Overland Hadley
on a journey
Just curious, why steel instead of aluminum?
bought our truck, starting a huge new build!
- Thread starter Jfet
- Start date
1) Easier to weld (don't have to purchase spool gun)
2) Cheaper (aluminum 2x to 4x more expensive for similar strength)
3) Better thermal isolation (I can use smaller cross sections and have more insulation foam between me and the metal)
4) Lower thermal conductivity
5) Aluminum welds destroy the stength of the aluminum near the weld
6) Better durability in rough vibration environments (steel yield range blah blah blah)
Overland Hadley
on a journey
Sounds like some good reasons, thanks.
What do you estimate the weight of the steel frame will be?
What do you estimate the weight of the steel frame will be?
That would be great. I sold the wrecker bed off my FG to a guy in BC and took the tunnel box/light bar down to the scrap yard (it was pretty rusty underneath) guess what it weighed ? Just the tunnel box and light bar weighed a whopping 840 lbs. No wonder I had a hard time lifting it onto the truck bed
We have made some progress on the frame. Here is a recent picture although I have added more triangulation bracing since this was taken. In the photo I am testing to see if 5mm Okoume mahagony marine plywood will bend around the 20 inch radius nose of the camper (it does).
I am still undecided about how to finish the roof and would love any suggestions where to look for examples. The roof will be two layers of the marine plywood cold molded to each other and sikaflexed and screwed to the 1x1 0.072 steel tube joists. There will be 2 inches of R10 rigid foam board under the plywood between the 1x1s. The inside ceiling will be 1/4 luan against the foam. I want to do something to the outside of the marine plywood (TPO, EPDM, aluminum, Skittles?) The roof should have no holes since there are no vents or anything, so I want a one piece something, glued to the plywood and preferably wrapped a inch or two down the sides.
I am still undecided about how to finish the roof and would love any suggestions where to look for examples. The roof will be two layers of the marine plywood cold molded to each other and sikaflexed and screwed to the 1x1 0.072 steel tube joists. There will be 2 inches of R10 rigid foam board under the plywood between the 1x1s. The inside ceiling will be 1/4 luan against the foam. I want to do something to the outside of the marine plywood (TPO, EPDM, aluminum, Skittles?) The roof should have no holes since there are no vents or anything, so I want a one piece something, glued to the plywood and preferably wrapped a inch or two down the sides.
fluffyprinceton
Adventurer
Whatever you do seal the ply with epoxy...Which I assume you will use (thickened) to bond the two layers.
A 6oz or maybe 4oz layer of fiberglass sheathing bonded with epoxy would be good - very common approach on boat cabins & hulls - not too hard to finish nicely as the weave fills easily with faring bog (easily sanded epoxy/filler mix. If painted with two part LP it's as durable as gel coat.
I've bonded alu sheet to epoxy sealed ply with sika successfully - it would be heavy & how do you deal with the corners? Maybe sika angle alu for the corners but that curved part will be a challenge. Great thing about this approach is NO Sanding...Sika makes a 291 LOP (Long Open Time) which I strongly suggest for all your sika bonding, the regular stuff sets up too fast for what you're doing. To get the alu to lay down nicely on the ply is the challenge and generally you only get one shot at it as the alu sheet often distorts if you try & pull it off to reposition. You can lay it down oversize & router off the excess...The curved part will bond great but the flats will need lots of evenly distributed weight & cleverness to avoid screws - I'd think screws on the edges where you have to hide the joint anyway would be a given - you might plan on roof racks/solar/vents/lights on the roof to give you a place to resort to screws...If you gently pound on the sheet as it goes down that helps the sika to flow & bond.
Why 1/4 luan on the inside? Okume is nicer & 3/16 (5mm) would be fine if you bond it to the foam...
Great build & thanks for sharing. Moe
I found this company in my travels last week, they have some good looking products for DIY. www.arthtech.net
height between the tire and rim???
I am not really updating this thread as I have moved over to RV.Net in the truck camper section. They have a lot more traffic and a good knowledge of truck camper type stuff. I like expeditionportal too, but maintaining two threads is time consuming. Here is the link: http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26735683.cfm
A teaser, here is the completed frame with the roof being installed (will paint the frame after the roof is on...will have to mask the area where I will be sikaflexing the aluminum siding).
mog
Kodiak Buckaroo
From my experience with a commercial box (a Marathon 14' on a Fuso FG) the front upper corners are spots that seem to be a target.
My box has cast aluminum bumper corners there and man are they strong. I hit the upper deck of my house (it extends over my garage) with my box at a pretty good clip and there was no damage to the box at all. The beams for the deck are 6"x14" so they had no give. You might want to reinforce that area, prior to skinning, or maybe cap after skinning for some extra strength.
Ford Prefect
Expedition Leader
So far it looks brilliant me! Though you may not continue to update this thread, I wish you well and look forward to trying to read as much as I can.