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Hi Glen, I used POR15 as a base coat last year on a 3pt snowblower for a couple of reasons. One was I did not want to get into a sandblasted or otherwise clean bare metal surface. The snowblower was rusty and somewhat pitted and I didn't want to go further than a fairly quick wire brushing to get off the loose rust. The other was POR15's reputation for being a very tough paint that could be applied over sound rust. I wanted to minimize any wearing down to bare metal in the discharge chute of the blower. I have a 1/2 mile gravel driveway and any paint on the inside of the discharge chute gets worn off after a while. The blower doesn't get used much and when the inside of the chute and impeller shroud begins to rust, the resulting relatively rough surface tends to impede the flow of anything but totally dry snow and the blower can plug up. POR15 is tricky to use if you are going to put an automotive urethane over it w/o a special POR primer but it can be done. I didn't trust and wanted to avoid POR's intermediate primer (even though it was recommended by them). I wound up using PPG OMNI MP170 epoxy over the POR and PPG DCC acrylic urethane over the epoxy. DuPont Centari was used as a topcoat for the screws, the gearbox and the impeller. The biggest problem I ran across is the time limits for putting anything over the POR. The POR itself takes about 4-5 hours to get "tacky". It should have two coats of POR and the second coat needs to be applied as soon as the first gets "tacky". Furthermore, an epoxy needs to also be applied when the second coat of POR becomes "tacky". Waiting until the next day is too late to avoid sanding the POR. Sanding POR after an overnight cure is difficult and is something that should be avoided. The prep for the first coat of POR requires an application of two different chemical solutions with a power wash after each one. The surface must be COMPLETELY dry before applying the POR since POR is a moisture cured urethane. I do all my painting outside and adhering to such a schedule became impossible in a single day and tricky if not. I did the wire brushing and the two chemical preps the first day. That allowed overnight for the surfaces to fully dry off after the final power wash. The next morning I applied the first POR coat as soon as possible, waited the 4-5 hours, applied the second coat, waited another 4-5 hours and finally got two coats of epoxy on just before dark. The urethane topcoat was applied the following day, well within the 3 day window for MP170. I wanted to use the epoxy as a good binder coat between the POR and the AU. I was fortunate I had decent weather the second and third days. After about a years time there is no indication of an adhesion problem. But I also don't have any indication of the durability when the top layers get worn down to the POR on the screws, the impeller or the discharge chute since I didn't need to use the blower at all last winter. So I don't have a conclusion on my decision to use POR on the blower project. I have neved used the Corlar but you should check local availability of it, together with the required additives before any decision. If John Bud sees your post he may offer some user experience with it. Corlar is a DuPont epoxy and I see no reason why you couldn't use the OMNI AU over it as long as you comply with any time window on the Corlar. Dupont would never recommend it but it should work OK. I also don't know how POR works on fully clean, sandblasted surfaces since it is promoted as a "rust paint". Sandblasting leaves metal surfaces in a very raw state that is susceptible to quick rusting in the presence of even minor moisture. Since you are going to have a repair period between the blasting and applying any paint product, you might want to consider an additional prep with something like Picklex 20 before any epoxy, whether it be the OMNI or the Corlar. If you go the POR route, I believe the special chemical prep with the POR prep products will accomplish the same thing as the Picklex as far as treating minor rusting during the interim period. If it were my loader in your situation, I'd apply Picklex 20, the OMNI epoxy and the OMNI AU and let it go at that. Rod
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