My gate stanchion was damaged and I’d like to replace it. Unfortunately, the forward base was badly bent and now seems to be galled into place and is very difficult to remove. It was able to go around about two times before stopping. The upper forward screw on the aft base was also tight. As I understand it, my Hunter had aluminum plates glassed into the hull, so there are no bolts to access underneath. Rather than risk twisting and breaking the screws, I’ve decided to pause for now and consider other options. One suggestion so far is to simply fill the gaps under the bases with 5200 and be done with it. Of course that’s not a very satisfying option. I’m wondering if a little heat, some PB Blaster and S-L-O-W motion would do the trick. Has anyone had similar successes or failures?
Galled stanchion removal
- Thread starter jdrutten
- Start date
First try liberal amounts of a penetrant like PB Blaster. Add some patience.
If that doesn't work. Try heat. If you have access to a MAP torch it will get hotter than a propane torch.
If that doesn't work. Try heat. If you have access to a MAP torch it will get hotter than a propane torch.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,243
Looking at the picture, I suspect the damage bent the screws and they may be cross threaded in the plate.
I would try the PB Blaster idea. You said they partially turned then stopped. I would apply the PB and try to tighten them a little. This might let you work the penetrant into the threads. No guarantee but worth a try. When you patience wears out, you can always resort to drilling them out. Then, clean out the hole thread and re tap the plate for a slightly larger screw.
If the plate has been damaged then one would need to look at an alternative. Perhaps drilling a hole and putting a bolt through to a backing plate as the plan C or D.
I would try the PB Blaster idea. You said they partially turned then stopped. I would apply the PB and try to tighten them a little. This might let you work the penetrant into the threads. No guarantee but worth a try. When you patience wears out, you can always resort to drilling them out. Then, clean out the hole thread and re tap the plate for a slightly larger screw.
If the plate has been damaged then one would need to look at an alternative. Perhaps drilling a hole and putting a bolt through to a backing plate as the plan C or D.
I managed to remove our broken stanchion with a impact screwdriver and hammer. Not the electric kind but the mechanical type. Once I got the fasteners out I had to chase the threads with a tap when I inserted the new bolts I used anti-seize on them and plenty of bedit tape under the stanchion. We have the same setup, aluminum material embedded in the fiberglass and stainless steel screws gauled into them.
Whoa! Not me. I’d worry about damage to the fiberglass composite from that much heat. I’d grind the heads off and drill the bolts out if needed, then re-thread. I’d try the PB Blaster idea first.
Screw drivers provide little torque. Battery driven impact driver may work. The weak point with removing sticking stainless steel phillips head screws is the head of the screw strips out easily. Should you arrive there try grabbing the screw head with channelock pliers and turning. Should that fail, grind off the edges of the head of the screw and remove the stanchion. Then try the channelocks again on what remains of the screw shaft. If that fails, then you are left with drilling out the screw. It is very difficult to drill in the center of the screw, especially if it is bent. Stainless is hard to drill and you may easily slip to one side and drill the aluminum plate off center. Good luck.
Cut the pipes with hacksaw, remove the load from the mounting screws. That will make it easier to remove the screws.
Haro
Haro
Great idea, but I'd rather destroy the screws than the rails and bases. Those bends in the bases will still be causing a load. If you're going that destructive route, it might help to cut the bent bases. (I'd use a Dremel or grinder with cut-off wheel, and immediately pour water on the remaining cut sections to cool them - to avoid heat damage to the FRP).
Thanks for all the suggestions. I may end up doing them all! I hadn't even considered cutting away the stanchion/foot to relieve pressure from the screw. No doubt that's a large part of the problem. I want to try to avoid drilling out the screws if I can. The replacement stanchion is set to arrive this weekend, so I'm not especially worried about destroying the old one. But I want to save, flatten, and reuse the old stanchion base/bale as the replacements are $$$. So I may end up having to drill some of those out. But hopefully once the pressure is relieved I'll be able to coax the screws out with the PB Blaster/heat/impact driver combo.
I'm curious about the galling on your screws. Galling generally occurs when materials of similar hardness are used (screw and nut from the same or similar material) without lubricant but you have stainless steel screws in an aluminum plate. Perhaps Hunter used stainless steel inserts in the aluminum plate which would be a good idea but could lead to galling. If they are something like Heli-Coil inserts then you may be able to repair a damaged thread in the plate if it comes to that.
It's just aluminum as I understand it. I also understand the difficult to remove fasteners as a common issue with these boats. It could have something to do also with the interaction of the dissimilar metals.
Stainless & aluminum like to bond with corrosion, doesn't it? I assume by your description that you were able to get some movement when you started. That's a good sign. I would be patient with the penetrant and working the screw as @jssailem describes. An impact driver is a double-edged sword. It might break it free, it might break off the head. It's probably a 50-50 bet! (at best). When I use an impact driver, I try to be tentative ...
Skipping ahead to the reassembly, get some Tef-Gel to prevent the corrosion.
BTW, if the backing plate is aluminum the problem you have is corrosion which is a better problem to have than to have than galling. Galling is also known as cold welding.
Getting some lubricant (PB Blaster) down into the corrosion and patience with gentle persuasion may be your best bet.
BTW, if the backing plate is aluminum the problem you have is corrosion which is a better problem to have than to have than galling. Galling is also known as cold welding.
Getting some lubricant (PB Blaster) down into the corrosion and patience with gentle persuasion may be your best bet.
Electric impact screwdrivers are more effective at removing frozen screws like yours than manual screwdrivers. With phillips head screws, be sure to place significant downward force (your weight) on the machine to keep the phillips driver from stripping the screw head. If you do not own an electric impact driver, suggest that you buy one for this job. Like all good tools you will eventually wonder how you got along without it.
I don't know that I'm psychologically prepared to handle taking down the headliner just yet!
Well, I have been looking for an excuse to buy one ...
Oh damnI don't know that I'm psychologically prepared to handle taking down the headliner just yet!
. I didn't realize yours was of the later vintage which is covered with a headliner. Several of my cleats have an panel near them which gives you a bit of a fighting chance.
don't see any cracks in the gel coat, try to preserve that if you can. I put my vote in for cutting the heads off fasteners, remove the stanchion and then you will have a stub of fastener you can grab on to to back out. You could bend the tang back straight and re-install.
The fastener is bent, and cheapest link in this chain. Trying to back out a bent fastener is an exercise in frustration, sometimes successful, sometimes not.
The fastener is bent, and cheapest link in this chain. Trying to back out a bent fastener is an exercise in frustration, sometimes successful, sometimes not.
Success! After getting back to the boat I loaded up on pb blaster and decided that it made sense to try to cut off the screw head on the forward arm. It took a while but once it came off everything else just pulled off easily. Looking back it seems that there never was any galling. Instead it was the bent screw heads getting stopped by the bent bases. There did also seem to be some gelcoat damage once I got everything disassembled.
But now I’m having trouble squeezing the new stanchions into place without bending the base out of whack. Several of the screws are very difficult to drive in and some are just too hard to turn and I can’t get them tight to the deck. I had to leave one screw out altogether since it wouldn’t line up. Does anyone have any good tips on getting multi-arm stanchions into place?
But now I’m having trouble squeezing the new stanchions into place without bending the base out of whack. Several of the screws are very difficult to drive in and some are just too hard to turn and I can’t get them tight to the deck. I had to leave one screw out altogether since it wouldn’t line up. Does anyone have any good tips on getting multi-arm stanchions into place?
The stanchion bases vary a bit but the one that I replaced, I had to bend it to make it fit the boat. A bench vise worked well for that but I did not have a bench vise at the boat. I measured, best guess, and came back to the boat and still had to flex it a little bit to get it to go together. It isn't easy but that's the nature of the beast. I do not believe I would try to use a lifeline stanchion that did not have all of the fasteners in it. This is a safety device that you do not want to compromise on.