West System Cure Times and Interlux.

[unbusted67]

So I just read this on the Interlux Web site for Prime Kote, the primer they suggest using on epoxy: " Allow three to five days for clear epoxies to cure fully."

Well I wished I had read that before I used Epoxy as a barrier coat. I am on a time crunch and was wondering if I could redo a barrier coat using 207 hardener on top of my current coat of epoxy. 207 reportedly doesn't have amine blush. That way I could get a coat of primer down the day after? Am I over thinking this whole thing? Should I just put some primer on the stuff and see what happens?

[unbusted67]

I guess the better question to ask would be: Has anyone had a problem applying primer to newly cured epoxy? How long before amine blush stabilizes so it can be cleaned off?

[minaret]

Are you trying to chemical bond the Primekote to the epoxy?

[unbusted67]

No just trying to make sure the primekote goes down and stays down. The way the literature makes it sound you run the risk of not having the paint key to the surface of the epoxy if you don't wait the requisite 5 days for the epoxy to completely cure and for the amine to rise if it is going to rise.

Here's what West System says about one part urethane :
One-part polyurethanes offer easy application, cleanup and better properties than alkyds. They are also more expensive and some may be incompatible with amine cure epoxy systems such as WEST SYSTEM epoxy, although 207 Hardener may offer better compatibility. Test first.

And what Interlux says about epoxy: Preparing CLEAR EPOXY Allow three to five days for clear epoxies to cure fully. Remove amine blush by using Fiberglass Surface Prep YMA601. Sanding does not remove contamination. Rinse with fresh water and allow to dry. Abrade with 80-120 grade (grit) paper. Remove sanding residue. Repair any defects with Watertite, then sand with 120-220 grade (grit) paper and remove sanding residue.

[minaret]

Personally I've never had any trouble doing this the next day, but I don't use Primekote and haven't for many years. Have done this lots recently with 545, no problems at all. You should, however, be aware that it is very unhealthy to sand epoxy which is not yet fully cured. Gear up!

[unbusted67]

I'm going to bump this one since I've got to make a move on this project today. Anyone out there have any experience using prekote over newly cured epoxy? I is this just west systems being over sensitive?

[Dale Hedtke]

Take a look at the MAS epoxy line. No amine blush with any of their products.
Their FAST hardner is quite fast, so take a look at their time/temperature charts to see what hardener makes the most sense for your working conditions, open time needs, etc.
All epoxies' cure times are temperature dependent. The warmer the cure conditions, the faster (and stronger) the cure.
I would consult the manufacturer directly regarding paint application time.
Also, as a previous writer mentiioned, use proper protective gear both when applying and sanding epoxy.

[keepondancin]

Read your other post about reactions to resins, etc. When sanding your epoxy, try to borrow or rent a sanding system such as Festool sander and vac. I made the investment several years ago, and sanding a strip kayak I built, there was almost no escaping dust. My shop stayed clean. This spring I need to sand the bottom and paint, and I am confident in how well my system works. After all, it's only your lungs.