POR-15 41108 High Build Primer - 1 pint

Let me say, this stuff is awesome. I used it on diamond plate which is a pita to paint without proper prep. It worked flawlessly ! I brushed on and a pint went a loooiong way.

Minor repair project on my car. Used POR15 rust preventative products on inner panels with great success, but this POR15 High Build Primer used on the outer surface before paint was a disaster. I followed directions to the letter, had a very clean surface (some bare metal, some polyester filler). Rolled on 2 coats with 15 mins between coats as directions indicate. Waited till next day. It sanded fine but it never seems to get "fully hard." Contacted POR15 customer service and they said this is normal. I waited another day before applying final primer (UPOL brand sandable primer) and it was a HORRIBLE SCENE. Wherever the primer contacted the POR15 high build primer there was wrinkling and puckering. Had to scrape and sand the entire mess off and start over. I am quite disappointed in this product. On the plus side, POR15 customer service did reply promptly and talk with me on the phone, but in the end I disposed of this product. I've read many mixed reviews so your mileage may vary. EDIT: I again spoke with customer service and that agent spoke to his in-house chemist - the conclusion is that the product was still out-gassing (i.e. curing) which caused my issue. I applied on a Saturday and tried to apply primer on Tuesday so it was not yet cured after three days in a warm garage in moderate humidity. Unlike POR15 rust treatment which cures in hours especially in humidity, the High Build Primer is solvent based and cures with time/temp/environment. The issue is this: how do you know when it's fully cured? Props again to customer service but I don't think I'll risk trying the product again.

I liked that it was everything that it was advertised to be! It went on heavy, dried quickly and spread evenly with cheap paintbrushes! Perfect complement to their high heat paint.

It goes on like a plastic primer it has to set overnight in order to dry properly before it can be sanded

I primed an entire bumper with dupli-color paint shop primer and it came out great except for a few flaws, so I sanded them and primed them with por-15 primer (ran out of the paint shop primer). I recoated the topcoat and the topcoat crazed in all the spots where por 15 was used. the rest came out perfect. What went wrong? UPDATE; AFTER CHECKING OUT USER FEEDBACK ONLINE, I REALIZED I PROBABLY SHOULD HAVE LET THE PRODUCT CURE FOR 48 HRS INSTEAD OF THE 24 HOURS I ALLOWED ACCORDING TO THE DIRECTIONS ON THE CAN. I SPRAYED THE PRODUCT WITH A 1.4 NOZZLE (2 LIGHT COATS) I DID NOT THIN IT. IT WENT ON NICELY, ATOMIZED NICELY, SANDED NICELY. PROBLEM IS, THE VEHICLE IS MY DAILY DRIVER. WHO HAS TIME TO WAIT 2 DAYS FOR PRIMER TO CURE? GOING BACK TO DUPLI-COLOR PRIMER BECAUSE OF THE TIME FACTOR. HAD TO RE-SAND AND REPAINT BUMPER. CAME OUT NICE BUT TOOK WAY TOO LONG. DISAPPOINTED.