Last week when I was doing a little fiddling around I inadvertantly wound up with a couple of galvanized pieces that I welded. I didn’t realize it until too late (just not paying attention). FYI zinc fumes are toxic and if I know that I’m going to be welding anything that might be zinc coated I grind it down, use my respirator, try and do it outdoors and stay away from those nasty fumes.
This time I wasn’t paying attention. It was cold so I was doing the welding inside and although I always have the garage door up a bit and my little fan blowing when I’m working inside, that didn’t cut it. I didn’t get much exposure to the fumes (I noticed pretty quickly what I was dealing with) so didn’t really get any effects. Zinc poisoning symptoms are flu-like and while it’s not normally going to kill you (unless you have excessive exposure) it can make you pretty sick. Apparently drinking milk before you do any welding of zinc coated (galvanized) stock is a good idea because the calcium inhibits the absorption of zinc in the body. Just a tip. 🙂
Anyway because of that I thought I would speed up the building of my homemade fume extractor. I had boxed in my fan a couple of weeks ago so it was just a case of putting together a shroud over the fan and plumbing some flexible hose. I sent Heather on a scavenger hunt to the SOS thrift store to see if she could find me a stainless mixing bowl about 10 1/2 inches around. Score! 99 cents well spent (she actually found 2 and I know what I’m going to do with the second one).
Once I got the bowl, I used my plasma cutter to cut a 4 inch hole in the bottom that fit a spare 4 inch blast gate from my woodworking dust collection system and sealed it up with aluminum duct tape. solid enough for what I needed and ready for the next step. I then mounted the bowl/blast gate assembly to the front of the fan and sealed it with latex caulk.
Once that was all dried up and solid I attached a chunk of my dust collector 4 inch flex hose and tested it out. Did a couple of beads with my Miller and it worked great to drag the fumes away.
I’m going to rig up some kind of adjustable assembly so I can move it aroud overhead wherever I need it. It ain’t pretty but it works and I feel a lot better knowing that if I want to work with the garage door lowered that I (probably) won’t asphyxiate myself. I’m thinking that I might just buck an exhaust hole in the garage wall and install a 4 inch chunk of PVC pipe. Then I’ll modify the back of the fan box with an outlet and some more flexible hose to connect to the exhaust hole and I can use it when the weather’s crappy and I don’t want the door open. It’s a thought.
I’ve got some 1 inch square tubing cut for Mike’s wine rack/ liquor cart and I’ll be doing a bunch of welding over the next little while so my Weldo-Exhaustomatic (pretty nifty name, eh? Came up with it myself.) should get a work out.