Mast track bolts stripped...best fix?

mrybas

Member
179
57
Hi,

Started heading south this morning from S NJ.  Got to the far side of the Delaware Bay when I went to go shake a reef.  The sail wouldn’t raise, so I’m looking around for snags, when I noticed about 5 bolts hanging loose from the mast track (the bat cars were catching the protruding bolts). 
I tried tightening them, but there’s no bite.  What’s the best way to fix this....helicoil?

8C40F7E9-1274-4929-B120-9B9F72B52561.jpeg

62EFD806-870C-4231-BF6C-E35D5D4A4C4E.jpeg

 

longy

Overlord of Anarchy
6,282
889
San Diego
Yes, heli coil those fasteners. Any other repairs involving new holes means moving track section around, and that will get very complicated/expensive

 

El Borracho

Sam’s friend
6,345
2,383
Pacific Rim
You need to test all the bolts. Might just be the lower bolts...but how many of them how far up? I would pull the mast out, move the track a bit, re-drill and re-tap new holes for the entire mast. If those pulled out the others cannot be far behind. But that is just me and my offshore safety thinking.

Otherwise Heli-coil is good.

 

Raz'r

Super Anarchist
59,898
4,598
De Nile
Depends on the thickness of the mast. Helicoils require some thickness of course, just like the original bolts did. Maybe Rivet Nuts?

 

IStream

Super Anarchist
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Once one fastener goes, it increases the load on its neighbors, which then give way like a zipper. It's entirely possible that the fasteners farther away from the failure are fine but you need to check them out thoroughly. I wouldn't just see if they're tight because it's possible that there's dissimilar metal corrosion that's eaten the mast threads and seized the fastener but doesn't really have the strength needed for the job. Pull them out, inspect the mast threads and, if okay, refasten with Tefgel or equivalent. If the bulk of the fasteners/threads are okay, I'd just helicoil the ones that failed (also with Tefgel on the insert). If not, you could pull the entire track and helicoil all the existing holes or take El Boracho's suggestion of moving the track up or down and re-tapping but that'll put a lot more holes in the mast.

 

casc27

Super Anarchist
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Are mast extrusions thick enough to helicoil? My first thought was rivnuts but not something I have any useful experience with. 

 

IStream

Super Anarchist
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It's not hard to figure out. Stick a small L or hook-shaped piece of wire into the fastener hole and pull it back until the hook contacts the inside of the mast. Mark where the track is flush with the hook, pull it out, measure the distance from the inside of the hook to the mark, subtract the thickness of your track, and that's your mast thickness.

FWIW, Heli-coils are available as short as one fastener diameter (e.g. 1/4" in the case of a 1/4"-20 fastener) so it's highly likely that mast thickness won't be an issue. 

 

SailRacer

Super Anarchist
3,521
87
If you are underway, get a (or many)  line/Sailties around the rig to stabilize the track until you get where you are going.

IMHO the less holes you put in the rig the better.

Sail Safe!

 

longy

Overlord of Anarchy
6,282
889
San Diego
If the bad bolts are below a halyard exit slot in the mast, you can make up a backing plate, drill & thread it, & maneuver it into location with location with wire coat hanger rod & string. This lets you increase the amount of thread engagement. Use same material as spar tube is made of.

 

Toecutter's Ghost

Anarchist
612
131
Earth
Helicoils work fine in a mast.  Mines got a fair number installed with no problem.  Use super strength loctite when screwing the helicoils into the mast. 

 

slug zitski

Super Anarchist
5,086
816
worldwide
Hi,

Started heading south this morning from S NJ.  Got to the far side of the Delaware Bay when I went to go shake a reef.  The sail wouldn’t raise, so I’m looking around for snags, when I noticed about 5 bolts hanging loose from the mast track (the bat cars were catching the protruding bolts). 
I tried tightening them, but there’s no bite.  What’s the best way to fix this....helicoil?

View attachment 397536

View attachment 397537
Heli coils plus a thread locker 

countersunk heads are notorious for working free...unscrewing 

if your holes are so rounded out , damaged ...shift to a Twin coil 

 
Last edited by a moderator:

CaptainAhab

Anarchist
795
201
South Australia
Depending on the size of the fasteners, Helicoils increase the holding power in soft materials like aluminium. The larger hole has more surface area. Every time a stainless fastener is removed from aluminium takes a little more metal. Helicoils are made from 304 stainless. Bed them in tufgel. 
 

Use a name brand like Helicoil or Powercoil. Make sure you order the correct depth. I think the typically come 1.5 x depth in the kit. They also come 1 x depth. 

 

IStream

Super Anarchist
10,730
2,932
Depending on the size of the fasteners, Helicoils increase the holding power in soft materials like aluminium. The larger hole has more surface area. Every time a stainless fastener is removed from aluminium takes a little more metal. Helicoils are made from 304 stainless. Bed them in tufgel. 
 

Use a name brand like Helicoil or Powercoil. Make sure you order the correct depth. I think the typically come 1.5 x depth in the kit. They also come 1 x depth. 
I think you mean diameter, not depth.

 

longy

Overlord of Anarchy
6,282
889
San Diego
Mcmaster sells 5 different lengths of Heli coils in 1/4 x 20 thread. Measure mast wall to decide. A little long is OK, you want full span of mast wall.

 

IStream

Super Anarchist
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2,932
Mcmaster sells 5 different lengths of Heli coils in 1/4 x 20 thread. Measure mast wall to decide. A little long is OK, you want full span of mast wall.
You don't want to go more than a half turn or so overlong. If you do, it can be tough to snap the tang without screwing up the insert. 

 
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