Screws or rivets???

[marshrunner757]

Getting ready to put aluminum floor in my boat. Screws or rivets? Heard arguments both ways. Will be covering with hydro turf. What's your experience?

[Goooh]

Had rivets, they didn't last. So as the rivets would fail I'd replace them with screws and the screws solved the headache.


Sent

[Shawn Braquet]

Use stainless screws but predrill your holes as to not snap the stainless screws.

[marshrunner757]

Thanks guys

[keakar]

aluminum rivets fail and don't hold up, they aren't worth using, I replaced them with good quality ss rivets and they have lasted 3 years so far and still solid as a rock, not one has loosened or has popped on me so they have worked great.

screws are just like rivets, weather they last or hold depends on the type and what they are made of as well as to how they are installed.

good luck with it.

[marshrunner757]

If I use screws they will be SS

[Goooh]

Also, screws are much easier to deal with if you have to modify or repair under whatever you are securing them with


Sent

[Gerald]

Originally Posted by marshrunner757

If I use screws they will be SS

Look to see or ask what grade the SS are the screw. Not buy if they are 304. The 304 grade will rust and you can check the screws with a magnet. 304 is more like steel and will attach to a magnet. Higher grades of SS are not magnetic.

[CajunChristian]

2 years ago, I visited with Gaylen, the owner and manufacturer of SouthFork Boats. That same week I visited with the owner and manufacturer of WeldBilt boats.
The question came up while talking with Gaylen about whether I should rivet or screw the flooring material I bought from him. His explanation made sense to me.
He said that when you insert a screw into a rib, the screw exerts pressure outward from the screw and holds by exerting that outward pressure. A rivet uses downward pressure to hold the material down and does not exert outward forces on the ribs. He claims you are more likely to crack a rib where you have drilled and inserted the screw because of the outward forces. He has been SUCCESSFULLY building hulls for nearly 30 years, so I tend to believe him. It sounded like a perfectly plausible explanation.
I posed the same question to Bill at WeldBilt, he gave the exact same answer. Those guy have made their living building aluminum boats for decades, I figure they know more than I do so I listen to their advice.
D

[marshrunner757]

This is one of the things that scares me with screws. The thing that scares me about rivets is them breaking. Seems most people tend to use screws. If I were to use rivets I guess SS would be the best option for that as well.

[Shawn Braquet]

Originally Posted by CajunChristian

2 years ago, I visited with Gaylen, the owner and manufacturer of SouthFork Boats. That same week I visited with the owner and manufacturer of WeldBilt boats.
The question came up while talking with Gaylen about whether I should rivet or screw the flooring material I bought from him. His explanation made sense to me.
He said that when you insert a screw into a rib, the screw exerts pressure outward from the screw and holds by exerting that outward pressure. A rivet uses downward pressure to hold the material down and does not exert outward forces on the ribs. He claims you are more likely to crack a rib where you have drilled and inserted the screw because of the outward forces. He has been SUCCESSFULLY building hulls for nearly 30 years, so I tend to believe him. It sounded like a perfectly plausible explanation.
I posed the same question to Bill at WeldBilt, he gave the exact same answer. Those guy have made their living building aluminum boats for decades, I figure they know more than I do so I listen to their advice.
D

Makes since I suppose

[CajunChristian]

Originally Posted by Shawn Braquet

Makes since I suppose

That is why I now own an air operated rivet gun.
D

[marshrunner757]

How many rivets per support do you typically put?

[Bdub]

Let me pass this along also...When you put a steel screw into an aluminum boat you will eventually have issues with electrolysis. Dissimilar metals touching create this and it's sped up quick in salt water...The screws will break when trying to remove them, if you haven't cracked the rib. Get the right type of rivet and a pneumatic rivet gun....also if you do need to remove the rivet, don't drill it out, just grind the head off it will make things a lot easier.

[marshrunner757]

Originally Posted by Bdub

Let me pass this along also...When you put a steel screw into an aluminum boat you will eventually have issues with electrolysis. Dissimilar metals touching create this and it's sped up quick in salt water...The screws will break when trying to remove them, if you haven't cracked the rib. Get the right type of rivet and a pneumatic rivet gun....also if you do need to remove the rivet, don't drill it out, just grind the head off it will make things a lot easier.

This is something else I have heard. But people use stainless rivets also because the aluminum rivets fail.

[Duffy.yyz]

Originally Posted by Bdub

Let me pass this along also...When you put a steel screw into an aluminum boat you will eventually have issues with electrolysis. Dissimilar metals touching create this and it's sped up quick in salt water...The screws will break when trying to remove them, if you haven't cracked the rib. Get the right type of rivet and a pneumatic rivet gun....also if you do need to remove the rivet, don't drill it out, just grind the head off it will make things a lot easier.

This is one of the most interesting and insightful things I have ever seen in site...lol Thanks for sharing!

[keakar]

Originally Posted by marshrunner757

How many rivets per support do you typically put?

depends but I like to put them in every rib and every 6 inches apart ant when I get to the ends I stay back from the end of the sheet by 2 inches to avoid and cracking or splitting from vibration.

it also is a good idea to put a small bead of silicone caulking on the ribs before you lay it down just in case there is a spot that is not level it wont move or have squeaks when you step there

[marshrunner757]

Originally Posted by keakar

depends but I like to put them in every rib and every 6 inches apart ant when I get to the ends I stay back from the end of the sheet by 2 inches to avoid and cracking or splitting from vibration.

it also is a good idea to put a small bead of silicone caulking on the ribs before you lay it down just in case there is a spot that is not level it wont move or have squeaks when you step there

I am putting a 3m rubber weather strip on every rib.

[marshrunner757]

Also, after removing the plywood, I noticed the ribs follow the vee shape of the floor instead of being flat. That being said, I think I'm going to have 1 1/2" angle welded to each rib to give me a flat floor.

[keakar]

Originally Posted by marshrunner757

Also, after removing the plywood, I noticed the ribs follow the vee shape of the floor instead of being flat. That being said, I think I'm going to have 1 1/2" angle welded to each rib to give me a flat floor.

that's a good idea but keep this in mind, most boats will turn up in the front but not necessarily the ribs will follow so on mine the third rib from the front needed to be raise a full inch and the one to either side a half inch to keep the floor straight and level even though it still tilts to the rear.

putting a good long straight edge across the ribs, you will find things are not as flat and straight as you think they are so adding the angle to the ribs can fix all that for you.

you would think the ribs are all stamped out and they would be the same but its amazing how much variance there is in the boat ribs height sometimes.

also run some tubing in the areas you have room to for running stuff plus one extra unused one as a spare because if you ever need to run or rerun wiring for trolling motor, lights, or even fuel lines for forward fuel tanks, it makes life so much easier. having an unused spare is great because badly shorted wires can often burn or melt the tubing gluing them into place and making pulling and rerunning wires in it not very easy or even impossible.