rotating masts problems

[Guest wwbaginski]

what I faced this season is not smooth rotation of the masts.  I hace wooden masts so I think they tend to increase their diameter in humidity, regardless they are godd protected . I'll appreciate any reports on such troubles and any tips how to aviod them.

[PeterP]

I think your hunch is correct - the wood absorbs moisture, swells and hence the tight fit. You may consider skimming some of the wood and building up it back up with fiberglass to keep things stable. Also, check the bottom of your mast - make sure you have a good solid seal down there - the moisture has a tendency to wick up the grain if it is left exposed. PeterP

[PAR]

Use HDPE bearing surfaces at the holes and heels of each stick.

[Ken_Potts]

  I had a similar problem with my mainmast.  Over time it seemed to be getting tighter in the mast tube.  The difference was that my masts are aluminum.  I took to storing the boat with the foreward hatch open and now there's no problem.  I guess the moisture that was trapped in the forepeak was swelling the mast tube (or the surrounding wood).

  If you don't already, try leaving the hatches open when the boat is under cover and see if that works.

[Randy Jones]

Not sure I understand your mast arrangement, but I can tell you that HDPE worked well for me.  My flatiron skiff (sprit sail) came to me with an oversized and out of round hole in the seat where the mast is inserted.  I put a length of 3" diameter copper tube over the bottom of the wooden mast and passed it through a new HDPE bearing bolted beneath the seat.  At the bottom end of the mast I drilled out a hole and inserted a length of solid round HDPE sized to fit the round hole of the mast step.

The friction surfaces are copper/HDPE at the seat and HDPE/wood at the step.  The results are a better than expected combination of smooth rotation and no mast wobble. The boat is an old thing traditionally built from wood planks (no ply, glass, or expoxy), so it worked out nicely that the HDPE is hidden from view.       

[Guest wwbaginski]

I have solid wooden masts, the mainmast is rounded with glass cloth/epoxy rings I exactly as it's shown in plans, to fit in the aluminium tube. The mizzenmast is the same, but runs directly through  the wooden twarth to the wooden nest in the bottom. Both masts tended to be blocked.

I guess HDPE is kinda polyethylene, in form of a strip, put around a mast in particular places? May be I should replace epoxy rings with HDPE ones in the bow, and mount such rings in the midship? Probably a layer of HDPE on the botto wolud help much, too.

I've also heard about a metal ball under a mast - centrally placed and partially hidden in the wood - to help rotate smoothly, too. 

[Tom Lathrop]

One good source of HDPE is kitchen cutting boards. Swipe your mate's old one and get her a new one.  I use a wood plug in the heel of my masts and screw a disc of HDPE to that.  At the top I use some past wax on mast and hole.  It works well enough.

[Guest wwbaginski]

just glued in  those metall balls - they are of 3 cm diameter each and come from bearings.