M116A3 Build

[lfhoward]

Thank you again, KC!

Switching topics, I have some questions about the camper's electrical system. Again, I'd like to get the details worked out ahead of time before I do any of the building.

I'm probably going to be doing a good amount of boondocking, but will be at campgrounds with electrical hookups sometimes as well. Because of the boondocking, I would like to run two 12V deep cycle batteries in parallel. I have a good quality charger that will be installed in the trailer, that recharges and tops off batteries automatically when hooked up to shore power. The charging unit also has a special 3 Amp DC circuit for running accessories while plugged into AC power, so they do not put a load on the batteries.

So, it looks like I can run three main circuits:
1) 120 V AC directly from shore power.
2) 12 V 3A max from the batter charger's special accessory terminals.
3) 12 V higher amperage from the batteries themselves.

Here is a sketch of one way I could hook things up. Thoughts? Questions? Potential problems?



My Questions:
I have a set of 120 V AC outlets that are powered from shore power. In my diagram I have separate 120 V AC outlets powered by an inverter hooked up to the batteries. Should I keep these circuits separate from each other or is there a way to have a switch that directs the input to all the 120 V AC outlets as coming from either the shore power hookup or inverter? What kind of switch would that be? It would be nice not to have duplicate outlets on the wall.

I'd love to have Air Conditioning and Heat, but I'm assuming both would need to be connected directly to shore power because they would be too much draw for the 12V system. Am I correct in assuming this?

Thanks!
Lauren

[noseoil]

Normal use of electrical circuits in a home protects the wire during use. A #14 wire can stand 15 amps, a #12 wire takes 20 amps. Just figure out your loads & protect the wire with a breaker, not the appliance itself.

[lfhoward]

My title documents should be arriving via FedEx on Friday. Looking forward to getting the M116A3 registered so I can use it to transport lumber from the store to my house and actually start this build!

[lfhoward]

The trailer is registered and I have a PA plate for it now. It's currently at the shop for an estimate on some welding and an inspection. The welding is to seal the holes in the steel deck and make it waterproof. It'll be interesting to see what it might need for lighting, as right now it just has the military brake/turn lights on the back and no side marker lights.

[lfhoward]

I got my first estimate from a welder for sealing the holes and seams in the trailer deck: $550-600. That's more than the trailer cost me to begin with.

Is this a reasonable price to be given for such a job?

What other good options are there for sealing these holes?

Thanks!

[S. Heisley]

I got my first estimate from a welder for sealing the holes and seams in the trailer deck: $550-600. That's more than the trailer cost me to begin with.

Is this a reasonable price to be given for such a job?

What other good options are there for sealing these holes?

Thanks!

I realize that the man's time is worth something and that there are a lot of holes to fill; but, for that price, I'd be very tempted to tape the underside of the holes and then fill the holes from the top with some J-B Weld two-part epoxy cold weld. (The tape on the underside helps hold the cold weld in place until it hardens; then, you can pull the tape off.) Since you could do that yourself, it might be worth a try on one of the holes and see what you think of the results.

[KCStudly]

Quote is probably based on about 10 hrs labor and consumables. Not a crazy rate for shop fees.

I don't recall if you ever stated what the bed material ended up being; steel or aluminum?

I suppose you could cut some small shapes from flashing material using tin snips and bed them over the holes with JB weld (as recommended by Sharon) or a bit of sealer and maybe a couple of rivets. Best to rough up the areas and remove paint locally first. Not the most "sanitary" looking repair method (i.e. kind of ugly), but would probably hold up okay.

How are you with a body hammer and dolly? Some of those holes look to be a little tweaked and would be better off being flattened out first.

[noseoil]

You could open them with a hole saw, then use stainless steel electrical or plastic plugs which fill in the holes like conduit in an electrical box. Bed them in silicone & that would work ok. Maybe not too pretty, but functional.

[titanpat57]

Take some flashing/flat stock and patch them with JB Weld as others suggest.....it's not structual, you're just looking for water (and vermin) tight.

[lfhoward]

Thank you for the advice everyone, I really appreciate it. I have never gotten anything welded before so it is good to know that I am being quoted a reasonable price for what I need them to do. The deck is 1/8" thick steel, so the welder would be welding patches over the holes and grinding the edges smooth. I'm going to get a second estimate from another welder on Monday to see if it's comparable.

I am definitely considering doing it myself with J-B weld, too. I might give that a shot on a couple of the holes to see how well it works. Of course I'd love to have real welds if possible, but it depends on the budget. I'll let you know what I decide to do.

[lfhoward]

I installed side marker lights and a license plate light and bracket today. I got some good practice with the soldering iron.







It should be ready for state inspection now.

In case it helps anyone, here are the federal standards for trailer lighting from the NHTSA:
http://www.nhtsa.gov/cars/rules/standards/conspicuity/Trlrpstr.html

[jadedave]

I love your electrical schematic ,, well thought out and looks like it is correctly arranged . Heres a RV schematic from another website

[lfhoward]

@jadedave, thanks for the electrical schematic. Glad to know I am on the right track!

In terms of other updates:
1) The trailer is currently in for state inspection and I expect it to pass. It should be ready to pick up this afternoon.
2) I got some metal mesh, a Bondo fiberglass kit, sandpaper, and some spray paint for filling the holes in the trailer deck. Total cost: $60. Much better than what it would cost to weld the holes closed! ($600)
3) My Kussmaul battery charger arrived in the mail.

I am getting closer to being able to start building. The steps left are:
1) Finalize my SketchUp design to incorporate a Steve Frederick-type roof joint.
2) Buy supplies (wood, insulation, windows, batteries, wiring, aluminum skin).
3) Build the walls and other components in the garage.
4) Assemble the cabin on the trailer from the completed components. Got to get it waterproof quickly in between rain storms, as it will be too tall to fit into the garage once assembled.

I would like to skin with aluminum, but am open to other ideas. I have seen folks use polyurethane over wood, fiberglass over wood, and canvas and paint over wood.

Question: What skinning method would be easiest and long-lasting? I am thinking of needing the trailer to be waterproof in a day or two, but also about up front cost and later maintenance.

Thanks,
Lauren

[lfhoward]

Ok, so I am about to make a completely random post. I found a entirely different direction for my off road trailer build and want to know what you all think of this option. I am not saying I am definitely going to take this direction, just looking for ideas and feedback because it seems quite good. So here goes...

Yesterday while browsing SteelSoldiers.com (the forum for civilian-owned military vehicles), I discovered that the military makes communication shelters that can fit on trailers or the backs of humvees. These communication shelters are made of aluminum sandwich with foam insulation between, so they come already waterproof and weatherproof. Because of the aluminum construction, they can be as light as 600 lbs! With some simple modifications, I could attach one to my trailer and have a ready-made camper. Here are the details:

There are two models of shelters, the S-250 communications shelter which is designed for an 8 foot truck or trailer bed, and the S-788 lightweight multipurpose shelter (LMS) that is designed for the back of a Humvee. These are made by a company called Wenzlau Engineering. I found one of each for sale at a surplus yard not too far from me, for $1500 and $1300, respectively.

S-250: http://www.wenzlau.com/S-250.htm





S-788: http://www.wenzlau.com/S-788.htm





The S-250 communications shelter has been made into a camper before, but using an M101 trailer with sides on it. Here is the website for the build. It is quite cool!
http://www.sanlee.com/jeep/S250camper/default.htm

Here is one of the author's photos:


Either one could potentially fit on my flatbed trailer, but some modifications would be required.
Some measurements of my M116A3 flat bed trailer (pics from KsM715 on SteelSoldiers):





My trailer is 96 inches long and 83.5 inches wide. The measurements of my trailer match the S-788 best. The S-250 is about 10 inches shorter than my trailer, and since my trailer doesn't have sides, the space under the benches (where the trailer sides would go) would not be used as indoor space. The S-788 makes use of this space, and is only 3.5 inches longer than my trailer. According to Wenzlau's info, the S-788 has approximately 50% more usable interior space than the S-250.

Both of these shelters require 48.5 inches between the wheel wells, and my trailer is only 45.5 inches across in that location. Here is where modification would be necessary. I would need to cut the inside of the wheel wells and move them out 3 inches or so. There is lots of physical room to do this, but it would require some metal fabrication, which I would need to pay a welder to do. I would also need to find a way to safely fasten the shelter to the trailer.

So... I think a lightweight multipurpose shelter might be a viable way to have a watertight, durable camper without having to build a shell from scratch... Would you do it?

[KCStudly]

I think it is reality check time. If you think the radio shack will fit your long range goal/needs and will get you where you want to be quicker and for less money, then it should be an obvious choice.

If you think that it is a compromise to what you really want, or is just a stop gap measure that will distract you from your true end goal, then I would think that you should just focus on the plan and not get distracted.

Like I said, reality check. Do you have what it takes to see the original plan thru and will you not ever truly be satisfied unless you follow that path, or is having shelter and getting it done quickly more important to you?

Speaking from the perspective of someone who has over 3 years in designing and building my vision, sometimes I wish I had kept things simple. On the other hand, when I look at where I am now in my build I wouldn't change much.

I know this probably sounds wishy-washy and doesn't help you decide much, but it is not an easy choice to make. Consider wisely, grasshopper.