C04.02
Mix only what you can place
Pot life is a countdown that starts the second Part B hits Part A. Batch size is set by how fast the crew can place material — never by how big the pail is.
- Size every batch to what the crew can place inside the sheet's working time
- Run the mixing rules that change by product — order, speed, time, induction
- Know why material waiting in a pail dies faster than material on the floor
The clock you cannot argue with
The MavCoat PC sheet says it in one line: material left in the pail will generate heat and have a reduced pot life. A full pail is a chemical reaction feeding on itself. The same gallon spread at 16 mils on the floor lives far longer than it does massed in the bucket. That is why almost every sheet gives the same two orders — empty the mixed material onto the floor immediately, in a bead, and never try to roll it out of the bucket or a pan unless the sheet says dip-and-roll. Batch size is a planning decision the lead makes from the sheet's working time and the crew's real placement speed — before the first mix.
Working time at ~72–77°F — from each product's data sheet (heat and humidity shorten all of these)
| Product | Working time | The line that matters |
|---|---|---|
| MavSeal RCU | 13 minutes | Spread within 2 minutes of mixing. Crew in position before you mix. |
| MavRapidPatch | Use within 2–3 minutes | Mix 20–30 seconds. Do not rework it once it sets. |
| MavCrete UM / MavGrout USP | 15 minutes | On the floor within 3 minutes of mixing. |
| MavCoat FC | 10–15 minutes | Fast-cure primer. Bead on the floor immediately. |
| MavPolyPatch | 15 min on floor (Fast: 10–15) | Mixing longer than 60 seconds makes it catalyze faster. |
| MavCoat SLE | Slow 35–40 / Standard 20–25 / Fast 12–17 min | Pick the activator speed for the job and crew. |
| MavCoat PC / CRE / HPE / OPE / MavClad EM | 25 minutes | Ribbon bead on the floor, spread on spike shoes. |
| MavCoat CES | 25 minutes | Hand-mix with a stir stick only. Never drill mix. One kit at a time. |
| MavCoat Metallic | 30–35 minutes | Blend 16 oz acetone plus the 32 oz Metallic Additive before Part B. |
| MavCoat Polyurea | XTRA Slow 60 / Slow 30 / Medium 15 / Fast 10 min | At 80% humidity those become 30 / 20 / 12 / 8. |
| MavSeal UPA | XTRA Slow 2 hr / Slow 70 / Medium 32 / Fast 25 min | At 80% humidity: 70 / 28 / 17 / 14. Dip-and-roll nearly doubles work time. |
| MavSeal HTU / UHD | 60 minutes | HTU: 5-minute induction after mixing, then stir gently. |
| MavSeal HWU | 35 minutes | One kit at a time. Never partial mixes. |
| MavCoat WBE | ~1 hour | 15-minute induction after mixing before it goes down. |
| MavJoint JF | Gel in 45–50 seconds | Dispensed through a static mixer — the gun is the pot. |
Mixing that holds up
- 01Measure, never eyeball
The ratio on the sheet, by volume (or by weight where the sheet says weight — MavCoat ESD is mixed in pounds). Premeasure before anything combines.
- 02Right order
Some products mix in a required order: MavSeal HTU is Wear Filler into Part B, then Part A. MavSeal HWU is Part B, tint, Part C filler, then Part A. Tints premix into the side the tint sheet names.
- 03Low-speed mechanical mix
Jiffy-type blade at low speed for the time the sheet gives. Scrape the sides and bottom — the PC sheet warns that unmixed material on the pail wall will never cure. Do not whip air in.
- 04Onto the floor, now
Empty the batch in a long bead 8–12 inches wide and spread. Do not scrape the sides onto the floor, do not invert the pail to drain.
- 05Full kits only
Where the sheet says full kits (MavSeal UPA topcoats, RCU, CRE), a partial mix is a ratio error waiting to happen. Do not split kits.
- Not this
Mix both kits so we're not waiting on the mixer.
ThisOne batch mixing while one is being placed. The mixer waits for the floor — never the other way.
- Not this
It's stiffening — thin it with a splash of solvent.
ThisDead material goes in the trash, not on the floor. MavRapidPatch says it flat: do not thin with solvents.
Takeaways
- Mix only what you can handle. If the crew places a kit in 12 minutes, you mix one kit — not two because walking back is annoying.
- Mass in a pail generates heat, and heat eats pot life. Get material out of the pail and onto the floor immediately.
- Heat and humidity shorten every working time on every sheet. A 25-minute product is not a 25-minute product in July.