Duct Foamer Plans

[Hummerbk]

We have several restaurants in which the ducts have bends in them, McDonalds for instance. We can generally snake a squirrel cage ( Mosmatic Duct Spinner) down the duct to the hood but since we could not apply chemical to the horizontal part of the duct we could never be totally sure it was clean.

This has been aggrivating since I knew if I could get foam to the duct the spinner would clean it, even if I could not see it.

I played around and came up with something that works well with the foamer.

I'll describe it as I made it along with possible improvements that I haven't yet tried.

I took 20 feet of 1/2 inch hose and attached a 3/8 male plug to one end that will connect to the trigger gun of the foamer. I put a 1/2 ball valve after the plug to close off the hose because I found that when disconnecting the duct foamer, foam would squirt back out of the hose onto your hands. The ball valve reduces squirt back.

At the other end I attached a two inch piece of 1/2 inch metal pipe using a threaded hose barb. Inside that pipe I put some stainless steel wool from a scrubbing pad. I did not pack it in very tight, I just wanted to re-juvinate the foam in case the 20 feet of hose degraded it.

At the other end of this pipe I attached a Ball Type Rinsing Nozzle. I bought this nozzle from Dultmier for $18.59 ( Part number SS VSM-44). The nozzle has 40 holes in it that squirt foam in all directions.

So you connect this to your foamer gun and lower it down the duct and pull it up slowly while foaming the duct. I did notice that it works best with a little higher air pressure.

If your going to build one of these I would suggest using 1/2 inch sewer hose or thermal plastic hose. The slick stiff hose will be easier to manuver around bends in the duct. Since there is virtually no weight on the end you need the stiffness of the hose to help push it around bends.

If you build one please let me know how it works for you and any improvements you make.

[mbryan]

Great idea David

[Oasis]

very very interesting...are you having good results with this...?

[Alexy]

I would suggest using a EPDM hose as they a chemically resistant, take pressure well up to 130 PSI and are not easilly cut by sharp edges in a duct. I have been using a EPDM hose for foaming for almost a year and only after I noticed some degredation in the outer casing did I change it out.

[Hummerbk]

Good advice on the EDPM hose. I'll pick some up and try it out.
I drilled larger and more holes in the ball. It works well on narrow ducts but the chemical shoots out of it in thin pencil streams which makes it hard to completely foam a wide duct.
I need to play with it some more to get it working better.