biackbenz

I am going to repaint the underside of my '78 hood. Not really sure what had been done before but some of the paint looked like birthday cake frosting. So I have sanded down to grey fiberglass. I was going to use Rustoleum hi temp semi gloss paint.
Before I do that I sure would like some help.

Do I need to put on a primer first? If so, what do you recommend?

Is there a different paint you would recommend?

Thanks

DUB

Are you planning on using an aerosol can????....OR......using paint gun???

Is the hood still mounted or have your removed it????

What grit sandpaper did you use when you prepped it????

Do you have an air compressor????

The methods to paint the underside of the hood are numerous....all depends on what it being used and the condition of the hood and so on.....and...how long a person wants it to last.

I can add more once I have answers to the questions above.

DUB

biackbenz

Thanks DUB the hood is off the car. I used 120 grit paper then went over it with 320 grit. I have an air compressor but no paint gun and don't really know how to use one. I'm hoping to use spray cans.

Dave Tracy

Because of the environment the underside of the hood resides, it must be VERY clean before painting. Washing with Blue Dawn dish soap is good in addition to solvents sometimes and commercial wax and grease remover. I am currently in the process of repainting my car and have dealt with my underside of my hood. After it was cleaned up I used PPG DPLV epoxy primer. This has to be sprayed but would seal the underside of the hood so contaminants (oil) can't weep through the fiberglass and create paint blisters. A/C oil is really bad if it weeps through the hood. My $.02.

biackbenz

I wasn't thinking. I also used a paint stripper. I wiped the whole thing down with mineral spirits.it's 2:00AM and I'm sleeping like a baby - crying. I wiped it down with a damp towel then wiped it down again with a dry towel. I have to assume that I have bad oil contamination but hopefully not to deep yet.

Now what do I do without making it worse?

I think the smart thing is to give it a heavy dose of dish washing soap let it soak an hour or so and rinse it down. Repeat several times.

The temp in my warehouse is about 60 degrees. Should I apply heat to the hood or will that make my problem worse?

I am thinking that other solvents might make it worse.

I will add a picture in the morning when I get back there.
HELP!

DUB

I am not saying that you can not use aerosol cans...but it will be hard to make it stay wet all the way across so you do not have 'zebra stripes' or dry spray lines.

What did you DAMPEN the towel with when you wiped it down???? Water, mineral spirits, etc.????

I will write this and those who care to see my point of view---fine...those who chose not to---that's fine also.

Hoods CAN BE finicky. IF water is applied to the underside and water gets inside the cavity of the understructre. REGARDLESS of any drain holes or openings That water will now be extremely hard to get all out. And due to water rises when it is evaporating...it is being stopped by the outer skin of the hood....and THUS....you have a greenhouse...the moisture is staying trapped or taking really long to get out....where in time....blistering or bubbles CAN begin to develop in that area where the understructure is bonded to the outer skin. I have seen it...and I am sure many of you also have seen it. And then to make it even worse...put an outside car cover on your car outside and see what happens.

DUB

Dave Tracy

Just a thought for the pros. Utilizing chemistry, what would the effect be if the hood was washed with denatured alcohol rather than water? The alcohol is infinitely dissoluble in water so if the hood, or any other piece, were washed then rewashed/rinsed with denatured alcohol to displace the water, then the alcohol will evaporate at a much higher rate and at a lower temperature. Just trying to apply my many years in the post high school liberal bastions to practical use.

biackbenz

Acter applying paint remover and scraping off the softened paint I wiped the area down with a damp towel. The towel was dampened with mineral spirits. I have not applied any water to the hood. We) I did drop o few drops on it to see if the water would bead up. It does not. I wiped it down today with a clean paper towel. The paper towel picked up a lot of gray dust.

The surface is bone dry and I don't see any discolor in the glass.

Is mineral spirits considered an "oil" that will penetrate the glass as dev restating as motor oil?

DUB

CLEARLY UNDERSTOOD!

I can NOT contradict or debate your comment and CHEMISTRY...and ...knowing the properties of the denatured alcohol..it only makes complete sense.

DUB

DUB

I did a basic search on it and the MSDS sheet stated that from Klean Strop...their mineral spirits is a distillate....used for thinning paint and varnish. I know that oil can be distilled also...so who knows.

I can not say for sure if it is going to come back and cause problems or not because I do not use it nor never have used it to wipe a surface.

DUB

biackbenz

Thanks DUB,

Mineral Spirits is a degreaser. It was used in dry cleaning clothes many years ago. It is a petroleum distillate. But it dries very quickly. I used very little of it, I damped a towel with it by holing the towel against the opening and tipping the can. I wiped the surface down and right away wiped it with a clean cloth. So, there was very little solvent on the surface for a very short time. A chemist friend of mine thinks it probably evaporated before it would penetrate into the surface.

I have continued by sanding efforts and do not see any oily color, just fine white / gray dust. I started with 120 grit paper, then 220 grit and will finish with 320 grit. I will probably wet sand the 320 grit process with dawn detergent in the water. Then wash the whole thing down in heavy detergent. Let it dry for a few days to a week.

After all that, should I wipe it down with acetone as I think you have mentioned in other posts?

I plan to then paint it with John Deere Blitz Black paint. Should I spray some type of primer on the sanded surface first?

DUB

Yes..I would wipe it in small section with the acetone and WELL VENTILATED AREA with NO types of ignition sources. Watch out for possible STATIC ELECTRICITY ...which can occur.

I use the PPG black epoxy primer myself....but if you are using the JD stuff...you might need to contact them or the manufacturer of that paint and see what they say.

DUB