Sunday, December 18, 2011

Old Rivets

I like to walk the deck before every sail and set my eyes on all the pins, buckles, etc.... pull the rigging wires in little circles, testing how much play they have.... make sure shes sound before heading out. As I was inspecting the mast base I set my eyes on the boom and noticed one of the rivets that fastened the boom to the goose neck was tweaked a little sideways. I inspected the rest and was shocked to see that three of the five rivet heads were gone! That left just one intact rivet and the tweaked one holding it together...not good!
How did I miss this on previous deck-walks! It was a reminder to take my time and be thorough in the inspections. I inspected the other rivets on the boom and the heads looked good but we decided to replace em all to be safe. Jeff and I spent the evening replacing the rivets at both ends of the boom. Even though the aft end looked good I would never trust it without pulling it apart and inspecting it for corrosion etc.

After that I looked up the mast at the long row of rivets fastening the sail track.  I hope I don't have to replace all of those!
Today I broke out my assender setup and inched myself up the mast a foot at a time on a special rock climbing rope. I wanted to inspect the rest of the rivets and fittings up the mast, if some of the forty year old rivets were bad.....what of the rest?
I got to the spreaders and immediately spotted some problems. The top rivets securing the port spreader plate had failed and the plate was separating from the mast. the starboard side looked intact but a thin gap that was not there before was evidence they were stretching out and needed replacing.
I swung around to the sail track and spotted six rivets with heads missing.
Ok.....a major rivet refit is required before sailing!
I descended on the grigri to the deck....no sailing tomorrow as planned......sigh.
If you have a "classic plastic" vessel with old rivets be sure to inspect them before every sail for potential problems. When things go bad under load it can really ruin ones day!

11 comments:

Bruce, de cuz. said...

those new rivets should hold until you are 80 years old... :D

Don said...

I sure hope so!

Anonymous said...

did you use stainless or aluminum rivets, i have my mast down and while i dont have any bad ones, probaly good idea to swap them, many people recommended stainless, i am thinking of going this route with tel-gel applied. do you have rond spreader sockets...thank you

Don said...

I replaced the missing sail-track rivets with aluminum as i didn't have any stainless ones available at the time and needed to move my boat to a different marina while they rebuild the marina I was in. Stainless is preferred and I will be swapping them out when I can. If you have the mast down and the track off; its recommended to apply rubber or plastic tape to the back of the sail track to act as a gasket and keep the stainless and aluminum apart. Tef-Gel is an excellent product, I use it on every fastener and recommend it.
My spreader sockets are round and welded to plates that were fastened to the mast with rivets. I drilled out the rivets and thru bolted the plates with stainless fasteners with a liberal coating of Tef-Gel.

Anonymous said...

thank you, i have the same setup. stainless spreader sockets, if i may ask, how did you thru bolt it? I have a large 1/2 bolt though the center of the 2 plates, that seem to hold the 2 plates to the mast pad then the mast. i have 4 rivets in each that i guess would keep the plates and lower shroud tangs straight. if this sounds like your arrangement how did you through bolt the plates. BTW i really appreciate the help as i am new to boat repair. thank you for the help

Don said...

Sounds identical to what I have. Between the stainless plate and the mast is a contoured aluminum "shim", contoured to the mast curvature and flat where the stainless plate is against it. First thing I did was use a large C clamp and clamped the top to remove the gap (mine had worked loose) and keep things in place when I drilled out the rivets. Before drilling I did some eyeballing and measuring to make sure the holes would line up for a thru-bolt before drilling. They looked good so I drilled out one set of rivets (one each side of the mast), applied a liberal amount of Tef-Gel to the bolt and thru-bolted it. It took some wiggling to get it lined up but it went fairly easily. make sure to use a bolt that is not threaded all the way down to the head. A bolt with a shoulder is much stronger. With the mast down its easy. Aloft I took a few different lengths with me to ensure I had the right one. A couple washer and a nylock lock-nut completed the assembly.
Cheers, Don
PS happy to help, feel free to ask with any questions.

Anonymous said...

Thank you, this helps. i have some small gaps as well. do you happen to remember what size bolts you ended up using? a bit of FYI, i took my spreaders off and found the holes where the attach to the socket wollowed out. this cause the spreader to start rubbing on the bottom of the socket. while my spreaders only had a little wear, i have read on A30 site where it cause someone to be disasted. i am having sleeves put in my spreader at the machine shop so that should take car of the rubbing. thank you again for all the help

Don said...

My pleasure, thanks for the heads up on the spreader sockets! I will have a good look at those when I go aloft again.

Don said...

oh the bolts were 1/4 inch and I cant remember what length I used, I took three sizes I think 4-1/2 inches might have been it but I cant be sure.

Anonymous said...

replaced rivets and cross bolted the spreader sockets. thank you for the help

Don said...

anytime, glad I could help :-)