has anyone seen any problems with the tubular boat trailer frames rusting from the inside out ? I doubt if they have any coating on the inside ?? every time you launch water goes inside then drains back out
On the trailer we use for the one jet-ski it is galvanized box tubes and it rusted from the inside out. I use the trailer more as a cradle in the off season and to tow the ski to the boat ramp about 5 miles away in the spring and then again in the fall to keep the ski at the house for the winter. The trailer is a Sea Lion trailer I purchased with my first ski 14 years ago but this is the 5th ski that used it.
All tolled I know there is less than 300 miles on it. This spring when I was getting ready to put the ski in I noticed rust along the main tongue beam which is about 8' long. Where it is bolted to the cross members I noticed a lot of rusting. I could feel soft spots in the length of the beam that feels like they are where the tube was seamed.
I ordered another tongue and will replace it before it is needed to pull the jet ski out for the season.
The trailer does get put in salt water but there was no viable rust last year so it definitely had water sitting in the tube and rusted from the inside out. If I hadn't been looking for rust I wouldn't know it was as bad as it was and could have ended up snapping the trailer at the ramp or losing the trailer on a turn and damaging the ski.
My boat trailer is aluminium I beam and is 10 years old and is also used in salt water and there is no sign of oxidation at all.
If the tubes have drain holes drilled in the proper places or, if you have drains on the back side and store it with the tongue in the air so the water will all drain out and, it is PROPERLY hot dip galvanized, no reason it should not last 30 yrs or so. But, the more penetrations/holes/attachments you add to it after it was galvanized, the more spots you'll get corrosion.