General Painting Help

[Anonymous-0]

Some of you might remember last winter when I had some questions about changing to a better type of paint then the paint I had been using. It was pretty well unanimous for my next step to be a single stage urethane from a major paint company. Since then I've added a supplied air system, tore the tractor down fixed all problems, reassempled the engine, transmission, and rearend, stripped everything to bare metal, and am ready to start painting. I've talked to several local body shops and found out I have a PPG dealer close by. So here's my plan, and go ahead and correct any errors I have:

1. Clean all parts with PPG MX 190 cleaner
2. Use PPG epoxy primer MP170
3. Apply PPG OMNI Acrylic Urethane MTK

Here is where the questions come from. What speed reducer and hardener do you recommend? Also what are the paint codes you prefer, both green and yellow for a John Deere 70?

Thanks for all the help. I appreciate it. I just don't want to mess up now after all the work I've gone through.

David

 

[Anonymous-0]

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. <a href="http://www.autobody101.com/articles/article.php?title=Surface%20Cleaners">Here's</a> 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

 

[Anonymous-0]

Hmmm,

The formatting didn't come out like I wanted. Try this:

<pre>
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
</pre>

 

[Anonymous-0]

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

 

[Anonymous-0]

It shows OK in preview but not in the resulting post. Oh well, you get the picture.

 

[Anonymous-0]

Yeah, I get that too, where it previews alright, but posts weird. I understand what you're saying. I appreciate all the help. Since I expect the temp to be around 75-80, I'll probably just go with slow on both. I'll look into the cleaner and the surfacer, and decide accordingly. I'm sure I'll be here asking for help if I mess something up. Thanks again.
David