Replacing Skiff Flotation Foam [[Carolina Skiff Rebuild Part 8]]

It has been a long time and a lot of work, but it is finally time to poor the new flotation foam in the skiff! I have been looking forward to this moment for a long time. As well as dreading it in some ways. For some time this has seemed like a daunting task. I have thought of every different way I can to make this go as smoothly as possible. Only time will tell if I thought of everything.
In these Carolina Skiffs the foam is a big part of their construction. It not only provides flotation, but stiffness as well. From my understanding, without the foam these hulls would be much less rigid. The foam seems to also be a key part of their strength as well. Without the foam they also could not cut them in half with a chainsaw. Like in the old commercials that ran in the 90’s.
As you will see not all of my ideas will pan out. I had big plans to aid the foam in forming to the cavity’s. My plan did not work at all. The foam would just push up my four by six. Even with two concrete blocks on top. I assumed the foam would stay some what liquid until it fully explained. Unfortunately the top begins to harden seconds after expansion begins. Therefore this was quite a large learning curve. I wasted some foam and cost myself a little more money, but now I know how the stuff works.
Two part polyester buoyancy foam is not cheap. I searched and searched until I finally found a kit that met my needs at a reasonable price. When I ordered the kit. I gave myself some extra for play room. By my calculations an extra 10 cubic feet, but like most of my plans. They fell apart and I still ran out of foam. I hastily ordered a small 1 gallon kit off of Amazon. Which was more expensive per gallon, but seemed to do just as well. Below I will link both kits that I used.
As you will surly see in the video. I had no idea what I was getting into. Just a general idea of what I wanted to do. As well as a idea of what needed to be accomplished. I believe it turned out half way decent for my first time. If I ever do it again. It would be a lot better, but that goes for most things. I hope some one is able to take something away from this video. Hopefully helping them with their own rebuild. I appreciate everyone who has watched, commented, and subscribed! Thank you so much!
-40 cubic foot kit
www.uscomposites.com/foam.html
-1 gallon kit from Amazon
TRUE COMPOSITES Liquid Urethane Pour Foam Base-2 Part Closed Cell Rigid Pour Foam-2 lb Density-Fast-Acting Formula-Boat Buoyancy, Flotation, Filling, Soundproofing & Insulation-1 Gallon Kit www.amazon.com/dp/B079W5G234/...
-Amazon Fumed silica. This is not the same thing I had. They no longer carry it, but this works a little better.
Cab O SIL Fumed Silica Flotant, 1 Gallon www.amazon.com/dp/B00BPW7MRQ/...
-Epoxy
www.boatbuildercentral.com/pr...
-Mixing cups
(Full Case of 100 each - Quart (32oz) PAINT MIXING CUPS) by Custom Shop - Cups are Calibrated with Multiple Mixing Ratios (1-1) (2-1) (3-1) (4-1) (8-1) BOX of 100 Cups includes 12 bonus Lids www.amazon.com/dp/B00IJD848A/...
-Microspheres. These are the two I have used.
White Glass Microspheres - Filler for Epoxy and Polyester Resin - Quart Tub www.amazon.com/dp/B07KPL163Y/...
www.boatbuildercentral.com/pr...

[@kirkmartin2223]

Fair the glass.....ALWAYS! The fairing compound will end up shattering like a windshield if it doesn't have a good backing

[@FishHuntCookTinker]

I was a little worried about that, but it was the only way I could come up with to fill in the small holes in the foam. Everywhere there was a larger hole I went back and filled it with foam. I mainly did a very thin skim coat in areas that had a bunch of little holes in the foam. My concern was if I did not fill the little holes and small cracks. It would cause issues in the first layup. Later I will fair the top of the deck. Thank you for watching and the advice!

[@kirkmartin2223]

@@FishHuntCookTinker I built an inboard jet boat using a 1972 skeeter metro boat and a 900cc jetski engine. My floor is pink panther purple foam insulation with 1708 on both sides and pour foam underneath. It gives me about 5.5" of foam in the floor. Similar to what you have. Filling the voids under the first layer of your floor was a good idea...but would have been better if you mixed in some milled fiber with the micro ballons to keep the fairing compound from "shattering" later on. Are you planning on using gelcoat to cover everything? I wish you would have weighted the boat before and after you are done. I'm curious on what the weight difference will be.

[@cubaniton74]

You did a great job. My suggestions: Next time, apply a thing coat of the foam and as the foam is curing, but still pliable, sink into it used empty water bottles (with the cap on), that way you will fill lots of space with just air trapped inside the plastic bottles (save hundreds of used water bottles in plastic bags to be used), and if you have enough space available , repeat the process until you are near the floor level, then only use the expanding foam to level things out. You could also use Styrofoam sheets, and cut them up into strips wide enough to fit into the channels, stuffing the channels full with the Styrofoam, then use a layer of the expanding foam on top until you reach the floor level (I do not know if the expanding foam will melt the Styrofoam though, so a test would have to be done). Ideally, if you could fill the channels with Styrofoam sheets only cut to size, and level the top somehow, then put on the fiberglass floor, if water was to ever get inside and if the channels were all interconnected with holes, the water would easily be able to drain through holes at the transom.

[@FishHuntCookTinker]

Those are some good ideas. I have heard of using bottles as flotation before, but never styrofoam sheets. I guess it could work well. Although any gas leak would probably melt it away. Flotation foam was one of the hardest things to work with I have ever used. Once it starts to expand you can’t touch it. If you do it it messes the expanding process up. After 5 or 10 seconds it already has a hard crust on the top. I tried sticking pieces I had cut off in it while it was expanding. All I did was make a big mess. I just gave up an did it the way the factory did. The foam adds stiffness and strength to the hull. Therefore I was a little chicken to mess around to much. Thank you for watching and sharing all your ideas!

[@02043828]

Ping pong balls, great filler

[@FishHuntCookTinker]

That would probably work. Have to find a surplus place to get them. Only problem would be stiffness. The foam is supposed to add some rigidity to the hull. I like the creativity though!

[@outdoorheretic8232]

Enjoyed this, I'm redoing a 14' Skiff, I drilled a hole and I don't think I've got water in the hull...at least that's what I'm hoping!

[@FishHuntCookTinker]

I am glad you enjoyed. Probably the best way to tell is to weigh the hull. I wish I would have weighed mine before I started, but you could tell a big difference in the water. Good luck on your 14’. Thanks for watching!

[@NFNADVENTURE]

I know I have some water in my 16 ft. I drilled a hole and put a garboard plug in. I didnt realize that there was stringers without holes so I got water out of 1 void.

[@KollynJ]

Mine got a small puncture in the bottom about 1/4 or less. Was on the water for 10 hrs I’m guessing it took on 100ibs of water. What did you decide to do?

[@antfarmmining7824]

The things we do to go fishing

[@FishHuntCookTinker]

You are not kidding. If I just fished as much as I worked on stuff to fish. Between the skiff rebuild and building my own rods. I probably have 20 hours of work to every hour I fish. Thank you for watching and commenting!

[@Eugene2ndW]

@@FishHuntCookTinker I would not own a boat if I did not enjoy working on it so much! My wife says, "at least it keeps you out if the beer joints"

[@antfarmmining7824]

Yep Bondo works fine

[@FishHuntCookTinker]

I probably should have went with Bondo. I used a lot of filler to make the fairing compound I used. Thanks for the tip and for watching!

[@02043828]

Ok, I see , you thought of it

[@02043828]

Take the trimmed foam and place in the next pour, it wil form right around the scraps, O waste

[@MaineGreenCrabs]

Next time use original Gorilla Glue mix about 10% water, it will foam up about the same volume, it is also closed cell. Or at least use to fill voids and adhere deck back before glassing.

[@FishHuntCookTinker]

That’s neat to know. I hope there never is a next time! Thanks or watching and commenting!

[@bipedalhominid6815]

That stuff WILL absorb water. Guaranteed. Every boat in the world with foam in it gets water logged. Next time fill it with pool noodles or old soda bottles. Your stringers are close together, it doesn't look like you need the foam for structural support.

[@FishHuntCookTinker]

I thought about going without foam. Then I thought about all the logs that are in the lake after a big rain. Also I feel like I would have to strengthen the bottom of the hull. It is relatively thin. Thanks for watching and commenting!

[@thomascooper193]

Little bit more foam down

[@bryanturner683]

Fish Hunt. I hate to burst your bubble but they say this is a closed cell foam. Problem is over Time it will break down and soak up water. Tipping the boat up wont drain it as its soaked into the foam. Here is a quote from the manufacture. "This foam is approximately 95-98% closed cell which resists absorbing water, however continuous water submersion can eventually lead to loss of buoyancy over a period of years." If you do a search you will see its a common problem . In aluminum boats it can cause corrosion and ruin a hull or require extensive repairs. If your chambers are water tight no problem, but drain holes will allow water into contact and can put you back where you started. Yes I know lots of manufactures use the stuff. It passed coast guard standards. Coast guard only tests for 30 days. Hopefully your sections will stay dry enough to avoid the problem. Great project to watch though. Polyethylene is a better material. Pool noodles are made from it. You can get it sheets also.

[@CaptainMcFartin]

Could you have just had a spray foam company come in and put in closed cell foam? Or is there a certain type that you have to use?

[@FishHuntCookTinker]

Yes you could. I talked to a guy that did spray foam. He happened to be spraying a job I was on. From what he told me it would cost a lot more than diy. Also most kits are USCG approved. Thanks for watching and commenting!

[@Eugene2ndW]

Did you find the source(s) of the water intrusion?

[@FishHuntCookTinker]

The water got in through all the screw holes in the deck. The console has been changed two or three times. As well as different cooler holders and different things. Unfortunately a lot of the holes were forgotten about and not sealed properly. Thanks for watching and commenting!

[@howiemoth3847]

Look up hot wire foam cutting on yt.. After watching the first 7 vids. I had to google C/S hull design because I am amazed at how they are built, no drainage and 20 dams filled with foam sponges, unbelievable. Closed sell foam soakes up water once the "skin" is boken. How has this company survived??

[@FishHuntCookTinker]

I don’t know why I didn’t think of that. Years ago I did a job for a foam packaging plant. They cut huge squares of foam into sheets. Then cut it for packaging boxes. That would have made life much easier. Carolina Skiff definitely had big issues on their older boats. From what I understand they have addressed most of them on their new boats. Thank you for commenting and watching!

[@howiemoth3847]

@@FishHuntCookTinker The blue and pink sheets from the big box home improvment stores absorb less by a huge factor and if cut where they would have a 1/2 gap instead of direct hull contact, zero. As far as Carolina Skiffs they hav'nt, looked up that on yt they other night ...still nightmares.