I have used a 25 gallon Craftsman shop vac on numerous occasions, running it for up to 6 hrs straight without it burning up...but cant' guarantee yours won't....not a very controlled way but it gets the job done...unlike a dedicated vacuum pump it will pull all the air out of a big bag in seconds...We use to use one to evacuate all
the air out of large projects before turning on the dedicated vacuum pump.

I like to note that when I used the shop vac itself for vacuum bagging I cleaned it completely out and ran it without the filter in place...it would suck so hard that the HD base would suck the sidewalks of the plastic tub. Not the best way but if you want to do it on the cheap and your resin jell time is less than 1-1/2 hrs it will do.

Regards,
Robert