Can I avoid stainless galling whilst using thread locker?

[chris-s]

I have a stainless pin that goes thru the top of the mast around which the capshrouds are secured using talurit thimbles. The pin fits flush with the sides of the mast and has fixing holes drilled into each end. The pin was previously poorly fixed in place with oversized washers and rusty galvanised screws 'jammed' into the end holes. I guess the capshroud tension would also have helped a little.

I've drilled and tappd the ends and intend to use M5x15 stainless bolts, but on test fitting I detected they started to gall, so carefully removed before any significant damage was done. I've cleaned out the threads with the tap again and will use some new bolts.

My original plan was to use some loctite 243 on the bolts to prevent them working their way out, but I don't know if the loctite will act as a lubricant sufficiently to prevent galling.

Chris

 

[Moodysailor]

Can you post a picture? It's hard to visualise from your description (sorry) and would be good to see the issue. I have a couple of thoughts but would like to be sure before giving bad advice.

 

[rogerthebodger]

Yes stainless steel can gall and some lubrication will prevent this. Never used loctite to prevent galling but it could.

First ensure the thread is clean and no grit in the thread as this is a guaranteed way to get galling.

Second comment drilling an tapping into the eng of a pin at the top of the mast IMHO is not a good design. In my view you need a positive locking to no only prevent the pin from working out but you also need to prevent the pin from rotating as this will cause the hole in the mast to open up especially f the mast is aluminum.

I weld a keep plate to one end of the pin and drill a single hole in the keep plate the use a single bolt tapped into the mast using Duralac to prevent corrosion.

The galling you experienced could also be due to the tapped home not being deep enough and the 15mm long M5 screw reaching the tapered botton of the thread. Galling needs some pressure on the thread to initially cause the pickup.

 

[garymalmgren]

Troy uses lanolin grease to prevent galling and explains his reasoning.
Gary

 

[Boathook]

I can't work out whether you have drilled all the way through the pin. If so, why not use split pins ?

 

[goeasy123]

I have a stainless pin that goes thru the top of the mast around which the capshrouds are secured using talurit thimbles. The pin fits flush with the sides of the mast and has fixing holes drilled into each end. The pin was previously poorly fixed in place with oversized washers and rusty galvanised screws 'jammed' into the end holes. I guess the capshroud tension would also have helped a little.

I've drilled and tappd the ends and intend to use M5x15 stainless bolts, but on test fitting I detected they started to gall, so carefully removed before any significant damage was done. I've cleaned out the threads with the tap again and will use some new bolts.

My original plan was to use some loctite 243 on the bolts to prevent them working their way out, but I don't know if the loctite will act as a lubricant sufficiently to prevent galling.

Chris

It says on the Loctite 243 date sheet...

'Prevention of galling and corrosion:
•Liquid film prevents friction welding or galling
•Sealing effect prevents corrosion
•Permits disassembly
•Excellent durability'

 

[doug748]

I am not a great fan of locking compound. It might be possible to apply grease and use locking washers:



You would need to file an indent in the end of the bar or the curve of the mast may hold it. When all is tight wack the edge of the washer over a bolt flat.

.

 

[Stemar]

Duralac or similar and a nyloc nut?

 

[chris-s]

ok guys, some pics...

This one is from some time back but shows the rusty screw jammed into the pin which goes thru the mast, cap shroud can be seen entering the mast just below it...



... and the pin - ignore the temporary manky bolts/washers...

 

[penberth3]

I am not a great fan of locking compound. It might be possible to apply grease and use locking washers:

View attachment 107099

You would need to file an indent in the end of the bar or the curve of the mast may hold it. When all is tight wack the edge of the washer over a bolt flat.

.

That lock washer would need a slot in the stud or bolt. There are other ways of doing it.

 

[VicS]

ok guys, some pics...

This one is from some time back but shows the rusty screw jammed into the pin which goes thru the mast, cap shroud can be seen entering the mast just below it...

View attachment 107105

... and the pin - ignore the temporary manky bolts/washers...

View attachment 107107

Instead of bolts threaded into the ends of the pin how about studs with washers and self locking nuts ( or make a pin with reduced and threaded ends)

with self locking nuts you could put a smear of anti-seize compound on the threads

Duralac, or an insulating washer, under the stainless washer to prevent corrosion

 

[doug748]

That lock washer would need a slot in the stud or bolt. There are other ways of doing it.

Well, it might, or it might not. As per my post really.

PS.

Just seen the photo. Yes, you could form new washers to the curve of the mast and fold up one or two tabs onto the flats of the bolt. You would need a couple of saws cuts for each tab.
Bearing in mind goeasy123's post you might just want to crack on with the threadlock.
.

 

[chris-s]

Thanks for the replies guys, lots of options there!

 

[Boathook]

ok guys, some pics...

... and the pin - ignore the temporary manky bolts/washers...

View attachment 107107

I now understand what you were explaining. A decent threadlock would be my preferred method.

 

[TernVI]

What I understand by 'galling' occurs in highly loaded threads like rigging screws.
Those bolts are just in mild tension, holding the washer in place, I don't think you'll get any galling.
I think thread lock compound would be fine.