Alum Floor Thickness

I'm looking at putting down alum sheeting for the floor in my boat. I've got the foam cut and level with the ribs on the bottom. So the floor will set flush on the ribs and foam. How thick of sheet metal should i go with? It will be well supported by the foam and ribs, but i'm not sure how think i should go with. what is everyone else using that is putting alum down on floors? Thanks!

Mine is about 1/8 and works fine.

Welcome..

agreed

.125 is ideal. I've successfully done so with .090 a few times, but wouldn't want to do it often. I definitely would go no thinner. The more brake bends you can put in it (wrap the floor up the side of the boat an inch or two), the stiffer it will be.

I used 1/4"...... I didn't even need any support other than the ribs for my floor.

I guess it would depend on how far your ribs are spread and how big of a fellow you are but .125 seems like it would work. Perchin- what is the spread of your ribs?

also,did antone fasten it straight to the boat ribs? Mine are 4 feet wide and drop about 1 1/8" in the center. I guess I can put it in a break and crease it in the center.

Floors factory in my boat,so can't say whats underneath it for support.
I don't think it's even .125 thick.
Does .125 actually measure .125 or is it like a 2X4,smaller?

Zum said:

Does .125 actually measure .125 or is it like a 2X4,smaller?

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I've mic'd some at .123, but aside from minor manufacturing variances, it should be real close to the number.

Howard said:

also,did antone fasten it straight to the boat ribs? Mine are 4 feet wide and drop about 1 1/8" in the center. I guess I can put it in a break and crease it in the center.

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If I can, I go straight to the ribs. On the G3 I completed last week, I used .090, as it was what we had the right size drop of. The ribs in that boat were about 12 inches apart, and it had a flange bent at each end, as well as the slight bend due to the mod v of the hull. Had I not been able to put the bends in it, supplementary support or .125 thickness would have been needed.

In the past though, there have been times (my old Yazoo, for instance), where I had 16 inch or so rib spacing, and only had .090 available, as well as a flat bottom, where I couldn't put a lower bend in, and the only feasible solution there was to add in structure, in the form of 1 x 1 tube placed lengthwise, on top of the ribs, with a much closer spacing.

Zum-- .125 (or 1/8 inch) is the thickness of the sheet

Bassboy- based on I am about 275 lbs and my spacing is 13 - 14 inches on center I think .125 will be better in my application. Do you think if I started from center and worked my way out that it would follow the angle of the rib? I have worked with 4 x 8 sheets of 10- 16 gauge metal but not aluminum. My rib is 4 foot wide and drops 1 1/2 in center.

Howard said:

Do you think if I started from center and worked my way out that it would follow the angle of the rib?

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Yep. I rarely, if ever, throw a piece of deck in the brake for the bottom angle - just for the side bends. Start in the center, and stand on the piece you are working on, and it should conform to the ribs. Be liberal with the number of rivets you use.

It will be a while but when time comes I will give it a go, thanks. I also have a couple of cracked ribs which this will tie them together and help on stress if I don't get them welded.

1/8 sheet and I used 2x1x1/8 "C" channel over top of the ribs and made the floor flat

I filled my floor (between the ribs) with foam that was the same height of the boat ribs, then used an .063 or 1/16th sheeting of aluminum to cover my floor. Used aluminum rivets to secure it to the ribs and it works perfectly. No sagging, and it was very light in weight which I need to watch because I'm running a jet. I could not be happier with the way the floor turned out. Now I'm working on the back deck....that will be 1/8 inch with supports close enough to prevent sagging in between. (this was all on my old tin though)

I'll try to remember to load some pics of the project later tonight maybe. If the weather holds, I'm going fishing after work though.

You can check out all the materials and pics of mine on the conversions and mods posted as New Aluminum floor in a 1648. This floor is very sturdy.