Bolt Together Aluminum Trailers. Yes or No? Possible Problems? - The Hull Truth

Saro · 10-01-2009, 03:25 PM

Hello all.
I have no personal experience with bolt together aluminum trailers and was hoping to get some feed back. From what I hear, the reason why they bolt aluminum trailers together is because aluminum has a fair amount of flex. If the trailer is welded together these welds can crack. Is this comment true? If you bolt an aluminum trailer together what are the best nuts and bolts to use, stainless steel or galvinized steel. I want a trailer that is almost rust proof so stainless seems the way to go, but I also hear that stainless reacts badly with aluminum. Is this true, does it react that much worse than aluminum does with galvinized steel? Do you definately need to insulate the nuts and bolts from the aluminum frame with some kind of rubber washer. If so what is the best to use? And lastly, do you find that all these nuts and bolts tend to keep vibrating loose leaving you with having to tighten them up every year or so?
Thanks for reading. Any feed back is good!!!

First Light · 10-01-2009, 05:35 PM

Good thing you asked, as you have heard some bad information. Aluminum boat trailers, like steel boat trailers "both" flex, and some flex a lot. To the best of my knowledge, all aluminum trailers are bolted together with either galvanized or stainless steel hardware (at least those boat trailers manufactured in coastal areas), and there are literally tens of thousands of aluminum trailers in use around saltwater today. I have three, and I've been using aluminum boat trailers exclusively for the past 40 some years.

As for galvanic corrosion, unless you leave your aluminum trailer in the water for prolonged periods of time, your aluminum trailer will outlive you, so isolation of the aluminum and galvanized or stainless hardware is a non-issue.

As for nuts and bolts vibrating loose - also a non-issue. If the trailer has galvanized hardware, the galvanizing on the bolt holds well to the galvanized coating on the nut. And similarly, if stainless bolts are used, most trailer manufacturers use nylock nuts or lock washers - nylock nuts have nylon inserts inside of the nut that locks the nut onto the bolt. This is not to say that a wise trailer boater does not have to check his nuts now and then.

Saro · 10-01-2009, 07:42 PM

Thanks for your input first light.
Another question. If the aluminum trailer has stainless nuts and bolts. Even though aluminum doesn't rust, neither does stainless steel. Is it, a case of, if salt gets in between these 2 metals then corrosion begins? If so does that mean that every time you dunk your trailer into salt water do you need to wash with fresh water every nut and stainless nut and bolt thats touching the aluminum?
Thanks again!

Quote:

Originally Posted by First Light

Good thing you asked, as you have heard some bad information. Aluminum boat trailers, like steel boat trailers "both" flex, and some flex a lot. To the best of my knowledge, all aluminum trailers are bolted together with either galvanized or stainless steel hardware (at least those boat trailers manufactured in coastal areas), and there are literally tens of thousands of aluminum trailers in use around saltwater today. I have three, and I've been using aluminum boat trailers exclusively for the past 40 some years.

As for galvanic corrosion, unless you leave your aluminum trailer in the water for prolonged periods of time, your aluminum trailer will outlive you, so isolation of the aluminum and galvanized or stainless hardware is a non-issue.

As for nuts and bolts vibrating loose - also a non-issue. If the trailer has galvanized hardware, the galvanizing on the bolt holds well to the galvanized coating on the nut. And similarly, if stainless bolts are used, most trailer manufacturers use nylock nuts or lock washers - nylock nuts have nylon inserts inside of the nut that locks the nut onto the bolt. This is not to say that a wise trailer boater does not have to check his nuts now and then.

MadScientist813 · 10-01-2009, 08:12 PM

Quote:

Originally Posted by Saro

Thanks for your input first light.
Another question. If the aluminum trailer has stainless nuts and bolts. Even though aluminum doesn't rust, neither does stainless steel. Is it, a case of, if salt gets in between these 2 metals then corrosion begins? If so does that mean that every time you dunk your trailer into salt water do you need to wash with fresh water every nut and stainless nut and bolt thats touching the aluminum?
Thanks again!

salt water can be a nasty force when it comes in contact with metal. even the aluminum will start to pit and you will develop some surface rust on the stainless. This isn't really enough to do the trailer in or weaken it beyond repair though. Just for safe measures, why not take the extra 2 minutes and rinse the trailer off. you need to rinse the leaf springs and brakes anyhow