I'm making a new high clearance belly pan for my Jeep. I've searched a few different times and haven't found the info I'm looking for. I've built the cross members to support the weight but I'd like to use something lighter than steel. Has anyone used aluminum for a skid plate? I even thought about Polyethylene or Polycarbonate both are strong materials.

Here are some good threads that don't just have a bunch of "search newbie" responses like this one will.

http://www.pirate4x4.com/forum/showthread.php?t=217459

http://www.pirate4x4.com/forum/showthread.php?t=181264

http://www.pirate4x4.com/forum/showthread.php?t=105683

If your not building a buggy what is a few extra pounds going to hurt?

I wouldnt use aluminum. Rocks will take chunks out of it and it'll crack.

I used 1/4" plate and reinforced it with 1 1/4" x 1/4" angle. Its strong as hell and one man can lift it while bolting it on at the same time. Just a thought

The skid plate is also in an area where weight is not going to hurt you too bad as far as gravity is concerned. I used 3/16" plate and did some bracing on the back side for support, works great.

I'm about to build one myself & have decided to bend up some 3/8" and not use any bracing...

Mine is only a skid, the tranny is supported by a xmember. I used 1/4" plate with bends mimicing the stock skid. It only drops 1" below the frame. I welded in some 1/8"x1" stiffeners. My pussy ass can install it easily.

I considered aluminum but the cost was high and durability was questionable. Like stated above the extra weight in that area will not be noticable or negative. I would rather know i wont need to replace it for 10 years instead of possibly replacing it in a few months if it were alum.

Good luck

if you really want to go with something other then steel try UHMW, Nylon, or HDPE. Check out McMaster Carr (www.mcmaster.com) they have all that stuff. As said before aluminum is not generally a good idea.

~Kirk

edit: when you go to McMaster search for "plastic"

AR plate is what I would use personally. It is the same material that is used for loader buckets and cutting edges and you can get it in many thicknesses as well. New it should have a purple tint to it.

I used 3/8 plate for the bottom and 5/16 from there to the rockers,i cut and welded all the pieces,then counter sunk tapered allen heads into the frame rails and tied to the rockers,could see if i can find a pic or 2 if some one wants to post em...waiting on red star.
took me a week of eves,but it's pretty tough my rigs wieghs about 5k and i've worked it pretty hard, it has a few bends and some big chunks missing but still bolts up,any thing less than 3/8 and it'd be trash
My .02

e-mail me the pics, I'll post them up for you....

headed out the door,will send when i return

5/16" Aluminum plate's been used successfully on rigs tackling the hammers. I'd stick with 3/16" steel. It's solid, will take a beating, and will help lower your COG.

If you really want trick, get your hands on some titanium. Much stronger than steel and much lighter.
Berylium would be interesting too, but maybe too brittle.
Aluminum has a softness to it that I would think would be rather undesirable for a skidplate. Rocks would be able to easily gouge it. It seems like it would actually be harder to slide over rocks with aluminum because of how soft it can be.

If you really want trick, get your hands on some titanium. Much stronger than steel and much lighter.
Berylium would be interesting too, but maybe too brittle.
Aluminum has a softness to it that I would think would be rather undesirable for a skidplate. Rocks would be able to easily gouge it. It seems like it would actually be harder to slide over rocks with aluminum because of how soft it can be.
Yup, titanium is just the material to use, if you have a lot of cash to blow, and want to be dragging the highest-tech stuff you can over the rocks. It's very strong, and about 2/3 the weight of steel (and must be welded in a totally inert environment, plus it's a real bear to machine.)
Berylium might be a bit too brittle... plus the fact that berylium particles are deadly to about ten percent of all people might make fabricating it and/or scraping it on rocks a bit unpleasant to anyone it happens to kill...
Mild steel isn't a bad choice.. It's cheap, has an excellent strength to weight ratio, it resists gouging when scraped over rocks, and it's easily fabricated...

I think UHMW is what I'll use. I used to work at a plastic shop so I can get it easy enough. I'm thinking 1/2" or 5/8" should last a while.

Use some teflon like from the bottom of an airboat on the bottom of your skid plate you could probably go thinner and it would slide right off of a rock. But Being in coonass country i guess that stuff is easier for us to find.