I replaced the bent dolphin striker rod but I can not find any reference to how tightly it should be install against the support tang. I seems like it would be pretty critical..
Jon
The dolphin striker V bar (suport tang)should have less 1/4 inch of play when you press on the center of each side.
I once read somewhere about stretching a masons line from end to end of the DS rod, then turning the nut to bend the rod upwards,(preload the beam) a certain amount.
MUMMP told me to just turn the nut til it makes contact with the beam, then turn it upwards another 3/8", that's what I did. I have pictures & a write up in the technical help section.
As HULLFLYER suggests, more than a 1/4" play is to much, here is the reference from the NACRA assembly manual.
"12. Periodically, check the dolphin striker strap tension. It should not move more than 1/4."
. . . to add, the 3/8" pre-bend is a factory spec.
Looked at your tech help pics, and I wanted to comment on them. Cutting through the rod with a hacksaw takes about 2 minutes. Certainly nothing to avoid, especially if you have your boat in a location without A/C or a compressor.
Cutting through the rod with a hacksaw takes about 2 minutes. Certainly nothing to avoid, especially if you have your boat in a location without A/C or a compressor.
Take even less time with a sawzall! I agree. Fastest way to remove the old rod is to cut it away. When I did mine, I turned it down till it contacted the beam and then a quarter turn more.
When I did mine I used an angle grinder with a cutoff wheel to get the old dolphinstriker off. Hacksaw with a NEW blade will work just as well and you wont have to worry about detempering the steel. A used hacksaw blade may not work on the hardened stainless.
Make sure you grease the threads or they could gall (they did for me but I overtightened them. I agree with Larry tighten to the beam and them go another half turn to full turn and no more. If you overtighten you will certainly strip the threads.
D.
You are right, don't shy from using a hacksaw if need be, 304 SS is not much harder than normal cold rolled steel.
I had the boat totally apart after I bought it at the beginning of winter, so the parts were inside with access to power tools. My rod was bent above & below the beam, so had to be cut in two places to remove. I have two angle grinders, one with grinding wheel & one with cutoff,(a necessity when building more docks!)so that's what I used.
Dave I wouldn't worry about changing the temper, if you are cutting the rod, it is now scrap. I think you had a bad thread or nut if you stripped it that easy. I tried to get the top nut off, I used a 12" wrench with a piece of pipe on the end as a cheater. I applied almost 200 ft lb before it stripped the threads & I had to make a second cut to get the rod out. Setting the preload to 3/8" was only about 10-15 ft lbs, no lube used.
Yeah I misspoke there, I meant to be worried about detempering the nuts if you are going to reuse them. Not a huge concern really and you are probably right about the bad threads. Better safe than sorry though, I've had too many stainless and titanium pieces cold weld under pressure so I use grease on all my connections. I didn't earlier this year when replacing my dolphin striker just because i was lazy and didn't have any readily available.
D.
I meant to be worried about detempering the nuts if you are going to reuse them.
Yes, that is worth remembering. It can be hard to find that size in nylock. I fried the nylock insert in one of the nuts as I had to cut quite close to it. It is easy to find 9/16 SS nuts, fine thread, but if you can't get aircraft lock nuts you either have to double nut,(looks ugly)or use lock washers.
Murrays has them for a few bucks each, but shipping up here is $30. That is my one gripe with Murrays, US Post will send that stuff here for a buck or two.
Setting the preload to 3/8" was only about 10-15 ft lbs, no lube used.
One lesson learned from past maintenance and my dealer. Nothing on these boats is meant to be torqued more than the low end of this quoted range. Thus a good torque wrench and thread lube are musts. I had learned my lesson and did not overtorque this bit but previously I had to redrill / retap two of my strap bolts. So if you find yourself applying the elbow grease, back off. Think a tad more than finger tight is what my dealer told me.