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Origin Pro™ Compare

Review side-by-side product details, technical notes, and practical differences.

Product Comparison

HP3 100% Silicone vs DOWSIL 999

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

Origin Pro

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

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Compared with

DOWSIL™ 999 Silicone Glazing Sealant

Core Performance & Application Attributes

Sealant Technology

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

100% Acetoxy-Cure Silicone

DOWSIL™ 999 Silicone Glazing Sealant

Acetoxy-Cure Silicone Sealant
Product Class & Movement (ASTM C920)

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

Meets the intent of ASTM C920 for non-porous exterior glazing applications

DOWSIL™ 999 Silicone Glazing Sealant

ASTM C920 – Class 25 (±25% joint movement)
Skin Formation / Tack-Free Performance

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

Skin 10–15 minutes / Tack-Free approximately 20–30 minutes

DOWSIL™ 999 Silicone Glazing Sealant

Typical glazing silicone skin formation; cure based on atmospheric moisture (see TDS)
Primary Application Focus

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

Exterior glazing and exposed joint sealing

DOWSIL™ 999 Silicone Glazing Sealant

Exterior glazing and sealing of glass and other non-porous substrates
Distribution

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

Online ordering. Case-based contractor pricing. Delivered direct to jobsite or office.

DOWSIL™ 999 Silicone Glazing Sealant

Commercial glazing and building supply distribution

Comparative Overview

Both HP3 and DOWSIL™ 999 are acetoxy-cure silicone sealants designed for exterior glazing and sealing of glass and other non-porous substrates.

Attribute HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure) DOWSIL™ 999 Silicone Glazing Sealant
100% Silicone Sealant
✓
✓
Acetoxy-Cure Silicone
✓
✓
ASTM C920 Class 25
✓
✓
Faster Skin Formation
✓
✕
Direct-to-Contractor Platform
✓
✕

100% Silicone Sealant

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

✓

DOWSIL™ 999 Silicone Glazing Sealant

✓

Acetoxy-Cure Silicone

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

✓

DOWSIL™ 999 Silicone Glazing Sealant

✓

ASTM C920 Class 25

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

✓

DOWSIL™ 999 Silicone Glazing Sealant

✓

Faster Skin Formation

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

✓

DOWSIL™ 999 Silicone Glazing Sealant

✕

Direct-to-Contractor Platform

HP3 | 100% Silicone Exterior Sealant (Acetoxy Cure)

✓

DOWSIL™ 999 Silicone Glazing Sealant

✕

Differences You’ll Notice

Key differences between HP3 and DOWSIL™ 999 include skin formation timing and supply structure. HP3 is designed for exterior glazing applications with fast skin formation and is available through a direct-to-contractor online platform with case-based pricing and jobsite delivery.

Ready to Make the Switch?

Professional-grade 100% silicone. Exterior glazing performance. Delivered direct.

View HP3 100% Silicone Details

The product comparison data provided is based on technical specifications published by the original manufacturers at the time of review. All references are for functional and category comparison only and do not imply product equivalence, approval, certification, or endorsement. Users should consult technical documentation and conduct their own performance evaluation to determine fitness for use in specific applications. Legacy Sealants, Inc. assumes no liability for third-party performance claims or changes in manufacturer formulations.