Paiting an exterior steel door

Now that it is summer, I have had many customers come in wanting to paint their front doors. These are usually steel and usually still have the factory prime coat on them. About 2 years ago we purchased a steel door for the store to do some testing.

Keep in mind the factory applied primer should be re-coated or top coated within 30 of APPLICATION not PURCHASE. Many people do not realize that more then likely their door sat in a warehouse for over a month prior to the installation.

The best system for painting the doors it this:
- Clean and SAND the door. We need to put a profile in the primer for the caotings to stick to.
- Prime with a good bonding primer or DTM primer. There are many of these on the market. Devoe 4020, XIM 400 White, Styx Bonding Primer, P&L 6650, etc. Kilz latex is not the best.
- After priming paint with a good exterior latex paint.
- Spraying gives the best finish but you can use a low nap roller if need be.

Key notes:
You must clean the door. You cannot paint a dirty surface and expect it to stick.

Primer is key here. We tested many methods of doing doors. We primed, just painted and used surface prep products like Wilbond. We found with the primer and paint method we could not remove any product from the substrate after everything cured (30 days). The areas we just sanded and painted nicked a little and areas with the various surface prep products (like Wilbond) came off in sheets. The factory applied primers are too hard for the Wilbond to bite into them.

One issue we still run across is the vinyl molding around windows. We found XIM Plastic and Vinyl Primer works about 90% of the time. Unfortunately it seems that door manufactures will change the formulation of the plastic occasionally so what works for one batch of doors does not work on the next batch. I have no easy solution for this.

 

Some good info BC!

I would add that while all new steel doors can be painted with latex, only a few can be painted with oil base paint. The metal used on most residential steel doors is thin and will flex with temperature changes - oil base paints won't flex which means it's apt to peel. Another thing is dark colors can be an issue in some locations. They will attract more heat and can cause the plastic parts to warp

I've never had an issue with painting the 'plastic' moldings or window sash. I've painted them both with latex or oil base paint and have never had to go back under the 1 yr warranty provided with all new homes. Don't recall any issues with the paint on these moldings when doing repaints..... other than sloppy workmanship by a previous painter.