Hunter 31 Mast compression post and balsa core deck

[Mad Dog 3]

I noticed many post about this common problem on the Hunter 31.

Does anyone have pictures of the cutted out area at the mast step or any other area where the deck has been cutted out for wet spots or delamination.

I am trying to determine the extend of repair to be done on my boat as mine show hunidity or aluminium plating inside the core!

Thanks

J-P

 

[Steve Dion]

I cannot help you much with photos but I think you fill find that water came in through the compression post and drained down through the crossmember and rotted you deck area.

I have been told that this is NOT balsa, but plywood.

 

[Allan12210]

J-P,

Check out this post for some pictures of underneath the mast from the inside. They may provide some useful information for you.

http://hunter.sailboatowners.com/in...mid=267&cat_id=31&aid=6641&page=article&mn=34

The wood coring in the deck is as Steve says, plywood. In fact it is little 3" squares of plywood especially under the genoa tracks on the side decks where you have indicated. I saw this myself at the Hunter factory in 1986. Check that the screws holding that track down are properly sealed.

Directly under the mast is not plywood cored, but rather a 1/4" plate of aluminium then a synthetic foam material and then fiberglass. If you have any issues in the overhead it is probably because water or just the compressive force of the mast has distorted the wood inside the fiberglass beam. There are much easier methods to repair the overhead than what I described so many years ago.

Allan

 

[Mad Dog 3]

Thanks Steve and Allan,

It is obvious that similar repair are needed on my boat in way the compression post!

The surveyor also picked up a moderate moisture level around the mast step, halyards organisers and roof's winches .

I do not know if other area of the boat was fitted with aluminium plates but if present, could these plates cause these humidity readings?

 

[Allan12210]

Thanks Steve and Allan,

It is obvious that similar repair are needed on my boat in way the compression post!

The surveyor also picked up a moderate moisture level around the mast step, halyards organisers and roof's winches .

I do not know if other area of the boat was fitted with aluminium plates but if present, could these plates cause these humidity readings?

Possibly the aluminum plates could indicate a false reading. I don't know exactly how the moisture meter works. If it is based on capacitance, maybe the presence of the metal plate may influence the reading. It seems that there will not be any moisture absorption under the mast area or where the line organizers are located as there is a substantial aluminum plate. Check farther forward toward the hatch where I know there is only a wood core for comparison and perhaps the anchor locker door. I believe there iare also embedded aluminum plates under all of the winches as well as the the turning blocks where the jib sheets come back towards the sheet winches. Also, there are aluminum plates under the line stoppers on either side of the companion way sliding hatch.

The area in front of your shrouds will have the wood core. Check to see if there are any cracks where water could have entered. Have the surveyor check the cockpit floor. That is were a number of these boats have seen water penetration.

Allan

 

[Steve Dion]

Do you have any deterioration of the actual compression post? I suggest that you remove the cosmetic covering and check this before you cut into anything. I have not heard of any problems with the mast step area that did not have compression post rot (not that I have heard it all).

This is easy to inspect. You just need to remove the bungs and unscrew the screws.

I would also consider have someone else checking the moisture in the side deck too.

 

[Mad Dog 3]

The compression post and bulkhead are partly rotted a the top area but no deformation is noted on the cross beam. I have planned already to replace the post and hope that the cross beam is no too affected!

Moisture on Side deck is obvious and the deck is cracked near the chainplate and now that I know what is under, it will simplify the repairs planning.
I will post the pictures once repairs are completed!

What puzzle me are those possible false positive showing humidity in way of aluminium plating. There are no visible signs of problem in those areas.
I sure do not want to peel off the deck and find that anything is wrong!
Has anyone came across false positive reading or moisture during a survey in the mentionned area?

Thanks

 

[Steve Dion]

You may want to consider cutting the area around the side deck with a skill saw. Remove the entire fiberglass piece. Repair/replace the existing rotten pieces, replace the fiberglass and then just reglass the piece into place.

I think if you can cut on the smooth area (rather than the non-skid) it will be easier to repair with little or no visual signs of the repair. You may need a pro to do the final glass work but you will have a quality job.

 

[Mad Dog 3]

Thanks Steve,

It is a plus to have knowledgeable persons like you and Allan.

all sugestion will ease my work for sure!

J-P

 

[Dan Johnson]

Mad Dog...

Look on the Big Boat forum for the current H34 compression post thread. There's 3 pages of discussion of what others have recently done about this problem, including pictures. These boats (H34 & H31) are almost identical in construction details so there's a lot of information on the H34 that applies to the H31 as well.