Trailer work, Round 2. Thoughts on Paint on Galvanize

[rothfm]

Doing lots of work on the 21ft Bunk EZ Loader. All new tandem suspension-complete with fenders and hubs. Replaced 2 crossmembers as well.

The side Rails are in decent shape but have areas where the Galvanizing is not good anymore, and spots are showing rust. I've checked these rails/Wishbones out, and they are solid.

Im thinking of a light sanding, and coating with something. I typically use a spray Cold Galv compound. But it has built up, flaked and traps moisture.

Any thoughts on what I could use on this trailer? Again, light sand the whole frame and apply something? Rustoleum, Galv Spray again, or maybe one of those Rust-Stop products then apply a coating?

The trailer is coming out very good.

 

[Scott Danforth]

Rustoleum has a primer that sort of sticks to galvanizing....sort of.

Wire brush....spray a heavy zinc coating (cold galvanizing) and go boating

 

[Chris1956]

I agree with Scott. If you use a paint, and you get it to stick to the galvanizing, it will hide rust spots for a while, and then reveal them and look like crap. Stick with the cold galvanizing paint and touch her up a couple times a year.

 

[dingbat]

Bear in mind that galvanize (zinc) needs O2 to maintain its protect properties. The minute you cover it over you’ve compromised your first line of defense against the formation of iron oxide, ie rust.

Best to use cold galvanizing in a can to repair the damage to the coating. Properly applied, it does not flake or peel but the surface must be throughly cleaned and dried before application.

Zinc-rich paint is applied to a clean, dry steel surface by either a brush or spray. Zinc-rich paints must contain either between 65% to 69% metallic zinc by weight or greater than 92% metallic zinc by weight in the dry film.

Inorganic and organic zinc-rich paints vary somewhat in their performance. Inorganic zinc-rich paints, which adhere to the steel with mild chemical reactivity, have good solvent resistance and can withstand temperature up to about 700 F (375 C). Inorganic zinc-rich paints do not chalk, peel, or blister readily, are easy to weld and provide simpler cleanup than organics.

Organic zinc-rich paints do not have the same temperature resistance of inorganic zincs, as they are limited to 200-300 F. They are also subject to ultraviolet (sunlight) degradation, and are not as effective as inorganics in corrosion resistance.

 

[rothfm]

Thanks alot for the feedback. I'm going to go with what ive used, Rustoleum Cold Galvanizing Spray. Dont want to complicate things and have it get messy. Basically for the side rails.

Thanks all

 

[rothfm]

Ok, Another question came up on my round #2 EZ Loader 21" bunk trailer.

To recap: last fall replaced the entire suspension brand new, with tires, rims, hubs, springs, and added an axle for Tandem. This spring, replacing all frame bolts, front boom tie member, Bolster, wiring/lights. Just about anything that needs it, its getting done.

Whilst crawling around under the trailer the last 2 weeks....I've come to notice that the Bunk boards dont hold tight up against the bottom of the boat, between Bolsters. I have 4 2x6 bunks mounted Horizontally. A set is low toward the keel, another set out wide toward the tires. I've had it setup like this for 6/7 years and it does very well on the road.

When I had the bunks removed, I noticed small spider cracks, directly above where one of the inward foward Bolster are mounted.

Could the boat actually be sitting on isolated 4 locations? Since these 2x6's dont seem to support alot in the middle of the spans? And the pressure atop the 2x6 at this location is flexing the hull?

Seems logical, but not sure. Its not bad looking, but the other 3 bolster area's dont have this look.

Thanks for any input.

 

[dingbat]

Thanks alot for the feedback. I'm going to go with what ive used, Rustoleum Cold Galvanizing Spray. Dont want to complicate things and have it get messy. Basically for the side rails.

Thanks all

Rustolem cold gal is an organic paint with 25-50% zinc by weight. Wouldn’t use the stuff on a water trough repair let alone a boat trailer restoration

 

[mike_i]

I've been cleaning up my galvanized trailer a little at a time. I've wire brushed and ground the loose galvanization and rust off then used ZRC cold galvanizing zinc paint. It works pretty good but you need to get to shiny bare metal for it to do it's thing. Getting to shiny metal is a lot of work. I did some more researching online and found mastercoat permanent rust sealer. It arrived today so I haven't used it yet and won't know how good it is until I dunk my trailer in saltwater a few times. You may want to see if it's an option for you.