Explorer Box Cost Estimate

How much will it cost to build?


There are a range of ways to successfully build an Explorer Box; some more economical than others. You can build an Explorer Box on the budget end of the spectrum for $1400 - $1500.
Entry level cost of building an Explorer Box (based on material cost Oct ‘09)

Frame $250
Wood $150
Int/Ext Finish $50
Miscellaneous $170
Tent Unit $799

Frames
An Explorer Box is built on a 4’ x 6’ frame. A 4’x8’ bolt-together frame kit is a suitable starting point. These are easily modified to be 4’x6’, available from a number of sources and regularly on sale for under $250.Most of the lower price kits come with 8” rims &tires, I like to upgrade to 12” rims & tires, expect to pay $100. For a fully welded frame expect to pay around $800. I also regularly see suitable used flat bed trailers for as little as $200 on craigslist.

Wood
You’ll need about $50 worth of clear grain fir or pine 1x2 for corner and shelf blocks. You have a few trade-offs to consider when choosing your plywood. If you go with ACX construction grade plywood, expect to pay $25 a sheet; you need four sheets. If cabinet grade Baltic Birch; expect to pay $40 a sheet, you’ll need three 5’x5’ and one 4’x8’. I prefer Baltic Birch for the floor and cabinets, then use marine BS1088 Okoume for the exterior. This combination saves 30-40 lbs and is very attractive with a clear finish. Expect to pay $95 a sheet for BS1088, you’ll need two sheets. Then one 4’x8’ and one 5’x5’ Baltic Birch.

Finish Type
This is another area with many choices.  On one end of the spectrum you could go with Acrylic Latex (house) paint inside and out for around $50.  I have not personally used it for a trailer box, but if you search the internet, you’ll find a number of small boat building sites promoting its use.  If you think about it, your house is exposed to the elements day in and day out, the last time I painted mine was 10+ years ago and it still looks good.  For a durable colored exterior finish, I like a roll-on bed-liner material called Durabak. It runs about $150. For a clear interior and exterior finish, I use Target Coatings EM2000 varnish, it runs $79 a gallon.  For an added measure of moisture protection I also like to seal the exterior with Smith Companies CPES, it runs about $60.

Miscellaneous
There are a number of items like hardware, hinges, door latches, tongue and stabilizer jacks, glue, sandpaper, door seals, etc. that run about $170 regardless of your build method. Basic hinges are +/- $5.00, you need five of them. The nicer stainless steel ones I like to use are $15.00 ea. There are a number of door latch options, basic barrel slide latches are $3.00 each, you need five of them. The locking, twist cam style latches I normally use are $18.00 each. Also, if you use all stainless steel hardware expect to spend an extra $50.