New TT with Rusty Bottom

Thank y'all again for your thoughtful replies. I'll pass him a link to this thread so he can read your posts. I'll let him decide whether to post any of his photos.

Y'all have been a great help. Really appreciate it.

Pretty common especially if was hauled during the winter through the salt. Nobody does an undercarriage wash on these things. If you see any signs of pitting or flaking then it should take care of it sooner than later. I usually just take a wire brush to get the loose stuff off, slap on some naval jelly, rinse, prime, then paint.

Not uncommon. We've been a victim of a TT being delivered to the west coast during a bad winter with lots of salt on the roads. The dealers make zero effort to rinse the salt off. The TT manufacturers could also care less. The frame steel has a minimal thickness of protective coating (powder coated) and plated fasteners and components like jacks and steps also have a minimal thickness. Corrosion is inevitable.

I think you could categorize the corrosion as cosmetic tho. The worst area could be in the A-frame where the battery is. Even though I moved the battery inside, I just noticed the angle steel where the battery was is now badly rusted. I need to get under our TT some day and do some touch ups.

Some kind of rust converter paint would work. Rustoleum professional is good and POR-15 might also be a good choice for this. Rinse metal well with water and use a wax & grease remover to get it nice and clean. Scrape and sand any loose paint down. Also scuff the paint with coarser grit sandpaper.

I don't think I'd use any phosphoric acid based metal prep product, but that's just me. You have to be extremely careful in correctly rinsing it off or the paint may not properly adhere to the metal and you can end up with paint failure. Most car restorers recommend against it for that reason. A rust converter paint would be the best choice IMO because you don't need to clean the metal to bare & shiny.

The plating on the nuts & bolts on our elec. stabilizer jacks was so thin, they started to rust badly after just one year and looked awful. I replaced them with stainless steel.

If your friend is 70, I'd leave it alone and go camping instead. Working upside down under a trailer and crawling around is not fun, even if a person was in their 20s. I would just do an inspection yearly and only touch up any possible spots that look like they need attention.

I sure do appreciate your replies. I'd like to post some photos, but they're not mine and I should respect my friend's privacy. The next time I speak with him I'll see if he'd mind.

So it looks like y'all don't think rust is much cause for concern. My friend is pushing 70 and I'd think he'd be better off not working too hard down there under the trailer. Well, I suppose he can find someone to hire if need be. Poor fella...

Jim@Hitek
What I've done to both of my Class A rigs with rusty undercarriages is stabilize it by spraying and brushing on Jasco Prep & Primer. It's inexpensive, Home Depot carries it in the paint department. It chemically changes the rust back into metal and halts it's progression. It can be painted afterwards but I don't bother. Just stabilizing it works fine.

Another discoverer of Jasco!:)
You can use the Jasco to remove oxidation in fiberglass, too.

I used to do fair amount of painting and Jasco was one of the products I used. There are stronger phosphoric acid based rust neutralizers but a user needs to careful with personal protection and over-spray. One of my favorites is Water Softener Cleaner, the green liquid in a bottle. It rivals some of the auto body etchants I've used and is a lot cheaper. I apply it, typically, with a garden sprayer or, for small jobs, with an empty Windex hand held bottle. Sometimes, I dilute it for just surface rust.

Not too uncommon; After purchasing a TT, I spend a few hours under the camper with a few cans of "bed-liner" rattle can paint; It's a touch paint when dry and has good coverage; Every winter I then apply a mixture of WD40/Marvel M.Oil to
the whole chassis. Does not allow rust to develop.

A can of rust converter, a paint brush and a couple hours of his time will cure the issue for his lifetime.

Like others have said, the chassis might be pulled to the manufacturer through salted slush and then sit for months before they get around to building a RV on it.

Good news is that rust takes years to eat through even a quarter inch of steel so your friend has a long time before the thing crumbles to dust.

What I've done to both of my Class A rigs with rusty undercarriages is stabilize it by spraying and brushing on Jasco Prep & Primer. It's inexpensive, Home Depot carries it in the paint department. It chemically changes the rust back into metal and halts it's progression. It can be painted afterwards but I don't bother. Just stabilizing it works fine.

The rust can make things harder to work on under there.

Some pics would be helpful. I’ve seen trailers manufactured in d cement and January that were shipped in the winter with minimal rust. I’ve seen others that looked how your friends is described.

I think we would like to see pics before we can comment any further.

The frames are bought from a third party that might put some paint on them when built. They can sit in the open for extended periods of time before the mfg builds a trailer out of them. Sadly common occurrence. Every trailer I have purchased new I've repainted the tongue and frame.