Still working on lock bolt
- Thread starter slowdog
- Start date
Are you buying one or do you already have it and want to know if it will work?
If you already got the bolt, use it. If not buy a stainless steel bolt. You can get the size you need at McMaster Carr.
Still got to get one I thought the brass or allumum would not be as hard on the fiberglass trunk . I can mak one I havea small lathe
I have heard of people using the nylon bolts that you buy for toilets. I have not tried it but the idea is that if lock down with a strong bolt and hit something hard... all of that energy goes into the keel trunk. The nylon bolt will sheer allowing the keel to swing up and save your trunk from damage. I think if you search the archives for nylon lock down bolt, you will find several threads on the topic.
If your keel bolts are stainless steel it I think it is a really bad idea. Dissimilar metals will react with other to weaken the both the bolt and the nut.
The keel on a Mac 22 is 600lb of cast iron. So SS would be better than brass if you are worried about electrolysis. Are you talking about the bolt that you use to keep the keel in the down position in the event of a knock down? You don't really use that bolt very often... at least I didn't. Only in rough weather.
So you are sugggesting the OP get a cast iron bolt and nut?....
As cast iron bolts and nuts are not available, What do you use in yours?..
Nylon?....
what is the SOLE PURPOSE of the lock down bolt?....
A nylon bolt wont even support the weight of the keel once the cable is slacked off so it doesnt hum...
The purpose of the bolt is NOT to hold the keel down, but to hold it up/extended if the boat should become inverted or during a severe knockdown or broach....
Brass or aluminum, NO....
Bronze, possibly cuz its stronger.... but stainless steel is still the best choice.
As far as a soft bolt being easier on the keel trunk if you ground the keel, i can tell you from experience that anytime you have to drive a bent bolt out of the keel hole, its going to cause a bit of damage.
A damaged keel bolt hole IS repairable, but a strong bolt like stainless will take about 4 times as much to distort/bend in the hole as a softer bolt , and one that is snugged up in the hole with a wrench will not bend as much as one that is only hand tight in the hole...
Its your boat so go with whatever option you want, but you wont go wrong if you choose a stainless bolt and nut.
Super bad idea... besides corrosion between dissimilar metals as mentioned above, both brass and alumium are soft metals and will shear off in a heart-beat. Stick with the stainless stock style bolt, use the thickest grease you have which will prevent thread galling and keep water out. If I had to choose another metal alloy to use it would be silica bronze. It is almost as strong as SS and has good anti-corrosion properties, but you'd still grease the threads anyway so why not just stick with the original?
That's why I mentioned keeping spares around.
He's also trailer-sailing his boat in inland lakes, which mitigates, but does not eliminate, galvanic response.
But, you're right.
