I recently shipped a ton of built rockets. Cardboard boxes are just fine if you pack them well. Especially if the rocket in question is a fibreglass one and built well.
Here's a few tips:
* "Make your own box". By this I mean..find a box that's close to the dimensions you need, and cut it down to fit just right. Rockets are odd sized items, and it's hard to find a box that's long enough that's not overly huge in terms of width/height. And shipping companies (FedEx, UPS, etc.) charge
by size as well as weight. So it behooves you to have a box that's big enough, but not not any bigger. So, "make your own" and make it exactly the size you need. DO use good packing tape (don't skimp on this detail, it's worth it to buy better quality here).
* A great source of boxes that are close is bike shops. The boxes that bikes are shipped in (to dealers) are usually very strong, good quality cardboard, and all that. And they are often a really good size in terms of length and width. Just cut down the height, and chances are you can end up with a box that's really close to ideal in many instances.
* Stuff the box really well with bundled up newspaper or some other "packing material". Bubble wrap and foam sheets are excellent as well IF you can reuse some that is cast off from some other project....otherwise it's very expensive stuff.
* Here's the real tip.....I found an excellent source for cheap(ish) shipping rates. Go to
www.bikeflights.com and ship through them. They are an online shipping agent that's focused on folks shipping bikes (which are by design expensive items to ship because of size). I don't know how they do it, but their rates are WAY cheaper than any other method I've found, by far. They are super simple to use, just follow the online instructions. For size, go to "custom size" (instead of using one of their pre sized choices), and plug in your actual dimensions/weight. They will ask what you are shipping...just write in "bike parts". You pay online, can arrange for the truck to come in and pick up at your door (for five bucks extra), and you print out the label at home. Easy.
* Another way to get cheaper rates......see if your destination address can be a business (as opposed to residential). The rates are cheaper then (usually saving about five bucks or so). So, whoever you are shipping to, see if they can use their business address to receive.
* Another way to get even cheaper rates......UPS and FedEx give special rates to businesses that ship often. Sometimes the rates are MUCH cheaper (like 30 percent of what you'd pay regularly). If you work for a company that ships stuff, or know someone who does, inquire if they'd let you ship your package through them. It's worth asking at least.
* It's not a bad idea to buy insurance for the delivery. Even the best packed boxes get crushed sometimes, or more often lost in transit. FedEx and UPS usually include insurance up to $100 or so free, and then it's like $1 for every $100 above that. This is usually worth it.
good luck with your delivery,
ssix