Primary vs secondary bond with epoxy

[Satyrjinn]

Hey everyone,

I did a cursory search for this in the forum, didn't find anything. Does anyone have an opinion on whether primary (chemical) vs. secondary (mechanical) bonding between epoxy coats (primer, 100% solids, and also the polyurethane topcoat) is superior in regards to bond strength, durability, longevity? I am debating on coating within the recoat window for the primary bond or to allow full cure, sand/clean, and aiming more for a secondary bond but I want best results. Any help is greatly appreciated, thank you! (First post)

 

[LegacyIndustrial]

Take advantage of the chemical bond if you can.
Preparing for the mechanical bond is a PIA. It must be done correctly to ensure good adhesion.

Generally, the mechanical bond method is necessitated by falling outside the re-coat window or you need to address surface anomalies. However, if you are using coatings that are not made by the same mfg, you suspect an amine-blush, you suspect contamination, environmental factors occur, etc... than the mechanical bond would be a must.

 

[Satyrjinn]

Thanks again Scotty! I was "the GOAT" that emailed you @ your company email earlier

 

[LegacyIndustrial]

Thanks again Scotty! I was "the GOAT" that emailed you @ your company email earlier

Sent from my iPhone using Garage Journal

 

[Armorpoxy]

We always recommend when possible to coat within the intercoat window to eliminate the need to re-prep for a mechanical bond.