ARCOR 121HT Comparison
Belzona 1391 & 5891
ARCOR® 121HT meets or exceeds all the ‘in service’ design specifications of Belzona 1391HT & 5891HT specifically temperature limits, chemical resistance and wear resistance.
ARCOR® 121HT is a 3.6 functional Novolac Epoxy coating with a modified amine system which improves temperature resistance 100F above that of ARCOR® 121 (as measured by Tg; refer to ‘ARCOR® Tech Rev Prod Cure’)
High functionality temperature & chemical resistant epoxies have a dangerous tendency for intercoat amine blushing resulting in intercoat adhesion problems and many documented failures. ARCOR® utilizes multiple amine structures in its curing agents to facilitate a ‘timed release’ cure that maximizes the full cure potential and minimizes the occurrence of amine blush particularly in the high functionality resins and the high temperature resistant products.
If humidity is maintained below 60%RH during application & cure, the 121HT Does Not require a solvent wash or abrasive blast between coats during the overcoat window.
Viscosity of high temperature epoxy systems can also be problematic.
The high functionality resin systems (3.6 functional) are semi-solid at 72F. To reduce the resin system viscosity low enough to roll or spray apply a level film others often utilize alcohols as diluents in solvent free systems. This method will result in a wax-like film that requires solvent wash & abrasive blast between coats otherwise there will be intercoat adhesion failure.
ARCOR® does not utilize any alcohols in its systems. The ‘ARCOR® Technical Review – Product Design’ outlines alternative methods used to allow for proper wetting and film formation for the 121HT system that dramatically improves application and resultant adhesion and film integrity for vastly improved long term performance.
ARCOR® uses combinations of reactive components and nonreactive fibers to mitigate the surface tension and internal stresses, high levels which are inherent to high functionality epoxies, which will improve adhesion and reduce the potential for internal micro stress cracking.
Our 121HT was chosen by GE Nuclear to coat all main steam isolation valve actuators in their new construction nuclear plants (first 2 units are in Taiwan). They will also replace existing units as they reach their obsolescence (We’re told this is a 4 year cycle). 121HT was ultimately chosen because of the products ability to withstand micro-cracking around sharp radius corners & edges (an inherent problem with high functionality Novolacs) and its high flexural, compressive & impact strengths as well as its ability to withstand high thermal cycles, acids , caustics during aggressive LOCE (Loss of Cooling Event) testing.
ARCOR’s ability to mitigate the intercoat adhesion issues and application issues with our 121HT has allowed for successful application on much larger projects. As the formulator, manufacturer and field applicator, we are in a unique position to be able to understand in detail all relevant issues concerning the products use and performance.
We are able to adapt the product to application needs and conversely adapt application to the product.
With the ARCOR® 121HT System it is as simple as this:
- Blast to a 3-4 mil profile and clean up.
- Chlorides and Nitrates Check, profile test.
- S-20 application at15 mil. Very easy to apply and get looking good.
- 4-8 hour cure at 25C/77F.
- First coat of EE-121HT @ 15 mil taking 1-3 hours.
- Immediate overcoat of EE-121HT @ 15 mil.
- Post cure as per application data and ambient cure.
- Put into service.
With our custom Plural component spray system we are able to address large scale tank coatings, impossible for others with a similar class of coating because of overcoat issues and viscosity issues; both of which we have eliminated;
- Halliburton International; Chemical Frac Tanks
- BP: Crude Oil HP, IP, LP Separators;
- PetroBraz; Crude Oil Dehydrators
- Cameron; Treater Tanks
- Meta Petroleum: Electrostatic Treater
- PeMex; Crude Treater
- TPS Siddrgonjero Pakistan; Chemical Neutralization Tanks
- KOPEC (Korea Power Engineering); FGD Inlet