like you would be better off with something like:

http://www.axminster.co.uk/product.a...=mastic&user_s...


For that money he could buy a compressor and an air powered gun. I
thought about building my own electric gun using a cheap cordless
drill but of course never got around to it.
I was recently using some sealant that I could hardly get out of the
tube using a regular gun but with my air powered one it was a piece of
cake.