Installing a Swim Platform - First Time

[habanero]

I will install a swim platform on my 1987 55' Hatt sportfish. Any tips, tricks or advice?

[ThirdHatt]

Is there access to the inside of the transom where all the platform bracket bolts will be coming through? Hopefully most of them will be accessable so that you can just through-bolt it, large flat washer and double nut on the inside and be good to go. It's the bolts that you cannot access from the inside that you will have to work harder to secure. Your transom is cored so for the bolts that you need to bolt into something without going through, you will need to mark the exact location of these holes.

Then the fun begins! You need to grind down or cut out a section of the transom but only the outer layer, to the core material. Dig out the core material and epoxy/glass in a piece of aluminum plate that is larger than the hole you made in the transom. After it sets up, precisely mark the location of the platform bolts and drill and tap for the bolt being careful not to puncture the transom's inner fiberglass on the other side of the core. My boat has a water tank there so I was VERY careful but your boat being a convertible will not have a water tank but who knows what else that may be "important".

Now you can do any paint/touchup work and bolt up your platform. By the way, I recommend the under-platform mounted swim ladders because they disappear when not in use and can be deployed from the water if you fall overboard!

You did not mention if you have a platform to install or not yet and here are MANY platform designs out there, but I would suggest one that is identical to the one offered as an option on your model Hatt or something close. BeachComber in Fl makes good products and has a platform that is quite similar to the original Hatt platforms, and Tom @ Slane Marine has the exact Hatteras mold and is who I had build mine.

GOOD LUCK!

[solanderi]

IMHO,

The PO had an aftermarket swim platform lag bolted onto the transom of our 45C. This boats previous life was a cruiser and I think that particular design served them well. However, that design did not suit us well and in the first few trips out sailfishing (reasonable and gentle reversing in mild to moderate conditions) we dislocated the swim platform. Since we also dive and we could see the utility of it, we decided to do the platform the "right way" once and for all.

So we went to Sam's and they sent us to a local machine shop armed with the Hatteras triangle stainless steel bracket dimensions times four. Next, we thru-bolted those on with stainless backing plates with lots of 5200 and we were good to go......so we thought.

The very next season we (mostly I) were able to damage the platform to bracket connection and that was about as much energy that I wanted to put into that platform.

Of note, you have a convertible so it begs the question of how gung-ho you are on fishing. I am absolutely not an advocate for charging across high seas in reverse whether in a tournament or not. Actually, it is much more favorable to chase down billfish, sharks etc with the pointy end of the boat into the seas. Not to mention how dangerous it is to take a wave over the transom, etc. Thats for T.V. and people with disposable boats. However, the very end of the game, whether tagging or gaffing or just getting photos and your lure back, may involve a little reverse work.

I would have to first question whether you really need a platform, (there is a good reason why most tournament and serious fishing boats don't have them just read the above if you can't remember). If your answer is yes you need one, then what I would have done differently, would be to put on a narrow, tubular metal platform. It seems to me that my application failed because the platform had too much surface area and an insufficient amount of drainage capability. In other words, you need large gaps or holes in the platform to allow for discharge of all of that water energy while in reverse in any kind of sea. I hope this helps,

Greg
45C
Hat Time
N. Bay Village, FL

[Vincentc]

The platform on my 43 DC 1983 is supported by 6 stainless brackets constructed with 1" tubing diagonals and approximately 3" x 1/4" flat bar bent in an L shape. The brackets are attached with 3/8" bolts, 4 per bracket. See attached photo.

After 25 years some of the platform coring had rotted and some of the attachment bolts had worked loose and there was water into the foam cored transom. In addition, some of the stainless fasteners were showing rust.

While the two top bolts for each bracket are accessible from inside and have a nut, a washer and fender washer, most of the lower bolts are not. They were "secured" by threads cut or molded into the 3/8" thick outer transom. Between the outer and inner walls of the transom there is a 3/4" thick foam core. The lower, inaccessible bolts ran into the foam but did not penetrate the inner transom wall.

Assuming you also have blind holes, I would consider the potential for corrosion before using an aluminum plate and stainless bolts; but instead would embed stainless nuts inside an epoxy core (described below) and would definitely go to the expense of 316 stainless fasteners.

With Lilly Marie hauled out:

I used a one inch hole saw to cut holes into the "outer" transom where the "blind" holes were located but did not penetrate the FRP inner transom. I then used an allen wrench and an electric drill to clean out the foam coring surrounding those holes for approximately a one inch perimeter. Water and foam particles were sucked out with a shop vac and tape flaps were put over the holes to keep out new water penetration while the core dried. Perhaps you will not have any moisture in your core, but I would not be surprised if you did.

I waxed 2" long 3/8 bolts so they would not stick to the epoxy to use has positioners for the stainless nuts to be embedded into the filled epoxy. I mixed a batch of high strength epoxy resin and hardener (Raka) and added colloidal silica, wood flour and chopped fiberglass cloth. I forced the paste into the holes and voids in the transom then inserted the waxed bolt with a nut screwed on to the end. I used the bracket, held in place by the upper bolts to position the waxed bolts in the proper location. Use pieces of "vis-queen" to keep the brackets from contacting and sticking to the filled epoxy. Once everything sets up hard, unscrew the waxed bolts, remove the brackets and smooth the surface with a sureform scraper while the epoxy is still a little "green" Depending on temperature, the epoxy will take days to fully cure.

I suggest that glass reinforced epoxy with an embedded stainless nut is stronger and less subject to corrosion than an aluminum plate. I am pretty confident that the threads on a stainless nut are stronger than those in an aluminum plate and the nut is held in place by 3" diameter reinforced epoxy disk that is 3/4 inch thick. Thinking about it, since the accessible bolts rely upon the inner transom wall, which is thinner than the outer wall and the fender washers are 1" diameter, my blind bolts may be better secured than the accessible ones.

If your platform is cored, be sure that all penetrations are surrounded by solid material. With the platform upside down, I used a hole saw to cut 1" holes from the bottom leaving the upper FRP in tact. I removed the balsa coring, taped over the small holes in the top side of the platform and filled the large holes with filled epoxy. I would not rely on caulk to keep water out of the core space.

I would certainly ponder and respect the force of wave action on a flat surface in evaluating any design that may come in contact with waves, have not forgotten Katrina.

Regards,
Vincent
43DC Lilly Marie

[stormchaser]

I recommend the under-platform mounted swim ladders because they disappear when not in use and can be deployed from the water if you fall overboard!

very good advice. When I add a boarding ladder (have a platform but no ladder right now), it will definitely be an under-platform model. This is especially important if you boat in areas of cold water and are ever alone on the boat. fall into cold water and you may only have minutes to get out before hypothermia sets in. Amanda lost a friend to falling into the harbor in winter when nobody was around to help him out. At our marina, there are no ladders on any of the docks, so a lot of live aboards leave their swim ladder down all winter just in case.

[rwetherington]

There is a lot of difference in install a swim platform on a MY and a C. You have the transom door to deall with. The door does not swing straight it swing down is be careful that the door does not hit the platform. You may have to purchase another set of hinges for the door to keep it from doing that. The top hinge will be smaller than the bottom hinge. Sams Marine will know what you are asking for if you have to do this.

[ThirdHatt]

Solanderi, I think the key word I read in your post is in your first sentence, "aftermarket". I most certainly agree about having the proper amount of drainage ability/water flow while reversing, hence my strong recommendation to Habanero for a FACTORY platform as Hatteras surely did their research. Their platforms were an option on convertibles so surely they were confidant in their ability to stay put. This is where "aftermarket" platrforms can become a problem as they do not have the resources for research and development that a large production boat manufacturer does so problems tend to arise when put to real-world use.

Vinventc, when I did mine in '07 I inquired here and the HOF experts (and also a local shipright) agreed that the aluminum plate idea was best for this application. Heck, this is exactly what Hatteras did on boats like mine with no access to the inside of the transom for through-bolting. Hatteras glassed vertical aluminum strips into the transom for drilling and tapping. It was good enough for the factory, so it was good enough for me. Several ideas were tossed around and contemplated including your stainless nut idea, but we dismissed it because we were concerned that the sheer lack of circumference of a small nut (even bedded in reinforced epoxy) was simply not enough surface area to guarantee not pulling out. I used thick (3/8"?) aluminum plates that were several inches long and a couple of inches tall and made sure that they were a good bit longer/wider than the hole I cut to remove coring and insert the plate so that the aluminum plate is actually supported by strong FACTORY transom on each side of the bracket in addition to being emmersed in reinforced epoxy. The immersion in epoxy should take care of any real corrosion potential. I carefully drilled through the reinforced epoxy and through the aluminum plate and through more reinforced epooxy until the bit touched the inside wall of the transom without penetrating it. Then I tapped the hole the entire way so that the bolt threads grab on to a couple inches of epoxy in addition to the aluminum plate. I used locktite to ensure the bolts would never back out and plenty of 5200 between the brackets and the transom.

I have since backed down on several occasions, even in seas without incident. On the trip to Orange Beach last year, I spent a night in Biloxi tied in a slip that had my transom facing east. A big storm roared that evening from the east for several hours and it brought 2-3'+ seas slamming into my transom and under/into my swim platform. With every wave impact the shudder was felt thoughout the back of the boat. Believe me when I tell you that entire evening I was wondering if I installed that platform in the best manner or not! Sure enough, the next morning before we casted off I checked and the platform was still as secure as when I installed it. WHEW!

If I had to do it all over again, I would do it the same way and stick with a factory-designed platform and use the same method to secure it that the factory used for this application. I just think that will offer the best results over time. Hatteras did too because they put their reputation behind it!

[Bottom Line]

does anybody know who makes/carries an under-platform ladder? Looked at the Miami boat show and didn't see any. Thanks.

[Vincentc]

Dear ThirdHatt;

I appreciate your very detailed description but still have concerns regarding threaded aluminum to stainless vs stainless to stainless threads. The aluminum may be encapsualted but the aluminum threads still contact the stainless bolt and underwater, even with 5200 I would not be surprised to see moisture make its way in.

Having pulled aluminum window frames and observed the corrosion where the stainless screws went through, my comfort level with aluminum on boats is not high.

Taking away the corrosion concern, I still believe the stainless nut in epoxy may be stronger. This is all conjecture, and I certainly do not claim more expertise than Hatteras; but no one is perfect and they did build my boat in 1983 with penetrations into the above waterline balsa core and below line foam core without sealing the surrounding area with solid material, such as epoxy. I still believe Hatteras is one of if not the best production boat and hope my comments do not render me a heretic.

How about if I take a hydraulic jack to samples of each method and see which fails first. Want to bet a drink?

Regards,
vincent

[ThirdHatt]

Bottom Line, There are a few designs out there to consider. Tom Slane had recommended a particular undermount ladder to me but I forget the brand that he suggested. I liked the design and sturdiness of it compared to most other designs but the price was very expensive, something crazy like $800. While I don't mind paying up for high quality, I felt that was out of line for a swim ladder and sure enough after considerable research I found one that looks identical to the one Tom suggested. It is the Windline SM-3XG. I think it was well under $200!

I actually sent my ladder to Tom so that he could beef up the area the ladder was to be mounted while he was building the platform. When he sent the platform and ladder to me, the fit was of course perfect and it has a real factory look which is exactly what I was after. It works great and I am very pleased with it.