In my past experience and from what others who have also used it in the past have said, POR15 is by NO means a miracle product and in fact has flaked off with nearly every application I have personally done and other friends as well. It is an encapsulator, not a converter and not an etch. It "supposedly" keeps air and water (oxygen and H2O) from the rust which ends it's ability to grow. One small crack, flake or pinhole and air is reintroduced and rust begins to once again creep under the remainder of the POR15 coating. I have LITERALLY seen metal pieces where the shape of the part was ONLY represented by the POR15 outer shell...the part has rusted away underneath. IMO the best bet is to remove via sandblast or wire brush or however possible AS MUCH RUST AS POSSIBLE, then convert it to black oxide (which is actually stronger than a rusted piece of metal) and THEN paint it. And besides, just how GOOD do you feel about LEAVING rust JUST so POR15 has something to adhere to? Isn't that similar to leaving dog **** on your lawn so the gr*** has nutrient to grow better? Please... Me personally, I'd rather remove as much rust as humanly possible and have a little more peace of mind in the end. IMO leaving rust you could remove with a little more effort is just taking the easy way out...very sloppy. Also, I hear repeatedly here and from others to follow the directions to a T, degrease everything (how will you EVER know?) I mean, if the rust is hard to get to, how will it be easy to degrease the same area?...makes absolutely NO sense. If you can thoroughly degrease it, then why not DERUST in the first place? And if you CAN'T thoroughly degrease it then you're better off converting it than trying to seal it from the elements...right? So...use it if you will, but it is not a long term solution as far as I can tell...
This is quite true. I would not use it on anything but pitted rusty surfaces. Use a brush and no thinner and it will flow out like you used a gun. If you are planning on top coating the same surface make sure you put primer over the por 15 while it is tacky ( depending on air temp 1 1/2- 3 hours after applying ). If you wait to prime after it dries completely the primer may not adhere.
This brings up yet ANOTHER disadvantage to using this product. They did a test about 5 years ago in Auto Restorer Magazine using POR15 and painting over it to test paint adhesion. The results were unsatisfactory, The paint either discolored, bubbled or flaked off after drying. Do yourself a favor and convert rust...don't trap it under a shell because it will still be there, under the POR15 AND in the back of your mind. Do it right the first time...
Yes it is, but if you can PREP it...why not remove the rust? I never understood the advantage of covering rust. There are SO many methods for either removing rust or converting rust. When it's GONE it's GONE.
I've had the same experience and used it the same way, cleaned the frame with a wire wheel an used it straight from the can when I needed to weld to the frame I had to use a grinder to get it off ,and it wasn't easy!
Quite true but you can only prep what you can get at. I only use this in small areas that i can't reach with anything else.
FOLLOW THE DIRECTIONS...it will stick to new metal..but prep as directed. Remember this stuff has isocyanates in it..the same **** as Imron. It will kill your lungs. Dont spray, and use a resporator. (sp?) Dont get in your hair unless you are trying to cover gray. It will not come out.
To answer your question, Naptha is the thinner you need to use. I bought a bottle "less than a quart" of their thinner and paid out the waazzoo. You can buy it by the gallon at Home Depot for a lot less. Just remimber it will not remove it once it hardened or dry. First time I used it I got some on my hands and had to wear it for about a week.
POR 15 is worthless over paint. It has to be applied to clean (degreased) metal, and it likes to be applied over non-flaking rust. You are wasting your money if you apply POR over a painted part (primer or original topcoat, say on a frame).
41Woodie, I also used POR15 in the past, and have been disappointed! I followed their directions also, prepped frame etc, and the stuff faked off in a year. I then tried Rust Bullet, great product! The stuff really seems to hold on, and you don't need to go through the three steps like POR 15. I heave heard from others; that the KBS rust coating is a good product? It is simmilar to POR 15 (three step process also) but seems to hold on better, from what I have been told. Eastwood's Epoxy paint holds on well also. Go with their new improved version.
Por15 is designed for heavily rusted metals where you wire brush the loose scale off, treat the metal with their metal prep and wash off with warm soap and water and wipe dry. You then paint it on with a brush straight out of the can. It will smooth and level it self out, and another thing it does not like heat or hot weather. If it is hot out it will take forever to dry and or harden up properly. Por15 likes cooler, damp weather. that is what makes the chemical reaction so that it dries hard and the longer it sits the harder it will get. Por 15 is also not UV resistant, so if you use it make sure it is only on the underside and not exposed to the sun or it will break down from the suns rays. The por15 is specifically designed for sealling, smoothing and the leveling of rusty surfaces. One should then scuff sand the entire surface of the por15 and brush over or spray over the por15 with ch***is black paint or any othe colour they sell. Por15 ch***is black paint is UV resistant and will stand up to the suns rays, and it can be thinned with their special thinner which if you smell it you will find is good old solvent. So if you cut it with solvent it is sprayable and also easier to clean up as long as it does not harden first, and ch***is black also comes in satin finish or gloss black. Por15 can also be thinned with solvent and painted or sprayed but you are defeating the entire purpose of what it was designed for.
I've used POR-15 a couple of times on my ch***is immediately after getting them fully sandblasted, and never had an issue. It performs as its supposed to. I can smash it with a hammer and it won't chip or flake. I thinned it with the proper POR 15 thinner to spray on, but only a little. Apparently, (this came from the dude at the paint store) POR 15 was supposed to be developed furthur to improve it's ability to adhere to other paints and resist UV light, but the company didn't want to. He said that KBS coatings are the same, but the new improved version, AND it's about 1/2 the price (here in WA) as POR 15,, so I'm going to use KBS stuff next time. Good luck.
You would think with all the negative feedback and testimonials that POR15 would improve their product, but maybe they're rich enough that they can afford to lose repeat and new customers...go figure.
I've used POR 15 black on old metal which was sandblasted. It gave a great texture for the paint to adhere to. I wiped it all down prior to painting using autobody lacquer thinner. Still looks like new after a couple years of use.
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