Galled Bottle Screws

[onlinelee]

Hi all,

thank you in advance for any suggestions made regarding this problem.
My boat is on hardstanding, I have to lift my mast to install a new step, however, I have 3 seized open type bottle screws on the shrouds of my Beneteau 361. Having soaked every day for a week with WD40 and applied some gentle heat they still won't move. I have one last thing to try suggested on another site of "tapping" the bottle with two hammers, but don't hold out much hope. I noted that the bottom part of the screws are moving and in the event that the tapping did not work my plan was to cut the bottle off carefully with an angle grinder, keeping the fittings ( as there is nothing wrong with the cable etc,. ) and just replace the bottle. You may feel it would just be simpler and not much more expensive to measure all 3 ( or the 4th as well ) and have new shrouds made so they could be fitted whilst the mast was lifted? The plan is not to totally remove the mast to remove the old and install the new step. Any suggestions greatly appreciated.

 

[woodster]

they may seized/gaulded beyond use ..if you do get them off with out damage to the terminals ...replace with bronze open body turnbuckles.... ss on ss equal gaulding bronze on ss equal good smooth operation...as for how to get them off you may have to work the a little at a time in both loosening and tightening direction and use some pb blaster or maybe even heat the body some and let some candle wax melt down on the threads .......

 

[Dennis Kitchen]

onlinelee,
Please be aware that when you do get the fittings wrestled apart, the threads on your cable stud will most assuredly be just as damaged as those in the "bottle" that they are engaging.
If you do cut the "bottle", cut it across the full length of the frozen threads, not quite all the way through; you don't want to nick the threads on your stud. Spread the created slot with a few taps of a chisel, lube threads and try to unscrew again.
Good Luck!

 

[justsomeguy]

I have one last thing to try suggested on another site of "tapping" the bottle with two hammers, but don't hold out much hope.

This is done to set up a vibration in the corroded parts, allowing the penetrant to work its way deeper. Give it some more time to work, however.
Good luck!

 

[centerline]

heat is the enemy of stainless steel threads....(any "after heating" of stainless steel of any type will harden it and it will be prone to sudden and total stress failure), no matter how gently you may have heated it, if you have heated a threaded stainless object beyond what you can hold in your hand, it has created an irreversable problem.... it galls, or attempts to weld the threads together due to the intense heat created. a very common problem with stainless nuts/bolts.

so its time to bite the bullet and cut them off.... they cannot be salvaged.

when you reassemble with new ones, coat the threads, inside and out, liberally with lanacote, or what I prefer to use on stainless steel threads is nickle based anti-seize compound... it has the highest molybdenum content and will prevent the galling of stainless threads even in extreme conditions, where heat and loading is severe....

 

[DougM]

You mentioned that you soaked the threads with WD 40, which probably wouldn't help much. Try PB Blaster as a penetrant. Even that might not help if the threads are galled rather than just seized.

 

[onlinelee]

Doug, not sure PB is available this side of the pond, but, WD40 is a penetrant too?

 

[onlinelee]

Thanks to all for your comments and suggestions, I will post how I end up resolving the problem.

 

[centerline]

penetrants can flood galled threads, but it makes no difference because galling is not a corrosion problem.... do a web search for galling, and read.... then get the grinder with a cut off wheel on it

 

[onlinelee]

Hi all,
I said I would come back with the results of my bottle screw problem, here it is...
The engineers in the marina had tried without success to free up 3 open type bottle screws on my B361
They even tried heating, something I am now aware of is not a good idea. Here is what I did...
1: Take tension off shrouds with halyard.
2: Pour boiling water over screws
3: Add a dash of WD40 or if you chaps from the other side of the pond prefer, PB Blaster
4: Spend 30 minutes tapping with 2 hammers - I used a small club hammer at the back whilst tapping away on all sides of the part of the screw not working.
Im happy to report this process did work, all screws now working as they should. I suppose the question is were my bottles galled or just frozen? I guess if galling is what has been described then they were just frozen.

 

[justsomeguy]

Thanks for the update, glad you've gotten them apart.
Now, inspect the heck out of them!
https://www.fastenal.com/en/72/galling

 

[onlinelee]

Hi Justsomeguy,
thanks for that and your earlier comment. I will do what you say, if in any doubt I will replace them, Lee

 

[justsomeguy]

You're very welcome!

 

[centerline]

a Lucky Man you are!.... it only happens that way about once in a lifetime
if the threads appear to be good, then it was just frozen, possibly with salt buildup. soapy water is better than WD40 for penetrating salt corrosion.
when you replace (recommended), or reuse them, use the lanacote or some other good waterproof antiseize/antigalling compound.. waterproof means it will stay put and wont wash out over the years... regular grease and oils are NOT waterproof.

 

[dziedzicmj]

WD40 is not a penetrating oil. As the name suggest it is a Water Displacement agent. It has some lubricating properties, but there are many better products.

 

[onlinelee]

Thanks again to all my friends over the pond, Im on a steep learning curve but with the help of this site and its members hopefully not too painful Lee