David,It sounds like you have a good plan to me. You may find that your PPG dealer doesn't stock the MX190 from the OMNI line. If not, use the DX330 from the Deltron line. They should definitely have that. PPG doesn't have a tech sheet that gives instructions on the proper use of surface cleaners. Here's the best generic explanation I have run across. I'm quite sure you will be pleased with both the 170 and the MTK. Excellent decision on your part to get the supplied air. You won't regret it. On the sheet metal, for sandscratches, you might want to look into the OMNI MP182 urethane surfacer, applied (and sanded) between the 170 and the MTK for the smoothest possible surface and the best mirror shine. I don't know the JD colors so can't comment there. Maybe someone who does will provide some input. As far as speed of additives, that is decided on based on ambient temperature at the time of spraying. Your metal temp should also be very close to the ambient air temp. Unfortunately, PPG doesn't publish temp recommendations in their tech sheets for the OMNI products. Anyway, here's my estimated use of the different MTK additives for different temp ranges: Reducers:
MR185 - fast - 60-70 degF
MR186 - medium - 70-80 degF
MR187 - slow - 80-90 degF
MR188 - very slow - 90+ degF Hardeners:
MR167 - fast - 60-75 degF
MR168 - slow - 70-85 degF
MR169 - very slow - 80-95 degF I prefer painting in the 70's and low 80's so my standard choices are either MR186 or 187 for the reducer and MH168 for the hardener. There's always some amount of overlap and it's not terribly critical, but I wouldn't get more than 10 degF away from the normally recommended ranges. I usually tend to go a little slower on the speeds of reducer, so if the temp was in the high 70's, I might choose the 187 instead of the 186. The slower the reducer, the better the flowout, but it also increases the possibility of runs, which you don't want. It's a balancing act. At least with the MTK, fixing runs is relatively easy - sand 'em out the next day and shoot it again. Rod
| 
