How should I protect the metal of a power rack that's kept outdoors?

Question

I plan on building a power rack for my home gym and was wondering what kind of metal/coating I should use when building it since it will be stored outdoors. Most commercial power racks are built using mild steel and are coated with paint to protect it from rust. These racks should last when used indoors but I'm not so sure if it will when it is kept outdoors.

If I were to build my power rack from mild steel, how should I go about protecting it from rusting? While the rack will stay outdoors, it will be situated under some kind of shade/tent similar to this:

The power rack will stand over concrete or plywood (over concrete), not grass/soil.

With these details in mind, can anyone suggest how I should treat/coat the mild steel? I've taught of powder coating it but again, I'm not sure how that would hold up. How about chroming? Is it too expensive/overkill?

How about using something similar to the following:

These are pictures of my old bench. Since the bench is still standing strong after so many years, I take something like its material would be appropriate for my use case. What do you call this kind of metal/coating, anyway? What properties does it have and is it difficult or expensive to produce/replicate?

Please provide details as to why I should prefer each method over the other. If you would prefer to use some other kind of metal(stainless steel, galvanized steel, aluminum etc), please state why. I tried Google-ing the pros and cons of each method of coating I stated above but I'm still unable to reason out to myself which one to use. If all of them would equally serve the purpose, I guess it will all boil down to which one is the most cost-effective to produce.

Answer 1

Normally gym equipment is powder-coated. in your picture, they have used an electrostatic powder coating process and finished with a sort of hammertone finish..

IMO- your options are as follows:

• Stainless steel is the best metal in terms of durability. it will never rust, however, its more expensive and is slightly harder to drill/bend. I would recommend pricing the bench with Stainless, then you can assess the viability. In terms of stainless, the most common stainless is 304, which is industry grade.. This grade is perfect... but will turn slightly yellow over time, if you are concerned with tarnished stainless you can go for the more expensive 316 stainless.

• Mild Steel is your other option, and obviously this will rust, so your rust prevention options are

  • Metal Oxide primer with enamel coating (paint)... which will not look as clean and will rust after a short time
  • Powder coating - you can imagine this as a sort of plastic coating which is baked onto the metal. in terms of finishes. this looks really neat, however the impact of the power bar on the bench will chip away the coating and it will show signs of rust after a while. not to mention that the coating is only on the outside of the tubing and the tubing will rust on the inside.

  • Chrome is another option, in which the metal is coated in chrome, this is also on the exterior of the metal, but I am not too certain if you will find a person who can chrome such a large item

  • Your last option (and most cost effective) is to galvanize the metal. this results in a zinc layer being coated on all surfaces of the metal (inside and outside) your second photo looks like it has been hot-dipped galvanized. the galvanizing will look really shiny at first, but will form a dulled coating and will last for many years.. Galvanizing comes in two types

    • Hot dipped , where your bench will be dropped into molten zinc and will come out with a thick layer of zinc covering all surfaces. with this your bench will last for 20+ years without rusting.
    • electrogalvanized, where the bench is dipped into a solution and a current creates a charge which attracts the zinc coating (this coating is a lot thinner so will not last as long), however the finish is a lot prettier. I would not recommend this in your case.

So to summarize, I would say your options are stainless steel, or hot-dipped galvanized steel. Both will be extremely durable but I like the look of stainless more

If you decide on Galvanized, I would also place some rubber strips in the areas where the power-bar lands on the bench, since the zinc coating will wear away there over time.

Answer 2

The finish shown is a type of paint - "Hammerite" is either the name, or the brand name of the most popular/first version. It's presumably on mild steel. However, any automotive paint should work (think about it) - and COULD be cheap if you have a cooperative paint shop and you don't care what color it is (ie, they can spray some excess when they spray something else, so it's not a special job where they have to mix paint and clean the spray guns just for your tiny job.) Some shops will, some shops won't - all you can do is ask.

Chrome is probably a bad idea - it's relatively expensive and the electro-plating process can increase the odds of steel cracking from hydrogen embrittlement.

Hot dip galvanizing (zinc coating) is probably a good option if you can find a shop with a tank big enough - ask around for places that do boat trailers - covers inside and out (be sure to put in holes so it can drain out, or you'll get a tubeful of zinc and a larger than expected bill for the coating process), and is durable in weather. It only comes in one color, which changes over time from shiny silver to a dull gray. It is preferable to using galvanized steel stock to build from, because you coat the whole object after fabrication, so the welded joints are protected.

Powder coating should work fine. It may chip a bit on the top section where the weight bar sits. It comes in many colors, and is fairly tough as compared to most paints - but hard to repair if it does chip.

By far the most cost effective method usually is to do through cleaning and preparation (the key to ANY paint job lasting) and paint it yourself, using a primer for steel (zinc chromate primer, for instance) and a topcoat - then keep an eye on it and sand and repaint whenever you see signs of new rust. You could use either the mentioned oil coating or an automotive undercoating on the inside of the tubes if feeling particularly cautious.