forums are notoriously difficult to start, and will be incredibly hard work with no responses. e.g. you'll have to post questions / threads, then set up fake accounts to respond to them etc. from my own stats, about 80-90% of visitors to a forum don't post. and you'll have spam bots to contend with.
the one problem you have is the word 'maybe'. maybe they will come, maybe they will buy, maybe they won't. you want to convert that maybe to a 'they will'.
afaik, people in the trade industry are mainly trained with some sort of qualification so will already have most of the knowledge (?); then there's the cowboys - will they really care for additional knowledge by having to ask on your forum and then buy the tools?
tools are fairly generic and can be purchased anywhere so you might be kicking yourself in the foot with a forum.
work on a blog, post informative articles that you've written. write for the reader, not for the search engines. answer popular questions, simple how-to's etc. e.g. the trade industry equivalent of 'how to poach an egg'.
remember that unless you sell very specialised power tools, there's a big home diy sector. if you do sell specialised gear - are you in a position to rent it out?
in short, unless people can only buy the product from you, giving free advice is time consuming with no / little reward and a kick in the teeth when they call you up regularly for advice without buying anything. your time is better spent doing other things.
