|
primes do nothing to protect a substrate from rust that is not what they are designed to do .
primers are used for adhesion epoxy primers are used over bare metals for this reason .
they are used for this because filler primes or build primers will not stick to bare metals all to well .
filler primers are used for things like going over body filler work or a substrate you want to block sand nice and smooth and straight .
if your doing a job in your shop that will take some time (say a year plus ) you will be ok to use an epoxy primer with out any rust problems but this is a kind of only to a point type thing .
moisture humidity will and does go right thru all primers epoxy , etch , filler no matter what type it is .
a chromated primer is more a type primer you would want to use . 1st the chromate will replace the zinc or galvanized coating on the car from the factory that your sanding and grinding will remover . then the chromate will also but only to a point help with surface rust .
not all epoxy and etch primers are chromated with the EPA laws becoming more strict less and less primers are being offered with chromates .
with a chromate primer it will buy you a little time but not much . again primers do not hold out moisture it's not what they are designed to do .
only a cars top coat will protect a cars substrate from rusting .
what we do in my shop on long term project cars is 1st cover the floor under it with big pieces of cardboard from bumper boxes . this will help stop moisture coming up from the concrete floor .
you would still have to replace the cardboard every few weeks as the cardboard will only soak up so much moisture .
we also cover cars with 36" masking paper then go over that with plastic sheeting you use for covering a car for painting .
the paper will also do the same as the cardboard and suck up moisture but it too has to be changed out every few weeks .
|