prop change

[67hat34c]

We hauled today and changed the props. We found the nuts were little more than finger tight. However we found that the props were torqued on to the taper. We reinstalled with big nut first then small nut and torqued the best we could. (From walking around the bone yard big nut small nut issue was about 50/50.) We also Lapped the props using valve grinding compound and found one prop did infact ride the key so corrected that.

Thanks for the help on my prior post and from the old posts regarding this issue.

Pulled at the Cape Marina, Port Canaveral Fl. I cant say enough about the way they handle things there. Never seen anyone cover the slings with a plastic coated paper before, but the cover all the slings above the water line to prevent sling stuff from getting on the boat. They also took great care in placing the slings. The travel lift had scales on each sling and they balanced properly between them. Now I know what our 1967 34c weighs. Front sling had 5000lbs and rear sling 15000 lbs so i guess you add them and get 20k lbs.
boat had full tanks of fuel and water, no gear

I also walked out on one dock where Wild Bill's boat is and found 10 Hatteras' on that dock and NO SEA RAYS.

 

[Genesis]

If they were little more than finger tight the props "walked" up the shaft because they weren't properly lapped on the last time! That's what happens if its not done right..... Good thing you caught it....

 

[REBrueckner]

The correct sequence of nuts is thin nut first,against the prop,
then thick nut second. Theory is that the thick nut second adds the most additional strength to the pair. Most shipyards I check (commercial) use that approach.

In practice it seems to make no difference and most recreational boat yards have no idea which is correct...they copy what's already there, just as they do when replacing zincs.

 

[yachtsmanbill]

And the SAGA continues--strain gauges and x rays are next. REAL props have a flanged nut. BEAT me up Scotty--theres no intelligent life down here. Email me and I will be glad to send you pics of 8' prop installs.
ps. the skinny nut is a JAMB NUT.

 

[Wild Bill]

[I also walked out on one dock where Wild Bill's boat is and found 10 Hatteras' on that dock and NO SEA RAYS. ]

We call that area Hatt Row. Sorry I missed the fun this past weekend, but as I said, I was out of town. Would have been nice to meet another forum member.

 

[Boatsb]

sorry there was 11 until I bought mine.

 

[67hat34c]

Wild Bill, we were actualy there on Monday, only day i could count on my dad,brother and the lift all at the same time. We are just down the canal at Harbour town so I will contact you next time I go over. Think next time will be Saturday after Thanksgiving.

noticed the guy that made the fiberglass window frames is on your dock. those are cool. not sure how he bonded the corners however.

The guys in the shop at the cape marina loaned us some tools, they said they usualy dont lend them but they were so impressed with the boat that they made exception.

 

[SKYCHENEY]

What is done in practice and what is scientifically correct as far as prop nuts may not be the same. But, if you read the Passagemaker article a few months ago regarding this issue, you will probably be convinced that the thin nut goes on first. I'm not saying that it is a problem to do it the other way around because it is done that way all the time. In reality, since you have a tapered joint, you really don't need any nuts if the fit is correct. Just look at how hard it is to get the prop off. So, you can put the nuts on in any order you choose, but I'm convinced that the thin nut first is the "correct" way to do it.