[gsinon]

Not all epoxies are created equal and some require much longer times then others to either topcoat or use as a foundation to then apply body filler.

If you are using the epoxy as a sealer and then going straight to surfacer or color, then you are in a way using the product as a sealer in which case you are using both mechanical and chemical adhesion. So yes, waiting the prescribed dry or flash time which can be as little as 30 minutes or as much as a couple of hours is all you need to do before spraying the topcoat.

In my previous reply about waiting for a full cure that was because I made an assumption that body filler would be applied as a next step. In that case, you really should wait the proper cure time. The styrene in body filler can slow or stop the curing process of epoxies if it is applied too soon.

As a "ppg guy" former tech rep and training instructor for ppg, I can tell you there are many different products and issues that can arise by not waiting or doing something out of sequence. When you look at a product like DP-LF, it can be used as a sealer in a "wet on wet" situation. However it still takes upwards of 7 days for full cure. At day four or five you can still take a finger nail and scrape it off of a panel, but by day 7 or beyond it would need to be sandblasted to remove it. But this is also why I don't like DP as a sealer. While it is still curing and gassing out it is casing my topcoat finish to tighten up or die back.

Have you ever used this type of product as a sealer, and when done the topcoat has amazing gloss and looks spectacular. But then about a week later it de-glosses some? Thats the epoxy going through the cure process days later and it is still releasing solvent and gassing out. There are better products for a sealer that won't let this happen. But, if it works for you and you are happy with the results then so be it.

And while I'm a PPG guy and only use their products, I do admit there are other brands and products that work just as well. Use what works for you. To me the biggest factor in what product line to use is what support do you get locally from your supplier?