Any of the suggestions already given will work but I can't help d feeling that at the print size and aperture you quote there is no way the correct exposure should be so short. So, yes, have a look at the bulb and if you can get a lower wattage then swap. This will avoid having to use " work arounds"

At 5x7 print size you'd be down to about 2 secs and even at 3-4 secs you cannot possibly do any dodging

pentaxuser