Soap Mold Failure

So, as planned,  I went out yesterday and bought some wood and nails attempt to put together a couple soap molds.  I bought a furring strip as was suggested by someone on the Soap Making Forum and had a minor problem when I bought it.  I had wanted some 3" segments for the ends and was informed that they couldn't cut them that small because the saw would just eat the pieces.  Not being daunted by the first kink in my plans, I asked to have the segments that were to be 3" each into 6" and I would cut them in half at home.

So, today, I duly worked at cutting one of the 6" segments into two 3" segments (with my Swiss army knife saw as that was what my partner and I had).  It was only an inch thick and 4 inches wide, so this was not too terrible... well, not as terrible as it could have been.  I decided it was okay if the lines weren't anything resembling straight on the outside edge.

Then, I attempted to nail the pieces of wood together and that is where things started to really go wrong.  The wood was very hard and I am a failure when it comes to using a hammer it seems.  I managed to get the nail into the wood about half an inch and then my partner had to take over.  He managed to get about three quarters of the way finished on the mold (with the caveat that it was a bit lop-sided but I could deal with that...)  Then we got to the last end piece we had to attach and the wood on the side piece split on us... So, long story short, it was a complete failure at becoming a mold. 

We do have another set that we can attempt to make into a mold, but with the wood being so hard and the tendency towards cracking, I am not sure if it is worth attempting at this point :-(

I also put myself into a soap swap on Bramble Berry with the though that I would have the mold to make some soap in.  I do still have the PVC molds and I am also looking at cardboard boxes as an option.  Cardboard boxes are cheap and make nice molds from all I have heard, I just have to figure out the dimensions and how many pounds of oil to make the batch for the box I am thinking of using.  I am also thinking that I am going to have to split it up into two batches unless I use the PVC molds.