Can't seem to stop the smell

I had an original GF unit that I used for about 5 months initially that got replaced, so I’ve been using a newer unit for about 4 months now.

The problem I’m running into is the smell. My older unit didn’t seem to stink up the house nearly as bad. The old unit only stank up the place a little when I had cuts sitting out or I had the lid opened for a bit.

This newer unit has had a stink problem from day 1. I’ve been using the AC Infinity fan with the internal fan off on both units. I first thought I must’ve not had a tight connection on a duct somewhere when I got the newer unit, so I re-did it all.

Long story short and hundreds of dollars thrown at it, I’m still stinking up the room its in to where it feels difficult to breathe in there about mid way cutting my second board of the day. It gets so bad that I got a respirator to use in my house after I’m cutting for a few hours.

I’ve tried different duct pipes, more aluminum tape, different duct attachments, Rockler ($$$) accessory suggestions, moved to a different room to exhaust out a different area, trying to tape up different intakes on the GF, etc.) I also keep it as clean as I can. I noticed that helps when nothing is being cut and the lid is opened.

I thought it might be blowing back into the house somehow since it currently exhausts into a covered porch area, so I’ve added extra stripping to everything. I also added a big fan out there to just continuously blow fumes outward.

I even made a setup to where the AC infinity external fan sits outside just to completely eliminate it as the leaky culprit.

After all that, I believe it’s leaking from the Glowforge itself somewhere. I suspect it’s a very tiny leak since it only seems to build up the smell after maybe 30-45 min of cutting.

Any suggestions?

The idea is that any opening is only a one way in so no smoke leaks out. If the fan is doing its job there should be no possibility of leaks. I have a 195 cfm Vivo and it works fine for all but the smokiest cuts without the internal as assist.

I also exhaust into the carport, so similar there too. What might be different is the house 25" away so the air only moves up or down the “canyon” between going either east or west even when the wind in general is say north-east. If your porch faces south and you have a south wind then the air pressure in the porch will be higher than inside, and the air will want to flow in through any opening.

I also run the Vivo 24/7 so there is no way outside air comes back up the hose, (there are many other places it comes in however)

Are you sure on this one? The intakes shouldn’t be taped up, air needs to get in so it can move smoke out.
Are you by chance venting out double hung windows? After months of chasing, taping, caulking everything in my hose/fan run it turns out I’d stupidly forgotten about the gap between the window pane frames due to window being partially open for the vent insert.


My Glowforge has been stinky since day 1. I thought it was normal, after all, we are burning wood. My forge sits about 6 inches away from the window, which cranks open sideways and is very tall. I have put a fabric vent cover over the whole open area and zip a spot open to drop out the remainder of the hose. the hose nearly touches the ground, so I don’t think the smell is coming back up the hose, and probably not coming through the fabric, though that is a possibility. My house is one of those long thin ones, and my husband 100 or so feet away inside can smell when I am cutting. I have cleaned all around where the lid closes and I haven’t removed the passthrough pannels (yet!). Some thoughts on what else to look at would be appreciated.

  • Make sure air can flow into your glowforge. You need good airflow to move the smoke outside. I believe the vents are along the bottom on the front? Maybe sides too… make sure those aren’t obstructed.

  • Make sure air can’t flow back into your house so easily once it’s outside. Your fan is creating a vacuum inside your room by blowing all the air out… air needs to come back in to equalize… so you may need to make sure you have a source of clean air that can flow more readily into your room that isn’t coming in the window that you’re venting out.

e.g., if I close the door to our craft room, I get more smoke coming back in the window I vent out, but if I leave it open, I don’t, because instead I pull air in from the rest of the house.

Good luck!


Supplies needed:

Laser pointer
Cardboard or other material used to cover Glowforge lid and block light from inside
Duct tape
1 sheet of MDF
A design that will run for approximately 10 minutes


  1. Insert your material and load the file, prepare to start the cut
  2. Cover the Glowforge lid so that no light escapes (a little is ok, but you want things dark)
  3. Turn off all the lights in your room and start the file
  4. Using the laser pointer, shine the beam along the path of your Glowforge exhaust, keep scannning back and forth along the entire length, watching for signs of smoke in the laser beam
  5. When you see signs of smoke escaping the exhaust duct, follow the smoke using the laser pointer as a guide, until you locate the point at which the smoke is exiting the exhaust path
  6. Once the source of the smoke has been located, apply a strip of duct tape to mark the location then move on to any other sources that may exist
  7. After the file is complete or you are certain that you’ve located all of the smoke sources, take some time to address each of the locations you’ve marked and thoroughly seal each source

Breathe better. :slight_smile:


Now this is an approach to finding the leaks that I had not considered. Bookmarking!


I’m with you that it doesn’t really make a ton of sense. I’ve experimented with taping up some intakes (not all at once obviously) because others have reported that it eliminated their stink. I’m more doing it because I’ve gotta try it all.

I’m currently venting out a sliding glass back door with this vent kit and these foam seal tape strips.

I did have a problem with a draft coming back in from the sliding door overlapping the other (I think that’s similar to what you’re talking about). I added this draft stopper vertically along it to fix that.

I may try taping up some of the joints of the door vent kit to see if it’s slowly coming in through there.

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That’s an interesting tidbit about creating a vacuum in rooms. I wouldn’t have thought of that. This thing is currently in my living room to make sure the duct piping is as short as possible.

It feels like there’s pretty good air flow into the forge just from watching the smoke in the unit. I may do a little extra to see if I can shorten some extra ducting on the end to see if that can help maximize my air flow because as others point out, maybe it is an airflow issue.

This is a great suggestion that I haven’t seen before. I’m gonna see if I can find a laser pointer to try this out next time I do some cuts.

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Hello @Kronok,

I’m sorry to hear you are getting a significant smell from your Glowforge. I’m happy to help troubleshoot the issue with you.

When your Glowforge is properly set up, you may have some harmless odor during printing which will rapidly dissipate. You may also smell something when you open the Glowforge lid after a print is complete. This is not harmful.

However, if you detect a strong, sharp smell that also causes eyes, nose, or throat irritation, or if there is visible smoke escaping while the lid is closed, shut off your Glowforge unit immediately. Smoke and fumes could be entering the room in excessive concentrations.

We’ve created a troubleshooting guide with illustrations. You can see it here: Smoke of Fumes During Print.

To help troubleshoot your exhaust, could you send me a few photos of your exhaust system? Specifically, please include pictures of the following:

  1. The exhaust fan from the inside of the unit. To capture this photo:

  2. Turn your Glowforge off

  3. Open the lid

  4. Using both hands, gently pull the printer arm towards you as shown below:

  5. Move your phone or camera inside the Glowforge on the left-hand side, past the metal rail, pointed away from you towards the exhaust hose, to capture a photo like the one below:

  6. A photo of where your exhaust hose attaches to the Glowforge, where your exhaust hose exits the room, and the path your exhaust hose takes from your Glowforge to the exterior vent or Compact Filter

  7. The exhaust connection on the back of your Glowforge, with the exhaust hose removed:

  8. Any area where you see smoke escaping from your Glowforge while printing

Once I have the photos, I’ll quickly review and follow up with next steps. Thank you!

It’s been a little while since I’ve seen any replies on this thread so I’m going to close it. If you still need help with this please either start a new thread or email