Vinegar water prep of light surface rust prior to priming: http://www.youtube.com/watch?v=GkjL97DF-RQ&feature=related
I wouldn't do that. Allways try to sand or grind all surface rust off. POR 15 also makes a nice metal prep for removing and neutralizing surface rust.
I've watched Pete's videos for a long time and he's usually spot on with his stuff. But I would go his ^^ suggestion, It will do you better in the end to get rid of all the rust.BD
Don't have a problem with vinegar. But a version of "Prep Solv" (actually dilute phosphoric acid) is available for cheap at Home Depot and other such places. Just remember to IGNORE their application instructions. They want you to wipe it on with something like a scotchbrite pad, chemically converting the iron oxide to a more stable substance ... and then rinse with water before drying. Do not, repeat do not, rinse -- that will only result in flash rust in all the places that didn't have it before. Simply wipe down and dry the surface. You're then good to go with little chance that rust is gonna come back to bubble your paint later.
I had a adheasion problem with the por stuff before ,now I always remove all the rust and use prep solv..good tip on how to save some $$$ on it,going to home depot next time.
Make sure you read the data sheet thoroughly for the primer that is going over it. Lots of epoxy primers cannot be shot over phosphoric acid. It causes serious adhesion problems.
we used to use it before painting over galvinized metal back in the day.i would da the metal first with 80 grit as grinding sometimes will fold the metal cuts over its self .....looks gone but not. did a 55 chev as a kid and three years later it started to bubble here and there like in the middle of the roof also make sure ur primer is made for direct to bare metal
There are a lot of cool simple household tricks for stuff. Many have been posted here. However, when preparing for paint I would tend toward correct, recommended chemicals. The money saved is not worth the risk of all that work and other materials.
Adhesion problems after a chemical rust removal are usually caused from not removing all the residue after the treatment. I always scrub the surface with a scotch brite and precleano and wipe down with a clean rag several times before primering. Most primers requie a etching primer to go down before a high build epoxy primer. I allways put a coat of Variprime (Dupont ) over everything before any other priming is done.
two videos, 20 minutes of blah, blah, blah, to show me how to wire wheel rust and wash it down with vinegar water. amazing.
That is the Gospel, right there... Cleanliness is the key. If you leave any chemical residue on the surface (or imbedded in the surface) you need to make certain the material you place on top is going to adhere. It's usually best to just make sure you clean the surface relentlessly prior to spray the etch primer. Check with the paint manufacturer to make sure about any compatibility issues.
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