I’m about to fit the floor and have a quick question.

Have I got to grind flat the welds to fit the floor and side panels?

I did run the grinder along the joins before I welded so should still have strong joins if I do but want to check? Suppose when the floor is fully welded in it will strengthen chassis anyway. Just checking this is correct and not going to loose too much strength.

Yes, you'll need the welds where you're putting sheet metal to be flat, don't go overboard and grind more metal than you need to though. I'd reccomend using flap wheels rather than a grinding disc because they're gentler, easier to control and leave a nicer finish. Knock any spatter off with a screwdriver.

Kingr

if you dont grind the welds down :

1. The steel floor wont lay flat.

2. The alu sides will follow the contours of the welded tubes and you will get bumps where the weld is pushing through.

When you weld the floor, be careful of distortion.

My floor didnt stay flat as I fully welded as I went along. I would suggest that you partially weld at various places, then if you need to fully weld, 'fill in the gaps' without spending too long at any one side or area.

Im not a welder, but I recon its gotta give a flatter floor than not using 'distributed' welding.

Alternatiely , dont fully weld and seal the floow after with some kinda sealant long the gaps.


atb

steve

if you rivet the floor in you get no distortion,put them every 2" or so and itl be plenty strong enuf

kingr

whats welding splatter???

Ive never seen it before. Is it good?

are you sure that a rivet every 2 inches is enogh? ( Is that ali rivets?)
Also if you use ali for the floor how thick does that have to be? will 1mm be enough?

aircraft and some racers are riveted together,thats what i did with sweet pea 1st and it didnt leak/rattle/fall out so i asume it must be strong enuf

and would 1mm or 1.2mm ali be thick enough for the floor?

thicker the better really, need some reinforcement round seat mount like a 3mm steel strip across the floor

I welded two extra 1 inch rhs rails across the floor where the seat mounts.

I dont know how you stand on the floor when you get in a locost (3 years into the build and I have still never even sat in a finished seven!) but I can imagine the possibility of standing with some force on 1mm alu, and its probably not a good outcome.......or does your bum and arms take the strain on entry (ohh err mrs).


atb

steve

I used rivets every two inches (~50mm) and urethane adhesive on my steel floor. The adhesive is strong enough by itself that you will destroy the floor to remove it. In addition, the seam is now sealed and watertight.

I weigh over 225lbs (100+ kilos) and can bounce on the floor with no sign of oit coming loose.

An added benefit is the way the urethane serves to deaden vibrations. When you tap the steel, you get a nice solid "thunk".

I used 2mm ali pop riveted with 3mm stainless rivets every 50mm...