The Stovebolt Site Forums The Shop Area Paint and Body Shop Spraying Alkyd enamel on my 46 truck

No doubt this has been addressed but I’m too lazy to search.
I’m preparing to spray my trucks bed with the original color of green to match the cab. What do I need to know to prep the Alkyd enamel as well as while spraying it? Techniques, tricks, cautions and such. Thanks in advance.
Bob

By prep if you mean primer, etc. then you can use an epoxy primer. Or if the original finish is in good shape, you can sand it and paint over the original finish. But any rust or bare metal spots should be coated with primer first.
Whatever alkyd enamel you use, you should get the tech sheet from the manufacturer and follow that.

I've used PPG's ALK-200 and it's pretty easy to use. You can either spray it straight from the can, or add ALK-201 hardener, and thin with Xylene if needed.

Be aware that alkyd enamel is stone age technology. It takes around 30 days for the binder to fully oxidize and let the paint achieve full hardness. Adding an isocyanate hardener speeds up that process somewhat, but be aware of the health risks when spraying material containing cyanide compounds- - - -NO exposed skin, and wear a very good quality "Darth Vader" respirator with the proper filter canisters. A simple dust mask isn't enough protection!
Jerry

I agree with Jerry on the safety precautions needed for spraying when used with a hardener. And I agree with the "stone age technology" of alkyd statement, why not use a more modern product? Also, no matter what condition the current surface is in, you want to use a primer sealer or primer surfacer to provide inter-coat adhesion.

"alkyd" is a generic term. What product are you proposing to use?

Commercial performance coatings ALK-200 from classic chevys web site. I’m using it because I learned it will closely resemble the paint on the cab. This truck is a patina rig and the bed was in grey primer when I got it. I’m not going to change the look much. Keeping the patina even on the bed after I paint it.

Primer soaks up moisture like a sponge. If that primer on the bed has been exposed to the weather, sand it all off and start over. Otherwise, you'll be trapping a layer of moisture under the finish which will lead to rust problems and/or paint lifting in the future.
Jerry

Thanks Jerry. I’m in the process of doing just that.

Jerry the spec sheet outlines 7 days fully cured time when utilizing ALK-201 hardener.

It's actually 7 days to fully cure with or WITHOUT hardener.

Much better than the stuff we used 40-something years ago. The conventional wisdom back then was "Don't even wash it for a month- - - -the paint might lift!" Some shops used big sun lamp bulbs in the spray booth to heat the paint overnight to speed up the curing process- - - - -called "baked enamel".
Jerry

Wow! 7 days! Seems like a long time compared to the stuff available these days.

I had a 72 gmc back in 1982 that I painted myself and I Remember getting off work driving home when a fellow worker riding his bike alongside tapped his knuckle alongside as I drove by ,it made marks ,the paint was fresh about a week or two painted with enamel with no hardener.

Drying time to handle is 1 hour without hardener and 3 hours with hardener. Actually fairly normal.
It's a little touchy on recoat times. Without hardener, if recoated between 6 and 30 hours to 4 days, it may wrinkle the first coat.

So basically wait a week before re-coating, right?

Check the data sheet and follow it. It's good stuff... Easy to apply, buff and repair. There have been threads on this before... Do a search on my name... RABAUT. For one of them...

Mike

It can be recoated before 6 hours if used without hardener. With hardener, the recoat time is a little fuzzy. The data sheet says dry to handle in 3 hours and recoat 3 hours to 4 days. With hardener, it doesn't have the caution about lifting of the previous coat, so not sure if that 3 hour to 4 day window is to be avoided.