Dymonic 100 vs Dymonic FC: which one for the job

Both are Tremco and Cranco carries both. Dymonic 100 is a polyurethane and Dymonic FC is a hybrid.

Dymonic 100 takes 2 to 3 hours to skin and Dymonic FC takes 1 hour. That, and how far the joint moves, is what usually decides it.

Which to take

Take Dymonic 100 where the joint moves a long way. Tremco rates it at +100/-50% in the field and at Class 50 under ASTM C920, against Dymonic FC's 35% and Class 35.

Take Dymonic FC where the schedule is tight or the run crosses EIFS. It skins in 1 hour against Dymonic 100's 2 to 3, is tack-free in 3 to 4 hours against 6 to 8, and its sheet adds EIFS to the substrate list.

Both are paintable, both come in a 300 mL cartridge and a 600 mL sausage, and both carry a fire test: Dymonic 100 is NFPA 285 listed and Dymonic FC is UL 2079.

What the data sheets say

Dymonic 100 against Dymonic FC, from the figures each manufacturer publishes.
Dymonic 100Dymonic FC
ChemistryPolyurethaneHybrid
Movement capability+100/-50% (field, ASTM C719 Modified); ±50% (ASTM C719 standard)35 %
Skin time2 to 3 hours1 hour
Tack-free time6 to 8 hours3 to 4 hours
Service temperature-40 to 180 °F (-40 to 82 °C)-40 to 185 °F (-40 to 85 °C)
Substratesconcrete, aluminum, masonry, vinyl sidingconcrete (precast panel joints), aluminum, masonry, vinyl siding, EIFS
Usesexpansion/control joints, perimeter caulking (windows, doors, panels), fluid-applied flashingexpansion/control joints, perimeter caulking (windows, door, panels)
PaintableYesYes
Package sizes10.1 oz (300 mL) cartridge; 20 oz (600 mL) sausage10.1 oz (300 mL) cartridge; 20 oz (600 mL) sausage
StandardsASTM C920 Type S Grade NS Class 50 Use NT T M A O I; TT-S-00230C Class A Type II; CAN/CGSB-19,13-M87; ICC Section R703.8; AAMA 714-15; NFPA 285 ListedASTM C920 Type S Grade NS Class 35 Use NT M A O; ASTM C1248; TT-S-00230C Class A Type II; CAN/CGSB 19.13-M87; UL 2079 (ASTM E1966), CAN-4-S115M

Is Dymonic 100 better than Dymonic FC?

Neither is the better sealant. Dymonic 100 is rated for a joint that moves more, and Dymonic FC is ready to touch far sooner. Ask the counter which suits the joint in front of you.

Which one for a window perimeter?

Dymonic 100's own sheet lists fluid-applied flashing among its uses, and Dymonic FC's does not. Dymonic 100's sheet also grants it "a unique capability to adhere to damp or green concrete without outgassing," which suits a rough opening that has not fully cured or dried out. Dymonic FC is not listed for flashing and takes both products' shared uses instead: perimeter caulking of windows, doors and panels.

What the manufacturers warn about

Use with adequate ventilation. Always utilize the accompanying SDS for information on Personal Protective Equipment (PPE) and Health Hazards. Not recommended for use in chlorinated, potable, heavy or waste water. Although Dymonic 100 is paintable, this does not imply adhesion to and compatibility with all paints. Consult Tremco Technical Bulletin No. S-09-05 or Tremco Technical Services for more information.

Tremco, on Dymonic 100

Do not apply over damp or contaminated surfaces. Do not use under polyurethane deck coatings. Use with adequate ventilation. Always utilize the accompanying SDS for information on Personal Protective Equipment (PPE) and Health Hazards. Not recommended for use in chlorinated, potable, heavy or waste water. Although Dymonic FC is paintable, this does not imply adhesion to and compatibility with all paints. Consult Tremco Technical Bulletin No. S-09-05 or Tremco Technical Services for more information.

Tremco, on Dymonic FC

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