Aluminum Boat Floor Replacement

[turtle1173]

Hi all,<br /><br /> I'm in the process of tearing out the floor on my '72 16ft Starcraft. I have a couple of questions.<br /><br /> It is going to be very difficult to cut the plywood without any gaps at all. What do you suggest to seal the edges of the plywood to the aluminum?<br /><br /> Is the pourable flotation the only option for under the floor? Is there a cheaper alternative and something readily available? It seems no one local has it and it's pricey online. Suggestions?<br /><br /> I'm sure I'll have some more questions after I get the floor completely up.<br /><br />Thanks for all the help.<br /><br />Shane

 

[swimmin' for shore]

Re: Aluminum Boat Floor Replacement

epoxy will seal wood to aluminum. I had a nice talk with ondarvr about this recently, and epoxy should stick just fine. Beyond that, if I were going to epoxy, I'd use some mat and/or woven roving to give the epoxy some structure. Your boat is going to flex, so you want to give it the strongest possible bond between floor and gunnels.<br />Flotation foam is not the only option. If you aren't worried about a leak sinking you, you needn't put anything under there. The plusses to foam are that you create an "airtight" cavity. That's why it's said to float you in an emergency. Another bonus is the stiffness that it provides for the hull. A 3rd is that it'll quiet the noise of you bouncing your boat across the water. Like I said, though, it isn't a must. That's up to you. How rough is the water going to be in? How structurally sound do you feel like the boat is? Is it loud now? <br />Cheaper options? www.uscomposites.com will have it. I don't know what you're comparing prices against, but they're the cheapest place I know of. You'll have to pay shipping, though, but they're probably cheap enough to make it worthwhile. Keep us updated.

 

[turtle1173]

Re: Aluminum Boat Floor Replacement

Well I got both layers of plywood out. That wasn't much fun. The bottom was filled up with Styrofoam. The top pieces looked to be in decent shape but the bottom pieces were quite heavy. Definitely a lot of extra weight in there. I got it all cleaned out. <br /><br />I guess the next step is to fill it up with water and mark all my leaks. Then I can start fixing from the inside.<br /><br />Shane

 

[drjrusso]

Re: Aluminum Boat Floor Replacement

Shane,<br />Thanks for your question. I am invloved in a similar project. I would rather not use pourable foam and am also looking for an alternative. I will be traveling to several boat repair shops next week and will tell you what I find. <br />Jim

 

[turtle1173]

Re: Aluminum Boat Floor Replacement

I got the foam cleaned out and everything shop vac'ed. Is there a way I could seal the rivets from the inside? Something to coat them with? Or is that a reasonable request. Perhaps I could just fill the boat with 5200, LOL.<br /><br />I really didn't want to have to fill this thing up with water to find the leaks but I thought that might be the best way, so I did. I filled it up until the water covered all of the bottom. Anyway, the leak in the front is real bad. Aside from that I've got about 7 rivets that had a bead of water on it and 1 that had a very slow drip. So I don't think I'm too bad off. I've got to get that front patched though.<br /><br />In the spot (on the inside) where it is leaking in the front, there's some red stuff on top of it. I don't know what it is but I'll have to probably take a wire wheel to it, so that I can see what the metal looks like underneath. This wouldn't be a patch because I know for a fact this is the first time the inside of the boat has seen the light of day since the factory (my dad was the original owner).<br /><br />I weighed the styrofoam that I took out. It was hard to get an accurate weight but 200-300 lbs would be a close estimate.<br /><br />It's amazing how light this boat is now. Before, I couldn't grab the trailer tongue and budge it at all (and I'm a fairly big guy)! Now I can lift it up to my head.<br /><br />I appreciate all the comments. Thank you and keep them coming.<br /><br />Shane

 

[swimmin' for shore]

Re: Aluminum Boat Floor Replacement

With the sub-floor, I'm in a similar position as you. I contacted a guy who has done a lot of expirementing with different epoxies. I was looking for something that I could "coat" the inside of the boat with. There's a more obvious option-GLUVIT-Gluvit is expensive, though, and I felt like I could find a similar product with the same properties for a lower price. At any rate, this is what I've come up with. You could coat aluminum in epoxy. No question about it sticking. The hangup is that pure epoxy dries and becomes brittle. An epoxy with solvents in it-otherwise known as a penetrating epoxy-will dry and retain a little bit of "flex". It seems to me that this would be ideal for a sub-coating. I did email the guy, but haven't gotten an answer. I'll email him again tonight and see if there's a product he'd suggest. If not, I may just buy something and give it a shot. I think that a sub-coating is a fine idea, turtle. We just have to work out the details. If anyone can add to this, I'd love to hear it. I've done a lot of research thus far, but still trying to pin down the best product for the job.

 

[turtle1173]

Re: Aluminum Boat Floor Replacement

I didn't mention this before because it wasn't necessary for my question but I have heard of some people coating the inside of their boat floor with a roll on bedliner. Anyone have any thoughts about that (pros or cons)? That's a great point you make about "whatever the product used" needing to have some flex to it in order to accomodate the flex of the hull.<br /><br />If the bedliner would work, you could "technically" buy the spray can and only spray the rivets without having to coat the entire floor thereby cutting back on the actual amount you would need to use.<br /><br />I'm certainly open to other options but I thought I would throw that idea out there.<br /><br />Shane

 

[Richard Petersen]

Re: Aluminum Boat Floor Replacement

Tighten the loose rivits with 2 hammers. One on the outside of the rivit and another tapping it enough to tighten it. Then remove all the oily stuff on the rivit and put a VERY small smear of silicone rubber on the inside and outside of the leaky rivits. I use Silicone Rubber to bed down the sealed plywood edges that touch the boat hull. Sticks great after it sets up in 4 days of sun.

 

[turtle1173]

Re: Aluminum Boat Floor Replacement

cyclops2, what kind of Silicone rubber (exactly) do you use to seal these rivits? I like the idea of sealing the edges of the plywood in this also.<br /><br />I know that most people seal their wood floor in epoxy or possibly polyester resin. Has anyone tried any of the wood sealers that are available at most hardware stores? Just curious.<br /><br />Shane

 

[swimmin' for shore]

Re: Aluminum Boat Floor Replacement

Turtle, I checked out the site that I mentioned. I came across the site on iboats, first, but I've crossed it a number of other times. I emailed for more information on the product, but here's a link to it. This stuff looks ideal, to me. Check it out. There are a number of products on the page, but take a look at the "liquid co-polymer rubber paint".<br /><br /> http://www.epoxyproducts.com/5_urethane.html

 

[Richard Petersen]

Re: Aluminum Boat Floor Replacement

Turtle. I DO NOT seal the edges with Silicone Rubber!!!!!! Use paint or Epoxy. I use the Silicone Rubber, ( home depot or lowe's ) to hold the plywood to the CLEAN hullbottom and any wood frames I have put under the floor to make it really solid. Removing the floors only requires a Crowbar and and big enough piece of flat wood so the lifting force of the Crowbar is spread out. I make no dents that way.

 

[turtle1173]

Re: Aluminum Boat Floor Replacement

Cyclops2, I did understand what you meant. Looking back at my previous post, I see that my words weren't very clear. I meant sealing the edges of the plywood to the hull bottom.

 

[KilroyJC]

Re: Aluminum Boat Floor Replacement

Turtle - <br /><br />I've got an '75 18' Starcraft that I got for free last year, so I've had to do (and still have to do ) some work to it. <br /><br />Your foam sounds like it had a load of water in it - Styro should not weigh that much!<br /><br />Personally, if you're not going to pour foam, I'd get 4X8 sheets of closed-cell foam, adhesive that is compatible with it (nothing that'll eat it up), and a hot-wire cutter. You can make your own cutter - check out do-ot-yourself surfboard sites for how-to.<br /><br />Laminate up the sheets into big blocks, and then use the hot-wire cutter to form-fit the foam as close as possible to minimize void space. Less void= more floatation.<br /><br />I was amazed at how LITTLE foam I had from the factory - not to mention the beat contiditon it was in after 30 years. <br /><br />Now I may be a bit biased, but I am thrilled to no end with how well the poured foam worked in my boat. I used 4lb per cubic foot, so that it would add some rigidity to the boat. It worked even better than I hoped. Also, going through waves & chop, it is quieter than my friend's Boston Whaler!<br /><br />What's more, this summer I had the boat up at Lake George, NY, and we caught the tail end of Katrina. Lots of heavy rain all day. My boat filled up with water to the transom drains in the splashwell - about 5 inches over the deck - and wouldn't go any deeper. (Yeah - time for a new switch on the bilge!) The water just drained out those two holes. That's very conmforting to know, in case I ever do the classic bonehead move & FORGET TO PUT THE PLUG IN.<br /><br />I wish I had pics from when I was doing the foam pours, but I was too busy working! <br /><br />My site below is all about the work I'm doing to my Starcraft.<br /><br />Good luck with whichever way you decide to go on this!<br /><br />Matt M

 

[turtle1173]

Re: Aluminum Boat Floor Replacement

Kilroy, are the 4x8 sheets of foam something you can by like at Lowe's or similar store? Would this be something similar to the foam they put on the exterior side of houses, before they put the siding on?<br /><br />Shane

 

[TimMattson]

Re: Aluminum Boat Floor Replacement

Shane ,<br /> The Foam works very good and mixing with a coat hanger in a battery drill has made this job very easy.Fiberlay,in Seattle, sells the stuff in bulk and it could be made into the shapes you want and then placed into the boat.The strength with it poured into the hull is great. <br /> I did my Glaspar by drilling rows of access holes,pouring into the middle areas first and then uses corks to "steer" the foam as it expanded.Smaller holes in the corners ensured total foaming.<br /> They sell Aluminum filled Bondo at the Auto paint supply shops that flexes very well and it is called All-Metal.<br /> Level flotation is achieved when a floundering boat still has foam at the water level and NOT below it.If all your foam is below decks ,you will be very tippy when swamped.With a foam block in the bow and two in the rear corners,a boat should sit pretty stable if filled to the rim.<br /> The higher up the foam ,then the LESS you need of it.If the foam is all below the floor then you need alot more to keep floating level.<br /> Weight BELOW the floor is called goodweight ,as it keeps you upright.A void in the middle can help keep some weight to act as ballast.<br /> The Styrafoam you had wasnt fuel proof and the Coasties now require fuel proof foam from builders which usually is closed cell,non-water absorbing.Spill some gas on the stuff before using it!<br /> Goodluck!<br /> Tim Mattson <br /> Sorenson Marine in Seattle

 

[KilroyJC]

Re: Aluminum Boat Floor Replacement

Hi - sorry for the delay.<br /><br />You can buy the sheets at Lowes/HomeDepot/Whatever. I can't say with any authority, but I'm thinking the white Styro sheets are better, simply because that's what's used for surfboard cores...<br /><br />Anyone know any advantages to the Pink stuff?

 

[Terry Olson]

Re: Aluminum Boat Floor Replacement

In reflooring my boat I was planning to use the pink foam from Home Depot as an alternative to poured-in foam but when I got my floors out I found the original is dry as a bone so I won't be replacing it. If money were no object, I'd use the pour-in, but on a budget or for ease of availability and use I'd get closed-cell foam (I think the pink stuff is closed-cell)and cut it to size. It doesn't need to be pretty, nor secured down. Once the floor is in it isn't going anywhere.<br /><br />On another note, I don't think I'd glass or seal the edges of the new floor to the hull on an aluminum boat. There's no way you're going to keep the area below the floors water-tight and the more it's sealed off the faster you new floors are going to rot. <br /><br />If you're all that concerned your time and money will be better spent upgrading to marine grade plywood rather than using exterior grade. You could encapsulate the plywood with epoxy before carpet and install, but every hole you put into it to secure it will allow moisture in anyway.<br /><br />When I refloor mine I am going to use exterior grade plywood cut to size using the old pieces as patterns. I'll wrap the carpet over the edges of the plywood, drop it into place, and secure it in place with screws. <br /><br />The original floors installed in this manner lasted more than 20 years. I don't see any reason to do this any differently unless you're going to do something that will last forever, like using a material that is completely impervious to the elements. I've been kicking that idea around too, but the expense can't be justified in my case.