Speedokote SMR-870 Universal Medium Urethane Reducer - One Gallon

In this review the Speedokote SMR-870 is evaluated as a practical urethane grade reducer for automotive finishers who need a reliable medium-flow reducer for moderate temperatures. The bottom line: this one-gallon Universal Medium 65-80F reducer is best for shop technicians and hobbyists who use urethane basecoats and want consistent spray performance and viscosity control. The reviewer found it especially useful when mixing with Speedokote products and notes the clear, consistent thinning behavior and dependable spray pattern when used within the specified temperature range.

Key Features

• Temperature range: Formulated for 65-80F conditions to deliver predictable drying and leveling in moderate ambient temperatures.
• Urethane grade: Designed specifically to thin urethane basecoats and clears for proper atomization and film build.
• Universal compatibility: Works with a wide range of urethane paints including Speedokote basecoats for consistent mixing results.
• One-gallon size: The gallon container suits shops or serious DIYers who need enough reducer for multiple panels without frequent reorders.
• Spray performance: Provides stable spray consistency and good flow, helping achieve smooth, even coverage when applied correctly.

Who It's For

This reducer is aimed at automotive refinish technicians, collision repair shops, and experienced hobbyists who routinely spray urethane paints and need a medium-speed reducer for milder weather. It is ideal for users who want a predictable thinning behavior for basecoats and for those who already use Speedokote products and prefer matching components.

Those working in very hot or very cold climates should look for fast or slow reducers matched to their conditions, and residents of California, Maryland, or Delaware should note a different product will be shipped due to regulations. Novice users unfamiliar with mixing ratios or spray techniques may prefer professional guidance before use.

Pros & Cons

Pros

• Consistent thinning that mixes well with urethane basecoats, improving paint flow and leveling.
• Provides good spray quality and atomization when used in the intended 65-80F range.
• Good value for a one-gallon container for shops and repeat projects.

Cons

• Not sold as-is in California, Maryland, or Delaware; customers there receive a different SMR-0075 0 VOC reducer instead.
• Medium speed may be less suitable in extreme heat or cold where fast or slow reducers are preferable.

Specifications

Product name	Speedokote SMR-870 - Universal Medium Reducer
Grade	Urethane grade
Temperature range	65-80F
Quantity	One gallon
Intended use	Thinning urethane basecoats and clears
Alternate for regulated states	SMR-0075 0 VOC reducer shipped to CA, MD, DE

Our Verdict

The Speedokote SMR-870 is a solid medium-speed urethane reducer for moderate-temperature spraying and offers good value in a one-gallon size. Professional refinishers and experienced hobbyists who need predictable sprayability and compatibility with urethane basecoats will appreciate its mixability and consistent flow; those in regulated states will receive the compliant SMR-0075 alternative.

Frequently Asked Questions

Is this reducer suitable for all urethane paints?
It is formulated as a universal urethane grade reducer and works with many urethane basecoats, including Speedokote products, but always test mix small batches first.

What should residents of California, Maryland, or Delaware expect?
If shipped to CA, MD, or DE the seller provides SMR-0075, a 0 VOC reducer, in place of SMR-870 to meet local regulations.

What temperature does this reducer target?
SMR-870 is tuned for 65-80F ambient temperatures and gives best drying and leveling within that range.