Long time listener, first-ish time caller.  Have been interested in FRP for some time, but have the attention span of oh hey, shiny!  Like many <many> here, I'd like to build some parts for my old BMW, some bits for my motorcycle, stuff around the house and generally just get out there and play in the garage making things.  My current line of work uses some interesting industrial composites, with some really remarkable (big) bits in beta. 

I was originally setting up for pre-preg work, but am stopping at VARIM first.  Am building a low-temp (<80 C) oven for curing out of recovered 1.25" PVC sheet and a 2nd-hand pair of programmable circulating heaters (no flame!).  Picked up a pair of (used) 0523 laboratory vacuum pumps (4.5CFM, 27"), some polyester resin, epoxy resin, 200gsm 2/2 twill, some heavier 670gsm plain and some CSM. Some vacuum bagging supplies and we're in business!  After some trial and error and learning with wet layup.

My workspace for this is my detached, heated garage but I have some safety-related questions.  Primary question - will an open flame (my traditional open-flame natural gas furnace) ignite polyester resin fumes / vapours? Epoxy?  I understand the liquid will burn (well, technically heat induced decomposition of solids and liquids creates gases and those burn, not the non-gases) and create all sorts of hellish smoke and death, but will I blow up my garage with fumes and an open flame?

Second question: For those that are not working in a climate with an outdoor temperature between 15 and 25 C all year round, what do you do for heated, ventilated space?  My commercial HVAC engineering buddy is happy to line me up with a $$$$$ make-up air unit but that seems excessive for a hobby and surely I'm not the only one who intends to not die building FRP things in their garage.

What's the reality of working with polyester and epoxy in your garage?

Thanks for the insight - much appreciated.