Acid-Bath and Hot-Dip Galvanizing

cps_goodbuy

Hi everyone

I'm playing with the idea of restoring a classic car with the above method, and would like to know peoples opinions on this for bodywork and chassis. I would consider this may be more suitable for cars with none structural rust, and hopefully minimal welding...

I've heard a few potential problems and I'd love to hear everyones opinions on them:

After the process you have to clean off the car completely before you prime and spray or you may get paint damage over time, can someone advise on the best method for cleaning before the prime?

Welding, done before or after the hot-dip method? Are there pros and cons to this? I've heard galvanized metal is harder to weld?

Drilling holes to allow the box sections to be fully immersed, anyone have experience with suitable places to drill and how to plug up after would be appreciated.

Can't think of much else to ask right now, I've heard of others thinking/toying with this method but havn't found anyone who has actually done it and havn't found any good answers yet. Thanks in advance :cool:

101sean

Having had Land Rover stuff done in UK, I'll make the following comments although I'm no expert.

Would work fine on heavier or well braced structural elements. No good for thin body panels, they will distort, a lot of heat is involved. Also bear in mind that galvanisers main work is heavy steelwork etc so potential for damage, I had a fuel tank carrier that had a beam dropped on it before it went in the tank, they did sort it though. Closed sections need to have vent holes drilled, stick to one size and use grommets after. Any threaded holes, bush location holes etc would need to be reamed out after.

Weld before, you need to remove the coating to weld plus the fumes are poisonous.

The component can come out with runs and drips which need to be dressed off if they will show. Prior to painting the parts will need a T Wash and etch prime or the paint will flake off in the long run.

Galvanisers charge by the weight of material used but have a minimum charge, probably about €100 so get eveything done at once. As an example, a Land Rover chassis costs about €400 to get done.

cps_goodbuy

For Sean: Thats quality info, Thanks for the help

I've actually been to a factory and seen the process done as part of my college course and forgot about potential runs and warping



I've a new question to propose:

Can anyone suggest a/the best and/or cheapest way to completely de-rust and protect (maybe thin) steel body panels.

Acid dipping still works as the de-ruster but protecting the steel is a problem now, has anyone experience with electroplating? Cost, places to get it done, and effectiveness?

Oh are there better ways to derust and protect a car?

cps_goodbuy

Anyone know anything about Zinc Phosphated Electrophoretic Immersion Coating, and where one may be able to have it done in Ireland?

ds20prefecture

Flame metal spraying is as effective as HDG, but I don't know anyone doing it in Ireland.

cps_goodbuy

Hmm, I'll look into that, thanks

chenacross

cps_goodbuy wrote: »

Hi everyone

I'm playing with the idea of restoring a classic car with the above method, and would like to know peoples opinions on this for bodywork and chassis. I would consider this may be more suitable for cars with none structural rust, and hopefully minimal welding...

I've heard a few potential problems and I'd love to hear everyones opinions on them:

After the process you have to clean off the car completely before you prime and spray or you may get paint damage over time, can someone advise on the best method for cleaning before the prime?

Welding, done before or after the hot-dip method? Are there pros and cons to this? I've heard galvanized metal is harder to weld?

Drilling holes to allow the box sections to be fully immersed, anyone have experience with suitable places to drill and how to plug up after would be appreciated.

Can't think of much else to ask right now, I've heard of others thinking/toying with this method but havn't found anyone who has actually done it and havn't found any good answers yet. Thanks in advance :cool:

Galvanizing Metal is not that hard to weld. You still can consider it as an option. It is very much similar to galvanizing steel.

The main issue with Hot Dip Galvanizing for metal is the fumes that it generates. Wear Welding mask to avoid fumes.
You can use flux core. Just make sure the polarity is correct (its reversed from normal gas welding).
After the welding is complete and allowed to cool, put cold galvanizing over the weld to maintain the galvanized steel's rust resistance. Cold galvanizing is available as a brush-on coating and in a spray can.

acier

Welding galvanised metal is not to be recommended. You'll end up with a weak weld full of porosity caused by the zinc turning into zinc oxide as it's burned by the weld. Just using a welding mask will not protect you from the fumes, you'll need a respirator. The fumes won't kill you but you'll have really bad flu like symptoms for a couple of days.
If you're going do do any welding it's best to do before galvanising or if you do it after grind back to clean metal the area to be welded .

unkel

chenacross, this thread is 4 years old. Please do not revive old threads. Please read the charter of this forum.