Help! Last weekend, I shot a motorcycle tank/fenders, etc. with PPG "shop grade" single stage metallic silver. I let it dry all week, didn't touch it, etc. Today, mounted the tank and put gas in it. Pulled the gas cap off later and a little fuel spilled down the tank, leaving a "cloudy" look where the gas went. It also got a little sticky where the gas touched paint. I quickly washed the tank off with car wash soap and water, which seemed to stop any damage, but I still have one spot where I touched the paint with a tack rag that shows a little "track." Question: Can I wet sand the cloudiness out or should I pull the tank and put on a few more coats? Since its metallic, should I not wet sand? I figured it could be buffed out later, but I'm not sure what to do.
With single stage metallic, I think your pooched. If you sand it or rub on it, it will change the "lay" of the metallic and it won't match the rest of the tank. If you used a hardner when you originally applied the paint, gasoline shouldn't have touched it.---You did use a hardner didn't you????
single stage metallics are really hard to scuff and buff because when you sand them you are actually removing some of the color and metallics. You will end up with some of the flakes looking a little wierd. You will have just shaved off the tops of the metallics. What is the name of the line of paint? I don't mean what brand I know you said PPG, but is it Concept? Or Omni? What hardners did you use? To me anytime you are spraying a metallic it should be done in a basecoat/clearcoat application. This way you can better control the meatallics but also protect the paint with the clear. Try buffing the area first, then see what happens.
The brand is called "Shop-Line" by PPG. I used a fast drying hardener, which I thought would stop any effect from gasoline (I talked to the body shop supply place before I did this so they'd know it would likely be exposed to gas). It has been drying in a cold climate this week, if that makes a difference.
I've heard Harley uses something extra around the tank area because of the gas. Maybe ask them. I think it was extra hardner. Maybe it will help.
Hey, You may well have a bad batch of hardner.....it has a shelf life. Too, the tempture may not be helping you. Can you drain and remove the tank, and place it under a heat lamp (after you - flushed it out with water and soap) to dry for a wile? Swankey Devils C.C.
Urethanes don't "dry"..they crosslink. To crosslink, they need correct temperature over a specified time line. Usually around 65 degrees minimum for 24 hours. They also need proper air movement during, and after the painting process. I leave the paint booth running for at least 30 minutes after spraying.... Check your product data sheet, and see if you followed their guidelines. If you didn't, the paint didn't crosslink, and never will. I would strip it and start over. The whole paint process changed when the govt started cracking down on VOC's....which are quite prevalent in air dry paints.....not so with catalyzed products. Repair it now, or later when the customer wants to kill you.
In addition to this, they require accurate measurments of their specified ingredients in order to crosslink properly. Proper crosslinking equals durability.
Dry, crosslink..... whatever.....I was just saying if it's 35 in his shop instead of 75, it may have not "kicked". Even with a chemical reaction if the temps aren't right the widow may have been altered.
There's no if about it . If the temps below 60 degrees most urethane based products wont crosslink and go into a delayed state of activity. We've been told by our manufaturors paint rep that you could put activated primer or clear into the fridge (Between 35/55 degrees) or outside if its cold enough and it would still be good the next day. While this was told to us we haven't been brave enough to try it. Check PPG's web site for further info or drop their tech support an email . Hatch's suggestion to remove the finish and redo is the best option .
So if I need to strip it off, what's the best way to do it? I had several coats of primer on before I painted.
There is no easy way to strip it....dry sanding makes it wavy....chemical stripper attacks everything, including primer and bondo.
I work with this shit every day. Ditto to what all of the above said. 'Cept the fridge deal...that stopped working the day DAU82 went away Anyways, if it didn't stay at 60+ for at least overnight yer fucked. Any reason you didn't base/clear? There is a Shopline clear also. For stripping you might try a little heat after the tank is drained and purged of all fumes. Take a heat gun and warm it some to get it started. If you find the right temp (trial and error) the paint will peel from the primer like contact paper. Sand the primer again, let it stand overnight and repaint within the proper guidlines. Good luck with it.
And that "65 degrees" is metal temperature NOT air temperature. Most panels will be around 10 degrees cooler than the air temp in the shop--unless it's right under an infrared type heater. overspray
I would put the parts in a warm room for a day or two and see if it cures. There is a good chance that it will, if the paint was mixed correctly. If it does cure all he'll have to do is feather out the gas drip re prime a little spot scuff the rest of the tank and re spray it. if you left the lid of your hardner it's fucked. the isocyanates are moisture sensitive, leaving the lid off exposes the isocyanates "which is what crosslinks paint" to moisture which in turn "kicks" them.