Q&A Forums

how to fix broken drill bit in mixing chamber Post New Topic | Post Reply

Author Comments
Posted: Dec 11, 2011 06:59 PM
how to fix broken drill bit in mixing chamber
We are new to this business and we need a little advice. We broke a drill bit in the mixing chamber of our Graco Fusion gun. Do you have any tips on getting it out or is it hopeless? Also how often do you recommend taking the gun apart and cleaning it? Thanks
Mike Asbra
Posted: Dec 12, 2011 08:44 AM
With the mixing chamber removed from the gun, I applied heat (with a small torch) to the mixing chamber, and it actually backed out the drill bit. We applied the heat, on and off, on and off, in such a manner that we didn't cause the mixing chamber to become red hot. Over the years, we used this method 8 or 9 times, with only 1 bit that did not back out. I took the risk because the mixing chamber was heading for the trash.

The heat was the last option after soaking in cleaning chemicals, and trying to blow it out with high air pressure.

Good luck
Craig Gifford
Posted: Dec 13, 2011 10:18 AM
I have had this happen more than once and believe it or not I simply pulled the trigger & the pressure of the foam blew it out (try this as soon as it happens don't wait long).

As far as cleaning the gun....I was initially told to break it down every time (WRONG) you can wear parts out quicker....when using closed cell I simply change out the mixing chamber daily....if there are no cross overs no reason to break down everything (thorough cleaning once/twice a month is realistic depending on amount of use). When changing mixing chamber a little cleaning fluid within the housing works well plus make sure no particulates get in while changing the chamber...keep it clean internally.

When spraying open cell and/or 1 lb the mixing chamber can be used several days in row without clogging...open cell is much less evasive on gun parts.
Brad Smith
Posted: Dec 14, 2011 04:45 AM
I've used the boiled antifreeze method several times and it works great.
I tried blowing it out of the gun immediately after breaking it by hitting the trigger but never found that method to be effective.
I put mixing chamber im boiling antifreeze for 10-15 minutes, lock end of mixing chamber into pair of vise grips and give it a wack over a table and broken bit comes out easily.
Make sure your outside when boiling antifreeze, I use a crock pot and a small range burner.
steven argus
Posted: Dec 14, 2011 02:17 PM
Yup, a little heat works every time. We take our gun apart and clean it every time it breaks. Seriously though, we try and rebuild it every Mon. morning. We have two guns, let one soak all week and get the other one running.
Daniel X
Posted: Dec 19, 2011 12:15 AM
Same thing here, I just hold the mixing chamber in a vise, apply heat with a propane torch to melt/burn whatever held up the bit in the first place.

Sometimes it can help to hold a gloved finger over the a or b side of the chamber and blow compressed air into it.

As far as how often we break down the guns... if you take it apart too often you're just wearing the o-rings down unnecessarily. I check the screens on the check valves every week or so, but the rest of the gun stays together until a problem actually occurs.
Rodney Schares
Posted: Dec 30, 2011 12:18 PM
I soak the chamber in a solvent for a couple days.Take the chamber out of solvent and redrill the nozzle port to feel if the cured material has disolved and the broken bit can move freely.

If so then I place the chamber on its side to semi-seal off one of the two impingement port grab the air chuck and give her a quick blast.

This seems to dislodge the broken bit everytime.I have never used heat to extract a broken bit.

Hopefully you have a couple three extra chambers in your tariler so this does not affect production
David Friedson
Posted: Jan 03, 2012 04:01 PM
Apply some heat with a propane torch. The broken bit will fall right out.
Tyler Boehs
Posted: Jan 20, 2012 09:02 PM
Yup. Heat is the best method we've found... Don't always work but its worth trying
Dennis Myers
Posted: Mar 27, 2012 09:14 PM
I let it soak a few days then I take a broken bit that has a point and use it to spin the bit in the chamber. Once you spin it a few times to get the soaked product out it should start to spin more freely. I used the smallest supplied pipe cleaner from the cleaning kit and cut the loop at the end so I could take the thin wire and use that to back the bit out. Took me a while to do it the first time, but on my second tip it took less than 20 minutes.
Chuck Castiglione
Posted: Sep 23, 2014 10:42 PM
If all of the above doesn't work, find a tool shop that has a "Hole Popper". This machine remove the bit in a few minutes. The operator needs to know the size of the hole.

You need to login to reply to this topic. Please click here to login.