1. I know there's something that trailer mfrs are supposed to do when they build a trailer with alum skin and steel frame... something to do with the fact that the skin and frame aren't supposed to directly touch.  What is it they're supposed to do?

2. Is it true that the average mfr's structural warranty "never covers leaks, not even in new trailers"?

Aluminum over steel trailers that I've seen have used a 3M tape to affix the aluminum to the steel frame. It's a double sided tape that they apply to the steel then stick the aluminum to it. They may also add a few rivets at structural points for added strength. The tape does two things. 1st it's a method to affix the aluminum panels to the frame. 2nd it provides an insulating layer between the two metals. So that they don't interact. Dissimilar metlsl can have a Galvanic corrosive effect on each other.  Even if the double stick tape is not in place, The steel is usually coated with a galvanized coated and the aluminum is usually painted. These surface finishes will also act as a barrier between two dissimilar metals preventing corrosion. But in a moving horse trailer where friction may rub the finish off, a tape is usually used.

Also certain metals are more compatible than others. Engineers use a chart that shows the compatability between various metals.I suspect most trailers manufactures consult such a compatability chart when choosing their metals.

Thanks PH.  Anyone else?  Anybody know about leaks being covered by warranties?

It is easier said than done to make the trailer water tight and many problems occur around the windows.  I constantly complain to the window manufacturer about leaky seals, no adjustment to the strike plate, etc. and I am not sure it does any good.  Many window manufacturers use a drip rail as a solution.  We have tried different window manufacturers and nobody makes a water proof window--Statewide, CG, Hehr.  Our trailers are water tested before delivery and occasionally they will still leak. 

Can you imagine if your windows in your house leaked and the company send you some drip rail??  Freaking ridiculous isn't it

Anyway, on to your question.  Most companies use a sticker that says something similar to "there is no warranty on leaking windows".  If your company won't help you, email me and I will help!  If the leak is coming from somewhere other than the window, you have a bigger problem.       

Thanks for your reply.    Unfortunately, it's not the windows.  I mean, the windows probably leak (the cut wasn't done smoothly and you can see some daylight) but the bigger issue is elsewhere.

My situation is freaky and embarrassing. 

I bought a new trailer that had sat on a lot of an RV dealership for 3 years, and I did my research on the brand from my home 12 hours away... by calling the mfr, looking at their website, asking for closeup pics of the trailer itself, and asking around for feedback on this brand. 

This mfr ONLY makes galvanneal steel skin / steel frame trailers, and the construction process is described as being as close to faultless as I could tell.  It wasn't until I got down there that I realized we had some issues with leaking. 

The dealer and my husband agreed it would be easily solved with a rivet gun so we brought it home.  AFTER an RV repair shop spent a few hours re-riveting and re-sealing, I noticed that it was still leaking.  It wasn't until I called the mfr back (this is like the fourth time I've spoken with him at this point, and the second or third time I've sent pictures) that he told me... get this...

My trailer is one of a dozen or so that they made with aluminum skin / steel frame.  They stopped making them because the manufacturing process was different enough from what they normally do, and time consuming enough, and expensive enough, that they wouldn't have been able to keep their trailers in their preferred price point.

So my trailer, in essence, is a failed experiment.  And nobody told me.  The ad, in fact, said it was galvanneal steel.

Yes, it's my fault for not realizing that if the skin is riveted, it's aluminum... ie not everything was as it should be.  I feel really dumb... but in my defense it was advertised as galvanneal steel and it looks just like the ones that are now on the mfr's website!

I sure hope these leaks can be fixed, I'd like to walk away having paid an excellent price for an aluminum trailer... not way too much for a sieve.

To properly seal rivets, they are individually dipped in a sealant primer before they are shot.(Fastened into place) If the roof rivets are the culprit, a roof coating could be applied such as an elastomeric product. If the sidewalls are leaking, a clear coating of automotive urethane could be sprayed.

Gard