Port Hole Leaks

Paul Watson, "Sea Quill"


In many older fiberglass boats the process of creating the original mold for the hull or deck was a "more or less" a precise science. When it came to creating a concentric interior liner mold, the process became a bit more difficult but way back then precision liner molds seemed less important for most production boats.

Many liners were designed simply to hide the rough, unfinished glass work of the underside of the deck or coach roof and therefore the prevailing thickness of the void was apparently not a critical dimension. Today the molds for liners are built using laser measuring devices that precisely implement a uniform measurement for the depth of the void throughout. More often than not the void is carefully cored with anything from balsa to more modern, high tech foamed materials that are almost without void or inconsistencies in mass or thickness.

The classic Allied Seawind Mk. II is no exception to the lack of todayís more accurate technology and the void. In each area that the hand-laid balsa coring was not capable of being trimmed to dimension it was often, simply ignored. It is likely the void between the one-piece deck and the liner is just full of inconsistencies. In fact the coring on the ASWII likely may cover only about 70% of the entire surface of the deck and house. Consider that each hole either drilled or cut through the unit afterward was rarely, if ever, sealed with epoxy. Had Allied poured a resin plug or had even a sealed sleeve been inserted into the fastenings passageway the job of preventing water from migrating throughout the linerís inherent voids toward the more convenient or direct exit places would have caused us considerably less grief.

Not unlike many other production fiberglass boats of the time; once the cabin sides were cut out for the port lights, the space between the outer cabin side and the finished surface of the liner was, not surprisingly, inconsistent. This detail may have seemed quite insignificant at the time and most were fitted with the new ports, bedded into the most modern sealant of the day and the craftsman just moved on to the next job.

These ports, fixed or opening, were all designed with an inner (the spigot frame body) and outer frame (the trim ring). The two parts were expected, by the designer and the manufacturer, to be adequately bedded and then squeezed together equally, parallel and hopefully the combined pressure of the two mounting surfaces would seat the ports evenly against the sealant and providing an equidistant as well as equal pressure across the entire seating surfaces. This rarely turned out to be the case. Water eventually found its way through the distorted and poorly sealed frames and mating surfaces at the least equally pressurized points. Not surprisingly this failure became evident, often within months or only years later as the various stress-related movement of the fiberglass and the deterioration of the sealant combined to allow water leaks. Eventually the water passed through the failed area and easily entered the void, migrating naturally to the lowest point of the liner.

As each deck leak is usually tracked no further than to some point along the integrally molded gutter at the outboard edge of the liner but it is rarely determined what the actual and original entry point was. Our grab rails, stanchions, mast step, sea hood, chainplates, inboard tracks, cleats and the like are all through-fastened at some point of the deck. Changing the bedding of these fittings should be considered normal, scheduled maintenance for any yacht owner. But it is the leaks from the ports that never seem evident until the leaks begin to stain the fittings that either pass through or are screwed into the liner. Often the first clue of port light leaks, in the ASWII, is that the cabin-side, plywood trim panels in the main salon begin to rot away.

Figure 1

This is the Port side forward opening port.

The rust stains show the deterioration of the fasteners. The aft end of the rough opening in this photo clearly indicates a leaky section of the void. The original, or intended, port had been of a different design. The intended port was one with a self-draining spigot. It appears this opening was cut out with the wrong template for the port fitted. Note also that the parallel dimension of the outer cabin side and the linerís inner surface is clearly inconsistent. The upper void tapers dramatically towards its lower dimension.

The repair indicated herein indicates the procedure for the Beckson PVC opening port but is similar for any port installed as well as the more common, large fixed ports in the main salon of the Allied Seawind II.

After the arduous job of removing the port light and clearing the old sealant from all surfaces is accomplished, the unsealed and inconsistent void becomes quite obvious. A measurement between the inner liner surface and the outer, cabin-side surface, with a caliper at several places along the perimeter will likely and very clearly prove a wide disparity in the parallel distances.

The job begins by providing for a similar measurement of each place along the perimeter.

Cut several soft wood wedges about 2-inches long. These will be tapped into place, in the void, along the perimeter to widen or some may need to be clamped in place to narrow the distance.

Figure 2

In this case the wedges were needed only to widen the gap and none were needed to clamp against for narrowing. The objective was to finish with a common dimension, typical of that of the upper dimension.

Once able to determine an overall thickness that was common; I used an 8-inch Crescent wrench with the jaws set to that dimension and its adjustment screw taped, and used as a measuring jig. The wide, flat inner jaw surfaces and the offset handle made the job easy.

Tape/mask both the inner and outer surfaces of the cabin side with three layers of masking tape.

Wipe the inner surfaces to be epoxy bonded as thoroughly as possible with acetone to help insure that the glass is clean enough to accept the epoxy. Caution: wipe, do not pour this very flammable and noxious liquid into the void.

If the space of the void is uniformly more than ľ" apart I recommend that either a length of flexible weather strip or thin plastic tubing be pressed into and fully around the perimeter up to 1" or more into the void. This will help contain the epoxy mixture within a workable perimeter.

The next step is to mix up the epoxy resin and hardener in a cup. The hardener used should be for FAST curing. I increased the mixture by a "full pump" extra measure as the high density filler will slow the normal cure rate considerably. Once the resin and the catalyst are mixed thoroughly add the high density filler slowly to the mix until it is the consistency of thick peanut butter. If the mixture is too thin it will drip out of the upper void on application and similarly, sag deep into the liner, at the lower opening, well below the area you wish to attend to. The mixture is then troweled and pressed into the void with a narrow, plastic putty knife. Once the perimeter is filled to approximately level with the edge of the opening, try to determine if the old screw holes had been completely filled from within. If they fill from within you may be certain that the mixture is packed in to a good depth. Those that appeared not to be, I smoothed in some of the mixture to fill the surface of the hole at the very least. These holes would be drilled out later.

Figure 3

In this photo you can see the first application of the mixture. Once cured it bonds the liner and the coach roof together and holds the desired dimension quite well. The wedges are then removed and the second application of the brew is applied into the spaces left by the vacant wedges. All those extra holes certainly indicate that this port may have been replaced at least once before and likely with the later version of the Beckson port. The earlier version had either been a self draining unit that required the large openings at the lower corners to provide room for the cambered drains or a similar unit that was not self-draining. I suspect that this installation error made these ports leak even worse.

Once cured thoroughly; remove the wedges and the next batch of epoxy mixture is troweled deeply into the spaces left by the now vacant wedges.

Sand out the various blobs, drips and high spots within the opening using a small drum sander attached to a high speed, rotary tool. Use the portís spigot as a guide and recreate the proper opening, leaving about a 1/8" gap between the spigot perimeter and the actual opening, all around to accommodate any dimensional instability.

Once the last layer of epoxy mix is cured; sand the one-inch perimeter areas of the cabin side and the liner until smooth with the random orbital sander and 100 grit sand paper. Inspect for any small voids or gel coat damage that may need to be touched up or re-filled.

Many of our Allied Seawind IIís are fitted with the Beckson PVC opening ports. The most common size seems to be the 5" X 12" unit. It is constructed of PVC plastic and assembled in two basic parts, the inner frame and the outer trim.

Part of the problem of installing this port in the ASWII, where the liner void has not been stabilized, is the point of compression between the inner and outer components where the, often used, through-bolts pass through. My boat has apparently had the self draining units removed, resealed and in the case of two of the Becksons, previously replaced. At one time in these repairs, the inner and outer frames were through-bolted but the void was never stabilized. The compression and deflection point of each through-bolt further deformed the liner and the coach roof panels inward and further exacerbated the original defects in the manufacturing production and made the leaks only worse.

As will often be the case, there remains a possibility that the space between the cabin side and the liner may not be opened wide enough to insure that the epoxy mixture cannot be uniformly inserted to a depth of one-inch around the entire perimeter. The very nature of the material thickness of the production layers may prevent accurate insertion to the one inch requirement. In this case the job to seal the opening may find the uniform depth considerably less that that one inch objective. In this case through-bolting the inner and outer frames may not be accomplished effectively due to the likelihood of serious deflection in the port frame body or the trim ring.

If for instance the mixture can only be forced less than one half inch into the space, the frame body and the trim ring must be fastened only to its immediate contact surface and not through-bolted.

In this case; the frame body is inserted into the newly cleaned up opening (from the inside of the boat) and the pre-drilled mounting holes marked for drilling. At this point the two options are; to fasten with stainless steel, # 8 or # 10 self tapping screws or to set up a #22 drill and a tap for #10-32 X Ĺ" machines screws. The thin fiberglass layer will accept a few threads for the basic fastening. The frame will actually be set into the sealant and the screws used only to draw the frame surround flush toward the sealant contact surface. *** The Beckson company, in their installation instructions, caution that sufficient space (1/8" between the frame and the opening) be allowed to compensate for the possibility of dimensional changes due to heat and cold. Through-bolting the entire frame certainly does not allow for this predicted instability.

The spigot frame body, once re-fitted and pre-drilled for either screw type, to the opening will be then sealed with a half inch bead of sealant (**** In a recent and very informative conversation with a representative from Beckson I was to learn two important recommendations: first, the sealant recommended is marine grade silicone, only as opposed to polysulphides or others. All other sealants will slowly attack the PVC and the deterioration will occur over one to three years. Use of the polysulphide will force the eventual replacement of the port. Secondly, the use of WD-40 to lubricate the plastic hinges will also deteriorate the plastic and the hinge surfaces will become brittle and break off) applied liberally into the 90 degree interior corner of the frame and the spigot. Press the frame firmly into the opening, evenly around the perimeter. Install the screws and tighten only to a firm resistance. Try to affirm that the frame surround has seated evenly and that a small amount of excess sealant oozes beyond the entire perimeter of the inside frame. Move to the outside and be certain that the sealant has oozed at least halfway though the opening of the entire circumference of the opening. If there is any gap in the perimeters sealant, try to fill the gap immediately to allow the fresh sealant applications to bond but do not fill with sealant beyond the flush surface determined by the cabin side.

Do not prepare to mount the trim ring yet

Once the sealant behind the spigot-frame body has cured, 24-hours, the interior screws may be tightened another half turn and the excess oozing cut away neatly.

The same screw-mounting procedure for the trim ring will be followed next. The trim ring may be mounted with stainless steel, pan head, self tapping screws of #ís 6 through 10 depending on your success in carefully drilling out the, now, epoxy filled holes. The 90 degree, 1/8th inch wide, expansion gap between the spigot and the cabin side will be filled liberally with marine silicone sealant, provide a bit of sealant around each seating surface for each of the screws, thus completing the most essential part of the job. Screw the trim ring into the outer cabin side only until slightly firm resistance. Again, allow to cure and tighten Ĺ turn to finish, do not over tighten.