I roam the sand beaches of Long Island often. Is there anything like undercoating I should do to prevent rust?

Would love to get a discovery instead for my off road adventures but my job will only chip in for a new vehicle.

Thanks

 

The only way to do it right is strip the frame/underside to bare metal and re-coat.

I put an oscillating sprinkler underneath my truck for 20-30 mins after I get home from the beach. Been doing that since high school. Rust will happen here, there's no real escape.

 

What vehicle are you using now?

Rinsing off would be a good idea. But I would also repair the finish on exposed metal. When the factory finish is damaged from scrapes and scratches, the metal starts to rust. Get underneath and find the spots that are already rusting and clean them off with a wire brush, remove oil, grease, and wax with a solvent (for example: Gunk for grease followed by brake parts cleaner for oil and wax). For more rusted areas, use naval jelly and/or a rust converter product. Prime and paint. You don't need to use a special paint like POR-15, but some people report good results with that. If you just used Rustoleum primer and paint you are better off than leaving the metal exposed and you can easily and cheaply continue to patch it. On top of the primer and paint, consider using a rubberized undercoating. Many of these products perform poorly, but I think the 3M "Professional Grade" product and the product from SEM are good ones. The key is having a clean enough surface that they will adhere.
There are more involved procedures you can undertake with Waxoyl products and even hot-dipped galvanizing, but indeed they would be more suitable for a frame-off rebuild/restoration project.

 

For boxed frames Eastwood sells a frame coating in spray can with special nozzel to coat frame interiors like a spray on zinc coating, a little pricey but worth it if it works IMO, we used it on my brothers truck bed in the hat channels and inside the bed skin, to early to know if it does anything, looks like primer when dry

Iirc the window sticker on my lr3 stated zinc coated frame