Fixing swimplatform on 87 Supra Sunsport

The swim platform on my 87 Supra Sunsport seemed a little unstable on one side...So I took it off, and was greeted with this...










The cracking looks pretty bad, but the area around it is actually pretty stable. It seems to be caused by whoever moved the platform before. Instead of a back plate, They used the smallest and weakest washers possible.

I'm planning on making back plates, but I'm wondering what I should use to fix the cracks. Some type of sealant? Fiberglass over them? What would you do?


Also, The brackets on my swim platform seem to have a bend where they connect to the boat, I'm guessing they were not originally like this...Can someone with a sunsport verify?

the brackets are bent because the bolts weren't holding tightly. it allowed leverage to be applied to the bottom of the bracket.

you really want to add backing plates on the inside of the transom. you'll have to remove the gas tank.

there's plywood backing on the inside of the transom already. looking at the amount of fiberglass damage, you probably need to patch those first. keep an eye out for rot, water was probably seeping in. with a good repair on the inside, you can sand down the outside gel coat and marine tex it.

you should really plug those holes, clean it all up inside and out, and start over with new holes and sturdy backing plates. not a small project looking at the damage. there are several rebuilds posted on the supraboats.com website...lots of sunsports.

There was a post on the Supra forum where a guy with an older Supra installed new removable brackets. Looked much better than the original ones.

Where can I find marine tex? Would that be better than fiberglass resin?

second the marine tex much stronger
fill all the holes and remove the gel coat to the fiberglass at least 1/2" or so past the cracks
inspect the fiberglass for damage and re glass if severe
sand the edges to taper the gel coat
add the marine tex
dry
sand
apply any gel coat to make pretty
then add the backer plate then retap the holes

If you need to replace your brackets call Jim Jackson at viper customs he has them in stock and is the cheapest on prices I have ever seen

If you need to replace your brackets call Jim Jackson at viper customs he has them in stock and is the cheapest on prices I have ever seen. His number is 865-388-4096

Just an update...Here's where it's at currently. What should I fill the holes with? Marine Tex? Or do I only put that on top of the fiberglass?

i bet that was fun. yeah, fill the old holes with marine tex. mix it up and put it into a plastic bag, cut the corner off and squeeze it into the holes. you don't want any air pockets.

you probably want to make a reference point on the hull with tape or something for when you re-instal the platform. you won't be able to see the old holes for long.

are you going to add backing plates?

be careful with the marine tex. when it hardens, it's a real pain to sand down. don't leave any blobs or anything behind. get a plastic squeegee or some other thin plastic, get it wet with water and it will smooth the marine tex like drywall mud.

ps drill those holes out a little first to remove any crap

Sean love the 87, she looks very similar to mine! Make sure you stop by Supraboats.com/bbs too! Where are you located? Is that the Black Pearl?

Hey Mikey. I've seen yours and they are definitely similar, Gotta love the old Sunsports. Yeah, It's the black pearl! I live in Fridley, MN.

So just to make sure I have this right...I fill the holes with Marine Tex, Fiberglass over that, sand...then add more Marine Tex over that? And then Gel Coat? Or does the gel coat go directly on the fiberglass?

DUDE I live in friendly Fridley too ahhhh that is awesome! I'm on East River Road by 694. But my boat is at my parents which is in Anoka also on the Mississippi. We have gotta hook up!

did you grind into the fiberglass?
how did the inside of the transom look?
are you adding backing plates?

the answer to those kind of dictate how to proceed.

re-glassing would be the ideal fix. gel coat over the top. you'd want to grind more out though. you'd start with a small piece of fiberglass cloth and keep adding larger pieces until you're at least 6" past the damage on all sides...really should even go larger.

if the transom is still solid and you're adding backing plates, marine tex will probably do. the instructions say you can't gel coat it, i've never tried. you'd still want to smooth the edges to a gradual bump instead of sharp line, gives the marine tex more to grab.

Haaa That's crazy! Where do you normally ride?

All the spots are ground down to...something that's not fiberglass...

The inside of the transom looks fine, except for an extra set of holes from where the platform was already moved. They had used dowel pins to plug the holes...

I drilled all of that out and filled all the holes with Marine Tex last night.

A friend of mine has access to the machine shop at his school, and he's hooking me up with some back plates.

I'm planning on raising the platform another inch or so to avoid the old holes. So it should be pretty solid. I'm still planning on fiber glassing it...Unless I don't have to. I don't have access to the tool I used to grind it down anymore though...How important is it to grind the whole area down?

Mississippi River between the Coon Rapids dam and the 169/Champlain bridge it's called the 7 mile recreational pool and it's dredged to 10-14ft side to side. Boat ramps at Coon Rapids dam and two near the 169 bridge. The boat is on a boatlift in the river.

the grinder is critical. you don't want to glass on top of the old gel because you'll have obvious bumps showing. you also want to grind the old glass a little so the new resin will create a better bond to the original layup.

you can get one at harbor freight for about $25.

it's hard to tell from the pics but it looks like i'd feel better about it if it was glassed...if it was my boat. if the platform wasn't going back in the same area, marine tex would be fine.

Well Harbor Freight had a grinder for 17.99...Ha. I smoothed the edges out a LOT more, but I'm really not comfortable going any bigger, especially at the bottom...Anyways here's some pictures...

Smoothed out more than before.

A close up of the middle spot.


Bonus! A shot showing the new carpet on the bottom of the passenger seat, along with a 12" sub installed there and another under the drivers cubby. (I wish I had before pictures)

And A shot of the new wood in the engine cover and engine surround. Both were COMPLETELY rotten, but they were 22 years old. All the new wood was coated in heavy duty sealant/paint.