Thread: trailers - painted or gal rhs

Yep the duragal is the way to go as there is a protective coating right from the start.

As per here https://www.woodworkforums.com/f184/f...r-bush-145855/ and here https://www.woodworkforums.com/f184/trailer-21592/

on my car trailer i gave it 2 coats of kill rust primer and about 4 coats of hammertone grey i just kept painting till the 4 litre tin was empty so i think that one wont be going rusty for a while .
mind you its kept in the shed out of the weather as well i think its only been rained on twice since it was built . im planning on this one to last a few yrs it will see my motor racing days out .

If you can get someone competant, all the metal parts, both tray and chassis, should be hot dip galvanised (not the ####ty spray on stuff) AFTER all the welding is done.

Then you etch the fresh galvanising - these days a few days of city rain will do it - before painting. Bsically its etched when its grey istead of shiny silver. Considering the clowns we all see on the road, maybe yellow/black hazard stripes all round would be a good coulour scheme.

Horses for courses.
If you're a business owner trying to make a profit;
Pre-galvanised RHS is more expensive than painted RHS. Are you charging more for the trailer?
Pre-galvanised RHS requires removal of gal at the point of each weld area to ensure a clean weld. (More time consuming, and OH&S issues with the residue from welding Gal.)
Other than the welded areas, Pre-galvanised RHS shouldn't require another protective coating for a while. But unless your selling the trailer with patchwork paint just on the welds, you still need to coat it with something.

If you're building the trailer for yourself, the cost difference is really irrelevant long term. It then comes down to what trailer you're building. A box trailer, stock trailer, boat trailer, car carrier, motorbike trailer... Each one would have different pro's and con's.

Another point to take into consideration if you decide to go for hot dipped gal.

You'll need to allow more time for drilling holes into any tubing that is butted into another piece to allow passage for the gal to get into those spots and to drain as well.

Thanks for your input. It seems the only difference is personal preference.I bit the bullet and ordered gal rhs. I am building a 3.5t flat top car trailer. I will use silver zinc rich paint on the welds so it should'nt look too bad. I figured it would save time in not having to sand, prep and paint,painted rhs. I am building it for private use and then selling it.

Originally Posted by Acco

Another point to take into consideration if you decide to go for hot dipped gal.

You'll need to allow more time for drilling holes into any tubing that is butted into another piece to allow passage for the gal to get into those spots and to drain as well.

Not only that, but if build a box trailer and get it dipped, if you just use the standard 1.6mm flat steel for the sides and tailgate, you can get buckling of those flat sections. A car carrier's not so bad as most of the construction is tubing, but the drama there is finding a galvanizer with a big enough bath.

Originally Posted by jex

Thanks for your input. It seems the only difference is personal preference.I bit the bullet and ordered gal rhs. I am building a 3.5t flat top car trailer. I will use silver zinc rich paint on the welds so it should'nt look too bad. I figured it would save time in not having to sand, prep and paint,painted rhs.

Mostly, it is personal preference, and for a private build you can justify the extra cost of the pre-gal'd, as well as the time to grind each join before welding.
With your pre-gal'd RHS, you can get an aerosol can that's supposed to match the pre-gal'd finish, you could Cold Gal first, then paint those areas to blend them in.

Well its nearly finished. Grinding the gal wasnt too bad and resulted in less spattering when welding. Converting the drawbar to tilt function was time consuming but worth it in the long run I think. I will probably paint it down the track anyway. I have found a paint system that can be painted directly onto the gal. It just needs a scuff over first. It's LIC brand made by Valspar. Expensive, $180 for 5L ( mixed colour in a RED ) 2 pack . I guess you pay for the convenience of not having to use an etch primer first.