POR 15 on galvanised bumper

[WarPig]

Im about to replace my front bumper for a galvanised one. Not sure whether to leave it looking galvanised or paint it with POR 15 to make it look black.

How well does POR 15 stick to galvanised metal?

Does it last?

Cheers

[kingrat]

I would leave the Galv a few weeks to weather before painting, but I would expect POR-15 to go on ok and last well on a properly prepared surface as recommended in the datasheet.

[cackshifter]

Only thing about POR15 is it's fine as an undercoat or out of sight but it is changed aesthetically after a while- sort of develops a bloom - when exposed to UV ie sunlight. So it might be best to give another coat of something else afterwards. Incidentally if your target colour is black, you might be better getting the POR15 in silver, as appararently the metal in the silver POR15 helps cover imperfections and you can see where you have and haven't painted when you do the black topcoat. If the galvanised is well weathered it'll probably stick to it OK - it sticks to most things, but be sure to wash and dry thoroughly the surface first, even if you don't take all the rust(if any) off.

Nigel

[WarPig]

Many thanks for both replies.

Might end up with a galvanised rear crossmember as well soon, so Ive got to decide whether to leave the surfaces galvanised, or paint black. Then I can add tree sliders etc to match.

Sometimes I think its a shame to cover a galvanised surface, in case it peels etc.

I used to think I was indecisive, but now im not so sure!

[smokinv8]

Incidentally if your target colour is black, you might be better getting the POR15 in silver, as appararently the metal in the silver POR15 helps cover imperfections and you can see where you have and haven't painted when you do the black topcoat.

Nigel

Now thats the sort of painting I like, so you can see where you painted the bloody thing with the 1st coat easily!

One I'l use for certain.

[AD90]

My experience of POR 15 suggests that the only thing it sticks to is human skin, I would avoid.

AD90

[Log]

If you want to paint anything onto a galvanised surface then you have to prepare the surface first by using a mordent solution like T-WASH. Its a watery chemical that you brush on then once set wash with cold water to remove excess. The cleaner/newer the galvanised finish, the better. Its also good to degrease the surface before applying it. It stops the zinc reacting to any paint applied on top and allows the paint to bond properly. Most galvanised metal fabricators use it and if you google it Im sure you will find it mail order. Its not expensive.

Cheers

Log

[WarPig]

Thats great, thanks for the replies.

[ajh]

I painted mine, did all the prep but it is still chipping easily so I will be pulling it and the sliders and spraying with a few coats of bedliner, once that hardens it is pretty tough.