I had a bunk failure wherin the bunk came off (mid bunk port side) due to the bolts failing. I am in the process of finishing up my trailer reclamation project. I replaced all the old bunks- most of the wood was in decent condition (it is a 2000 X) except one of the V bunks split when I took it off so it was ready to go. The bolts were atrocious- I think they were steel- they were unrecognizable as bolts- the threads were even gone. I had to get info on them from Bill at Boats 4 Sail since I couldn't exactly match them due to their state. (BTW- I am in salt water, and the PO's launched in salt water as well.)
I used 1/4-20 2 1/2" SS bolts with SS nylock nuts. I also replaced all the wood and carpet on the bunks. I thought seriously about installing longitudinal bunks, but decided against it as I bottom paint on the trailer and that would make it more difficult, plus the transverse bunks keep the CB up in case the line fails.
I also stripped the trailer metal, knocked off some of the surface rust and coated it with POR-15. That stuff is heavy duty! It isn't the smoothest finish (I did coat it with Chassis Coat Black also); I wouldn't paint the exterior of my car with it, but it is excellent for the trailer.
Having said that, for those wanting to redo your trailers. I would seriously think about just buying a new galvanized trailer when yours starts to show signs of failure rather than rehab the whole trailer. I recommend keeping your trailer alive with good PM as long as you can safely do so- then replacing. The work required to strip, sand, brush, and repaint the whole trailer is very significant. I have POR-15 on my skin that won't come off after 1 week, a spot got through my painting jeans onto my knee. I have scrubbed it, used acetone- it is on me until all affected layers of skin have left me. It is nasty stuff- good for the trailer though.
I also rewired the trailer as the old wiring was wearing out. Replaced the trailer lights as well. I hesitate to mention any of this as I don't think I'd do it again- but I know this place is full of DIY'ers. I thnk that my trailer will be good for a LONG time now. POR-15 won't even sand very well- it is pretty tough.
Here are some test results on the stuff:
ASTM B-117 Salt Spray - The oldest and most wildly used weather cabinet test. It introduces a spray in a closed chamber where specimens are exposed at specific locations and angles. It creates a 100% relative humidity condition in the exposure zone.
Two separate B-117 tests. One with new steel and the other with rusted steel.
No change in 3 panels of new steel exposed for 250 hours at 98 degrees. Thickness = 2 mils
No change in 3 panels of rusted steel exposed for 1000 hours at 98 degrees. Thickness = 2 mils
Here is the site:
http://www.por15.com/product.asp?productid=6
Jeff S