gate valve ok to use

[Feukair]

Hey all, i have a question about using a gate valve. My dad picked up a champion cast iron blower with an electric motor mounted on it. I doesn't look like a modification someone made, it looks like original condition.

Question is... how does using an electric blower, left on all the time, and using a gate valve to control air flow compare to using a hand crank blower?

For a while now I've been using this electric blower, which my dad attached a potentiometer to control air flow, but it's hard to vary the airflow this way because it's very touchy.

How well does a gate valve work and could anyone recommend a good gate valve, i think i need about a 3 inch one... Can you control the air flow from just a little air all the way up to full blast? I'm worried that a gate valve once you get it open about 1/4 the way that the air would come thru full blast.

Thanks
Lt

[HWooldridge]

Works great and it's really how you are supposed to utilize an electric blower. I have a factory Buffalo rig and the lowest setting on the factory pot is way too much blast without an air gate but it can be choked to a whisper with one in place.

Any slide gate works - Centaur sells them if you simply want to buy one and 3 inch is a good size. I have also built them from scratch. It's important to be able to close it off completely and it also helps to make the fit a little sloppy so they'll still slide with the inevitable coal dust that falls down in the groove.

[keykeeper]

Currently I'm using a salvaged electric blower. The blast was far to much, so I have devised a simple airgate using sheet metal that slides up and down between the blower and a flat plate that then plumbs to the air tube. Works great, I just slide it up or down to control the amount of air I need.

There is a blueprint on a home built air gate on here, BP0428 in the blueprint listings.

There are many people who use gates, and like them.

As far as using something electrical in line to speed up or slow down the motor, it is my understanding that if the motor is a single speed, the varying speeds will burn the motor up.

Maybe some of the more experienced smiths here can help, as I am a newbie and just learning what works, and what doesn't.

Your mileage may vary on what I've used.

[BT]

Originally Posted by keykeeper

As far as using something electrical in line to speed up or slow down the motor, it is my understanding that if the motor is a single speed, the varying speeds will burn the motor up.

Keykeeper, most of the old universal type electric forge blowers were designed to be run on a rheostat. I have run my old Buffalo electric blower on a simple light dimmer switch for the last 25 years and the only maintenance needed to the motor was a new set of brushes last year.

You will destroy a modern induction type motor though if you try to run it on a rheostat.

[habu68]

Look at the design of the blower and see if it would be practical to put a movable cover on the intake side of the blower. Limiting the output side makes the blower work harder unless you divert the blast, but if you llimit the intake side the motor will begin to run faster, ie: the load will be reduced and make your motor last longer.

that is a can lid on mine using a screw on the fan, I have a normaly off foot switch for when I'm away from the forge.

[the_sandy_creek_forge]

For what it's worth, I've used duct tape as a temporary cover on a squirrel cage fan to choke back the airflow, It was dirty and cheap, but it worked until the duct tape got damp
-Aaron @ the SCF

[Ed Thomas]

Feukair: As Hollis said, that is the ideal solution... a constant speed blower, with a gate on the output.

habu68: For every forge blower I've owned or used, gating the output provided better air control and has never hurt the motor.

[Feukair]

cool, thanks for the info guys, i'll take a look at that BP and thats probably the way i'll go.

Lt