Thread: Penetrol versus Por15

I haven't used POR15 but I was under the impression that it is a surface protectant; if that is so then there is no comparison between the two products, because they do different jobs.

Penetrol is my new best friend and is second only to a molasses bath Penetrol penetrates into the rust and drives the air out, thereby eliminating the oxygen and stopping the rust. It is designed to be painted over and it can be added to some paints as well. In my field-testing it not only out-performed the other compounds I tried, but it also exceeded the manufacturer's claims!

Check out the website http://www.floodaustralia.net/produc...FcMvpAod2CilZg

Cheers Charlie

I use both.

As Chazza says both do different things.
POR-15 is great, but its hard to use, as you have to clean the item, then use the rust converter stuff and then paint. Its very susceptible to crawling if the surface is too smooth and not very clean ( it didn't stick well to my ali panels first try), or orange peel/bubbling if you try to coat to thick, but its great for underbody - chassis, axles, etc. and is insanely hard to chip crack etc. If its exposed to UV, you'll need to topcoat it ( and it repels some paints )as it fades quite quickly to a dull finish. It is a brilliant product but you need patience and good prep.
Penetrol is better to get into really hard to reach places, inside chassis, bulkheads, etc and really easy to apply. I often use it where I notice some rust, as a temporary coating until I can get round to painting it properly (and thats sometimes never).

Its not an 'either or' question - use both.

POR (Paint Over Rust) seems to be mainly used on chassis parts.
Fades in direct sunlight and some people have had trouble getting it to stick to components and definitely problems painting anything over it.

POR has good self leveling properties but add penetrol to an enamel paint and that gives it good leveling properties as well.

If the surface is rust free (or Penetrol has been applied) there are lots of epoxy enamel paints that can be used. Available in pressure packs or tins from Bunnings etc.
If brush painting it's best to stipple the paint on but you do need a good quality bristle brush. Stipple application is 'stabbing' it on with the end of the brush, if done carefully it looks like it's been applied with a spray gun. best done with an enamel because it doesn't work with fast drying paint.

Post 22 in the thread below shows a few parts stippled (not the house roof !).
http://www.aulro.com/afvb/other-powe...es-3-a-13.html
I tend to spray paint smaller items and brush larger underbody parts.


Colin

Hi Colin
Thanks for the helpful replies.
Why do you brush the larger parts? I am assuming this is because you can apply a thicker coat.
Thanks, Martin

Originally Posted by marting

Hi Colin
Thanks for the helpful replies.
Why do you brush the larger parts? I am assuming this is because you can apply a thicker coat.
Thanks, Martin

Martin,

Often I'm painting in situ so brushing means no need to mask up surrounding parts. Spraying means more expense if using rattle cans and more time and expense if using a spray gun (cleaning, solvents etc.).
Underbody parts I'm not too worried about the finish, I just want to protect the surface (& look OK from a distance). Small loose parts are sprayed for convenience. Hang them on a wire, wander outside the garage to spray then back in to hang up & let dry. With small parts it's often difficult to get full coverage using a brush especially on sharp edges, spraying is a bit easier.

I've seen a lot of people criticising painting using a roller on this forum but it isn't a bad solution on large panels.
The hardtop on my Series 1 is home made using exterior grade plywood covered with canvas. I repainted this using acrylic house paint and it looks OK.
On the UK forums you'll find a lot of people painting whole Land Rovers using a brush and or roller. Ideal for a working vehicle where you want to save money but improve the looks, if it's going to be a trailer queen then spraying gives a better finish.....


Colin

Originally Posted by marting

Why do you brush the larger parts? I am assuming this is because you can apply a thicker coat.

Don't try to apply POR15 to thickly. It'll go on fine, but it leeches out CO2 as it dries and in thick coats causes it to bubble.
Although on a chassis and axles, will you really care as long as there's good cover

I've used POR quite a bit over the years. It is NOT a magic cure like people seem to think. It can fail like any other coating. Having said that it really is a brilliant product if used appropriately. It's a moisture cured urethane, so careful of the fumes it puts off. Get it on your skin and you *will* be wearing for quite a while.

Last time I had issues with it, I eventually worked out it was the paint brushes I'd purchased. They must have had a contaminant in the bristles that caused the POR to separate out all "dotty". It will stick to any surface with some texture like **** to a shovel. It hates clean fresh metal. I'd be happy using it in any hidden place. You will still need to check every now and then for failure like any paint system though. Don't put it where you don't want it.... It'll be hell to get back off

I like using it on the "Hull" ( kinda like a huge chassis) on Citroen DS's. Most of the old black paint on these will scratch off with your thumbnail. So you just hit it with a wire brush in an angle grinder and splash on the POR15.

If you want cheaper POR15 ... KBS rustseal appears to be the identical product.... absolutely identical ... but cheaper (see the spec sheets etc). I've used this and it's identical to POR from what I can tell.

Rust Stops Here - Paint - Tank Sealer - for rusty surfaces - KBS Coatings

Penetrol is a completely different product.

seeya,
Shane L.