Advice on repairing rust/corrosion

[CJA12005]

Hi all,

Two small problems that i need to do something about sooner than later.

1 - Have noticed that my boat trailer is starting to bubble up in places due to rust. Seems to be in areas such as the holes which allow the cables through for the lights and so on. Also in the corners were the welds are.

Now that the galvanized coat is compromised it looks as though the rust will continue as the salt water can get under quite easily.

Need advice on the best way to repair this...Was thinking about using a needle gun and giving all the awkward areas a real going over then a hit of rust converter and then epoxy paint??

2 - Also seem to have some flaking areas on the outboard due to salt water corrosion breaching the paint work.

What works best to deal with this, as it seems that trying to sand these areas down by hand would be a real nightmare (very awkward places) and would not result in a good job anyway.


Appreciate any words of wisdom.


Cheers,

[Wombat200]

For your trailer - take it down to your local sand-blasters & ask him what he'll charge - it might suprise you. There will be no better way of clearing up the rust. Then you can rip in with your chosen rust preventitive paint. I did this recently with a trailer I built from scratch - I had to stop work on it for several months & left some unprotected welds out in the weather.... One day & $60 later, every weld on the trailer had been blasted, ready for primer...

The same will work for the outboard - although bead blasting will be better (many sand blasters will also bead blast, using plastic or glass beans - gentler on the alloy). However, depending on what pat of the motor it is, you may need to disassemble - at least in part. You don't want beads, etc, inside the waterways.... They can be masked, at your risk. A good etch primer will work well on the alloy, before top coating.....

[PAR]

I think sand blasting a trailer for a few rust spots is a little over kill. It's not unusual for the "entry points" to develop rust first on a galvanized trailer. A cheap method of preventing further spread of the "illness" is to lock down the exposed mild steel and let the galvanized areas continue doing their jobs.

The best thing I've found for this is a polyurethane paint like goo that is used for coating tool handles. I know this sounds weird, but it's the same goo (pretty much) as used on truck bed liner coatings and very tough with a very high adhesion and resistance to moisture. You find it at the hardware store and it's design so you can dip your tool handles in it for better grip, insulation, etc. Most of the time is come with a small brush, so you can paint it on stuff.

Naturally you want to clean the metal, then apply this stuff directly after cleaning off the metal. A few coats of this thick liquid will protect the bare spots.

Lastly, you can use a spray paint made specifically for this task. I've found this stuff is fine for touch ups, just before you sell the trailer to some unsuspecting sole, but not much else, though I imagine if given enough coats (several) it would work to some degree.

The lower leg of your outboard is probably suffering from salt and galvanic corrosion. You can't sand blast a lower leg, it willl work harden the casting and weaken it. Bead blasting, soda ash, walnut shells, whatever the blaster recommends as the "softer" alternative. Personally, I wouldn't bother. I'd just knock off the flaking stuff, feather the edges, prime and paint as needed. When everything is good and dry, several layers of wax on the leg and make sure the zinc(s) are in good shape.

[CJA12005]

Thanks for the advice PAR and Wombat200, cheers.

[Wombat200]

PAR - I'm only talking about spot-blasting the affected areas - not the whole trailer. $60 to have this done was very cost effective - faster & more efficient, and ultimately more effective - than me trying to clear up the rust by hand. A needle gun would work well, of course, but still take ages....