CD30 Companionway Hatch / Drop Board Gap

[John]

On the CD30 (and other CD's) most owners I think will note that the junction of the after edge on the sliding hatch and the top edge of the upper drop board do not fit well. There is a substantial gap all the way across the companionway joint of these two parts where they are supposed to meet when closed.

That gap may be good for ventilation as a side benefit but it sure does not seal up the cabin from insects and dirt and blowing rain.
That entire area is a poor fit and not well designed at all. I've worked for a couple of yacht builders and believe me when I say it is a poor design for a boat of the quality of a CD. Everything on the boat otherwise fits very well except for that companionway hatch aft end.

Who has dealt with this problem and what changes did you make and how good were the results? I am needing to address the problem and am seeking input of ideas from owners before I finalize my own design for modification.

I've considered eliminating the drop boards and constructing teak cabin doors. Has anyone done this and are you satisfied with the conversion from drop boards to doors?

The CD30 has a small platform area about 5"x7" to the port side of the companionway that is obvious when the hatch is slid forward. It is trimmed with a teak riser that joins with the drop board trim. That platform area poses the greatest modification design problem in attempting to seal off the hatch joint. Any suggestions?

[Larry DeMers]

I have a CD30, and also think that they could have paid someone with some talent to make a better fitting hatch/drop board interface that would be watertight in case of a knockdown. My plan to eliminate this problem is to mount a batten on the sliding hatch cover, that will mate up with the arc formed by the fixed riser and the removable drop boards. This will cut the opening down probably 80%. We are also adding a jamb bar that goes between the back of the teak piece that has the companionway lock tang installed on it, and the companionway frame itself. This is to prevent someone from forcing entry into the cabin while we are aboard. It will store along side the companionway frame nicely.

Larry DeMers
s/v DeLaMer

On the CD30 (and other CD's) most owners I think will note that the junction of the after edge on the sliding hatch and the top edge of the upper drop board do not fit well. There is a substantial gap all the way across the companionway joint of these two parts where they are supposed to meet when closed.

That gap may be good for ventilation as a side benefit but it sure does not seal up the cabin from insects and dirt and blowing rain.
That entire area is a poor fit and not well designed at all. I've worked for a couple of yacht builders and believe me when I say it is a poor design for a boat of the quality of a CD. Everything on the boat otherwise fits very well except for that companionway hatch aft end.

Who has dealt with this problem and what changes did you make and how good were the results? I am needing to address the problem and am seeking input of ideas from owners before I finalize my own design for modification.

I've considered eliminating the drop boards and constructing teak cabin doors. Has anyone done this and are you satisfied with the conversion from drop boards to doors?

The CD30 has a small platform area about 5"x7" to the port side of the companionway that is obvious when the hatch is slid forward. It is trimmed with a teak riser that joins with the drop board trim. That platform area poses the greatest modification design problem in attempting to seal off the hatch joint. Any suggestions?

demers@sgi.com

[John]

I have a CD30, and also think that they could have paid someone with some talent to make a better fitting hatch/drop board interface that would be watertight in case of a knockdown. My plan to eliminate this problem is to mount a batten on the sliding hatch cover, that will mate up with the arc formed by the fixed riser and the removable drop boards. This will cut the opening down probably 80%. We are also adding a jamb bar that goes between the back of the teak piece that has the companionway lock tang installed on it, and the companionway frame itself. This is to prevent someone from forcing entry into the cabin while we are aboard. It will store along side the companionway frame nicely.

Larry DeMers
s/v DeLaMer

Yeah, I agree with the batten application to make the closure with rear side of the top edge of the upper drop board. I was thinking of routing a 5/16" slot the length of the batten for the width of the drop board and glue in a length of closed cell foam with a smooth face. It would then make a weather tight seal. I can't remember the part # of the foam but its available at Goodyear industrial product centers. It's identical in quality to the Bomar hatch seals, nice stuff. Most cities with industrial areas will have one of Goodyears outlets nearby. Their weatherstrip is far better in quality than the stuff you would typically find in a hardware or boat store.

At any rate, you did not mention the ledge (or shelf) area to the port side of the companionway opening. It presents a problem because it doesn't seal with the sliding hatch underside surface and if a batten or sealing surface of some type is attached to the underside surface of the hatch there will be a problem opening the hatch. In other words, any appendage sticking down from the underside of the sliding hatch will impede the hatch from sliding all the way open as the appendage will strike the trim board riser at the forward end of the deck hatch opening. Do you follow what I'm trying to describe? If an appendage is added that would clear the forward trim board riser then that would mean the appendage isn't going to protrude down far enough to seal off that aft shelf area gap.

My best solution so far has been the idea to install a teak block of the appropriate size and thickness to take up the space between the underside of the sliding hatch and the trim edge around the shelf area and install a rubber seal about 1/8" thick just at the position that would allow the seal to make a positive seal against the shelf trim when the hatch is closed. When the hatch is fully opened the seal would simply flex out of the way when striking the forward deck trim riser and allow the hatch to be opened fully. It would flex the opposite way when the hatch is pulled closed. I would use a semi-stiff neoprene to make that seal and I would route a pitched slot into the teak block that I mentioned and glue the seal edge into the slot. The resulting seal would then be in a pre-stressed position so that it seals tightly when it comes in contact with the shelf trim when the hatch is closed.

Got any feedback on that idea?

Here is a tip for you that I did to seal the companionway from intruders possibly trying to get inside the cabin while we're aboard sleeping. I used three "heavy duty" cast Perko bronze barrel bolts and three bronze sleeve bearings from the hardware store. I fabricated three teak standoff blocks shaped the same as the Perko barrel bolt bases. The teak blocks were about 5/16" thick. You need the blocks to get the barrel bolt "bolts" to line up far enough from the edge of the hatch trim boards so that the holes they will lock into will be strong enough. Put all the drop boards in place then slide the hatch shut, working inside line up the barrel bolts on top of the matching teak block and line each barrel bolt up to the edge where it would strike the trim and mark the bolt strike location by drawing a circle around the bolt tip where it strikes the trim. Mark the base mounting positions as well. Do one on each end of the top drop board and another one at the top near the center.

The bolt travel distance of the Perko barrel bolt is long enough to reach the underside of the sliding hatch from the upper drop board. Once everything is laid out and the bolts and teak pads are all mounted to the drop board reinstall the drop board and confirm that the circles you drew on the trim and hatch underside still line up. If they do just drill the appropriate size hole with a barbed wood bit and epoxy in the bronze sleeve bearings. You may need to cut down the length of the bearings before installing. If you place the bearing sleeves in a vise to cut them be sure to slide a piece of wood dowel inside the bearing before tightening down the vise or the bearings will distort and then the barrel bolt won't fit. When everything is done correctly it looks like a factory installation and locks the boat up very well. Because the Perko barrel bolts come with a anti-rattle plastic shim that fits under the barrel they can't move unless you pull the bolt knob. Vibration, etc. won't cause the bolts to unlatch.

Another benefit is that when sailing in conditions that dictate the drop boards be in place but the hatch need not be shut, you can lock in all the drop boards just by securing that top drop board with two barrel bolts.