How to make this floor flat?

[buckinitup]

Well i want to make a floor in my boat its a mod v and the ribs are angled so im trying to figure out how to make a level floor so i came up with this(picture) taking a 1 1/2x 1 1/2 piece of angle aluminum and cut it down to where it will fit to the and will be level but my concern is will the angle pieces hold all of the weight (people walking around and a barrel of fish) with it pop riveted to the ribs or do i need to brace it more or should i not pop rivet it? I was also thinking c channel but the ribs are not the same width from top to bottom i think it is 1 1/2 up top and 2" at the bottom so idk about c channel any ideas would help a lot

 

[Stump Bumper]

The previous owner of my boat, my father in law, used a simpler solution.

There are 3 1"? x 1"? x 4"? pieces of wood screwed to the center of the rib. The front of the floor slides under the front deck about a 1/2" and the sides are notched out for the ribs. The floor is marine grade plywood wrapped in marine carpet.

No sag or bounce in the floor. The side walls are the same material and they are screwed to the ribs going up the sides of the boat. They lock in the floor so it can't come out with out removing the sidewalls.

 

[buckinitup]

Yea i guess i didnt mention im putting aluminum sheeting down for this ive got .090 thickness

 

[onthewater102]

if you're not dealing with salt water, pop riveting with stainless rivets to the top of the angle and face of the angle should hold it, as far as the weight load, you might want to put a vertical support at the center line of the boat. Not sure with .090" if you're going to need foam behind it for support, but if you're riveting everything down it wouldn't hurt.

 

[rscottp]

If I was doing it I think I would run a support down the middle length wise to make it level with the height of the sides. If you take a look at some starcraft mod threads you will see what I mean. Just my 2 cents, good luck and post lots of pics.

 

[buckinitup]

So you think the way i show in the picture with the angle just pop riveted to the braces then put the foam down with it to level it (which foam should i use and would this help with flotation) and pop rivet the floor down to the beam. Now this wont be a bass fishing boat its gonna be a bow fishing boat so its gonna have a good bit of weight good bit of fish plus 2 bigger guys or so and a deck even though most of that will be supported by the boat beams if so think 1/4 inch rivets would be fine?

 

[bamabill]

That's nearly the same configuration I'm using in my Lowe 1648 Makeover. 1 1/2 X1 1/2 X 1/8 6061 aluminum
angle. I put two 3/16 rivets in the top of the rib near the ends where i had good contact. Then I put
two #10 SS screws in the
side of the ribs near the two center channels. I also added a 1x1x1/8 spacer either under a rivet or screw as needed to close any gaps between the angle and rib.

 

[onthewater102]

So you think the way i show in the picture with the angle just pop riveted to the braces then put the foam down with it to level it (which foam should i use and would this help with flotation) and pop rivet the floor down to the beam. Now this wont be a bass fishing boat its gonna be a bow fishing boat so its gonna have a good bit of weight good bit of fish plus 2 bigger guys or so and a deck even though most of that will be supported by the boat beams if so think 1/4 inch rivets would be fine?

Extruded foam board from home depot or lowes will work for you - if you can cut it so it follows the contour of the boat and lines up flush with the underside of your sheet you'll be golden. No foam provides flotation unless the boat is swamped.

As far as the rivets - the size depends on the rivet material. You can get away with smaller rivets if they're made of stainless vs. aluminum, but they're going to be a lot harder to set. Look at the sheer and tensile strength of them in the expanded detail from the link "click for spec page" if it doesn't take you there already: https://www.rivetsinstock.com/rivets/blind-rivets/nail-type-basic-blind-rivets.html

A 1/4" aluminum rivet has a sheer strength of 460 (ft/lbs i believe) and a tensile strenght of 560 where as a 5/32" stainless rivet has a sheer/tensile rating of 650/820 - barely more than half the size and almost 50% stronger...if you're going to be on salt water the different metals will corrode one another (it will happen in fresh too just at such a slow rate you'll be dead long before anything starts breaking down) so if you're going to be on the salt use very large aluminum rivets -- I'd recommend 1/4" or bigger if you can find them - I had 3/16" aluminum rivets fail on a trolling motor mount I built just from road vibration.

 

[Flat_Bottum]

My floor looks identical to yours. What I am doing is adding 1.5x1.5x1/8 aluminum angle across all ribs like you have shown in your photo. I then added more horizontal braces in-between the original ribs and then I will be adding center supports running parallel with the boat. Kind of hard to explain for me but I think it will be ok. As for the rivets, I used all 3/16" aluminum rivets on my build so far. I started out using 3/16 SS rivets for the strength but after 3 or 4, it destroyed my little rivet gun. I will finish up all the framing and then I will be welding everything on the back side for added support. My floor is also .090 sheet but I will probably just end up riveting it down so it will be easier to pull up if need be. My build thread is under the Jet Boat section under 14' Polar Kraft. Good luck and keep photos coming.

 

[minuteman62-64]

You can get aluminum rivets in 5052 grade from Grainger, among others. Don't remember the specs., but stronger in shear and tensile strength than the common hardware store types.

If you are doing a lot of rivets (for me that's more than 4), take a look at the HF air operated rivet gun. I used it for my deck add and will never to back to hand squeezing.