Dust collector exhaust alteration on H.F. green blower

[Mayo Pardo]

I'm getting things set up and have mounted my green Harbor Freight blower in the attic of my garage. I have all the vent pipes taped on the seams, and the exhaust exits through a hole in the gable on the garage, and that has one of those louvered dryer vent covers on it.

I engraved a small amount of acrylic last night (see post about rulers) and afterwards when I went back into the attic to make sure the blower was still securely mounted - it was the maiden voyage, so I had to check...
I could smell a lot of engraved acrylic odor. Just in the attic - not below in the garage.
I went outside and verified the louvers were opening and I could smell acrylic outside also.
(I did not leave the engraver running unattended - this was after I was done engraving, but with blower still running)

So placing my hand near the running blower, I noticed a lot of air escaping from the
exhaust flange where it joins the flat side of the machine. Not the 4 inch fitting itself - the wider flat part that connects to the blower.

So I'm thinking of either removing the entire piece and installing a rubber gasket of some sort, or maybe just running silicone sealant all around the perimeter of it.

I hope the usual amount of heat in the attic on sunny summer days is not going to be an issue for the blower motor - it's ridiculous hot up there.

[Kevin Gregerson]

I'm getting things set up and have mounted my green Harbor Freight blower in the attic of my garage. I have all the vent pipes taped on the seams, and the exhaust exits through a hole in the gable on the garage, and that has one of those louvered dryer vent covers on it.

I engraved a small amount of acrylic last night (see post about rulers) and afterwards when I went back into the attic to make sure the blower was still securely mounted - it was the maiden voyage, so I had to check...
I could smell a lot of engraved acrylic odor. Just in the attic - not below in the garage.
I went outside and verified the louvers were opening and I could smell acrylic outside also.
(I did not leave the engraver running unattended - this was after I was done engraving, but with blower still running)

So placing my hand near the running blower, I noticed a lot of air escaping from the
exhaust flange where it joins the flat side of the machine. Not the 4 inch fitting itself - the wider flat part that connects to the blower.

So I'm thinking of either removing the entire piece and installing a rubber gasket of some sort, or maybe just running silicone sealant all around the perimeter of it.

I hope the usual amount of heat in the attic on sunny summer days is not going to be an issue for the blower motor - it's ridiculous hot up there.

Usually recommend mounting your blower outside and just get one of those wireless remotes to turn on the power to it. It's safer, works better, and usually quieter.

[Mike Null]

Outside is ok if you can do it without irritating the neighbors and exposing the blower but I'd prefer an inside installation but why buy a Mercedes engraving machine and a Yugo blower.

[Bill George]

I'd use some red RTV sealant and let it dry for a day or so before running it again. Separate the flange enough to coat and fill the joint and then bolt back up.

[Bill Stearns]

MAYO -
Just a side thought - 'cause I personally tend to get leery of machines of any kind running unattended elsewhere in a building - maybe, a small fire detector 'n the attic might be 'good idea? (Heck, I even unplug the toaster, when not in use; saw one spark and flame up once.) Anyway, just a thought ....

Bill

[Bruce Clumpner]

Smart idea, when my HF green blower failed this summer, it was the switch that went... It was a pretty good pop, a bit of smoke and sizzling, but the breaker didn't trip, so I agree, you need some sort of monitoring if it's unattended. Why not put it back down in the shop and push the exhaust through the attic to the eves?

[Gary Hair]

I could smell a lot of engraved acrylic odor. Just in the attic - not below in the garage.

That's exactly why I have my blower outside and it is drawing the exhaust out instead of trying to push it. I have 4 of those blowers, two for lasers and two for sandcarving and I can guarantee you that they will leak no matter how well you seal them. I took the first one apart and sealed the seams with metal duct tape and the bolt holes with rtv - still leaked. I'm not sure you could spend more money and get one that doesn't leak somewhere. Put it outside and be done with it.

[Mayo Pardo]

Thank you everyone that responded -

Putting the blower in the attic of the garage accomplishes several things.
1. it pulls the fumes at least twice as far as it pushes the fumes out of the garage.
2. the exit for the exhaust is unobtrusive and high up where I was hoping the fumes would be diluted more than if the exit was at first floor height.
3. my garage is cluttered enough without adding another piece of equipment to the floor.
4. Placing the blower outside would require more construction to enclose the not suited for outdoors blower, more electrical work, and putting a hole in the side of the garage. It also puts the fumes at "people height" and I have neighbors.
I have disassembled the blower and removed the plastic grate which was covering the exit port. I left the grate which covers the entry port just in case some small parts get sucked through the system. The blower blades are steel though, so it is unlikely anything small enough to get through both the Trotec grid and the blower grid would do any harm to the blower blades. I'm tempted to take the grid off the blower entry port also.

I made an additional foam rubber gasket to mount beneath the existing rubber gasket on the flange that was leaking. After putting it all together with contact cement and bolting it back in place, I also ran a bead of silicone around the perimeter. I made an additional gasket for the exit port since I removed the plastic grate, and I also ran some duct tape around it. When I screwed the bolts back on the exit port I discovered how easy it is to strip them - so if anyone is contemplating doing the same thing, use caution tightening the bolts. I only stripped one but it wasn't very tight before it stripped.

Although the blower will be located in the attic, the blower switch will remain on and I will be turning it on and off by a switch located in the garage. The only time the blower will be on is when I'm in the garage using the engraver. I have access to the attic by means of a pull-down ladder. There is a fire extinguisher in the garage.
I could put a fire detector in the attic as long as the normal attic heat won't set it off - I'll look into those and see what temperature sets them off.


If I could have afforded a "Mercedes" exhaust system, I would have bought one.
The "Hugo" car mentioned above probably refers to the YUGO which actually sold for $4000 - which is about what the Trotec Atmos system costs from what I was quoted. As long as my neighbors don't complain about the smell, I can replace this blower 30 times for the cost of one Atmos system. If they do complain then I'll construct an exhaust fume cabinet and still be ahead on the money spent. This was a way for me to get started, hopefully make some money, and eventually move into an actual shop space where I can make as much noise and fumes as legally allowed in an industrial area!

[Mike Null]

Mayo

Thank you for correcting my error. I apologize for my reference though I still hold that opinion of HF blowers. I wasn't suggesting the Atmos but perhaps a good, and quiet, in-line blower which could be purchased for less than $400. I've been using one for 17 years and as long I don't mess with the connection to the laser I don't have leaking. I can also carry on a phone conversation while standing next to it.

[Neil Pabia]

I've been using a Penn State DC3 blower for the past few years, its a lot quieter than the HF blowers and since it is mounted right next to my laser, the noise level is still low enough for me to have a phone conversation while it is running.

And yes, I did decide not to sell the laser. I have found a good home for it at a sign shop that actually pays me for my time and the lasers time.

[Mayo Pardo]

The dust collector blower that I got from H. F. is not what I would call loud.
There is some noise of the motor hum but I can have phone conversations near it without a problem.
I have it mounted on rubber feet (I didn't use the casters) on top of a board which is screwed to the rafters in the garage attic.

Outside there is the noise of a strong fan coming through the vent opening but it's not as loud as some pool filters I've heard throughout the neighborhood while I'm out on dog walks at night.

It appears to be constructed almost exactly like the Penn State DC3 with the exception of the CFM being lower than the Penn State.

Mike I'd like to know what make and model of in line blower you use - I'm open to changing things for convenience, safety, and efficiency etc.

[Mike Null]

Mao

My blower is not available any longer but I got it at Grainger and it is a 6" inline at about 300 cfm. I have a short run of about 8 feet from the machine through the wall of my house. I reduce it to 4" at the wall and use a dryer vent there which has a flapper on it to keep out insects.

There is no shortage of in-line blowers so finding one won't be a problem. Grainger is not the low price dealer but at the time they were the only place I knew to shop.

[Eric Claiborne]

the green hf blower is less than half as loud as the red one. i have it outside through a basic duct, total of about 8-10 ft. from the laser. with the garage door closed and laser and air assist on, i can't even hear it.
the red one sounds like a plane taking off....

[Robert Delhommer Sr]

The green HF uses a induction motor where the red one has a universal motor and runs at higher rpm's. I have the green one and like it, I would not have the red one.