Newbie owner looking for boat specific details

[Jermy-Jinky]

Hey all, I've been running all kinds of boats for the better part of my life and I already own a PWC, but just got my first boat. It's a 1990 ThunderCraft 1560 SE. I got it super cheap. It needs a little work, all of which I'm more than capable of doing. The biggest issue that I see, is the deck has some bad spots, and the seams on the seats need to be stitched (they aren't torn, just the thread has worn away).
Hoping to dive into it this weekend, so long as the weather cooperates. I know ThunderCraft went under a long time ago, but I was hoping to find some specific information about this boat. The previous owners were an older couple that bought it as a project, but were selling it because of a job relocation. I know flooring repairs can become pretty expensive and aggressive. But I have my fingers crossed. Plus, I know I can flip it for a profit in it's current state.

Any information, help, tricks, or tips would be awesomely appreciated!

 

[roscoe]

First off, welcome to iboats.

"I know I can flip it for a profit in it's current state."

That would be a good idea.

Most of the time a boat rots from the bottom up.
So if the floor is soft, it is likely that the stringers and the lower transom are already rotted.
Along with saturated flotation foam.

There is a huge restoration forum that can answer your rebuild questions.

Boat Restoration, Building, and Hull Repair

sponsored by Spectrum Color

forums.iboats.com

And a Thundercraft specific forum, which unfortunately isn't very active.

Thundercraft Boats

forums.iboats.com

Make sure the paperwork is in order and the boat, motor, and trailer are in you name before spending ANY money on the boat.

I'm seeing a 1991 SE, and a 1990 SS.

1991 Thunder Craft 156 SE​

This Thunder Craft outboard runabout has a fiberglass hull, is 15.5 feet long and 78 inches wide at the widest point. The boat weighs approximately 950 pounds with an empty fuel tank

 

[tpenfield]

Welcome to iBoats

Your level of optimism certainly indicates that this is your first boat ownership. We have heard your story many times . . .

• 30 year old boat
• Super cheap
• Got it from an older couple - they moved away (smart of them)
• Consider yourself handy
• Just got a few soft spots in the floor
• Looking for information - Don't ask about an owner's manual - please.

Best thing to do is get after the floor and see how far wide and down the rot goes. The seats may have to be re-upholstered, not sure the stitching alone can be easily re-done.

 

[Jermy-Jinky]

Ha, I appreciate your replies! I am for sure handy. I’m currently rehabbing houses 4 & 5. Plus I’m incredibly mechanically inclined and my oldest son is a certified mechanic (albeit diesel, but still). This isn’t going to be a full overhaul. It’s a starter boat to play with for a few seasons as we build up to upgrade. I’m not going to drop a “ship” ton of money into it...just make it useable for the short term. Most of the flooring is really solid, even at the transom. It’s bad spot is in the center towards the port side (mostly around the ski locker area). I’ve watched a TON of videos and read a TON of articles about redoing the floors, and none of it is out of my “wheelhouse” (I’ve even done a little fiberglassing before). Definitely not looking for an owners manual...too many things have been changed out over the years for it to be of any use, plus, it’s a super basic boat. No bells and whistles aside from a cheap, aftermarket stereo. It doesn’t even have the electronic trim anymore or a towing cleat. It’s just the floaty bit, basic nav lights, and an outboard motor. Just got it to get our feet wet, and cruise some lakes until we land a bigger, nicer boat. I’m going to try to peel back the old floor this weekend and see what’s going on in there.
How do I tell if the floatation foam is bad? Is there anything that can be done if it is? What are some other things I should look for?

 

[Grub54891]

Flotation can be checked in a few spots, it requires drilling a few holes about 1.5" in the floor. use a large drill bit and see what comes out. Be careful you don't drill through the bottom of the hull. You can patch the holes later. If it's wet you'll know it. I bet it is.

 

[jbcurt00]

And checking the foam requires multiple holes all the way down to the hull, not simply an exposed surface inspection..... expect it to seem overly invasive. If it doesnt seem that way, you're probably not checking sufficiently...

 

[briangcc]

"This isn’t going to be a full overhaul."

And how did the core sampling of the stringers and transom go?

As some of the seasoned pros will say, and have already said, the floor is the last thing to rot. So more than likely you are looking at a complete gut to make the boat safe to use.

 

[Scott Danforth]

if you dont want to sink a bunch of money into refurbishing a boat, start with an aluminum boat with an outboard or buy a boat that is less than 10 years old

no such thing as an owners manual on boats (with very very few exceptions)

the stitching is gone because the thread long ago rotted. however the vinyl was no longer usable after the first 5-10 years as it looses its elasticity

boats rot from the bottom up, never seen a soft floor in a boat where the transom and stringers and foam were good. ever.

if you can flip the boat and break even, do so, or plan on sinking $4k into the hull and about $3k into the interior.

 

[JASinIL2006]

You can core sample foam by taking a piece of 3/4" copper pipe and tapping the pipe into the foam (gently) until you hit bottom. Then twist the pipe and pull it out. You can push the core sample out of the copper pipe with a wood dowel.

I'd do this in a number of places, not just a few.

 

[hugh g]

If you have a soft spot in the floor I'll bet money the foam is wet. Which means it has to go because there's no way to dry it out. Boats of that vintage were built to get them out the door to the dealers because the industry was booming. Build quality sucked to put it frankly. I know because I owned one & found out the hard way. Good luck with it.

 

[Jermy-Jinky]

"This isn’t going to be a full overhaul."

And how did the core sampling of the stringers and transom go?

As some of the seasoned pros will say, and have already said, the floor is the last thing to rot. So more than likely you are looking at a complete gut to make the boat safe to use.

I pulled all of the flooring carpet out from transom to bow, and the only rotted spot was the port side of the ski locker. Transom, surprisingly is solid. I cut out a section of the floor 12" behind the rot to in front of the seat mounts (I decided to just replace the seats), and all the way from side to side. Surprisingly, the floor showed no other signs of rot, and the stringers were dry and solid (I was fully expecting them to be toast, especially because of having a ski locker). I didn't do a foam core sample yet, because everything I've found thus far has been positive and I really wasn't sure how to go about doing it; so now that I know about the copper pipe method, I'll be doing that (if it ever stops raining here). I have a pretty big area of the foam exposed, and on the surface, it looks good, and it feels solid and there didn't seem to be any water damage. I know I need to look deeper though. Everything above the deck in the bow looks good, the under seat compartments are actually clean, and the wood is solid. I'm still going to do a core sample though. What I was most surprised by is just how little foam there seems to be.

 

[Jermy-Jinky]

if you dont want to sink a bunch of money into refurbishing a boat, start with an aluminum boat with an outboard or buy a boat that is less than 10 years old

no such thing as an owners manual on boats (with very very few exceptions)

the stitching is gone because the thread long ago rotted. however the vinyl was no longer usable after the first 5-10 years as it looses its elasticity

boats rot from the bottom up, never seen a soft floor in a boat where the transom and stringers and foam were good. ever.

if you can flip the boat and break even, do so, or plan on sinking $4k into the hull and about $3k into the interior.

Why so much on the hull and interior? My hull is actually in excellent condition for this boats age. Same for the interior (except for the main seats and transom seat bottoms). Even the carpet was still in good condition, and surprisingly barely faded from the original color. I'm going to thoroughly clean and polish the hull. For the interior, I'm probably replacing one of the back to backs with another, and the other, I'm probably replacing with a pedestal, I might do two pedestals instead, I haven't decided on my new seating arrangement yet; it only has a 5 person capacity and has built in bow and transom seats already. This isn't, and wasn't a luxury vehicle. I'm rebuilding it for fun. I'm not trying to turn it into a ski boat or a deep sea fishing boat, or anything else for that matter. It's a lakes and rivers cruiser. I like operating the boat, and my buddies like drinking on a boat. So that's what she is destined to be, a brew-cruiser (and before I hear about it, I NEVER drink and boat. Not even one. If I've had anything to drink, the boat stays docked.)

 

[Jermy-Jinky]

If you have a soft spot in the floor I'll bet money the foam is wet. Which means it has to go because there's no way to dry it out. Boats of that vintage were built to get them out the door to the dealers because the industry was booming. Build quality sucked to put it frankly. I know because I owned one & found out the hard way. Good luck with it.

Thanks! I know about this era of boats, I've read about ThunderCraft in particular, they went completely belly up the year after this boat was built. Same with the jet ski I own. It's a Polaris Freedom, a year or two later than the one I have, Polaris stopped production on PWCs. But, I still have a hell of a nice one. And the story behind it is very similar to the story of my boat. Hell, my ski still looks like it just rolled out of the showroom and runs like a dream. I'm just making this a fun little cruiser. Not trying to win any beauty pageants or speed records. I just want to listen to music on a lake with my buddies.

 

[Jermy-Jinky]

Here's a few (not very exciting) pictures of demo day 1. (red hat is my brother, black hat is our buddy, and I'm in the grey t-shirt)

 

[Jermy-Jinky]

Welcome to iBoats

Your level of optimism certainly indicates that this is your first boat ownership. We have heard your story many times . . .

• 30 year old boat
• Super cheap
• Got it from an older couple - they moved away (smart of them)
• Consider yourself handy
• Just got a few soft spots in the floor
• Looking for information - Don't ask about an owner's manual - please.

Best thing to do is get after the floor and see how far wide and down the rot goes. The seats may have to be re-upholstered, not sure the stitching alone can be easily re-done.

I'm taking a little of your advice with the seats...I just decided to pull 'em and get new ones.

 

[Jermy-Jinky]

You can core sample foam by taking a piece of 3/4" copper pipe and tapping the pipe into the foam (gently) until you hit bottom. Then twist the pipe and pull it out. You can push the core sample out of the copper pipe with a wood dowel.

I'd do this in a number of places, not just a few.

Holy cow, dude! I just looked through your thread on your transom restoration. Yikes! Knock on wood, mine has been "good" so far.

 

[JASinIL2006]

Mine looked great, and ran great, when I bought it. The outdrive didn't flex and everything seemed great. Until I tried to tighten a bolt holding the boarding ladder... and it just spun. That led to a more thorough investigation. In all places, the foam in my boat looked fine... on the top. When I started checking it out, though, I found the bottom two or three inches were saturated. You just can't tell from appearances, or knocking on the transom, etc.

I hope your boat doesn't have any more extensive problems, but if you plan to take family or friends out on the water, it's really on you to thoroughly check to make sure the structure is sound. You have no idea how many boaters come here with just a soft spot in the floor only to find more significant problems. No one wants your boat to need more work, but boats of that age are just such likely candidates to have more extensive rot.

Best of luck, and be sure to drill sample your stringers and transom to make sure they're sound.

 

[Jermy-Jinky]

Thanks! I checked the stringer going up the center and the rear cross stringer by hitting a screwdriver with a hammer into it in a few places and they were good and solid...now that I'm leaning more about these restos and checks to do, I'll drill them in a few other spots to check the shavings. With the drill holes, do I just fill those with 5200?

 

[JASinIL2006]

Thanks! I checked the stringer going up the center and the rear cross stringer by hitting a screwdriver with a hammer into it in a few places and they were good and solid...now that I'm leaning more about these restos and checks to do, I'll drill them in a few other spots to check the shavings. With the drill holes, do I just fill those with 5200?

Yes, fill the holes fully with 5200 and you'll be fine. Also, the tests you did will reveal the worst cases of rot, but that's about all. Good for you for checking more thoroughly with a drill.

 

[Jermy-Jinky]

Yes, fill the holes fully with 5200 and you'll be fine. Also, the tests you did will reveal the worst cases of rot, but that's about all. Good for you for checking more thoroughly with a drill.

I didn't get to the drill test or core sample yet. It was late when I got a chance to go out to look at it. I had a piece of tubing that I jabbed into the foam to see what I could see, and it didn't seem like it went all the way down to the hull...what little bit there was, was dry though (i know this means nothing at this point). I had cut the floor back even closer toward the transom, and found a couple of spots on both sides of the boat where it looks like an air pocket in the foam had formed when it was poured and those were dirty and wet. Just curious, because I noticed something as I was digging around these spots: I was able to dig out the wet foam and get to dry. If my actual core samples come out dry, would it be possible that I could just dig out these wet spots to get to dry foam? (I know this is wishful thinking, but hey, we all gotta have dreams); and If that's the case, do I just fill the voids with new foam?

Another question...let's say the foam is toast and I do decide I want to salvage this boat and decide to re-foam it. How much do I need to get? What type? I was looking at flotation foam online and couldn't really make heads or tails of it. I saw a 2lb density, 2 gallon kit that says it fills 8 cubic feet and provides 300lbs of floatation per mixed two gallons. Would this be what I need? How do I determine how much I would need? It seems to me like there isn't a lot of places for the foam to go and one or two of these sets would replace it all...no?