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Re-attaching boom block


My aft boom block started to pull out so I needed to completely remove it. I am going to re-attach it about an inch from the original location. Does anyone know what size rivet is used to attach the block to the boom?


Check out what they are selling at the bottom of the page for $5. I've raided the medicine cabinet (dental floss) and for the rest in my tool box. I think they are 10-24 machine screws, fender washers and locknuts. The key is don't go thru both sides of the boom. The dental floss gets the washers onto the screws ect. Much stronger than rivits. And likely less than $2.50 if you needed to buy everything.

Fred P

OK, I give up: how do you get a washer and a nut insude the spar and on the screw with dental floss?!!!



Remove both end caps from boom. Drill out rivets new holes etc. Push dental floss into hole, blow on end of boom until the floss comes out, connect other end to end of machine screw, place washer, lock washer and nut on end that was blown out the end of the boom. Put screw into boom etc. Something like that or spend $4.95 to get the pictures from APS.


Sounds like a challenge. I could see if you put the floss up through the washers and nut and then secured it to a toothpick that would cross the top of the nut that you could pull the washers and nut in and over the hole in the spar. I would wonder how you would keep the nut from turning in the spar. Maybe, if you could get the bolt started, downward pressure would keep it from turning. Love to hear from someone that has actually done this repair. Sometimes the directions don't relate to actual results without a lot of practice.


New Member
I think what I did was much easier, I took an open end wrench and duct taped it to a long stick. I then put a piece of duct tape on one side of the wrench and stuck a self locking nut to the tape. I put some contact cement on the nut and a washer and put it in place. Then I laid the stick along side of the spar and marked at the end where the hole and nut aligned. After putting this into the spar to the mark the screw fit perfectly into the nut. Repeat 3 more times and you are done. After you are set up it is almost as quick as putting in rivets.