PPG OMNI Mixing Ratios: A Chart for MBC, MTK, MC270, MP170, MP282 and More
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PPG's OMNI line uses five mixing ratios. MBC and MBP basecoat mix 1:1 with reducer. MTK single stage, MP282 primer surfacer, and MP23x urethane sealer mix 4:1:1. MC270 clear mixes 4:1 with hardener. MC260 clear, MC161 clear, and MP17x epoxy primer mix 2:1. MAE acrylic enamel mixes 4:1 with reducer, or 8:1:1 when a hardener is added. The chart below lists each product with its hardener, reducer, and pot life, taken from PPG's OMNI product bulletins and catalog.
What are the mixing ratios for PPG OMNI products?
Each ratio is written in the order PPG prints it: the product first, then the hardener or catalyst, then the reducer. Pot life is the working time after mixing at 70°F (21°C).
| Product | Mix ratio | What goes in | Pot life at 70°F |
|---|---|---|---|
| MBC Acrylic Basecoat | 1:1 | MBC : MR reducer | Indefinite |
| MBP OMNI Plus Basecoat | 1:1 | MBP : MR reducer | Indefinite |
| MTK Acrylic Urethane Single Stage | 4:1:1 | MTK : MH167, MH168 or MH169 hardener : MR reducer | 8 hours |
| MAE Acrylic Enamel | 4:1 | MAE : MR reducer | Indefinite |
| MAE Acrylic Enamel with Hardener | 8:1:1 | MAE : MH101 or MH202 hardener : MR reducer | 8 hours |
| MC270 4.2 VOC Production Clear | 4:1 | MC270 : MH276, MH277, MH278 or MH279 hardener | 1.5–2 hours |
| MC260 Quick Clear | 2:1 | MC260 : MH167, MH168 or MH169 hardener | 1.5–2 hours |
| MC161 High Solids Urethane Clear | 2:1 | MC161 : MH167, MH168 or MH169 hardener | 3 hours |
| MP170, MP171, MP172 Epoxy Primer | 2:1 | MP17x : MP175 catalyst. Acetone is optional, up to ½ part | 8 hours |
| MP282 High Build 2K Primer Surfacer | 4:1:1 | MP282 : MH283 or MH284 hardener : MR reducer | 1 hour |
| MP213 GP Sealer | 4:1 | MP213 : MR reducer | Indefinite |
| MP231, MP235, MP237 2K Urethane Sealer | 4:1:1 | MP23x : MH283 or MH284 hardener : MR reducer | 1 hour |
"MR reducer" means OMNI MR185, MR186, MR187, or MR188. The bulletin for MAE without hardener also lists the MR486, MR487, and MR488 enamel reducers.
PPG prints the same limitation on each of these bulletins: "Omni products should not be combined with components of other product lines." Use OMNI hardeners and reducers with OMNI paint, primer, and clear.
How much hardener and reducer is that in ounces?
A ratio counts equal parts. For 4:1:1, measure four parts of product, one part of hardener, and one part of reducer in the same unit. PPG's catalog lists MC270 in quarts and gallons and its MH276, MH277, and MH278 hardeners in 8-ounce and quart cans. A quart of clear with an 8-ounce can of hardener is 32 ounces to 8 ounces, or 4:1.
Here is the arithmetic for common sizes, using 32 fluid ounces per quart:
- MBC or MBP, 1:1: 1 quart of color plus 1 quart of reducer makes 2 quarts ready to spray.
- MTK, 4:1:1: 1 quart of color, 8 ounces of hardener, and 8 ounces of reducer make 48 ounces.
- MC270, 4:1: 1 quart of clear plus 8 ounces of hardener makes 40 ounces. A gallon of clear takes 1 quart of hardener.
- MC260 or MC161, 2:1: 1 gallon of clear plus 2 quarts of hardener makes 1.5 gallons.
- MP17x epoxy, 2:1: 1 quart of primer plus 1 pint of MP175 makes 48 ounces.
- MP282, 4:1:1: 1 quart of primer, 8 ounces of hardener, and 8 ounces of reducer make 48 ounces.
- MAE with hardener, 8:1:1: 1 quart of color, 4 ounces of hardener, and 4 ounces of reducer make 40 ounces.
Which OMNI products have more than one mixing ratio?
Four bulletins list a second ratio for a specific purpose.
- MTK: the standard mix is 4:1:1. PPG also lists a higher solids mix of 4:1:½, with half the reducer.
- MP282: the standard mix is 4:1:1. For high build, the reducer "may be cut to ½ part." As a spray filler, MP282 mixes 4:1 with hardener and no reducer.
- MP17x epoxy: the 2:1 mix can take up to ½ part of acetone. The bulletin marks the acetone as optional.
- MAE with hardener: the standard mix is 8:1:1. With MX201 Gloss Enhancer, PPG lists MAE: MX201 : hardener: reducer at 8:1:1:1–2.
MP282 has a shorter working time with less reducer. PPG lists its pot life as 1 hour at 4:1:1, 30 minutes at 4:1:½, and 20 minutes at 4:1, all at 70°F. Mix only what you can spray in that window.
Do I need to let OMNI epoxy primer sit after mixing?
Yes. The MP17x bulletin says to "allow a 15-minute induction period before applying." Mix the MP170, MP171, or MP172 with MP175 catalyst, wait 15 minutes, then spray.
The same bulletin sets a time limit. MP17x epoxy primers "must be scuffed and reapplied if allowed to sit more than 3 days (72 hours)." Our guide to epoxy primer, 2K primer, and sealer explains where each one fits in a paint job.
Which reducer and hardener speed should I use?
PPG's bulletins list reducers and hardeners by temperature range. The mix ratio stays the same.
OMNI reducers:
- MR185 Fast: 55–65°F
- MR186 Medium: 65–75°F
- MR187 Slow: 75–85°F
- MR188 Very Slow: 85–95°F
MC270 clear hardeners:
- MH276 Fast: 55–70°F
- MH277 Medium: 60–75°F
- MH278 Slow: 70–85°F
- MH279 Extra Slow: 85°F and above
Topcoat hardeners for MTK, MC260, and MC161, with the ranges PPG gives on the MC260 and MC161 bulletins:
- MH167 Fast: 55–65°F
- MH168 Slow: 75–85°F
- MH169 High Temp: 85°F and above
PPG's printed ranges for MH167 and MH168 leave 65–75°F uncovered. Ask PPG or your supplier which to use in that range.
For MP282, PPG says MH283 "should be used in cool to normal temperatures" and MH284 "in hot temperatures or when a longer pot life is needed."
Our reducer and activator speed guide covers this choice in more detail. If your shop is below these ranges, read our guide to painting a car in cold weather first.
Does OMNI basecoat need hardener?
No. MBC and MBP mix 1:1 with reducer, and both bulletins list the pot life as indefinite.
PPG lists hardener as an optional additive for both. The bulletins say the hardener used in the clearcoat for the repair "may also be added to catalyze the basecoat," at "10% to unreduced RTS or 5% to reduced RTS." Check the bulletin for your basecoat before you add it.
MAE acrylic enamel works the other way. It can be sprayed without hardener at 4:1, but PPG says a clearcoat can go over MAE "only if MAE is catalyzed with MH101 or MH202." The bulletin adds, "If clearcoating, MAE Activated must be used." That is the 8:1:1 mix with hardener.
Where can I find the OMNI tech sheet for my product?
PPG numbers its OMNI product bulletins with an OB prefix. The OMNI catalog lists these numbers:
- MBC: OB10
- MBP: OB40
- MTK: OB9
- MAE: OB17, and OB16 for MAE with hardener
- MC270: OB42
- MC260: OB32
- MC161: OB2
- MP170, MP171, MP172: OB11
- MP282: OB38
- MP213: OB31
- MP231, MP235, MP237: OB6 in the catalog. The bulletin itself is numbered OB55.
OMNI mixing checklist
- Find the ratio for your exact product code in the chart or on its bulletin.
- Pick the reducer and hardener speed for your shop temperature.
- Measure every part in the same unit, in a graduated mixing cup.
- Use OMNI hardeners and reducers only.
- Let MP17x epoxy primer sit for 15 minutes after mixing.
- Mix only what you can spray within the pot life.
- Follow the respirator, eye, and skin protection directions on each label and safety data sheet.
OMNI products at AutoColorOnline
- Basecoat kits: OMNI MBC complete paint kit with reducer, MC270 clear, and hardener, in a quart kit or gallon kit. Custom-mixed color is ordered separately.
- Single stage: OMNI MTK reducer and hardener kit and MTK9300 black
- Clearcoat: MC270 in a quart kit or gallon kit, MC260 Quick Clear, and MC161 High Solids Clear
- Epoxy primer: MP170 gray with MP175 catalyst, in a quart kit or gallon kit
- Primer surfacer: MP282 with MH283 or MH284 hardener, in a quart kit or gallon kit
- Sealer: MP213 GP Sealer and the MP23x 2K urethane sealer kit
- Reducers: MR185 Fast, MR186 Medium, MR187 Slow, and MR188 Very Slow
To put a full system together, use Build Your Kit.