Mast step bolts disintegrating

[LifesBetterWhenYoureBeating]

It looks like the heads of the bolts on my (keel stepped) mast step are gone. What are the risks of leaving it like this until I can unstep the mast (provided I find a way to drill the bolts out)?

[psk125]

Risks? The mast could fall over, taking out bulkheads and floors as it levers at the partners and destroys the cabin top. Falling over would likely kink the mast at the same time, making it unusable. Hopefully the bolts are not the only thing holding the step in place, but it is hard to know how well any adhesive or sealant under that plate is actually working. Drilling the bolts (Are they actual bolts or are they lag bolts?) out and replacing them with new ones would seem to be indicated. A new bead of 5200 around the edges of the plate might not hurt either. With a long bit (perhaps welded up to make it long enough) it should be possible to drill out the rusted fasteners with the mast in place. If what they connect to under there is questionable - rotted wood or...air? - the mast will need to come out so that the structure itself can be fixed. If the underlying structure seems ok, you might be able to mix up some epoxygoop into the fastener holes, let it set, and re-drill for the new ones. Good luck!

[LifesBetterWhenYoureBeating]

Right, I understand the damage that can happen if the mast falls over, I was just trying to gauge how urgent it is that I try to at least replace the fasteners as you describe.

As I understand it these bolts don't carry so much load as the weight of the mast won't allow much movement, no?

I believe they are fastened to a threaded steel plate built into the fiberglass (as is the case with other deck hardware on this boat). Still trying to confirm that

You seem to imply that the bolts would not be enough to secure the mast step and that 5200 would improve things significantly. Is that usually the case with keel stepped masts or do the bolts look too small for the task?

[Ballsnall]

Pretty low risk in my opinion. The base of the mast can not move unless the top of the mast moves. The heads of the bolts may be gone but they are still preventing any sideways movement.
Some options for your peace of mind.
1. Use some timber chocks and wedges around the base to secure it.
2. Drill and remove the bolts and replace with larger coach screws.
3. Drill some new holes and fit additional coach screws

[Searles]

It maybe low risk ,in my opinion it’s high risk ,that base could move athaught ships or fore and aft at any time at the slightest imbalance ,chocks and wedges asap but best just fix it as recommended by others.⛵️⚓️

[HeinSdL]

Low risk, provided the rest of the rigging is in good shape, ie under sufficient tension and there is a decent amount of support where mast goes through deck. The compression on the mast is so big that the friction between mast and keel does most/all of the work keeping base of mast in place. If that wasn't the case those bolts keeping the mast step in place would be a lot bigger. On my boat those bolts are quite small too.

Edit: 1. having said that, it does need to be tidied up. I would obviously not advocate to sail around indefinitely and certainly not in challenging conditions (upwind, slamming) with a mast step which can start to shift. 2. the bolts still there in place might be corroded but still unlikely to shear. And if this were to happen, there would be more issues with the rig allowing this kind of sideways movement at the base of the mast then just the corroded bolts

[Ballsnall]

Originally Posted by Searles

that base could move athaught ships or fore and aft at any time at the slightest imbalance.

Yeah right, exactly how can it move if the top of the mast is held firm by the stays & shrouds and the lower mast is secured by the deck collar. All that rigging tension is forcing incredible pressure on the mast step so friction alone will ensure 0 movement.
Yes flogging to windward may not be advisable, but that mast step is not urgent. The shrouds and stays would have to come loose and the mast raise up over the bolt stubs before it could move. It's taken a long time to get to this condition and should be addressed in a timely manner, but there is extremely low chance of any adverse event.

Just waiting for the "O no, your boats not in perfect condition, your going to die crowd" get a grip.

[Rumrace]

You may consider a threadsert or helicopter depending on what the upright stud is threaded into.
Standing water solution should prevent a repeat.

[boatpoker]

Originally Posted by gsalgado

It looks like the heads of the bolts on my (keel stepped) mast step are gone. What are the risks of leaving it like this until I can unstep the mast (provided I find a way to drill the bolts out)?Attachment 265511Attachment 265512

Photo #2
Looks like ss plate, ss washer, steel nut ( bolt ?) and copper bonding tab.
If I'm correct that is quite the galvanic soup.

[LifesBetterWhenYoureBeating]

Originally Posted by boatpoker

Photo #2

Looks like ss plate, ss washer, steel nut and copper bonding tab.

If I'm correct that is quite the galvanic soup.

Shouldn't the step be aluminum, like the mast? The washer is definitely stainless and is in perfect condition, the bumpy, disformed blob fore/aft of the bolts is 5200 (or similar).

Since taking the photos I've removed the 5200 above the plate, chipped away more on the leftover studs and removed the washers. Now I'm left with seemingly solid studs reaching up about 2mm above the step, and the hole on it is rectangular (filled with 5200). I'm inclined to try and drill holes for new bolts within the rectangular hole of the step, without trying to drill out the existing ones

[psk125]

Originally Posted by gsalgado

I'm inclined to try and drill holes for new bolts within the rectangular hole of the step, without trying to drill out the existing ones

If the understructure is solid, that would be a good quick fix.

[boatpoker]

Originally Posted by gsalgado

Shouldn't the step be aluminum, like the mast? The washer is definitely stainless and is in perfect condition, the bumpy, disformed blob fore/aft of the bolts is 5200 (or similar).

Since taking the photos I've removed the 5200 above the plate, chipped away more on the leftover studs and removed the washers. Now I'm left with seemingly solid studs reaching up about 2mm above the step, and the hole on it is rectangular (filled with 5200). I'm inclined to try and drill holes for new bolts within the rectangular hole of the step, without trying to drill out the existing ones

Correct, the plate should be aluminum but it looks more like SS.
if plate aluminum and nut/bolt is steel, the aluminum would corrode.
If plate is ss and nut/bolt are steel, the steel would corrode.

Is there a ground wire involved ? Photo looks like maybe a ground tab.
Got any better photos with it cleaned up ? It's difficult to tell from the photo
so I'm just guessing right now.

PS. Retired Certified Marine Corrosion tech.

[LifesBetterWhenYoureBeating]

Originally Posted by boatpoker

Correct, the plate should be aluminum but it looks more like SS.

if plate aluminum and nut/bolt is steel, the aluminum would corrode.

If plate is ss and nut/bolt are steel, the steel would corrode.



Is there a ground wire involved ? Photo looks like maybe a ground tab.

Got any better photos with it cleaned up ? It's difficult to tell from the photo

so I'm just guessing right now.



PS. Retired Certified Marine Corrosion tech.

There was no bonding wire anywhere around the mast step, and when cleaning it seemed like there was only a washer under the bolt's head. Here are some photos after the cleanup, including of the area where the mast enters the plate. By the way, I thought the plate was soldered onto the mast but it looks like it has a hole the size of the mast base, and the mast is just sitting there. If that's the case I should be able to unstep the mast without having to drill out the corroded bolts, and that would make it a lot easier to drill them out.

[boatpoker]

Two types of steps I've seen.
1. the mast step has a male protrusion and the tube of the mast fits over it.
2. The mast step has a raised female wall into which the mast fits.

Never seen one where the mast fits into a hole in the plate