[Unplugged]

I tried to paint an aluminum handle and got some awful results in the end. Apparently, the clear coat I used is incompatible with the enamel. Please see the attached pictures.

Steps:

- Plasti-kote sandable primer (fast-drying lacquer, acetone, toluene, xylene)

- 2 days drying time

- Rust-oleum gloss protective enamel (acetone, dimethyl carbonate, petroleum distillates, aromatic hydrocarbons)

- 4 days drying time

- Rust-oleum gloss clear (acetone, n-butyl acetate, glycol ethers, xylene)

The clear coat ruined the enamel almost immediately. Note that I didn't use the enamel on the inner surface and just left the primer there; the clear coat did fine in that area.

Any comments/suggestions?

Thank you!

 

[mark sr]

What does it say on the rustoleum can about recoat time? You probably needed to give it more time to harden before applying the clear [or apply it within 1hr of the color coat]


Not sure why you bothered with the clear, the rustoleum enamel has plenty of protection without it.


Obviously the fix is to sand it down and repaint.

 

[Unplugged]

What does it say on the rustoleum can about recoat time? You probably needed to give it more time to harden before applying the clear [or apply it within 1hr of the color coat]


Not sure why you bothered with the clear, the rustoleum enamel has plenty of protection without it.


Obviously the fix is to sand it down and repaint.

Enamel: apply a 2nd coat or clear coat with 1 hour or after 48 hours. I let it dry full 4 days indoors before applying clear coat.

The formula of the clear coat is close to that of a lacquer, it seems, and that could be the problem. But I could find nothing specific on the can, except the ingredients I mentioned above.

 

[mark sr]

The wrinkling of the paint is a symptom of the solvents in the next coat of paint/clear partially dissolving the underlying finish. That is why the can states recoating within a certain window or after a set amount of time. For some reason 4 days wasn't enough time to prevent the clear from reacting with the underlying paint. From what you stated the clear does have stronger solvents in it than the paint did.

 

[Porsche986S]

The part looks small enough to place in an oven . When you repaint after the final color coat dries for a day hang it in an oven at about 125 degrees . I would think about 20 - 30 minutes would do . Shoot the clear the next day .

 

[Unplugged]

The part looks small enough to place in an oven . When you repaint after the final color coat dries for a day hang it in an oven at about 125 degrees . I would think about 20 - 30 minutes would do . Shoot the clear the next day .

So, what you saying is that after 4 days it was not dry enough?

Thank you.

 

[mathmonger]

So, what you saying is that after 4 days it was not dry enough?

Thank you.

It seems like you are doing everything right, but where did you get that paint??? I couldn't find any PlastiKote cans that look like that. And NASCAR stopped using that logo in 2016... That might be part of your problem.

 

[Old Thomas]

I would glass bead blast it clean and start over without the clear.

 

[Unplugged]

It seems like you are doing everything right, but where did you get that paint??? I couldn't find any PlastiKote cans that look like that. And NASCAR stopped using that logo in 2016... That might be part of your problem.

I bought this primer some years back. In any case, it is fine with the enamel and fine with the clear coat (see the inside surface).

Both Rust-oleum cans, on the other hand, are fresh from a h/w store.

 

[Porsche986S]

So, what you saying is that after 4 days it was not dry enough?

Thank you.

It would appear so but just a guess . What was the ambient temp and humidity when you were letting the part dry ? That could have affected the drying also .

 

[Unplugged]

It would appear so but just a guess . What was the ambient temp and humidity when you were letting the part dry ? That could have affected the drying also .

It was left indoors at 70-72F, with low humidity.

 

[woodco]

It has nothing to do with dry time. The enamel and the clear are incompatable. YOu need to get a different clear, with different solvents. Maybe even just use a polyurethane.

Also, if youre clear coating, dont use a gloss as a base coat. Use a flat.

 

[Unplugged]

It has nothing to do with dry time. The enamel and the clear are incompatable. YOu need to get a different clear, with different solvents. Maybe even just use a polyurethane.

Also, if youre clear coating, dont use a gloss as a base coat. Use a flat.

I was suspecting something like that, but I am not sure what I would look for when choosing paints and coats.

Their support, however, insists that this is a drying issue.

 

[mathmonger]

I still think it's the old primer. Or maybe I'm just really proud of myself for spotting that. Do some tests on scrap metal. Try to remove variables. Try it without the primer. If the orange and clear are incompatible, it should still wrinkle. Try two coats of orange two days apart. If it wrinkles itself, it isn't a compatibility issue. You just have to tinker with it. Nobody knows the answer.

It could be user error too. Maybe not enough shaking the can or applying the paint too thick. Maybe something weird with the temperature (drying air temp is only part of the equation).

 

[ZTMAN]

Why do you want to clear coat a gloss paint? That Rustoleum is pretty durable.

 

[Unplugged]

It has nothing to do with dry time. The enamel and the clear are incompatable. YOu need to get a different clear, with different solvents. Maybe even just use a polyurethane.

Also, if youre clear coating, dont use a gloss as a base coat. Use a flat.

Their support actually confirmed that both are enamels, and there should not be any compatibility issues. They also mentioned that gloss on gloss should be fine and warned against doing any sanding or buffing of the enamel prior to coating.

Why do you want to clear coat a gloss paint? That Rustoleum is pretty durable.

For the same reasons clear coat is usually used: to protect the underlying paint.

At any rate, the issue was indeed caused by the paint not being sufficiently dry. I made another attempt using the same materials and got fine results this time. :smile: The white stripe was done by applying water-based acrylic paint on top of the enamel. The clear coat was applied on top of all that. Please see the attached picture.

Thank you for your input, everyone!