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Hi Paul, Here's my opinion: 1. does the primer finish matter if I'm sanding? Not really. 2. should I have tried to add reducer to thin it out? The spec sheet doesn't mention any reducer. Do you guys us those viscosity cups (one came with my gun) to determine the right thickness? Or should I have thrown it out when it looked too thick? You really should not have to reduce it. Are you sure you stirred it well before each prior use? That's about all I can think of unless you are using too small a tip size or too low an air pressure at the gun. I haven't used a viscosity cup in years. I once had a problem with DuPont's Centari where I just couldn't keep it from running, even when mixing exactly like the label instructions. I finally checked with a viscosity cup and found I could only reduce it 25% (or 33%-I can't recall) instead of the 50% specified in order to get the recommended spraying viscosity. That experience led me away from DuPont at the time and to PPG. I have not had such a problem in recent years with either PPG or DuPont. I have found their mix ratios as indicated on the appropriate tech sheet to work fine without the need to check the actual viscosity. As a matter of fact, I don't think PPG even indicates a recommended spraying viscosity on any of their tech sheets. 3. What is the best way to store paint & primer? Apparently the top wasn't fully sealing. Should I pour the last remaining inches into a bottle to reduce the amount of air? Would it help to encase the can in plastic? How long can you store partially used cans? I just make sure that the can rim is pretty much clean of paint and that the cover is tightly installed. I don't take any other precaution. I have used paint from partially full cans that are several years old with no problem. P.S. Do you recommend MP174 (epoxy) over the 182 prior to MTK? No. There should be no advantage that I can see of topping the 182 surfacer with the 170 epoxy primer. I think you mean MP170 - I have never heard of a MP174. As to your other post - Recoating MP-174: How roughed up does it have to be? What do you recommend: Scotchbrite, sandpaper(grit level?) I recommend a ScotchBrite pad. I use the the general purpose 3M #7447 (maroon color) for just about everything like that. After roughing, should I recoat with 174 before top coating (MTK), or topcoat directly? Again, I think you mean MP170. The tech sheet says to re-apply after the window. That's to get the best adhesion of the topcoat. Do you absolutley have to do it? Probably not - but I would. I don't think it's a big deal to shoot another coat after the window. Why not do everything you can to obtain the best adhesion?  Rod
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