88 supra mariah top cap removal

[roll.model]

I purchased a 88 supra Mariah with 454 last summer. It’s my first direct drive boat. Originally thought floor was solid but after running a season found Rot in my stringers. I’m just getting started restoring it. How hard is it to remove top cap and once it’s removed will boat Hull shift/flex to the point I won’t be able to get top cap back on?


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[michael hunter]

I did a comp be very careful to support the top cap it has a lot of flex and can crack it not supported well. The hull did bow out but it wasn't too hard to push it back . You may need a couple friends to help.

[Salty87]

Nice grab.

Removal isn't difficult but the topcap is a little clunky to handle. The bow/dash/windshield is pretty heavy while the back end is feather light in comparison. You're only limited by your imagination & equipment in choosing a removal method. If that's your workspace you're off to a great start. Check my signature link for pics of what I did.

The hull will flex a bit once the cap is off. The sides will bow out in the middle. You'll want to push them in a bit so your new floor doesn't end up too wide. The trailer will do a good job of keep the bottom in proper position if you're leaving it on the trailer. You can also remove/replace one side of stringers before doing the other so there's always at least one set in place.

Good luck and take pics!

[roll.model]

Ok ya gonna get it ready to pull today hopefully I can drag some friends over this weekend and pull it . Is there some specific places to lift on when doing this?


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[roll.model]

Nice grab.

Removal isn't difficult but the topcap is a little clunky to handle. The bow/dash/windshield is pretty heavy while the back end is feather light in comparison. You're only limited by your imagination & equipment in choosing a removal method. If that's your workspace you're off to a great start. Check my signature link for pics of what I did.

The hull will flex a bit once the cap is off. The sides will bow out in the middle. You'll want to push them in a bit so your new floor doesn't end up too wide. The trailer will do a good job of keep the bottom in proper position if you're leaving it on the trailer. You can also remove/replace one side of stringers before doing the other so there's always at least one set in place.

Good luck and take pics!

Ya that’s my shop it’s got more crap in it now lol i got a semi parked on one side but should be enough room to lift it off and work on it also got access to couple forklifts and a couple engine hoist.


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[Salty87]

I left mine in the sling for the duration of the work although some lumber was propped under it to take some weight off the front lifting points. Made cleaning up some wiring easy.

http://i8.photobucket.com/albums/a10/salty87/IMG_0269.jpg~original

The cleats were used front & rear to lift from above. Since the bow/dash is so heavy we added a lift area just aft of the windshield. There's some lumber stacked in the curve of the topcap to provide support so it wasn't being lifted by the thin fiberglass. Mine already had some support there for tower leg bases.

The more guys the better. What's your plan?

[roll.model]

I left mine in the sling for the duration of the work although some lumber was propped under it to take some weight off the front lifting points. Made cleaning up some wiring easy.

http://i8.photobucket.com/albums/a10/salty87/IMG_0269.jpg~original

The cleats were used front & rear to lift from above. Since the bow/dash is so heavy we added a lift area just aft of the windshield. There's some lumber stacked in the curve of the topcap to provide support so it wasn't being lifted by the thin fiberglass. Mine already had some support there for tower leg bases.

The more guys the better. What's your plan?

Well your system look like it worked pretty good I’ll pry try to lift it off using forklifts and engine hoist I’ve already taken windshield and everything off so that should help with weight a little. Once it’s lifted I’ll set it down on a flat bed trailer I got. Should have 2-4 guys helping as well.


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[roll.model]

https://uploads.tapatalk-cdn.com/20180301/14e1f0f77e2acdd49d6cf09f5d32fc98.jpghttps://uploads.tapatalk-cdn.com/20180301/258ecec8f41129d211e67bc99fd4c438.jpghttps://uploads.tapatalk-cdn.com/20180301/6068be7148330f0192c8dec66a7e75f5.jpg got the top cap ready gonna pull it tomorrow rigging up pulleys from a After’s in my shop to pull it it’s all loose already thanks for all the input.


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[Milliken37]

When I put my cap back on after 3 months for the stringer and floor rebuild I found that the rear and front were had dropped down, so getting it back on was more difficult to align. I had just set it in the back yard as is, so all of the support was in the middle leaving the front nose and rear unsupported. Additionally the sides had bowed outwards under the pressure. I learned just how much fiberglass can creep over time. Anyways... I would suggest providing additional supports along each side of the cap to even out the load while it sits to prevent warping.


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[roll.model]

When I put my cap back on after 3 months for the stringer and floor rebuild I found that the rear and front were had dropped down, so getting it back on was more difficult to align. I had just set it in the back yard as is, so all of the support was in the middle leaving the front nose and rear unsupported. Additionally the sides had bowed outwards under the pressure. I learned just how much fiberglass can creep over time. Anyways... I would suggest providing additional supports along each side of the cap to even out the load while it sits to prevent warping.


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Ok good to know ya I just proved it up on flat bed trailer on boards and put cover on but I’ll try to brace it up tomorrow pulled all measurements I could think of and gonna start cutting tomorrow doing one side at a time https://uploads.tapatalk-cdn.com/20180302/9b83d51e709adb10dac8e8802b712783.jpghttps://uploads.tapatalk-cdn.com/20180302/99f365d0b5d883ac56b4e39a1ce85721.jpghttps://uploads.tapatalk-cdn.com/20180302/6880ce4886f11a0397547bc3197b8799.jpghttps://uploads.tapatalk-cdn.com/20180302/c82246a6dcc8336e28574d4b21da8f0a.jpg


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[michael hunter]

Before you put the cap back on it will be a good time to put blocking in under the gunnels to support the tower mounts.

[Milliken37]

Before you put the cap back on it will be a good time to put blocking in under the gunnels to support the tower mounts.

I’ll second that! I got into a rush to get my cap back on when I moved. Now it’s time for the tower install and I’m at a stand still until I transform into a human noodle to wiggle my way into the sides of my boat



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[roll.model]

Before you put the cap back on it will be a good time to put blocking in under the gunnels to support the tower mounts.

What is best option for bracing in gunnels fiberglass in extra wood support or just put plate under mounts? Or like how long should they be?


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[michael hunter]

I would cut 3/4 marine plywood as large as will fit and maybe 15'' long coat them with fiberglass then epoxy them to the underside of the gunnel.You can use the tower mount bolts to pull the blocking tight to the top cap. The epoxy will fill the gaps in between . The plates can be added after it dries . The whole idea is to spread the load over a larger section of the cap.

[roll.model]

What’s the best way to cut stringers out? Don’t I need to cut all the way down to Hull? And what’s the best foam to put back in? I got s buddy that does spray foaming would that work?


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[Jetlink]

What’s the best way to cut stringers out? Don’t I need to cut all the way down to Hull? And what’s the best foam to put back in? I got s buddy that does spray foaming would that work?

I cut mine down as low as I could on one side, then started fabricating mine, then ground down the remainder and glassed in from there. Best foam is no foam, that was the option I went with.

[roll.model]

Ok so the foam doesn’t serve a purpose then?


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[Jetlink]

Ok so the foam doesn’t serve a purpose then?

The principle behind foam is to attempt to prevent your boat from totally sinking in the event of a hull breach however the open cell foam that was used in the old Supra boats actually ended up retaining water, making the boat heavier and also contributed to the stringer rot issue. Some have gone back and used closed cell foam in various forms and methods. I elected to go with no foam so that I can better air out the boat and avoid issues going forward, plus I was on a mission to make it into a better ski boat and weight is the nemesis of that so I opted to forgo it. You cannot really go wrong either way, I like mine because I can air it out, see what is going on and I know the limber holes I added for any drainage needs can work effectively.

[roll.model]

The principle behind foam is to attempt to prevent your boat from totally sinking in the event of a hull breach however the open cell foam that was used in the old Supra boats actually ended up retaining water, making the boat heavier and also contributed to the stringer rot issue. Some have gone back and used closed cell foam in various forms and methods. I elected to go with no foam so that I can better air out the boat and avoid issues going forward, plus I was on a mission to make it into a better ski boat and weight is the nemesis of that so I opted to forgo it. You cannot really go wrong either way, I like mine because I can air it out, see what is going on and I know the limber holes I added for any drainage needs can work effectively.

Sounds good I will pry go that route as well then no foam! Definitely adding drain holes in it. Thinking about fabbing a little bit of ballast on each side not sure tho we wakeboard and wake surf a bit


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[roll.model]

Sounds good I will pry go that route as well then no foam! Definitely adding drain holes in it. Thinking about fabbing a little bit of ballast on each side not sure tho we wakeboard and wake surf a bit


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https://uploads.tapatalk-cdn.com/20180312/6b29ae070258feb3ed978591a23e3cfb.jpg
What does it take to remove center strip how far back does it run?


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[Salty87]

Is that pic from the bow looking aft? And which part do you mean by center strip? The underside of the hull transitions from a deep v for the bow to a more shallow v under the stern.

Did the bilge area toward the bottom of the pic look like that when you removed the floor or did some glass peel up? My '87 bilge was entirely like the smooth glass at the top of your pic.

http://i8.photobucket.com/albums/a10/salty87/IMG_0301.jpg~original

[roll.model]

That’s under where cooler went i think it goes back about 1.5 ft or so I did most my grinding today still haven’t taken that little strip out. That section was under where the cooler went https://uploads.tapatalk-cdn.com/20180315/1b9aa7929c6af2f108f8f98910b43fd5.jpg I’ll still have to cut it out eventually gonna get starboard stringers cut tomorrow hopefully and lay some glass down to over starboard side to help reinforce and glue stringers in Friday if all goes as planned


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[roll.model]

That’s under where cooler went i think it goes back about 1.5 ft or so I did most my grinding today still haven’t taken that little strip out. That section was under where the cooler went https://uploads.tapatalk-cdn.com/20180315/1b9aa7929c6af2f108f8f98910b43fd5.jpg I’ll still have to cut it out eventually gonna get starboard stringers cut tomorrow hopefully and lay some glass down to over starboard side to help reinforce and glue stringers in Friday if all goes as planned


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https://uploads.tapatalk-cdn.com/20180315/ec0a723eca8efc2d8de26e0af986a002.jpg this is where that’s at. The bilge raises up a bit right under cooler and after I cut it all out found that little strip and there’s foam and water still under it. The raised section was the nastiest underneath lots of water in the foam therehttps://uploads.tapatalk-cdn.com/20180315/01c144ef13b21edeb9c9b392ef5f9d9a.jpg



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[Mischief IV]

https://uploads.tapatalk-cdn.com/20180302/99f365d0b5d883ac56b4e39a1ce85721.jpghttps://uploads.tapatalk-cdn.com/20180302/6880ce4886f11a0397547bc3197b8799.jpghttps://uploads.tapatalk-cdn.com/20180302/c82246a6dcc8336e28574d4b21da8f0a.jpg

Looking good so far. Been following the thread but missed this the first time...what were they using the white PVC pipe for I see in bilge? Never seen that before. Seems odd.

Also, was that the location of the blower? High up on transom? If the top cap was on and the gas tank in, how would you access it? Is there access through ski locker?
Mine in Rider is over on port side next to gas tank. I don’t have to pull tank to replace. I just pulled my tank and it was a certain kind of pain in the ass.

Anyway, keep posting. Looks like you’re having lots of fun.

[Salty87]

That’s under where cooler went i think it goes back about 1.5 ft or so I did most my grinding today still haven’t taken that little strip out. That section was under where the cooler went https://uploads.tapatalk-cdn.com/20180315/1b9aa7929c6af2f108f8f98910b43fd5.jpg I’ll still have to cut it out eventually gonna get starboard stringers cut tomorrow hopefully and lay some glass down to over starboard side to help reinforce and glue stringers in Friday if all goes as planned


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Where the hoses from the sides vents (by the windshield) went under the floor? If so, that's one of Supra's most head scratching designs. On the Saltare that was a really nasty spot to accumulate water. You can kinda see at the bottom of this pic I went with a shelf to direct that water to the bilge so the pump could remove it.

http://i8.photobucket.com/albums/a10/salty87/IMG_0484.jpg~original

You're making great progress with the grinding. Wish I had tackled the rudder seal at the time. It's on my spring wish list. Glad to see you're knocking it out.

[roll.model]

Looking good so far. Been following the thread but missed this the first time...what were they using the white PVC pipe for I see in bilge? Never seen that before. Seems odd.

Also, was that the location of the blower? High up on transom? If the top cap was on and the gas tank in, how would you access it? Is there access through ski locker?
Mine in Rider is over on port side next to gas tank. I don’t have to pull tank to replace. I just pulled my tank and it was a certain kind of pain in the ass.

Anyway, keep posting. Looks like you’re having lots of fun.

Ya that’s where the blower was mounted had to pull ski locker to access it and the pvc I believe there’s supposed to be some sort of a block system that silicones to the transom and hooks up to the pvc I believe the blower was essentially supposed to be plumbed into that not sure tho. Gonna have to design a new system with 2 blowers like it’s supposed to have but I’ll gross that bridge when I get the stringers done lol it’s been fun so far the grinding kinda sucks lol but done with that for the starboard side atleast


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[roll.model]

Where the hoses from the sides vents (by the windshield) went under the floor? If so, that's one of Supra's most head scratching designs. On the Saltare that was a really nasty spot to accumulate water. You can kinda see at the bottom of this pic I went with a shelf to direct that water to the bilge so the pump could remove it.

http://i8.photobucket.com/albums/a10/salty87/IMG_0484.jpg~original

You're making great progress with the grinding. Wish I had tackled the rudder seal at the time. It's on my spring wish list. Glad to see you're knocking it out.

Ya I decided if I got it all apart gonna change all the wood and throw in plenty of glass to help reinforce it previous owner beached it so it’s got some damage to gelcoat so was gonna clean up those areas in particular on inside of hull and overlay some fiberglass in as well. From what I can tell it’s just the gelcoat that’s damaged but I figured what the heck extra glass can’t hurt.


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[roll.model]

What’s the best way to get green glue off transom? Been grinding at it for awhile nowhttps://uploads.tapatalk-cdn.com/20180316/789e209ab53c489d09329d58d067f640.jpg


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[roll.model]

Finally got all glue removed and grinding done gonna start building stringers. Got a question tho from what I’ve read i wanna have my stingers glued in a 1/4” off the hull is this correct? And what’s the best way to suspend them for the glueing.


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[roll.model]

Finally got all glue removed and grinding done gonna start building stringers. Got a question tho from what I’ve read i wanna have my stingers glued in a 1/4” off the hull is this correct? And what’s the best way to suspend them for the glueing.


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https://uploads.tapatalk-cdn.com/20180316/74ff674728efe2a39a2e53336c635c61.jpg



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[roll.model]

https://uploads.tapatalk-cdn.com/20180316/0e3d6071cc8a10053564dcd0f3678132.jpg

Gonna start laying glass as soon as I get help


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[roll.model]

ok so I'm looking at fiberglass and reading everyones forms on how they laid in their stringers and I'm not sure what fabric to go with. I've did glass work before but nothing this big and I want to get the stringers done right so they last. What cloth or fabric is best for stringers floor ect. my local shop carries 8oz 6oz cloth and .75oz chop strand mat will any of these work or do I need to find something else? any help is greatly appreciated.

[Salty87]

Okie's rebuild stands out in my memory for using a hybrid type cloth. The details escape me but something like cloth and mat combined in a roll. You might check out his thread or just look on US Composite's site. You can use any of what you listed but laying chopped strand mat separately from the cloth is just extra time/work and the mat is a little frustrating. It didn't like laying down over bends at the tops of the stringers even with their edges rounded off.

Working with bigger sections of cloth it helps to make everything as smooth going as possible. Imo, worth some extra bucks. I remember grinding the freshly laid glass off my first stringer because of air pockets where glass wouldn't lay down so it didn't get wetted out properly.

[roll.model]

Okie's rebuild stands out in my memory for using a hybrid type cloth. The details escape me but something like cloth and mat combined in a roll. You might check out his thread or just look on US Composite's site. You can use any of what you listed but laying chopped strand mat separately from the cloth is just extra time/work and the mat is a little frustrating. It didn't like laying down over bends at the tops of the stringers even with their edges rounded off.

Working with bigger sections of cloth it helps to make everything as smooth going as possible. Imo, worth some extra bucks. I remember grinding the freshly laid glass off my first stringer because of air pockets where glass wouldn't lay down so it didn't get wetted out properly.

Thanks salty87 I talked to a different glass shop near me and he pointed me in the right direction sending me some more stuff my way gonna lay multiple layers of each start with the mat then several layers of cloth. Glasses in some spots where I felt It got ground down too much. Any advice on keeping air bubbles out of glass when wrapping over stringers ? Or how to remove them effectively?


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[flipz96]

I have an 88 Mariah that I just sold today. This brings back memories. Is this the one that was on Boat Trader listed for $12k a couple months back?

[roll.model]

Nope I give 6 for it not realizing it needed floor replacement;( oh well it’s a fun project gonna paint it as well and run it for a few years till I can afford a newer 24v


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[angus2112]

use 1708 glass round the top of the stringers and make a nice round transition (fillet) where the the stringer meets the hull i use liquid nails it takes some time to dry but does not shrink like pl glue. if you have use of a sand blaster blast the inside of the hull before you start glassing it gets rid of the the resin and leaves the glass so the new stuff bites to it. not trying to jack your thread pm me your number if you want to talk i can give you more suggestions but writing a ebook takes to much time

[roll.model]

use 1708 glass round the top of the stringers and make a nice round transition (fillet) where the the stringer meets the hull i use liquid nails it takes some time to dry but does not shrink like pl glue. if you have use of a sand blaster blast the inside of the hull before you start glassing it gets rid of the the resin and leaves the glass so the new stuff bites to it. not trying to jack your thread pm me your number if you want to talk i can give you more suggestions but writing a ebook takes to much time

That sand blaster sounds like a great idea grinding the was a mess! Thanks man any advice I can get will help man wanna do it right so it last me a few years till I can get a newer supra or moomba vdrive lol atleast that’s what I dream about!


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[Cooose]

Thanks salty87 I talked to a different glass shop near me and he pointed me in the right direction sending me some more stuff my way gonna lay multiple layers of each start with the mat then several layers of cloth. Glasses in some spots where I felt It got ground down too much. Any advice on keeping air bubbles out of glass when wrapping over stringers ? Or how to remove them effectively?


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On the air bubbles question...much like painting the key is in the prep work. I like the plastic style bondo applicators that come in a 3 pack. I lay the 1708 mat side up and wet it out, then wet out the area I'm going to glass, then put the glass and use a chip brush to start working it out. Pick up one of the oil drip sheet trays in the automotive section of walmart to use to wet out the glass. They are cheap, close to 3'x5', and work really well to wet out the glass. Next i just keep working the bondo applicators in a "squeegee" fashion to chase the bubbles away.

I also keep some harbor freight throw away scissors on hand to make relief cuts where needed on corners and such after the glass is wetted out.

I have some of the bubble rollers, but find the squeegees to work better most of the time.

[roll.model]

On the air bubbles question...much like painting the key is in the prep work. I like the plastic style bondo applicators that come in a 3 pack. I lay the 1708 mat side up and wet it out, then wet out the area I'm going to glass, then put the glass and use a chip brush to start working it out. Pick up one of the oil drip sheet trays in the automotive section of walmart to use to wet out the glass. They are cheap, close to 3'x5', and work really well to wet out the glass. Next i just keep working the bondo applicators in a "squeegee" fashion to chase the bubbles away.

I also keep some harbor freight throw away scissors on hand to make relief cuts where needed on corners and such after the glass is wetted out.

I have some of the bubble rollers, but find the squeegees to work better most of the time.

Thanks for all the tips got some 1708 coming and will end up using that and my 6oz cloth and mat that I have already gonna get some squeegees as well got my main stinger ready to glue in my outside stringer wood won’t be here until Thursday hopefully glue them in this weekend so we can start the other side next week. How long will I need to wait to glass over Liquid nails?


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[chris young]

I too have done a lot of glass work, building windsurfers, and a few years back I watched a video from a shaper on Maui who used a wet out technique that I wish I had known of or thought of 30 years ago. He uses a large flat table to which he tapes a fresh sheet of poly, wets out the glass on that, then rolls it onto a chunk of PVC pipe and unrolls it onto the board. I can guarantee that the next time I have to do any kind of lay up that's what I'll do.

Good luck

[roll.model]

https://uploads.tapatalk-cdn.com/20180829/cbb52e83ed5feac4f29e11183365f530.jpghttps://uploads.tapatalk-cdn.com/20180829/448ee427fc0096bb955f1150539f45df.jpghttps://uploads.tapatalk-cdn.com/20180829/c2e49800abf0f8da6d0ccb05f5785e40.jpg



Haven’t posted for awhile on this but finally got the project done been a crazy summer audio isn’t finished and wanna build a new swim platform and powder coat the tower and paint the trailer yet but that’ll come this winter put about 25hrs on her in the last week good times


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[Hagman]

Boat looks awesome. I'm looking at replacing my floor and stringer's this winter. I can't complain been running the boat for 32 years. Question how many gallons of fiberglass resin did you go through.

[roll.model]

It was like 25 gallons or so I believe I bought it in 5gallon buckets from us composite online I believe


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[Ohio]

What brand/type of flooring did you use? I like that look and wonder how it's held up for you.

[roll.model]

It’s just that Eva foam off of Amazon so far it’s been holding up well


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