As the lwb sits so low I tend to drag the crossmember amongst other things and as the fuel tank took a hit at the Pyrenees I want to put some protection underneath. What thickness is good? I have been thinking that 3mm might do the trick. The same plates should also work under the SWB as well i have found some pics where they have used 3.4mm and 5mm thick plate. What do you think both about the thickness and design? I'm open to suggestions.
If the plate is designed with sufficient stiffeners/ribs, 3mm should be fine. a 5mm thick plate of the sizes posted will be pretty heavy, and with the design posted, also offer a poor strength/weight ratio.
In relation to fuel skids, I like the idea of a thin and close fitting plate with neoprene (wetsuit material) between the plate and tank. This prevents rocks/mud chewing out the tank and the sandwich effect means light plate is plenty strong enough as it has been backed up by the tank itself.
A word of caution - Wayne and Christine had an crisis near Alsice springs when they holed their sump due to a small rock sitting ebtween the bashplate and the sump.
Like most modifications, they can be a bit of a minefield.
michaelpiranha2000 wrote: The rear is in great condition. but has a broken crown wheel and pinon
gwagensteve wrote:If the plate is designed with sufficient stiffeners/ribs, 3mm should be fine. a 5mm thick plate of the sizes posted will be pretty heavy, and with the design posted, also offer a poor strength/weight ratio.
That was my thought. There would be a lot of weight if it was 5mm. That middle plate alone is around 1200mm x 300mm.
gwagensteve wrote:
In relation to fuel skids, I like the idea of a thin and close fitting plate with neoprene (wetsuit material) between the plate and tank. This prevents rocks/mud chewing out the tank and the sandwich effect means light plate is plenty strong enough as it has been backed up by the tank itself.
Mmmm, hadn't thought about that idea. Doesn't sound too bad, might be the way to go. I know most aftermarket long range tanks are done with 2mm bottoms with 3mm being the heavy duty option. What thickness do you reckon for a plate with neoprene in between?
I would have thought 2mm of steel would be plenty, with 5 or 8mm of neoprene then the normal tank bottom. The effect of spreading the load means it will be almost impossible to dent set up like this. Of course, there are limits, but strength/weight has to be taken into account. Sure 10mm of bisalloy would be the shizzle, but who wants the weight?
I got the neoprene idea from Camel Trophy - Land Rover plated the fuel tanks on camel trophy cars with about 5mm of aluminium and padded neoprene between the tanks and the plate. I did this with the tank on my Gwagen after discovering it was almost holed with abrasion between the factory skid plate (about 2mm thick) and the tank (somewhat thinner)
That was about 8 years ago. It's had more hits than elvis since, and although the bottom of the tank isn't dent free, it's pretty good considering the weight of the car and the use.
The real key is shaping the skid with rolled edges or a lip to stiffen it.
Steve.
michaelpiranha2000 wrote: The rear is in great condition. but has a broken crown wheel and pinon
Don't forget to design in allowance for going backwards.
Rear end of any plates needs slideability, too.
The Moke bash plates became spades in reverse, causing a huge build up under the sump, and bogging of said Moke.
and as the fuel tank took a hit at the Pyrenees 
I want to put some protection underneath. What thickness is good? I have been thinking that 3mm might do the trick. The same plates should also work under the SWB as well 
i have found some pics where they have used 3.4mm and 5mm thick plate. What do you think both about the thickness and design? I'm open to suggestions.
I think it's worth looking at.