's figures for the cured paste, not for a part under load — near a manifold or an exhaust, choose the cartridge and keep the repair off the hottest face.
Will the metal rust underneath it?
Not where the paste is sealed to clean, bright metal — that is most of the point of using it on a water tank or a radiator. Rust that is left in place under the repair carries on, though, so take the surface back to sound metal before you fill rather than burying the problem.
Does it conduct electricity?
Treat it as an insulator. A metal-filled epoxy looks like metal and is not one electrically, so do not rely on a repaired section to carry an earth or a bonding path. If the part is part of a circuit, restore the electrical path separately.
Can I paint over it?
Yes, once it is fully cured and sanded. It takes primer and paint like the metal around it. Give it the full day first — painting a half-cured repair traps solvent and the finish stays soft over the patch.
Will it hold up to vibration or pressure?
It handles the vibration of ordinary machinery and the pressure of a domestic water system on a properly prepared surface. What it does not like is flex: a panel that moves under load will eventually part company with a rigid filler, however well it was bonded.
Can I use it on a damp or wet surface?
Apply it dry. The paste is waterproof after it has cured, not while it is curing — water on the surface sits between the paste and the metal and takes the mechanical key away. Dry the area, warm it if you can, then repair.
How do I get it off if I need to?
Mechanically — chisel, file, abrasive or a burr. There is no convenient solvent for cured epoxy, which is worth remembering before you fill a thread or a mating face you may want back.
Why would I buy a twin pack?
Because the second repair always arrives at the worst moment. If you maintain machinery, run a farm or look after rental property, two on the shelf costs less than two bought separately and saves the day you would otherwise lose waiting for a delivery.
Shipping & returns
Delivery in 7–15 business days from the time you order — that window already includes the 1–2 business days we take to process. Tracking is emailed as soon as the carrier scans the parcel. Shipping & Delivery.
30-day returns. Items must be unused and in their original packaging. Email support@nexuratool.com to start a return.
Nexura Tools
Tools for repair, maintenance and the jobs in between — chosen for specs we can verify.
