Hot dip galvanizing vs Cold galvanizing spray

[leafsprung]

The result is a pure metal coating which offers the same protection as hot dip galvanise

There are some big drawbacks to metalized zinc spray. The hardness of the resulting coating and the bond strength of the coating to the steel are much less than with hot dip galvanizing. Hollow sections are not protected at all and it costs much more. It is far less effective.

[Metallisation]

In the interests of clarity, I'd like to respond as impartially as possible to the Leafsprung post.

Metallised zinc spray is not all things to all men and neither is hot dip galvanising. There are benefits of both. Some applications would favour metal spray, some favour hot dip and there is also a considerable cross-over in the middle.

Hardness of the coating is very dependent on the steel substrate when hot dip galvanising. If the steel has a low silicone content, then the interface layer between the steel and the galv will be hard but the zinc on top will be just pure zinc. If there is a lot of silicone in the steel, it will produce a very hard galv coating but this will also be brittle which is not good either. Metal spray is effectively a pure zinc coating and has the hardness of zinc.

Metal sprayed zinc bond strength is not as high as properly applied hot dip galv but it is around 5MPa (725psi) and I challenge anyone to select their largest landrover hammer and remove it - so not as well bonded but still bonded well enough (good enough for offshore oil platforms, security barriers, fishing boats etc.

I did mention that it's a line of sight process so it will not coat the internals.

As to cost, it can be cheaper, it can be more expensive - it is very much application dependent and what is important to you. Also depends on if you include the cost of correcting heat distortion in your calculation for example or grinding off spikes and runs, re-drilling / tapping holes etc.

I only mentioned it as a well accepted alternative to hot dip which is widely used in many industries.

Regarding a New England applicator, please contact our distributor in the USA via http://www.tmsmetalizing.com/ - I'm sure they'll be able to put you in touch with someone.

[leafsprung]

In the interests of clarity, I'd like to respond as impartially as possible

Probably going to be difficult to be impartial when you work in the industry, are actively advertising your process and have the user-name "metalisation" (its actually a "Z" in there.)

Hardness of the coating is very dependent on the steel substrate when hot dip galvanising. If the steel has a low silicone content . .

Silicone is for hollywood types trying to get ahead, silcon is a steel constituent. There is not really any cold rolled, high silicon content steel in the items you would galvanize on a land rover, so you dont have issues here with hot dip.

Metal sprayed zinc bond strength is not as high as properly applied hot dip galv but it is around 5MPa (725psi) so not as well bonded but still bonded well enough (good enough for offshore oil platforms, security barriers, fishing boats etc.

The bond strength of hot dip is more than triple metalized zinc spray. The bond strength is largely mechanical for metalized zinc spray. The service life of hot dip galvanizing is longer in every environment. The only reason you see metalized zinc spray on large installations is because they are too big to fit in a tank to hot dip them.

I did mention that it's a line of sight process so it will not coat the internals.

Land rovers rust from the hollow spaces outwards, with no protection in the hollow spaces means metalized zinc spray is next to worthless. I would honestly rather have a painted frame than a metalized zinc sprayed frame. The same level of maintenance is required to keep it from rotting away.

As to cost, it can be cheaper, it can be more expensive. Also depends on if you include the cost of correcting heat distortion in your calculation for example or grinding off spikes and runs, re-drilling / tapping holes etc.

Every land rover chassis manufacturer including the factory have used galvanizing to protect their frames, if the risk of distortion and cost of cleanup were so high, do you think they would bother? Metalization is always FAR more expensive. Initially its more expensive to have it done because its more labor intensive and long term its more expensive when your chassis rusts away anyway because the important parts havent got any coating on them . . .

[yorker]

Probably going to be difficult to be impartial when you work in the industry, are actively advertising your process and have the user-name "metalisation" (its actually a "Z" in there.)

. . .

http://www.metallisation.com/

[leafsprung]

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[meatblanket]

Silicone is for hollywood types trying to get ahead.