Tried searching around on the pelican megathread, but didnt find enough.

I went to a new lake yesterday that had really sharp small rocks, and after having to manhandle it myself, I put two very small 2" scratches deep enough to puncture through the plastic. Its a 12' Intruder made with the Ram-x stuff.

 

Currently debating on buying this plastic welder from harbor freight:

http://m.harborfreight.com/80-watt-iron-plastic-welding-kit-60662.html

Is this necessary, or can I use some JB Weld marine from the local hardware store?

Any help would be greatly appreciated.

The marine JB Weld will work if you scuff the area first and clean it well. It's only going to hold for a while though, and then you'll have to reapply it. Depending on how well you seal it you may get a few months or a few days. You might want to keep the remaining JB Weld in your tackle box, because you might need it on the water if the repair fails. The good thing about the marine weld is that you can apply it to a wet surface, so it's not a big deal if you spring a leak out on the water. Carry a sponge or a bail with you.  

3M 5200 will also seal it if the holes are small. The 3M product stays tacky so it will flex with the hull of the boat. This stuff will also adhere to a wet surface and cure under water.

Walmart and any hardware store has 2 part epoxy resins that hold up really well on plastic.

3m 5200 works great,just clean the area before you apply.

Google kayak repair as there are few good YouTube videos and articles on plastic boat repairs.

https://search.yahoo.com/search?fr=mcafee&type=C111US977D20150312&p=how+to+repair+ramx+canoe