Preventing rust after welding

[Eric_Phillips]

I need to do some minor welding on a galvanized tube fence gate. Yes I am aware of the issues welding galvanized metal. So what is the best way to keep things from rusting once I burn off the galvanizing where I welded it? I would prefer not to paint since that would mean needing to paint the whole gate for esthetics. If I must I will but is there anything else?

 

[Inspector507]

Would a cold galvanize spray can do any good after cleaning it? Don't know myself, just throwing it out there for discussion.

 

[Shield Arc]

This is the best stuff I have ever used on galvanized material. Apply with a torch, and wire brush in. Acts a lot like solder.
Very pricey tho!

 

[SandburRanch]

I need to do some minor welding on a galvanized tube fence gate. Yes I am aware of the issues welding galvanized metal. So what is the best way to keep things from rusting once I burn off the galvanizing where I welded it? I would prefer not to paint since that would mean needing to paint the whole gate for esthetics. If I must I will but is there anything else?

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An acetylene torch and solder might do the trick since there is about 400 degrees difference in zinc and lead solder melting points.

 

[dcyrilc]

You can get the sticks of zinc like Shield Arc showed or there's a spray on zinc galvanizing by Crown which does a very good job. Most aren't worth what you pay for them, but the Crown brand does a good job.

 

[PILOON]

Oh shucks, just brush on Tremclad flat aluminum paint and in about a couple of weeks you'll never know it was welded.
Wire brush clean first and if you paint it on while the metal is still hot it will be 'baked on'.

 

[Skyco]

Cold gal spray paint is excellent. It is what is used and recommended by communications tower manufacturers for touch up.
As mentioned the Crown brand is very good although harder to find than Rustoleum, which also works almost as well.
I've used a lot of it over the last 25 years and always had great success with it.

 

[weldingisfun]

Cold gal spray paint is excellent. It is what is used and recommended by communications tower manufacturers for touch up.
As mentioned the Crown brand is very good although harder to find than Rustoleum, which also works almost as well.
I've used a lot of it over the last 25 years and always had great success with it.

Skyco, is this the one you are recommending? ::: White Knight Paints

 

[dcyrilc]

I'm not familiar with the White Knight product. The Rustolium is easier to find as Skyco said and is pretty good. I still think that Crown is about the best there is though outside of using a zinc stick applied with heat.

The biggest trick with Crown is always turning the can upside down and clearing the tip after using or it is guaranteed to clog the tip.:laughing:

Aervoe 7007 Cold Galvanizing Compound-Spray Can
http://www.capital.edu/15621.pdf

 

[Mark @ Everlast]

I used to work for a company that specialized in galvanized farm gates. They'd weld the galvanized material, then they'd use the cold galvanized paint to touch up the weld area. It did work, and it lasted for some time.

 

[Skyco]

The biggest trick with Crown is always turning the can upside down and clearing the tip after using or it is guaranteed to clog the tip.:laughing:

I've had that trouble with just about every cold gal paint I've tried...the White Knight stuff in a bulk can might be just the ticket, use a disposable brush then chuck it:thumbsup:

I assume you've also noticed the nozzles on cold gal sprays have a much larger orifice than regular paint nozzles...kind of interesting if you get one mixed up and put it on a regular paint spray can....be ready for some high speed painting:laughing:

 

[dcyrilc]

I've had that trouble with just about every cold gal paint I've tried...the White Knight stuff in a bulk can might be just the ticket, use a disposable brush then chuck it:thumbsup:

I assume you've also noticed the nozzles on cold gal sprays have a much larger orifice than regular paint nozzles...kind of interesting if you get one mixed up and put it on a regular paint spray can....be ready for some high speed painting:laughing:

Never noticed the larger nozzle orifice. I have noticed that most brands spray about like water though. You have to spray the Rustolium or Crown pretty thick to even begin to have to worry about runs. Just too thick.:laughing:

 

[2manyrocks]

Another possible option is to spray it with clear enamel just to stop the rust.

Aluminum colored paint is a pretty decent choice, too.

Neither one is a perfect match.