aluminum boat deck questions

[tmcalavy]

Got the old floor and assorted accumulation of trash/gunk/dirt out of my aluminum runabout today. Huzzah for the shop vac! Can you get panels/sheets of closed cell foam at the box stores? Need to replace the little styrofoam that was below my old deck. What type of screws should I use to secure the new coated plywood deck panels to the aluminum stringers? Will a standard cordless drill/driver be enough to set the screws? Plan to leave the back bilge panel removable for cleaning, water removal, etc. Thanks in advance.

 

[Fish n Geer]

Re: aluminum boat deck questions

I know my 19 volt Kawasaki cordless has been a good friend in my project and will continue to be so! As far as styrofoam cant help ya.I imagine home depot or equivilant should have it.

 

[Mr.Stuart]

Re: aluminum boat deck questions

what about that sheet foam that you can get at home depot? like blucore fan fold or something? you can get it in different thicknesses and i don't think it's all that expensive

 

[tashasdaddy]

Re: aluminum boat deck questions

i think th pink is closed cell. i have a complete set of Ryobi 18 volt cordless, 4 batteries, and chargers. fit and set your deck, i use 1 1/4 stainless screws, predrill your hole,slightly small bit, or the stainless will twist off if you don't.

 

[tmcalavy]

Re: aluminum boat deck questions

Thanks for the info guys. Hope to get the old outboard off and the rotted transom board out this weekend. Then I can get my plywood decking, paint/seal it and think about the deck install. Figured out the flotation requirements yesterday and I will need about 11 cubic feet of foam. That's roughly 2 sheets of 4X8X2 closed cell foam if I can find it in sheets. It may be a challenge to get that much in the cavities available but it should add structure to the floor. What about beveling the edge of the deck to match the slope/angle of the V in the hull? Guess I can do that with a circular saw and then seal the gap where the deck and hull meet, or not. Any opinions?

 

[John_S]

Re: aluminum boat deck questions

I used 4" x 4' x 8' blue foam. I thought it was closed cell foam, but not 100% sure. A small piece forced to the bottom of a glass of water, did not appear to absorb any, over a weeks time. I cut it with an assortment of knives and hand saws. Cutting a rectangular or square, not much problem. Conforming to an ever changing angle, was a lot of trial and error (cut and refit) for me. I do recommend running the foam down the length of the boat. The foam would rest on the cross support ribs, and allow for a space that water can drain underneith.

 

[tmcalavy]

Re: aluminum boat deck questions

Yeah that's what I plan to do...run the panels lengthwise on top of the aluminum stringers. Don't know whether I need 1 or 2-inch thick foam though. Have to visit the box stores and see what's available. Also thought of bonding the foam panels together and maybe shrink-wrapping them to make them more water-proof. They say closed cell foam doesn't soak water, but I want to be able to pull the floor panels and foam if I get a lot of water in the boat. The floor stringers and cross members are cut for some drainage but there is no bow-to-stern channel for water to follow/drain into to get back to the stern drain. Is beveling the edge of the floor panels worth the effort? How about ideas on sealing the edges to the hull...plain old silicone or caulk?

 

[John_S]

Re: aluminum boat deck questions

Check carefully where the ribs cross the V. On mine, there is a small gap to let water drain back. I spent some time, making sure they were all clear of sand and debris. I used a butter knife and shop vac.

As far as bevel of the panels, I went to 45 degrees with circular and jig saw to match as best as possible. Some places on the original floor, it went more than 45 degrees, but that was as far as my tools allowed. If you just use 90 degree staright cuts, I think you will end up with some very big gaps.

Caulking the edge: Original floor had none. I primed, sealed, and base coat painted the panels before installing. I should not have, but I did add silicone caulk to the gap afterwards. In less than a year, it has allot of dirt impregnated in it, and looks ugly. Will remove this spring, before yearly floor touch-up paint.

I am not sure on how your floor design is, but mine has way too many screws, to ever think about removing for any maint action.

 

[tmcalavy]

Re: aluminum boat deck questions

Picked up some foam samples from the box stores today. The pink stuff from HD appears to be closed cell foam...wouldn't soak any water after four hours submerged. Checked my stringers and longitudinal braces in the boat. The braces are notched for drainage where they pass over the stringers, but the stringers are solid to the hull...water can only flow to the stern around the tips of the stringers. No space underneath them for drainage. With all the foam under the floor, I may never have occasion to pull it again...but I'll install with that in mind someday. I'm going to use two pieces of dimensional lumber for movable bench seats...with two movable bass boat seats that clamp to the benches. The back bench will only be used/installed when I have 3 or more folks in the boat, which is rated for 5 max.

 

[tmcalavy]

Re: aluminum boat deck questions

Got the old rotted transom out today, from under the splashwell. Also pulled all the screws/bolts and other stuff off the outside transom skin. Now I have to decide whether to pull the splashwell panel out or cut along the top seam to remove the top piece and then fab top piece after the new transom goes in. Will require some exterior plywood, 3/4 and 1/2 inch bonded together, to make the 60 X 20 transom. Then the floor and flotation foam will go in.

 

[tmcalavy]

Re: aluminum boat deck questions

Ended up drilling out the rivets holding the splashwell panel and removing it. Got the transom boards cut, sized, adjusted, primed and 1st topcoat of paint on today. 2nd coat tomorrow morning. Then I'll install the boards, glue them together in place and start replacing the through bolts that hold the aluminum skin to the transom boards...got some 3M 4200 sealant for those. Next step is the same process for the plywood deck panels, if the weather holds out.

 

[tmcalavy]

Re: aluminum boat deck questions

Made good progress today. Finished the transom boards, installed both, got the aluminum skin rebolted/sealed to the transom, put the splashwell in and started bolting it in. Soon I can start on the deck.