Different types of Ventilation for casting setup

[44 WCF]

Weather is crappy here in Utah today, so cast some 40's n 45's and waiting for temp to come up mind kind of wandered;
I'm very interested in what types of ventilation set ups other casters use. I'm very very sensitive to any kind of smoke so I have to keep the smoke generated from fluxing vented out of my shop, and I guess it's good idea anyway. I used a bathroom vent fan, screwed it to the wall, duct the discharge through the wall and used 6" aluminum stove pipe I picked up at yard sale for a buck. If I had my druthers, I would use flex vent and not ridgid. I was going to make a hook to sit over my Master Caster but just use aluminum foil and then I can adapt to my RCBS and old Lyman 61 pots as well. Hope others will post their set ups too. Attached some photos,

[Dale53]

My thinking is to have a distance between the top of the pot and the vent pipe. If you seal it up, then there is no air to allow flow.

Probably the most efficient way is with a kitchen vent hood with outside exhaust. I had a similar vent built into my dedicated casting station in my utility barn. However, I should have used a motor that allowed adjusting the speed. Faster for fluxing, and slower for general ventilation. My fan is a furnace blower and actually moves too much air. In the summer most of the A/C goes up the flue. In the winter, the heat does.

Currently, I have the parts for an inline fan in a 4" dryer vent. I'll run it down to the top of the pot (get it within a foot or two) and that will allow adequate ventilation without exhausting all of the cooled and heated air from my barn.

Dale53

[44 WCF]

The back side of the pot, the aluminum foil is loose to allow air intake, I squeezed it tight to keep dust out till next casting session. You make a very good poiint, if you seal it too tight the fan wiil collapse it for sure. I too had to big of a fan my first go round, and it pulled heated out just as you say.

[midnight]

I wish I knew how to post pictures so I could show you my setup. I worked 40 years in hospital laboratories and have used many "hoods" when working with bacteria and fungi. You don't have to closely enclose the furnace. You only have to create negative pressure in the area where the furnace is located. I built a fume hood on my bench top. The bench is 24" deep. The back of the hood is 24" high and the front is 16 in high. The whole thing is 36" wide. The top has an 8 in flat shelf against the wall where the 6 in stove pipe comes out and then it slopes down to 16 in at the front. I used a 10 in squirrel cage fan I got for 10 bucks at a rummage sale at the top and it blows through a 4 in dryer vent to the outside. I cut a half circle out of the hinged top and mounted a piece of sheet aluminum with a piano hinge over the hole for better access to the pot for loading. Even when I use bullet lube to flux it carries away the smoke. My front opening is 3 ft x 16 in but the fan creates enough negative pressure to keep all the fumes out of my basement.

Bob

[44 WCF]

Believe I have concentrated too much on trying to enclose the immediate area around the pot. I'm going to experiment with "area" or range type hood rather than what I have and fix hinge for loading etc.
One shooter told me he brough in cool air from outside for the blower on his master caster and that tiny bit of positive pressure made a big difference in his exhaust fan setup.
Thank for the input, great stuff.

[cajun shooter]

This topic has been dissused in depth on more than one ocassion. If you do a search I'm sure that you will come up with the information that also contained some good pictures of different ideas.