Riveting

lilcumpi

Member
Hi, recently I snapped the kicker tang on my mast and so I need to replace it. I was wondering what size drill bit will I need to drill out the current rivets that remain and what size/type of rivets do I need to attach the new fitting?
thanks
 
You'll need a 3/16 drill bit or 4.5mm drill bit. I prefer monel 6.6 monel rivets (3/16 / 4.8mm rivets with a grip length of 6mm). You can also use stainless steel rivets instead of monel nickel rivets. It's also sensible to use an corrosion inhibitor between the rivets, fitting and the bottom section, I use zinc chromate paint which has the local trade name of Duralac, more popularly known as yellow gunk or cockie s***. I've tried other corrosion inhibitor compounds, but have returned to Duralac.
 
I sheared the Vang tang off'n my boat too. If you just have the rivet stems (without the head) in the mast tube all you have to do is take a nail and hammer and punch them on through and turn the bottom section upside down to dump them out.

If you ever need to take out a rivet get a large drill bit and drill off the head of the rivet then punch the stems through you don't need to drill them out in the hole.
 
When using an oversized drill bit, you run the risk of increasing the hole diameter. You're better off using the same size drill bit, which will still remove the head of the rivet. But Wessel is correct, the aim is to remove the head of the rivet so that the remainder of the rivet can be punched back through, you don't try to physically drill the rivet through the hole. Sorry I should have clarified that earlier.
 
if the rivets have the head on them, take a large drill bit and drill them (in the center) down until the head comes off, the head will come off before you drill into the mast, then pop out the rest of the rivet by lightly hammering them with a nail punch

if the originial holes are damaged you should go to a bigger rivet so that the repair will last, if the holes are in good condition you can use the original rivet size

if the alluminum is corroded badly around the holes its probably time for a new spar
 
if the rivets have the head on them, take a large drill bit and drill them (in the center) down until the head comes off, the head will come off before you drill into the mast, then pop out the rest of the rivet by lightly hammering them with a nail punch

if the originial holes are damaged you should go to a bigger rivet so that the repair will last, if the holes are in good condition you can use the original rivet size

if the alluminum is corroded badly around the holes its probably time for a new spar

If the holes become oversized and/or corroded, I would thru-bolt with a washer on the inside instead of re-riveting.. But that's just me.
 
IMHO, through-bolting w/ arced washers on the inside and good quality SS hardware is always preferable. Everything on my boom and main sheet block is through-bolted, and next will be the padeyes for the hiking strap.
 
Thanks AlanD for your advise, using the technique you suggested I have completed the repair today and all went well. thanks again
 
IMHO, through-bolting w/ arced washers on the inside and good quality SS hardware is always preferable. Everything on my boom and main sheet block is through-bolted, and next will be the padeyes for the hiking strap.

Including the vang plate on the boom?
 
RE: "Including the vang plate on the boom?"
Correction - I forgot that my vang strap is currently riveted. It was in fine shape when I through-bolted everything else and I ran out of time. If I had the time, I would've done it and porbably done something to round over the edges of the nuts. Sorry for the confusion.
 
Ask and ye shall receive.

The last picture on this thread and the description will give you the basic idea. I prefer to use SS fender washers and bend them to match the curvature of the boom. Using the method described, when you have the screw sticking through the boom (and you should make sure you buy ones long enough to do this), put the block in the strap and put it over the bolt. Thread on a plain nut, add loc-tite and tighten. Next, clamp a pair of Vise-Grips on the end of the bolt and tighten the nut completely. Cut the bolt off about 1/4"++ above the nut w/ a Dremel or hacksaw and clean the threads. Then add what is called a "Nylock" nut, which has a nylon insert and will not come loose. In case you are wondering why you don't use nylock nuts from the beginning, it is because they are designed to be extremely difficult to thread over a long distance. Once the nylon insert engages the threads you will not be able to rotate it with your hands and there is no way to keep the screw from rotating without ruining the threads.

Code:
http://sailingforums.com/threads/nuts-bolts-rivets-boom-repairs.7679/#post-46915

Also, you can never use too much Lanocote.
 

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