Mast Platform Repairs on 2004 HC - Inspect for rot!

[harrys]

The other day my son commented that the stays seemed to be slacker than normal. I agreed and did a quick investigation. I first inspected the caulking around the mast collar and it was evident that the mast had dropped about 1/4 inch since I had applied new caulking this spring. I went below and noticed that the wood platform was dished around the foot of the mast and that the mast step was loose. I strongly suspected that the platform was rotting and losing strength. I contacted the factory and asked if they had a standard solution. They did. It was to install an aluminum plate that covers the whole mast platform. The factory shipped the plate within a week (to Canada) and it was easy enough to install. I cut out the rotted area and removed the plywood cross brace (no longer needed as the aluminum plate was at least 3/8 inch thick). I leveled the boat and made sure that the mast stub was perpendicular to the world before marking the location of the mast step. Drill and tap a couple of mounting holes and used 3M 4000 for sealing the step to the plate. The new plate is then bolted to the original wooden plate using supplied lag bolts and sealed around all edges and bolts with marine grade silicone caulking.

I strongly recommend HC owners to inspect the condition of the mast platform. If this platform gives way, you will have a demasting situation to deal with.

[rbh1515]

Wonder if this has happened to anyone else?  I was getting a fair amount of water in this area when I first got my HDC.  The factory explained that water is supposed to collect here instead of going into the bilge, and you just have to sponge it out.  I ended up putting caulk in the "sail track" of the mast post, and so far this year this area has been bone dry!  I think if it is getting wet all the time, you are in for trouble.
Rob

[rbh1515]

Harry,
I went back to look at you previous posts, since you only had 15.  Noticed that back in 2010 when you bought the boat, the previous owner had over tensioned the stays and had damaged the mast.  Also noticed that your bow sprit had pulled out a few years later.  Maybe the current problem has something to do with the previous owner over tensioning the rig.  May have played a role in the bow sprit pulling out later on.  When I got my boat new from the factory last year I was initially worried about the slack leeward shroud.  Called Gerry, and he reassured me that's how it should be.  I'm continuing to keep my rig loose, but keeping a close eye on it!
Rob

[Tom L.]

This seems to be a common problem for the H-Cat and most likely the Sun Cat as well. There is a discussion of this problem on the second page of the first category in this blog entitled, Safety Tips When Stepping The Mast.
Com Pac came to the aid of the H-Cat in that discussion several years ago. As remarked it's important to keep the mast sealed at the deck and to make sure the sail track groove is sealed, This area is often overlooked. Good work Rob in sealing that sail track.
I have made sure our Sun Cat is sealed both at the deck and at the sail track slot. I have no issues with water in that area.

Tom L.

[harrys]

Tom L,
In more recent models, this problem may already be taken care of with an aluminum base or, if a wooden base, may not have developed into a problem, yet. In either case, this area will collect water coming down the mast stub (when the mast is lowered), the sail slot, or around the deck collar.

In my case, with a wooden base, the screws fastening the mast step to the base had become loose due to lateral stress and movement from the mast which allowed any water to seep throw the screw holes into the vault below and rot the base on its way. As time went on, the screws got looser and the base became more rotten. The surface stayed relatively dry and I just thought I was just doing good job keeping the water out. But, as I discovered later, trouble was brewing below.

Yes, this problem was discussed in a previous thread a couple of years back and the cause was blamed on the previous owner drilling a hole through the plate to install a grounding cable. Based on my assessment, I believe the previous problem was also caused by the screw holes and not the grounding cable hole. Being aware of the previous problem made me cognizant of the situation which lead me instantly to the cause of the mast inching south.   

No matter how dry you try to keep the area, over time rot will develop; it is just a matter of how long.  For ease of mind and relatively low cost (<$100), I would retrofit any wooden mast base with the aluminium plate solution. And yes, any water coming down the mast or by the deck collar will collect here and that may be a good thing. At least it is not seeping to any wooden support areas below.

Rob,
I don't believe the bow sprit disaster was a result of over tightening the stays. It was the result of an undersized bracket. The replacement bracket was substantially stronger. If you look closely at the pictures, you will see the difference. If you have an older boat, make sure you have the beefier bracket. I am sure ComPac will gladly send you one at minimal cost.

Hope this helps,
Harry S.

[Tom L.]

Harry I agreed the aluminum plate is a good solution. Most owners aren't aware of the water intrusion or what happens when ignored.

I trailer sail my Sun Cat. For that reason I made a cover for the mast stub when the mast is hinged down. I try and eliminate any water into the boat, but it's not an unheard of problem. I owned a Tartan 37 which has a keel stepped mast. Rain water could get in at the mast head where the sheaves were open. Nothing could be done about that but at least the Com Pac cats can be kept dry both with the mast up or down. Really easy solutions.

Tom L.

[rbh1515]

Harry,
Yep, I agree the fitting for the bowsprit appeared undersized, but over tightening over the years probably caused metal fatigue.  Its amazing how much force you can get on a rig by over tightening.  On previous boats I always used a Loos gauge to get it right.  With the HDC I just snug it up a bit, and make sure the leeward shroud has some slack when sailing.
Rob