POR-15 & brush marks? Spray Version?

[pjsmetana]

I'm getting ready to use some POR-15 for the 1st time, and its going to be used on some visible areas. Do I need to pay attention to brush strokes or does it dry without showing any? Yes I show my car, but I'm much more concerned with rust.

Is there a spray can alternative that works just as good? I don't have a compressor.

 

[NutmegCT]

Pete - I used the "standard" black POR15 for some floorpan work. Dried hard as a rock, shiny, and with no "brush marks". But I doubt it will blend in 100% with an exterior painted steel area.

Tom

 

[tdskip]

Be <span style="text-decoration: underline"><span style="font-weight: bold">very</span></span> careful before spraying POR15, it's nasty stuff from a health point of view an you'll need a fresh air system to do it safely.

As far as alternative spray can options, it depends on where and what you are using POR15 for. POR15 will discolor in sunlight, so it needs to be top coated.

Where is it going Pete?

 

[pjsmetana]

Where is it going Pete?

Right here, in the engine bay

 

[JohnnyMead]

Pete,
My experience has been that it lays very smooth (no or few brush marks) on flat surfaces. Like Tom says, it looks great on floor pans. I've used it on other places and have had good results, but with a top coat of regular paint. Example: trunk interior. I used POR15 on some areas on the floor and on the sides, just brushed it on.
then I lightly sanded, brushed POR's primer on, sanded and sprayed regular paint. The result was perfectly smooth. I did the same to the battery box.
I'm interested in what parts of your car you want to cover.
John

 

[tdskip]

I've become a huge fan of ZeroRust. Similar to Eastwood Rust Encapsulator but works better in my experience (not a scientifically valid sample I might point out).

Wire brush all of that, use Naval Jelly on it and then ZeroRust. Top coat and you should be good for a long time.

There are variations on that theme....

 

[dklawson]

Pete, if you want to spray POR, it's very easy to do but as mentioned by TD, use a well ventilated area. POR goes down fairly smooth by brush and with a high-build primer on top should be OK for most locations. However, if you spray, use their solvent to thin (only a tiny amount of thinning is needed... if any). When I have sprayed POR I have used cheap, single-action air brushes as opposed to regular paint guns. Badger makes a model (#250 ?) that is ideal. Generic copies of the Badger unit are available at Harbor Freight and Northern Tool (among others). The cheap air brushes are easy to clean and economical enough to throw away after a few uses if you can't be bothered to completely clean up.

Regarding primer on top of POR, I have not used their new etch primer but I have used their Tie Coat primer. I hate Tie Coat. It holds their solvent in for way too long requiring many, many days for off-gassing before you can apply your top coat compatible primers and/or top coat. I have had much better luck waiting until the second coat of POR reaches that "finger drag tacky" stage and applying a fog coat of my top coat's primer. Once the POR is fully cured (24+ hours) I apply a heavy coat of high-build over the fog coat and go from there.

As with all paint, the final results come back to the amount of effort spent on preparation. Do post pictures as you work through the process.

 

[pjsmetana]

Is POR15 not water proof? I keep hearing about topcoats and so on. I'd really like something I can put down and forget about. Obviously my engine bay is not going to get much water in it, especially since it only comes out of my garage on bright sunny days, but with the salt air here I can't chance using something that is not water proof.

 

[TR4nut]

Other than cosmetics, I think the topcoat is there for UV protection - POR15 alone doesn't like to be in direct sunlight.

 

[TR3driver]

Other than cosmetics, I think the topcoat is there for UV protection - POR15 alone doesn't like to be in direct sunlight.

ISTR the POR folk also say that the UV damage is only cosmetic and doesn't affect the performance of the paint.

 

[JohnnyMead]

I've never seen any color change on areas I've used it on cars with no top coat: wheel wells, under side, under the hood. I think its direct sun that does it.

 

[pjsmetana]

How long in direct sun are we talking about? When I've got it in a show the bonnet is open all day.

 

[DNK]

I got it on my trailer tongue and it just fades from that shiny color.

 

[dklawson]

The reason I mentioned top coating is that the bulkhead is a very visible place. You may wish to paint it some time with a color coat. If you don't put a primer down over the POR at the time of application you only have three choices: trust their etch primer to create the primer bond later, manually sand the contours of the bulkhead to create "tooth" for the primer, or strip the POR off to bare metal. The last choice is nuts. Once you apply POR, the only place it's usually willing to come off of is bare, sound metal that was never rusty and not etched enough to get a good "tooth" for the POR to lock into.

Even if you think you don't want to paint a color coat... I would consider putting down a primer over the POR now, even if it's just flat black rattle can primer. However, their etch primer may be good enough to address this later. Others will have to comment on it as I have not used the stuff.

 

[CinneaghTR]

I painted my differential and various parts with POR-15. It smoothed out very well, but be careful about putting on too much because it is thick.

My policy is to use that stuff in out-of-sight areas because it is black and the UV issue.

Oh, also take a look on the Eastwood site. There might be something that would work, too.

I know this is an alternative opinion, but I would disassemble that area as much as possible, tape it off, use some sort of rust converter, prime, and paint it. There is a website for a guy named Paul Tegler (www.teglerizer.com?) and he did that with his Spitfires so you can see what is involved there.

Good luck.

 

[pjsmetana]

Fading to not so shiny is OK, even to flat would be fine, I was just worried it would fade to gray in the matter of a few hours. I'd prefer white, but black is just as good in the location its going. And yes, I'll be doing the entire area. I've been pulling parts and repainting them in preparation.

Thanks for the sound advice fellas!

 

[sail]

I've been pulling parts and repainting them in preparation.

Just curious, doesn't POR go on bare metal?

 

[pjsmetana]

I've been pulling parts and repainting them in preparation.

Just curious, doesn't POR go on bare metal?

Yeah... I've been pulling and painting everything except what I'm putting the POR on... for example, the Coil Bracket, Washer Fluid Bracket, etc

 

[dklawson]

Just curious, doesn't POR go on bare metal?

Yes... but NOT well. Sure it will look OK when applied. However, unlike when it's applied to treated rusty surfaces and heavily etched or sandblasted metal... it has nearly no adhesion to smooth, sound metal.

 

[UmmYeahOk]

Just curious, doesn't POR go on bare metal?

...and your skin, and your clothes, and the driveway....