Corroded hole

[obmij]

My mast gate is closed by a thingy, held in place with a wing bolt. Recently the wing bolt refused to stay where put and further investigation revealed that the hole had corroded slightly. The mast, I believe, is aluminium. Not sure what the fixing is.

Right now the thingy is being held in place by a bodge. Can I replace this with a larger wingbolt, and would this self tap?

Any info or input appreciated.

 

[macd]

If the corrosion isn't too extensive, the best fix would be a thread insert*, thus retaining a fastener of the original size. It may also be possible to tap overzsize (say to 8mm if formerly 6mm), if you don't mind a slightly bigger wingnut.

* such as Recoil, Helicoil.

 

[savageseadog]

Only problem with a thread insert is there's very little thickness to set it into. My own choice would be a stainless threaded insert, a Nutsert, a bit like a pop rivet with threads. If there's no problem doing so, simply a larger thread is OK too.

 

[vyv_cox]

I cannot quite picture your thingy but if you can introduce some plastic between the non-aluminium of the thingy/wing nut and the aluminium of the mast, future corrosion will be reduced or arrested.

 

[bigwow]

Dipping your wing-nut thingy in Duralac might help

 

[alahol2]

I had this problem, I drilled and tapped the hole out to the next thread size and used a larger bolt. If the 'thingy' has a slot, that may also require enlargement. Perfectly OK now for last few years.

 

[neilf39]

I also had the same issue and tapped it to the next thread size. I also then used a normal bolt (with Duralac) as the sail used to catch on the wings when being hoisted, and the only time I need to open the gate is to put on or take off the sail at the start and end of the season.

 

[obmij]

Thanks guys. All advice taken on board. I'll duralac / plastic coat either way.

 

[vyv_cox]

Thanks guys. All advice taken on board. I'll duralac / plastic coat either way.

The plastic doesn't need to be sophisticated. Sticky-back plastic is good for flat bolted or riveted fittings, e.g. on booms. I use plastic water-pipe as bushes/bearings in my gooseneck. Pieces cut from 5 litre bottles make good isolators.

 

[TiggerToo]

I had a similar problem. This was solved using a "RIVNUT". No problem at all over many seasons, now.

 

[VicS]

My mast gate is closed by a thingy, held in place with a wing bolt. Recently the wing bolt refused to stay where put and further investigation revealed that the hole had corroded slightly. The mast, I believe, is aluminium. Not sure what the fixing is.

Right now the thingy is being held in place by a bodge. Can I replace this with a larger wingbolt, and would this self tap?

Any info or input appreciated.

I cannot quite picture your thingy but if you can introduce some plastic between the non-aluminium of the thingy/wing nut and the aluminium of the mast, future corrosion will be reduced or arrested.

I suspect that the OP has a Proctor mast

and that his problem is nothing new as this link shows. ...... http://www.ybw.com/forums/showthread.php?365161-Proctor-mast-gate

.

 

[sailorman]

SS Spars had a similar sail gate

 

[obmij]

That's the one Vic!

I am nowhere near my boat right now - I'm guessing the hole is suitable for an M6 insert..sounds right? Maybe M8?

 

[VicS]

My mast gate is closed by a thingy, held in place with a wing bolt. Recently the wing bolt refused to stay where put and further investigation revealed that the hole had corroded slightly. The mast, I believe, is aluminium. Not sure what the fixing is.

Right now the thingy is being held in place by a bodge. Can I replace this with a larger wingbolt, and would this self tap?

Any info or input appreciated.

That's the one Vic!

I am nowhere near my boat right now - I'm guessing the hole is suitable for an M6 insert..sounds right? Maybe M8?

Just some thoughts

Drilling out and taping for a larger screw size will probably result in a bigger thread pitch. The mast wall thickness may not be sufficient for this to be a good idea


An insert, such as a Nutsert or Rivnut, should really have a countersunk head so that the gate can still lie flat against the mast surface.


This might be a time when Tef Gel would be a better choice than Duralac.