Replacement Boom Vang Tang

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J-109 Emoticon
Posts: 16
Joined: Tue Aug 18, 2015 3:41 pm

Replacement Boom Vang Tang

Post by J-109 Emoticon »

Has anyone had to replace the tang on the Sparcraft F550 boom? According to the website it’s part #35241.406.043 performance size 3&4 however wanted to see if anyone had some experience with replacing. Mine has developed a hairline crack so will look to replace before a hopefully breezy NA’s.
Mvallus
Posts: 44
Joined: Mon Sep 22, 2014 9:40 pm
Location: Michigan

Re: Replacement Boom Vang Tang

Post by Mvallus »

Replaced mine this spring. Similar issue with hairline crack on aft-facing edge, which freaked me out. I would recommend others take a close look at their tang welds. I ordered the replacement from Rig-Rite (make sure they send you the version that is the matching replacement; they originally sent me a beefier version that would have required drilling new holes).

Replacing requires drilling out the rivets on the tang (4 rivets), on the two swivel padeyes for the main sheet attachment (2 rivets each), and the boom end fitting (5 rivets-I think). Surprisingly, with the right sized bit, the rivets came out a lot faster than I thought. Everything should then slide right out of the track. The boom-end fitting may require a few taps with a hammer to get off and back on. With the fitting off, I found this a good opportunity to clean/check the mysterious outhaul blocks. I would recommend you do this on land to prevent losing any parts and to be able to stand the boom vertically to retrieve any sheered rivets.

Of course, all of this requires you to rivet things back into place, which actually tends to go quite quickly. The various part numbers are listed below, including a much more powerful rivet gun than the older style.

Rivets: https://www.mcmaster.com/97524a110

Rivet gun:

Tang piece (scroll down to part NB2-16-16): https://www.rigrite.com/Spars/Sparcraft ... 0_boom.php

Phoenix 251
sfbarber
Posts: 8
Joined: Tue Jun 30, 2020 12:42 pm

Re: Replacement Boom Vang Tang

Post by sfbarber »

Have you been able to find this tang anywhere else? Rig-Rite is closed until end of August and mine is broken along the weld. I need to replace this soon. do you have a part number or manufacture?
Mvallus
Posts: 44
Joined: Mon Sep 22, 2014 9:40 pm
Location: Michigan

Re: Replacement Boom Vang Tang

Post by Mvallus »

May want to try Charleston Spar. Check out page 17 of the Charleston Spar J/109 Mast manual (should be in the document section under "info"). Also, as an update to my previous post. The aluminum rivets I originally used became loose. I re-secured with stainless rivets. Much stronger. Rivets were purchased from McMaster: 1/4", 0.251-0.375" https://www.mcmaster.com/catalog/127/3577

- Charleston may also stock proper rivets.
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