Tower bolts sheared off

[Eastern shore wake]

Thanks for all your replies. KKO, do want to clarify that we did not have anyone actually wakeboarding after one bolt sheared just that we continued to use the boat which was probably not a good idea as the "jostling" the tower takes as we move through wakes probbaly was enough to shear the second bolt.

Talltigeguy, my tower is similar to the one in your picture but has "Tige" on a top section. The way the structure attaches to the boat, though, looks exactly the same.

I did get it repaired which cost an eye popping $500 as they were not able to 'easy out' the bolts. Took over 5 hours of labor. Also, very difficult to access the underside. Had to go through section which has the throttle on it and had to take apart and then reassemble some of the throttle stuff.

Anyway, we are back on the water so life is good.

thanks!!

[talltigeguy]

Mine does say TIge on it.

Too bad that the bolts didn't shear off on the port side. I have looked at tightening mine down, but they are already very snug. Seems like I would need an Allen wrench that is way longer than the usual 3 or 4 inch puny thing.

[gman]

The industry is now full of counterfits. You need to be very careful as to what you are getting. I saw a one year old tige that had every bolt/screw in the engine compartment totally rusted. Tige and other assembly operations need to purchase to a spec and then test incomming product. Random tests should be performed also. I was in a manufacturing plant and saw stainless steel bolts that were so magnetic that it was not funny. They had the stainless stamp on them and were made in China. The box even had certified test reprt. After some testing it was determined to be the wrong alloy, hardness etc.... Unfortunately this is what happens when you keep pushing for low cost. Manuf just substitute and do not tell you.

[mneal]

The issue with hardware is that manufactures go after lowest cost. The alloys that make up the dozens of different types stainless are very specific and consistent. The problem is the manufacture of those bolts is not (i.e. China). Some industries do use only "certified" hardware (MIL-Spec) and that hardware is certified to have the right alloy, corrosion resistance, mechanical properties such as breaking strength etc. All it costs is $$, that hardware typically costs 2-3X more then non-cert. If they got crap hardware and testing can prove the cert is false that is a bigger deal and they can the leverage to hammered the vendor and should. A stainless bolt being magnetic alone is not really a good judge of it's "quality" some alloys are slightly magnetic, magnetic or some not at all. 308 is really not a viable option, 316 is plenty corrosion resistance for any marine application and far more available.

Oh, the white powder is plain ol galvanic corrosion that happens when a stainless bolt threads into an aluminum thing with no electrical isolation, not a factor in the bolt failure here I bet.
The hardware was not failed or injured in the assembly and simply lacked the tensile strength I would be shocked, that is REALLY bad hardware. There is so much margin in those bolts the "china" hardware or , substandard hardware would have to be like 10% the strength of the nominal value. (I am guessing it was ~1/2" DIA)

[anhaney]

Something else that needs to be brought up is the torque ratings of stainless. In many cases the bolts are over torqued which causes them to sheer off. Stainless it equivalent to a grade 5 bolt in specifications for torque and strength. so if you are needing something stronger upgrade to grade 8 or 9 and use paint as the lock tight. In other words paint the whole bolt install it and touch up the threads from putting the nuts on after it is all installed. But also remember maybe the bolt is the safety point and the place where things are designed to break.