When to add flex agent

[Leonard]

I am getting ready to paint my 1985 Mustang. If I am painting the whole car at once, at what point should I add the flex agent for the bumper covers?

The car is going to be 2-tone solid colors. Should I just paint the bumper covers off the car at a different time?

Thanks for the help.

[go2fast]

I am getting ready to paint my 1985 Mustang. If I am painting the whole car at once, at what point should I add the flex agent for the bumper covers?

The car is going to be 2-tone solid colors. Should I just paint the bumper covers off the car at a different time?

Thanks for the help.

My local PPG jobber says no. I've used it in the past and it caused color match problems after some sun exposure. I'd ask your paint supplier.

[Len]

I am getting ready to paint my 1985 Mustang. If I am painting the whole car at once, at what point should I add the flex agent for the bumper covers?

The car is going to be 2-tone solid colors. Should I just paint the bumper covers off the car at a different time?

Thanks for the help.

Flex additive is usually added only to the "hardened" materials. Read the technical data for the additive and paint products you're using. Use a flex additive made for your specific paint, don't use aftermarket products until you have a good grasp on the other materials you're using.

If I were painting that Mustang I would paint the bumpers separately, either off the car or on. If the bumpers are already off I would paint them off then install them after the paint hardens. Be careful because flex additive causes the paint to flow a lot more than without flex and can cause the paint to run more easily. I would use a good clear and a good flex additive because (like g2f said) some products can cause the clear or color to yellow causing a mismatch.

[MARTINSR]

I have to tell you, flex additives are a thing of the past at least with the paint system we use. Paint the bumpers off (just so it is a nice job) but don't add a flex additive unless your paint manufacturer says so, most do not. The norm these days is add hardener to your base and use no flex in the color or clear. I install these type bumpers nearly every single day (did four today) and we use NO flex what so ever. We do 150 cars a month with a lifetime warranty by the way.

READ THE TECH SHEETS FROM THE PAINT PRODUCTS YOU ARE USING!

Brian

[Len]

Hi Brian
Yes, I agree that there are some paints that remain more flexible longer than others. I've found that PPG stays flexible longer but I'm not sure that it remains as flexible as the same products with flex additive. We did some experiments using different paint products with and without flex and found that some without flex remained flexible for several weeks but eventually became more rigid as time passed. The amount of flexibility needed can also be a factor; parts that need to bend or flex more may need an additive while bumpers and other parts may be able to get away without it if they are more rigid. Like we both recommended... "Read the technical data for the materials being used."