Several bubble products are available to locate air leaks. Steve Ferguson recommends Rectorseek. This product comes in 2 types (MT and LT). I have no idea what the difference is. This product is not widely available. Bruce Tara posted a phone number for Rectorseal Toll-free 800-231-3345 call them for information. Gary Worobec posted a product called Bubleak by www.kanolabs.com . Emery Stora uses \"Harvey\'s All Purpose Gas Leak Detector\" available at Ace Hardware. It comes in a 2 oz spray bottle. Ken Henderson suggests that if all else fails try using some kids bubble soap. He says it works better than plain soap and water but not as good as leak detector. I found this Mega Bubble at my local plumbing supply house. I would suggest that you look in your Yellow Pages and look under plumbing supplies and call several to see what product they carry for detecting leaks (gas, oxygen, propane etc.)