Vinyl coatings on metal

"Plastisols & Organosols"
by Harold A. Sarvetnick

on AbeBooks

or eBay or

Amazon

(affil links)

A. Hello, Jean-Francois. It sounds like you are interested in "plastisol coating". This is usually done by a dipping process onto a properly primed substrate, although it is also possible to spray it. There do exist air-dry plastisols, but the better plastisols are oven cured. Any plating rack manufacturer will have plastisol dipping capability, but this site is for technical issues, and we don't recommend specific vendors. Good luck.

A. Hi Jean-FranÁois!

Re your question, WHY vinyl, why not other 'coatings'? Why the colouring? What's the environment?

The most expensive but the toughest coating is called PLASTISOL. This calls for a liquid PVC monomer into which one dips the product, then lets it drip 'dry' for a short while, then one puts this into an oven to cure. Tough, resilient, very acid/alkaline resistant coating. Not a smooth, perfect finish and far thicker than paint.

As far as paints are concerned, ask your local paint people. They would have a far better colour choice but not necessarily vinyl!

Hope that helps you un petit peu.

A. Here in the U.S., I know it's possible to have vinyl dyes [affil links] custom blended if this is what you're looking for. Specifically what I have had done recently was a combination system. It was a Dupont branded vinyl dye in a Sherwin-Williams packaging aerosol system.

Spray on just like spray paint, I'm sure something like this can be formulated in larger quantities and packaged more accordingly to your needs. Consider contacting Sherwin-Williams Automotive division if this sounds like the product that might be of help to you. It's nowhere near as thick as a plastisol coating. It's very thin, dries quickly and can be blended in a very wide range of colors.

Just offering you another option in case the plastisol coatings aren't exactly what it is you were talking about.

A. This type of coating is typically used on parts that are exposed to very corrosive environments, and also on tool handles, and wire form products.

A. Hello, Who Jang. If this is for personal use, you can try simple commercially available dips.

If that doesn't offer sufficient quality for your needs, you can look for a plating rack manufacturer. Most plating racks are plastisol coated for extreme corrosion resistance and electrical resistance, so most are set up to offer this coating service for you. Good luck.

Regards,

A. Hi, Hank. The principle is correct that good adhesion requires an oven-dried adhesive primer, especially on such difficult surfaces as galvanized or stainless. But I can't comment on whether the surcharge is in balance.

Regards,

A. Hi Hank, I think the adhesive that your supplier refers to is a primer made by vinyl chloride terpolymer; its carbroxyl group can provide good adhesion to metal. Something like a deep drawn can; without a prime, ink cannot maintain adhesion during deep drawing process.

A. Hi, John.

If the finish performed well for 10 years, that's not bad at all. If the finish is now peeling, actually curling away from the pipe, I doubt that any paint or plastic will fix it.

I think your choices are to:
- paint bare areas for color match, while expecting the problem to get worse, rather than considering it a fix.
- remove all the vinyl and repaint the pipes in situ
- replace the poles with new factory painted/powder coated poles, or remove them for factory painting

You could paint the bare areas for color match and then wrap the poles in something like clear packaging tape or industrial weight plastic wrap (the stuff they use to hold pallets together). If you start at the bottom, and the top is out of reach of kids' prying fingernails, there is at least a chance of a few years service from that. Note that this is just brainstorming from a guy who hasn't tried it :-)

Regards,

Hi Aniruddh. Plastisol will only adhere to a very clean and metallurgically active surface, preferably with some "tooth". Many plated surfaces have been handled and are full of fingerprints and not clean; often made of metals like nickel that deliberately form very passive surfaces. Plating is often 'self-leveling', i.e., designed to eliminate any "tooth"; and release agents like chromates are sometimes on the surface.

It is not impossible to design a pretreatment sequence for good adhesion of plastisol on plated surfaces, but it is unfortunately not realistic to expect good adhesion of plastisol on plated surfaces without serious effort.

Regards,

A. Air dry plastisol that I am aware of is not tough. There are some spray can vinyls that are not bad, but a bit on the hard to find. You can find "brush on" at most auto stores.
You might want to try the spray-on_rubberthat is currently advertised on TV. It is carried by most of the big box stores. Saw two in the last month.

A. Hi Erv. If the PVC coating is done right, there should be no problem at all. PVC coating of even plain carbon steel makes it acid resistant for difficult duty. However, if this 'cable' is repeatedly wound tightly on a drum, or used in some other way which might crack or split the coating, then it might not be satisfactory.

Regards,