Thread: gal or paint?

I've galvanised 2 land rover chassis (one coil and one leaf). As has been said, Land Rover chassis rust from the inside out and paint is not going to help much in this regard.

If the chassis has been heavily oiled internally, the gal coating may not take well to the inside although this may be dependant on how long its left in the acid bath prior to dipping in the zinc.

I would think (but am not 100% sure) that a good gal coating on the outside would still provide some degree of electrolitic protection to an inside surface which was not coated properly, in much the same way that adjacent areas on the same surface are protected - can any corrosion experts elaborate on this?

Most galvanising companies require that previously painted steel be sandblasted prior - this will also result in a thicker coating due to the increase in microtexture - it tends to attract more zinc. But the sandblasting is an additional cost which needs to be factored in.

how much was the sandblasting and the galvanizing

Just wanted to say that this thread has been very helpful! I'm thinking about doing a full rebuild on Safara (my Defender) next year, including chassis protection. Was already leaning more toward galvanising - I reckon I'll definitely go with gal now.

Not wanting to hijack the thread, but would there be any advantage in both galvanising and then painting with something like POR15?

im actually probly leaning towards paint just because the chassis can warp when galvanizing

Originally Posted by samuelclarke

Not wanting to hijack the thread, but would there be any advantage in both galvanising and then painting with something like POR15?

As you may know, galvanising is a sacrificial coating - it slowly corrodes instead of the steel.

Some people are of the opinion that it works best when unpainted, but others don't paint it just because paint won't stick unless you use a good etch primer.

IMHO there is no harm in painting it. The service life may even be extended by doing so.

Originally Posted by schmierer LR at singleton

im actually probly leaning towards paint just because the chassis can warp when galvanizing

There is little or no chance of this. I haved galvanised one chassis, and I know countless others which have been galvanised without issue.

Series III and later chassis are probably the most suited as the dual c-section construction makes them better able to expand and contract. The flat plate IIA chassis I galvanised had some rippling along the side (vertical) plates after galvanising, however the chassis was still just as square as when it left the factory.

I have never had a part rendered unusable after galvanising. I even galvanised a radiator support withot issues.

Ben, have you galvanised the B pillar and sill rail?

Originally Posted by abaddonxi

Ben, have you galvanised the B pillar and sill rail?

Not personally, but I have looked closely at a couple that nhave been galvanised. No issues I could see.

I have done plenty of door frames and other similar bits. I have never found even the slightest bit of warping with them.

IME it is flat panels which warp (e.g. footwells and tunnel on firewall). Conversely, radiator support panels don't warp - presumably because the edge is rolled, and no thicker than the middle. Anything with some shape in it doesn't warp IME.