1981 Sportcraft 270 repair underway - transom, stringers, & repower

[WalleyeSniper]

Where do you get the spare bronze plugs from? Never mind - I see that iboats also sells spares.

I've come to like the ones with a little tab and a hole coming off the back of them. I can just use a screwdriver through the hole, or almost any size wrench, or pliers or etc. Really convenient when the 9/16 is up inside the boat but the screwdriver or another tool is right nearby. I can get pretty lazy like that sometimes .

 

[WalleyeSniper]

Oh... lol... Maybe in batches to final. Forgot about that. Yup just check for hairline cracks/fractures.. Might have to redo.
Been there done that. If its too deep or wide for the fill then you get the heat. If you have fractures then knock it out and fill back in layers not as deep.
Ohhh the memories.

How far off the transom do I need my tabbing schedule to start or go? I have 40yds of 12" 1708 tape available. Is 6" too short of a tab to end up with? Like, 3" then 6" tabbing? Or, am I looking more to have like around 8-12" tabbing coming off of the transom?

 

[kcassells]

Somewhere like 6 and 9 worked for me. 3 and 6 would do the job but I wanted more hull contact. In addition I had alot of thru bottom of my hull screws that went clear thru from the prior owner. They were filled with pb like you did and I carried the glass over them.
On another note I reglassed my entire bottom hull.

 

[kcassells]

This is what I used. Simple, effective, lasts forever. I keep a spare plug in the boat and in the truck.

Seadog Garboard Drain Plug Only with Pin

Garboard Drain Plug Only w/Pin Features: Made of pressure cast bronze Tested and accepted for labeling and Listed by the UL laboratories Flange diameter is 2" Plug diameter is 1/2" NPT Plug has square top for wrench or socket wrench

www.iboats.com

I have seen those too but with a wire thru the plug attached to the faceplate so you don't lose it as easily as I probably would.

 

[zool]

Your transom doesnt have alot of pressure on it, being an inboard....so u cant really screw it up as long as it stays encapsulated and in place.

Everything is looking good so far :]

 

[JASinIL2006]

Where do you get the spare bronze plugs from? Never mind - I see that iboats also sells spares.

You can also get them at hardware stores. Brass pipe plugs.

 

[WalleyeSniper]

Somewhere like 6 and 9 worked for me. 3 and 6 would do the job but I wanted more hull contact. In addition I had alot of thru bottom of my hull screws that went clear thru from the prior owner. They were filled with pb like you did and I carried the glass over them.
On another note I reglassed my entire bottom hull.

Hey heyyyy, I really like that tabbing schedule. One of my favorite numbers, sounds like I might need the wife to help me with that 69 tabbing schedule. (I'll show myself out now)

On a serious note though, that's what I'll go with too, 6" and 9" seems like a good middle ground. Like Zool said, shouldn't be too much of an issue or worry since it's a full inboard and I've already built it up beefier and more professional like than even the manufacturer did. So, I like my odds so far of this thing not totally disintegrating if I get caught in some stormy weather. Lol

 

[WalleyeSniper]

Well, finally able to post some updates and finally get back on here as often as I'd like. Had some work issues that took up all my time the past couple weeks and only got a few things done.

The first tall stringer is in place, along with the transom. I wanted to guy the boat entirely, but with a flimsy as it would be, I want to get both tall stringers in first before I entirely tub the hull so it holds shape better.

Transom went in without a hitch, and just had to get into the first tall stringer. The process I used was a follows:

- cut out and cleaned stringer until bare hull
- mapped the stringer curves with popsicle sticks and hot glue.

- cut out stringer from southwest pine kiln dried lumber. Completely coated stringer lumber in resin until nice and heavy coated for waterproofing.

- due to the length of the boat, the stringer needed to be built in 3 sections (the cost, and sourcing unavailability in my area prevented us from going the pure plywood route). This means I have two areas where butt blocking/sistering needs addressed. One joint is midship, and the other is up near the first 3' of the stringer in the cuddy area. Surprisingly, the manufacturer just had 4 different sections SITTING in the stringer caps, with no blocks, no gluing together, and literally just dry butted up against each other. I suppose they were relying on the hulls strength more than they were the wood underneath the glass?

- adding the plywood sandwich sisters in the front is going to add around 60lbs to the front cuddy area of the boat. But, I figure it's STILL lighter than when this entire thing was waterlogged and mushy. So, I'll just have to factor that weight in. I don't think 60lbs should make or break anything. I just wanted the bow area of the sole to be rock solid due to crashing of waves and etc.

- I bedded the stringer on hairy PB, using little foam 1" squares about 1/8-1/4" thick as spacers to space it off the hull (I may or may not have accidentally forgot one or two of the spacers under the stringer, and they cured inside the resin)...

- I glued the butt ends of the three sections of stringer using hairy PB, and sistered them in place. The front section in the cuddy, I used an extra large 3/4" Marine Plywood designed sister on each side, and normal 2x10" butt blocks for the middle joint at midship at around a 1:3 ratio. That joint is going to be stronger than anything else in the boat FOR SURE...

- I kept the joints near where bulkheads are going to be, so I'd have extra support sideways as well, in addition to the butt blocks.

- After putting in the stringer, I glued the joint to the transom using thick hair PB, and the stringer feels strong as a rock!

- I then put the second tall deck support section on top of the stringer to gain full height deck support like the stringer originally had.

- I cut open a rear water drain channel against the transom at the floor of the sole of the boat, and made it a 3.5" round area. So, any water that makes it into in-between the outer stringer and gunwhale, can just run into the bilge via the transom area and get pumped out.

Next step is the stringer on the mirror side. Then, the hull will have enough fore to aft shape stiffness for me not to worry about the rest of the build by tubbing everything else out. THEN the fun begins and should go a lot quicker.


Spacing the stringer.


Transom connection and water drainage channel.


The midship stringer with one sister in place. Mechanically fastened with 12 screws as well as Hairy PB surfaces together. Rounded off the ends and edges to make filleting and laying glass easier.


Front template for plywood sisters of the front of the stringer section.


Plywood sisters. The lined marked area (with the diagonal lines) is where the stringer will be inserted into the sisters/where the sisters are sandwiching the stringer. Stringer will be in contact on 3 sides, because the top is going to also be connected via HairyPB for whatever little extra strength that may or may not provide.


Where the stringer will be inside the sisters.


This is the front portion of the stringer without sisters yet. All bedded and resin'd in.


This is the front 3rd of the stringer, now with sisters in place. They are attached mechanically and with Hairy PB.


This is the deck support portion of the stringer. Bedded on top with Hairy PB and mechanical side supports will be removed when glassing in entirely. Everything is resin coated thus far and seems to be going good.

I can't believe how much support just one stringer have to the hull! It's just amazing how this thing even floated and was running the seas in the condition it was in!

I feel the new front stringer will be just fine, especially considering this was the original front stringer -

The original stringer...

 

[88 Capri (2022 SOTY)]

Well, finally able to post some updates and finally get back on here as often as I'd like. Had some work issues that took up all my time the past couple weeks and only got a few things done.

The first tall stringer is in place, along with the transom. I wanted to guy the boat entirely, but with a flimsy as it would be, I want to get both tall stringers in first before I entirely tub the hull so it holds shape better.

Transom went in without a hitch, and just had to get into the first tall stringer. The process I used was a follows:

- cut out and cleaned stringer until bare hull
- mapped the stringer curves with popsicle sticks and hot glue.

- cut out stringer from southwest pine kiln dried lumber. Completely coated stringer lumber in resin until nice and heavy coated for waterproofing.

- due to the length of the boat, the stringer needed to be built in 3 sections (the cost, and sourcing unavailability in my area prevented us from going the pure plywood route). This means I have two areas where butt blocking/sistering needs addressed. One joint is midship, and the other is up near the first 3' of the stringer in the cuddy area. Surprisingly, the manufacturer just had 4 different sections SITTING in the stringer caps, with no blocks, no gluing together, and literally just dry butted up against each other. I suppose they were relying on the hulls strength more than they were the wood underneath the glass?

- adding the plywood sandwich sisters in the front is going to add around 60lbs to the front cuddy area of the boat. But, I figure it's STILL lighter than when this entire thing was waterlogged and mushy. So, I'll just have to factor that weight in. I don't think 60lbs should make or break anything. I just wanted the bow area of the sole to be rock solid due to crashing of waves and etc.

- I bedded the stringer on hairy PB, using little foam 1" squares about 1/8-1/4" thick as spacers to space it off the hull (I may or may not have accidentally forgot one or two of the spacers under the stringer, and they cured inside the resin)...

- I glued the butt ends of the three sections of stringer using hairy PB, and sistered them in place. The front section in the cuddy, I used an extra large 3/4" Marine Plywood designed sister on each side, and normal 2x10" butt blocks for the middle joint at midship at around a 1:3 ratio. That joint is going to be stronger than anything else in the boat FOR SURE...

- I kept the joints near where bulkheads are going to be, so I'd have extra support sideways as well, in addition to the butt blocks.

- After putting in the stringer, I glued the joint to the transom using thick hair PB, and the stringer feels strong as a rock!

- I then put the second tall deck support section on top of the stringer to gain full height deck support like the stringer originally had.

- I cut open a rear water drain channel against the transom at the floor of the sole of the boat, and made it a 3.5" round area. So, any water that makes it into in-between the outer stringer and gunwhale, can just run into the bilge via the transom area and get pumped out.

Next step is the stringer on the mirror side. Then, the hull will have enough fore to aft shape stiffness for me not to worry about the rest of the build by tubbing everything else out. THEN the fun begins and should go a lot quicker.

View attachment 351272
Spacing the stringer.

View attachment 351273
Transom connection and water drainage channel.

View attachment 351274
The midship stringer with one sister in place. Mechanically fastened with 12 screws as well as Hairy PB surfaces together. Rounded off the ends and edges to make filleting and laying glass easier.

View attachment 351275
Front template for plywood sisters of the front of the stringer section.

View attachment 351276
Plywood sisters. The lined marked area (with the diagonal lines) is where the stringer will be inserted into the sisters/where the sisters are sandwiching the stringer. Stringer will be in contact on 3 sides, because the top is going to also be connected via HairyPB for whatever little extra strength that may or may not provide.

View attachment 351277
Where the stringer will be inside the sisters.

View attachment 351279
This is the front portion of the stringer without sisters yet. All bedded and resin'd in.

View attachment 351278
This is the front 3rd of the stringer, now with sisters in place. They are attached mechanically and with Hairy PB.

View attachment 351280
This is the deck support portion of the stringer. Bedded on top with Hairy PB and mechanical side supports will be removed when glassing in entirely. Everything is resin coated thus far and seems to be going good.

I can't believe how much support just one stringer have to the hull! It's just amazing how this thing even floated and was running the seas in the condition it was in!

I feel the new front stringer will be just fine, especially considering this was the original front stringer -
View attachment 351282
The original stringer...

Geeze and I had alot going on with my project, looking good!
I did want to mention that before you tab them grind to clean fiberglass first otherwise you may have adhesion issues.

 

[WalleyeSniper]

Geeze and I had alot going on with my project, looking good!
I did want to mention that before you tab them grind to clean fiberglass first otherwise you may have adhesion issues.

Yeah, I DEFINITELY still have a long way to go in the grinding and tubbing, eh!? Lol.

The only places that were truly spotless to the red/main glass and acetone cleaned, was the areas where any bonding was gonna take place, hehe.

I only left around an inch or two of play on either side of any areas I cleaned for bonding, mainly because I am hustling to make sure I get both of these main stringers bonded in before the first freezing temps come in (northern Ohio, we've already had a few 40's days, so just kinda hustling along now racing mother nature).

Once I'm able to get these two main stringers bonded in, then I should smooth sailing and not have to worry as much, because I can cover it up with a tent and not have to worry as much about the fore/aft mis-shaping, arcing, or hooking that I've been so concerned with. Then, I can just go to town tubbing and cleaning the rest without fear then at that point. Up until now, it's been a "fingers crossed butt-puckering" kinda moment, every single time I cut something out or move wrong in the boat!

So, I'll be happy when these main two stringers are bonded in and I can get moving on the rest of the cleaning and cutting. I have 12 stands and a couple crib frames under the boat, but they built these things SUPER flexible it appears.

Thanks for the feedback, I appreciate it! I'm always open for advice, pointers, and corrections on everything I'm trying here.

 

[KJM]

Man, thats a lot of work, but its looking real good! It will be better then original and last for years.

 

[88 Capri (2022 SOTY)]

only left around an inch or two of play on either side of any areas I cleaned for bonding, mainly because I am hustling to make sure I get both of these main stringers bonded in before the first freezing temps come in (northern Ohio, we've already had a few 40's days, so just kinda hustling along now racing mother nature).

I live in upstate NY so I have lived that race against time

 

[WalleyeSniper]

Man, thats a lot of work, but its looking real good! It will be better then original and last for years.

Thanks! Yeah, it's a crap load of work for sure. Much different than the few little 16' & 18'ers I've helped restore lol. But, I think it'll definitely be worth it in the long run.

We're planning on using it for our charter, so I figured instead of spending $100k+ for a new charter boat, we could just build this to suit and never have to buy one again. Hopefully I'm right, lol.

 

[JASinIL2006]

Nice work!

 

[WalleyeSniper]

Nice work!

Thanks man. I just kinda looked at what everyone else was doing with their projects and problems, and kinda figured my way out from there on the different joint issues and etc.

I think on the next stringer, I'm going to start from the front, and work my way backwards, to eliminate having to have another pain in the ass joint in the cuddy/bow area again. That was a nightmare to figure out all the angles, sweeping angles, and geometry to line up. Lol

But, I think it'll be fine in the long run. I couldn't believe that the stringers weren't running along inside those chine rails... Is that common for chine rails to be hollow like that without any structure or anything inside them?

 

[Reserector_]

Good progress! I hope the weather holds out for you.
I had one thought/concern about the drain where the stringer meets the transom. I understand the logic behind it, but wont that also allow water to get INTO the outer sections as well as out of them?
Would it be better as an air-tight/foamed compartment? If so, (theoretically) no water would get in, and so nothing would have to drain.

 

[kcassells]

Air tight compartments blow on a boat this size. A little skippy yea ok.
Boat is made to do rough waters. Simplicity is water in and water out. Proper prep is what this is all about.

 

[Reserector_]

I follow. That answers my question.

 

[WalleyeSniper]

Good progress! I hope the weather holds out for you.
I had one thought/concern about the drain where the stringer meets the transom. I understand the logic behind it, but wont that also allow water to get INTO the outer sections as well as out of them?
Would it be better as an air-tight/foamed compartment? If so, (theoretically) no water would get in, and so nothing would have to drain.

So, as Cassels said, air tight compartments on a boat this size are a no go for a few reasons.

Yes, it'll allow water to drain into the bilge (and theoretically into the side compartments). But, if I have water THAT high to start getting into those side compartments, I have wayyyyy bigger problems than worrying about the water.

The original sportcraft design had those channels in the same spot, but half the size I made mine AND they left them open and exposed with no glass over them. So, anytime water even splashed that way, the wood was rotting. Ours is resin soaked, glassed, and sealed from the elements.

The reason foam would be a no-go, is because the boat is so large and the area so vast, that water is going to inevitably get into those areas no matter how well we seal it up. Water drizzling down the gunwales in between the tubbed sides and outer hull from a loose screw (in which there are 115 of those screws around the boat trim. So, chances of one leaking at some point is very high).

We could just foam the entire area, but then we'd be adding a crap ton of weight to the system on both sides. When, really that weight should be in the middle if we were to add that much I'd think.

The other reason, is as Cassels said. This is a rough water boat that's going to take a massive pounding on Lake Erie's extremely close 2-4' chop water. So, it's definitely going to see tons of stress and will likely develop SOME type of leak path for water to find its way into the compartments regardless. Then, we'd have trapped water soaking into the foam over time and turning it into wayyyyy more weight and muck over the long haul.

So, for us, simplicity is the key. Every single part of this boat will be designed to bail water as fast and efficiently as possible, no matter where it enters at. You'd be amazed at how wet boats get on Lake Erie, especially if you go out in anything over 2'ers haha.

But, we will be adding buoyancy foam to the bow area as well as the rear under certain areas near the tank and a couple other areas that will be easy to self air and self shed any water the areas might intake. So, we're trying to get the best of both worlds.... HOPEFULLY... lol

 

[WalleyeSniper]

Well, fully rebuilt our Velvet Drive 72 series 1.91:1

I can't believe how simplistic, and rock solid, these transmissions are! It looks as if someone has already rebuilt it at some point recent without many miles on it. But, figured since we're repowering her and doing all this work, may as well tackle a new trans while we're at it.

- Replaced all seals
- replaced all clutch discs
- replaced all FWD gear clutch discs & plates
- replaced main drive bearing
- replaced all gaskets
- replaced all bolts and hardware
- replaced reverse gear clutch discs & plates
- cleaned all gears, shafts, and the sun gears to mint condition
- all mating surfaces were gasket'ed AND permatex'd on both sides for long leak proof operation (aviation permatex)
- washed and cleaned all old fluid out and ordered a new inline oil cooler
- using Dexron III instead of the typical oil like they used to run in them. Better performance and longer run life that way.

Here's a few pics along the way, with the finished pic at the end













All finished, and ready to go when we pair a motor up to it. If anyone is rebuilding any Velvet Drives and has any questions, feel free to contact me, haha. I learned A LOT of tips and tricks along the way, especially with Chris's help from Hale Marine. Most knowledgeable Velvet Drive builder that I know of.