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Need a satin chassis black to paint various bits. I constantly hear this stuff is bombproof. Will I be able to paint over the items I have already sprayed in ZINC182 primer or will it react? I don't really want to spend £60 on dedicated primer AND POR15. Cheers. Mark

I believe por 15 is best on bare metal, I have used it myself before but would now rather clean metal and use a good epoxy primer followed by chassis black paint

As above, POR is supposed to be applied to bare metal, not on top of another coating. POR does not stick well to smooth, sound metal. It needs the tooth left behind by a cleaned rusted surface... or one that has been sandblasted and acid etched. If you apply POR over other coatings or on smooth metal it is possible that once damaged (and you can/will damage it) it will peel off in sheets.

POR15 IMO is great, but it's high gloss, probably not what your after.

I do no the black I used is not UV stable

If you use it wear gloves......or be prepared to spend two weeks with it on your hands! Good product though. I've got brackets etc painted over 10 years ago that are still in perfect shape.

Had loads of issues with that stuff - have a search for my previous post - dont waste your cash !!

Pad

Mark I use a chassis paint from Ccs paints Romford . The Matt finish is dependent on how much hardener is used . I've got some here and won't use nothing else . Two coats of it and it looks like it's been powder coated . .... Ken

Stuff that lifts off in sheets. No.

Cold galv.

pad4 wrote:Had loads of issues with that stuff - have a search for my previous post - dont waste your cash !!

Pad

I remember your post, couldn't agree more. I went back to Hammerite & my rear subframe is as good as the day I fitted it 15 years ago. The smooth black Hammerite is not too far off the appearance of chassis black.
Regards, Rich.

I used POR15 on all of my running gear, calipers etc. 5 years ago and its still like new. If the surfaces are prepared and cleaned with the POR products it will definitely last and should be tougher than Hammerite but obviously more expensive.

111Robin wrote:I used POR15 on all of my running gear, calipers etc. 5 years ago and its still like new. If the surfaces are prepared and cleaned with the POR products it will definitely last ....

As with all painting, the end results depend heavily on the quality of the prep work.

As I mentioned earlier, POR does not like sticking to smooth, sound metal. It will stick great to all the castings and rough forgings. If you want it to stick to smooth metal you will have better results if the surface is "modified".

Degrease the parts. Once they are really, really clean, sandblast to leave a rough surface, then acid etch the surface. POR has changed the name of its prep chemicals over the years but the first product they tell you to use is a strong caustic cleaner. After that is rinsed off you are supposed to use the second chemical to do the acid etch. For smooth metal, etch much longer than you would for rusty surfaces. You want a dark grey color. If the acid dries on the surface you will see a white flaky coating which is "bad". Wet the surface again with acid and scrub the white off. Continue etching until you get the dark grey appearance, then rinse with water, blow dry, and wipe down with isopropyl alcohol. Very light flash rust produced during the last stages of prep is NOT a problem for POR.

Again, POR is great stuff for treated rusty surfaces, castings, and forgings. More careful prepwork is required when it is used on smooth metal. I simply cannot stress that enough.

I have found the same as what Doug has said.

POR15 is great, BUT it is very dependent on preparation. I met our local agent a few years back and he ran me through what it will do, all the usual sales speil, but he did go on to say that while it's not UV resistant, UV won't take anything away from it's protection abilities. it only makes it go chalky.

The other very important part he went it to great detail with is the preparation needed and he did say, it will ONLY work if preparation is done to the letter (and really pressed that point).

The first time I used it, I did what the instructions say, next day, I tried to remove it, just to see I did get it off, I couldn't blast it with my sand balster, but the wire wheel eventually got it off, took a lot of work! And yes, I found out the hard way, my hands were black for about 2 weeks, well, it's only paint isn't it? (wrong!)

I too have found that it can come off in sheets, but only when the preparation - to the letter - isn't done, so I can hardly blame the product for that.