The original black stuff is Sikaflex, 291 I believe. Obtainable from RS Parts Store in UK, but outside UK you'll have to find a local source as it's a hazardous material to ship.
Until recently it is what Selden used to bond the collar to the mast.
I understand the most recent adhesive is Epoxy, as per the change in Collar Repair kits supplied by RS Parts Store in UK.
My opinion is that clear silicone won't hold for long.
The other is that the latest internally splined collars are a loose fit on the mast boss; it is not easy to ensure correct and accurate alignment when mounting.
My suggestion is that you contact RS After Sales and Technical Support for the best way forward.
Mine is in the same state - I thought the rubbery stuff was put in by the prev. owner, but this is the factory solution? I tapped the collar down and I was able to pull it off the mast by hand. Mine is a 2019 7m rig. I've been taping the collar in place with plenty of duct tape, but that's not a solution. I was thinking of clear silicone adhesive to bond it to the mast.
Your latest comment got me thinking that the fit of the bare collar and geater care needed to align for a raised deck ring may well be the root cause of creaking as my 7 rotates. I've since discovered that my 9 does similar, but not as loud.
Measuring that part of the mast boss the collar fots over still bare of adhesive I get a diameter of 64 mm.
I have two old collars: one early vinrage smooth bore, and one later splined bore.
The smooth bore measures 65 mm inside diameter. The splined bore measures 66 mm.
Both are clean of adheisve, so these are mm accurate measurements.
If this is repeated for the new kit collars then this gives a play of 1 mm all round on the newer splined bore collars.
That would make it difficult to align with sufficient accuracy such as to ensure the collar below a raised deck ring does not bear on the hull mast pot gel cpat & laminate.
After sailing yestaerday I can see a wear ring that coincides
All mine have been on later boats. I haven't looked at an earlier but I think you're right - if the surface bearing the load is smaller then the alignment is going to be more critical.
I've done 3 or 4 collar fixes with Araldite (all on different masts) and haven't seen this problem.
However, coincidentally, I did one this week and the collar was a bit of a looser fit than others I've done. I don't know how good my alignment will be but it may be slightly out like you've found. I'll report back in due course if I have a similar issue.
End November last year I had both my 7 & 9 mast collars come loose, start swivelling.
Cause was the raised deck ring wearing such that the collars were bearing part on on the deck ring & part on the mast tube gel coat & laminate, 1141 is a 'white collar' ie pre recessed deck ring boat, 2014 vintage.
Deck Ring replaced, and the two mast collars. Collar kits had an Araldite slow cure, 24 Hrs, Epoxy adhesive; not the Sikaflex referred to in the instructions, and used on the failed collars.
The 7 mast Collar was just pushed up over the boss on the mast and is not quite aligned to the mast; it's only a degree or two out in both fore -aft & port - stbd planes; but it jerks & makes loud creaking noises when sailing upwind on port tack & playing the mainsheet. The stronger the wind the louder the noise.
the 9 collar was pushed on with a fine helical screw thread motion, and is better aligned, but it too makes some noise when rotating; albeit a lot less.
Both now seem to be wearing rapidly. Both are scored, as is the deck ring. And this after only a couple of months use.
Has anyone else expereinced similar?
Is collar failure and periodic deck ring replacement confined to or more prevalent on the earlier 'white collar' pre recessed deck ring, June 2015(?) boats?
Or is it also a facet of recessed deck ring boats?
UK RS afterSales hadn't seen a similar case before, but have concluded it should ease itself out in time.
I supect this may have been the case if Sikaflex had been used, but suspect Araldite Epoxy sets too hard to have any give in it to align on use.
Is it feasible to break the joint & re-make, say with a new collar?
Make sure that the internal grooves in the collar are cleaned out of old adhesive as well. A junior hacksaw blade carefully run down them one by one usually does the trick.
That looks right. Just need to measure to get the right position (see the RS instructions) and, as you say, rough the surface before applying the epoxy.
The mast collar has been floating about for the last couple of weeks but only noticed when racing on Sunday so time to fix it - Thanks Hairsy - the trick with the jubilee clip worked a treat to remove the mast foot undamaged. I have removed the rubbery type substance that was either side of the collar but now looking at the mast - does this slightly thicker material need removed? Mast is around 62mm diameter and at the mast collar area it is around 64.4mm diameter. Does this have to be brought down to 62mm or just roughened up?