What SHOULD I have done?

[Scott Loven]

decided that I needed to paint a JET bandsaw base to match the Delta bandsaw top that I purchased from Redmonds a while. back. http://www.sawmillcreek.org/showthread.php?t=21565 (showthread.php?t=21565)
I decided to use spray paint out of a can that I purchased from the local Farm&Fleet. It was a light gray that was meant for the old ford tractors. I could have purchased matching paint from Sherman-Williams but did not want to spend $30 for a gallon of paint. The Borgs are 80 mile from where I live so have to deal with limited choices.
Anyway, I wiped the base down with denatured alcohol and proceeded to spray the paint onto the base out in the driveway. It looked good, and was a good match color wise. I went out last night to spray a second coat of paint and noticed a big scrape on the lid down to the original color. I decided to scrap my finger nail across the paint, and it easily came off down to the original paint. It had been 3 days since I painted.

What did I do wrong
1) bad paint (It was spray on enamel)
2) not enough surface prep
3) surface was to hot (Paint skinned over before it hit surface)
4) Humid conditions (It was moved to a hot humid garage after I sprayed it)
other ideas?

Thanks
Scott

[Jeff Sudmeier]

Did you rough up the original paint with sand paper at all before painting? I have had that problem when I just painted over something previously painted and didn't rough up the surface.

[Ray Bersch]

Scott;
Any number of the things you mentioned could have caused the problem, but I would stick with the basics - if you only wiped down the surface, all that you did was clean it - as Jeff said, you should have roughed up the surface to kill the gloss of the original paint - there are chemicals that will do the job (deglossers) but they are nasty and not necessary, a simple rub down with sandpaper - not too rough, say 100 to 150 - would do the job. Seems like you have a strip, prep and re-paint job ahead.

Ray

[Lee Schierer]

Many manufacturers use a baked on powder coating that is nearly impossible to paint over. It is an epoxy type paint that is heat activated. You may find that unless you strip off the original Jet paint that you will not get new paint to stick to the surface even if you scuff it up a bit. Note that "stripping off'" the old paint may involve some industrial strength sand blasting as ordinary paint strippers won't touch powder coatings either.

[Jim Dannels]

Scott: For 4 of the 14 yrs I built Farm Machinery I was a spray painter.
Ag Enamels cure very slowly so the hot and very humid conditions we have had this past week would have slowed the drying process. When we went from Baked enamel to air dry this happened fairly regularly until we learned how to handle it.
As was mentioned surface prep could be a problem, scuffing before painting could help.
Also with ag enamel don`t be too quick to paint another coat. I have seen curdling of the first coat when the thinners broke it down and lifted the first coat. Ag enamel is fine paint for some applications and this is one I think it would have been fine for. We used to use it on dirt track stock cars(AC Orange), since it was cheap and touching up dings was a weekly project.
If there is more I can do let me know.
By the Way, how are you fareing up there during this monsoon season?
See there has been lots of rain and a few tornados up north.

[Maurice Ungaro]

Scott,
After scuffing the original paint, I would hit it with a coat of primer (gray).

[Scott Loven]

Thanks Jim, you are the 3ed Iowa guy I have met on the creek this week! Why would ag enamel dry slower then other paint? The can said that it should be dry enough to recoat in 24 hours. I will wait until this weekend to see if it has improved.

We had 4 inches of rain last night BTW.

[Jim Dannels]

And you are probably wise to go more with the paint companies reccomendations than mine. It seemed like the paint would skim over and be dry on the surface but took longer to really cure under the skim. Even at 4 mills thick, it took time.
If a repaint needed to be done it seemed to take 3-5 days to assure no lifting.
Or dang it I had to go into a booth smaller than most shops and put on a space suit and sandblast it( But thats another story,er I mean nightmare).
That was over 20 yrs ago and may have had more to do with the paint brand" Iowa Paint" and or the thinners we used??

The company I worked for is no longer in business, Farmhand Industries was bought out by a Texas company and moved to Texas.