Stanchion problems

[brians]

I have stainless steel stanchions and aluminium stanchion bases and the two have 'welded' together and I cannot remove the stanchions. Any ideas what I can do without damaging either part or the grp deck?

What is the best silicone to use whem rebeddng the bases?

 

[VicS]

Take them off and heat them. Initially in boiling water but if that does not work try direct heat, stopping short of melting the aluminium of course. The aluminium expands more than the stainless steel and so should release its grip.

Refit the bases on Sikaflex 291 if you do not expect to be removing them again otherwise any Marine silicone sealant. In both cases do not squeeze all the sealant out but tighten down once the sealant has cured.

 

[chrisc]

Try coco-cola that is pretty good for releasing aluminium corrosions.

 

[Blueboatman]

Have you tried to twist (rotate) each stanchion a bit to 'break' the corrosion bonding effect first ?
The trick -and I hesitate,be careful- is to use Mole or vice grips clamping firmly (but not too firmly,see?) onto insulation tape and cloth wrapped around the stanchion: Too loose a grip and the grips will slide and quickly scratch the s/steel,too tight and theoretically you might crush or distend the stanchion wall,depending on its quality.So be judicious in adjusting and readjusting the molegrips until firmly gripping and then try to twist the stanchion imperceptibly back and force. If there is a through hole and clevis pin arrangement,why not remove each pin and displace all the trapped salt water within with wd40 or oil and let soak/play a flame or hot air gun gently on the vertical bit of the base,whilst monitoring the deck temperature with your free hand.
Failing all that,then you will probably have to remove each base,as VicS has suggested but which can be a total pain in the butt...
The better quality arrangement is of course to have s/steel bases,or where alloy ones are incorporated-say into the alloy toerail- there should be a) a drain hole to prevent them filling up with salty water and b) a loose enough fit that a plastic insert sleeve separates the s/steel and alloy components.
Once freed ,lift up each stanchion,clean up the alloy internal faces with sandpaper and gloop it up with silicone or-far better imo is Sikaflex(why not,you can always remove the stanchions again in the future using the above twisting method)...

Good luck and be patient rather than brutal /forums/images/graemlins/smile.gif

 

[Poignard]

You can buy a very good penetrating fluid called PlusGas from car accessory shops. It's best to buy it in a can with a spout and not an aerosol. Apply it to the seized joint and let it soak for a while before you try and move the stanchion. Repeat a couple more times, if needed.

However, if that fails, heat might work if you can apply it without hurting the deck. After that it needs something more drastic and, as advised by a previous poster, take the base and stanchion right off and do the job on the bench. Don't apply too much force whilst it is still fixed to the deck because repairs to a damaged deck are much more difficult and costly than replacing stanchion bases

 

[owen]

i have just been in your situation. however my stanchions were made out of a mg/al alloy and the base i think al only.as you say they weld themselves together. i have tried all methods but i found mine were impossible to move. eventually i used an angle grinder and cobalt drills to remove the bases and replaced with new. when i investigated the corroded bases at home i found they were impossibly corroded to the stanchions.nothing would have separated them bar brute force.

 

[Krusty]

I had the same problem a few years ago. I trickled Plus-Gas into the joint with the base and left it for a day or two. Then this worked for me, but needed two people:
Remove the mid-height wire guardrail and insert the largest screwdriver it will take:
Trickle in more Plus-gas; arrange a hose (or assistant) to trickle water over the deck all round the stanchion base to safeguard the glassfibre; apply a blowtorch, on a low flame, to the upstand of the base, and start twisting the stanchion with the screwdriver, back-and-to.
As soon as any movement is sensed, remove blowtorch, and apply more Plus-Gas.
Repeat until it gives!
I (we!) had it free in an hour.
We then cleaned out all stanchion bases, smoothed the insides with rolls of emery cloth, smeared with Turbogel teflon grease; cleaned and polished the stanchions bright and reassembled.
Since then I have removed and replaced every Autumn as part of pre-Lay-up maintenance,and have never had another one sieze. I believe the Turbogel keeps water out.

 

[savageseadog]

Use boiling oil.

 

[jmh2929]

As ally expands more with heat it contracts more with cold. Try freezing them

 

[jmh2929]

sorry wrong way round

 

[VicS]

[ QUOTE ]
Try coco-cola that is pretty good for releasing aluminium corrosions

[/ QUOTE ] I've never tried it but it is often suggested. HOWEVER try it before soaking everything in penetrating oil orWD30 Once it is all oily the Cola won't stand a chance.

 

[VicS]

[ QUOTE ]
As ally expands more with heat it contracts more with cold. Try freezing them

[/ QUOTE ] The question iwas about stainless steel stanchions in aluminium bases so you need to HEAT. The aluminium expands more than the st.st. so with luck it releases the grip. For maximum effect heat the base more than the stachion. If you try freezing the aluminium base will contract more than the stainless steel stanchion and increase the grip. If you have access to a plumbers pipe freezing kit then cooling the stanchion while heating the base would have the maximum possible effect though.

 

[charles_reed]

Certainly

the aluminium into aluminium stanchions originally on the boat, were the most difficult to move, but extreme heat, in a vice, finally did the job (with lots of brute force).

Trying to use a lever in the mid-hole in the stanchion merely caused the stanchion to twist and deform.

 

[KREW2]

I have just tried to loosen mine with no joy, I took them to a metal fabricator to have 1 straightened and they couldn't do it either. They had to cut the post weld it up and polish it.