There are several products on the market
A system I've used on two boats is Spartite
. About US$150 for a kit for my 44 footer.
<font color="red">This system is fo<font color="red"></font id="red">r an Aluminium mast in an aluminium or fabricated s/s collar, and does away with the need for (a) wedges and (
boot.(it is not suitable for traditional wooden masts) </font id="red">
The process is as follows:-
1. A mastic putty dam
is pushed into the underside of the aperture between the mast and the collar.
2. The black mastic spartite mix is poured into the aperture, to a level approx 10mm from the collar's rim. This sets to the consistency of hard rubber.
3. The top 10mm is filled with a whitish mastic which protects the spartite from ultra violet and can be trowelled into a neat seal.
4. The putty dam is removed when the spartite has set.
The result is that the mast is set firmly in the collar.
I don't know, but I suspect, that the efficacy of this system is that the mast and collar are roughly complementary in shape - i.e the gap between mast and collar is pretty constant. I don't know how well it would work, for example, with an oval mast in a square collar.