Sunray Swim Platform Rebuild

Written by Bayliner Owners Club
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      Last year we noticed that while stepping on our swim platform there seemed to be soft spots and we noticed fine hairline cracks in the the gelcoat. The following article details the rebuilding of our swim platform step by step from start to finish. I hope this will assist you should you have the same issue on your boat. 


swim platform port

Above is the swim platform from the port side. The platform is in two parts separated by the rub rail. Note the gap where the lower portion of the platform meets the stern.

Swim Platform Separating Top And Bottom Sections

 View Of Swim Platform Ladder

This is a view of the Swim Platform Ladder Note the damage around the ladder to the gelcoat. This is the area that I assume before I remove the platform that the water has been infiltrating the platform. The rub rail has already been removed in this picture and you can see the remnants of the caulking the was used to seal along the rub rail.


 The removal of the platform was extremely difficult due to how it was attached to the boat. Four bolts attach the platform to a substructure that is only accessible from the engine compartment. Unfortunately my arms were not long enough to reach the nuts on the bolts to remove the platform. Luckily the rot had progressed so far that the bolts actually broke free from the core of the platform allowing us enough room to cut the remaining bolts and remove the platform.

Platform Substructure

This picture shows the substructure under the platform. Notice the caulking between the vertical and horizontal surface. It looks like the previous owner cut the top of the substructure away from the stern and then caulked it with household caulking. I will remove the caulking, fill with epoxy and fiberglass over the gap to seal.

 It also appears that what I had first thought was a two part platform may have been a single piece at one time that was cut in two by the previous owner. You can see what looks like a rough cut along the bottom piece of the platform. this would have joined to the underside of the deck of the platform.

Below is the underside of the platform showing how water has seeped into the platform and rotting the wood that is encapsulated in the fiberglass.

In this picture below you can see the rot through the fiberglass on the underside of the platform indicated by the brown spots that almost look like mould. 


I was a little worried about cutting the bottom layer of fiberglass off the platform with a grinder for fear of going all the way through the fiberglass  the wood core and then though the top of the platform itself. To resolve this I picked up an oscillating multi-tool from Princess Auto. This is probably the best tool I have in my shop especially for the cost which was $59.00. It has several attachments which made this part of the job very quick, less than an hour. The main attachment used was the half circle saw to cut the fiberglass and the scrapper tool to finish the job. A picture of the tool is shown a little later in this article. 

 Below you can see where I have cut away the underside fiberglass cover to revel the wood core. The wood was completely saturated with water and the wood in an advanced state of rot. By the time all the wood was removed the weight of the rotten wood alone was about 30 lbs.

 Below is the platform with all the core removed. The edges will still need to be scraped and sanded flush to allow for a bed of epoxy and the new plywood. 

 Here is the top side of the platform you can see where the ladder was attached.

This image below indicates the damaged gelcoat around the ladder where the water infiltrated the whole core.

For those who are interested here is a picture of the tool I mentioned earlier from Princess Auto.

I picked up the marine plywood today from Adams and Kennedy The Wood Source in Ottawa. The cost for a 4x8 sheet of marine plywood was $177.00 taxes in. I will be doubling up the plywood rather than a single layer and several individual blocks for support. This will also I hope stop water from being trapped below the platform. 


Worked some more on the swim platform this weekend. We removed the caulking from the substructure on the boat and I installed the first layer of marine plywood to the skin of the platform. I also found a little time to take the big step and drill a 2 3/8 hole through the transom for the Perko underwater light.






In order to reach the bolts that fasten the platform to the substructure without going through the engine compartment I will install a hatch that I can reach through from above and tighten the bolts. The following pictures show the cutout and the hatch dry fitted in place.



 I also sent out the rails for the swim platform to have new bolts welded on. Bob From Johnsons Welding in Ottawa did a great job !


 I have been looking at different coverings for the swim platform and have created a template using heavy plastic which makes it much easier to trace out the pattern. I looked at different products such as SeaDek a foam covering that comes in many different colours and patterns. While this covering has many attractive features the life expectancy of 5 years is a drawback.

I also looked at NuTeak which comes with a 20 year warranty, is light coloured to reduce the heat and can be sanded to remove stains.  I have sent the template out to the Montreal Distributor, SRG to obtain an estimate.

 Well I recieved the quote back for the NuTeak. The distributer was very helpfull and informative about the product and other products on the market. However the cost at $750.00 it was just a little too expensive for this boat.




and the final touch, custom snap on carpet


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