Bitty Squaredrop questions

[SandraMort]

Hi, guys!!!! I am so excited! I've been watching videos for a few months now. Other than my youngest, the rest of my family is pretty much uninterested and ignoring my latest obsession. Even I wasn't entirely sure if I was going to drop the ball on this one.

Yesterday, I made a decision. A small trailer isn't a good long term solution, but a large one is going to cost me more than I ought to spend on something that may end up being dropped due to finances or lack of knowledge.. Worst case scenario, if I drop the ball and don't make another, I still have a trailer, which can be used for hauling trash or whatever.

So, anyway, yesterday afternoonI bought a used 4.5ish' by 6' trailer from a guy upgrading to a larger one. There's a little bit of surface rust on it, so I stopped at Lowe's and picked up a wire brush and some of the rust prevention paint spray to put on over it. I was wondering how to tell if I've scrubbed long enough? The areas without rust don't seem to do anything when I scrub them, so I'm guessing I should just scrub until nothing more flakes off... but maybe I am wrong there?

I originally was going to bribe my teenagers to brush it for me due to sensory issues, but I decided that I wouldn't until I made sure that I really COULDN'T do it myself. I got home and tried. Lo and behold, it was nothing like I'd anticipated and I will be doing it MYSELF, thank you very much. This is my project and I'm not going to fail straight out of the gate because I didn't bother to even try.

Sooooo, here's my question. I love the youtube videos, but I need more. Are there any books on building squaredrop campers that I can actually read in detail? Plans, either for free, or not too expensive? I'm trying to keep this as cheap as possible, since I can't really afford a. LOT.

Also, the trailer says it can hold up to 2,000 lbs. However, what I don't know how to do is to figure out how much weight the floor can support safely.

Second, I don't know how to calculate how much weight the walls can support for shelves, cabinets, folding down furniture and whatnot.

Lastly, I need to figure out how tall or square I can build it before it starts to mess with my mpg. I'm currently driving a Prius Prime, which is a smallish car, but I'm hoping to upgrade to a RAV4 before the thing is done being built.

That's another thing -- if I don't get the RAV4, there's no point in building a big one, since the Prius probably can't pull it. How do I find this information? Thank you!!!!

[CanuckShooter]

Read through the build forums to learn a lot about different building methods.

First you have to determine what size and shape you want to build and go from there. A teardrop, a standy, something simple or something complicated with a lot of compound curves.

Start there. If you want light, start in the foamy section.

[S. Heisley]

It's not just how much weight you can haul but also how much you can stop. You will have to do your own research on that but I did find this, which I found concerning:

Why does regenerative braking not work sometimes?
Vehicle deceleration due to regenerative braking may vary depending on the current state of the Battery. For example, regenerative braking may be limited if the Battery is cold or is already fully charged.

As far as how much a Prius Prime can tow, I found this:

How much weight can a Prius hitch hold?
Impressive Towing Capacity: Rated for 375 pounds tongue weight at the trailer ball and 2,500 pounds towing weight. ***

And this:

Exterior Details
Wheelbase: 106.3 in. Overall Length: 182.9 in. Tow Capacity: 3500 lbs.

I don't know if I agree with that because I also found this:

Can a Prius pull a small trailer?
Toyota Prius Questions - can a 2006 Prius pull a small ...
Toyota recommends that the Prius not be used as a towing vehicle. There are of course some people that install hitches and pull very light trailers (under 1,000 lbs) with them, but it is not recommended. I would NOT do it.

Assuming your trailer does not have brakes, you may be more limited than the above. It depends on where you live. Here, in California, the weight limit is 1500 lbs. In New York State, the weight limit is 1000 lbs. Some states have no limits and some states allow up to 3,000 lbs.

As far as how tall you can go before your mpg is compromised, it is automatically compromised just by towing. Also, wind can be a mitigating factor. The taller the trailer is, the more risk that the wind will cause unstable steering or might even cause your trailer to tip over. As far as mpg goes, if you look below, in the signature area, you will see that my trailer is basically a square drop. The top 6" is above my tow vehicle's height, but by making a radius cut-curve in the front of that part, you can help the wind to move up and over easily. I lose approximately 4 to 5 mpg when towing on the highway and nothing in the city. When you curve the front just a bit like that, you don't lose much storage space.

Can you do this? Yes, you are capable. While my wood trailer was built before many people had started using Styrofoam, I would suggest you take a look at some of the foamies. If you use Styrofoam with minimal framing, you can save a lot of weight, but it's up to the builder to be conscientious. Also, Styrofoam is very forgiving of new builders. Do not use 2x4's as that would be overbuilding. 1x2's are usually enough except in places like the doorway, where you may want a 1x3 or a 1x4. But check some of the build threads. Remember that the strength of the structure is the sum of its parts.

Not knowing exactly what your used trailer looks like or how it is made, I would suggest you take it to a weigh station and find out what weight you are starting with. If the deck of the trailer is made of 2x4" boards, you may want to remove all those boards and rebuild from the metal frame up, using new wood with less weight. You have a lot of thinking to do and decisions to make. Best wishes!