# Cordless DeWALT spitting fire and recovering **URL:** \ **Category:** Factual Questions\ **Created:** [September 19, 2013, 9:25pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266 "2013-09-19T21:25:08Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![MonkeyMensch](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@MonkeyMensch](https://boards.straightdope.com/u/MonkeyMensch)\ **Post date:** [September 19, 2013, 9:25pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/1 "2013-09-19T21:25:08Z")
An off-hand question really, but a week ago I finally got around to sanding down and then polishing the headlamp covers on my fifteen year old truck, a Nissan Frontier. Ever since the sealed-beam lamp went out of style, using glass, the polycarbonate covers are prone to eventual fogging from UV light and abrasion. The package of materials from 3M worked like a charm and now my headlights no longer illuminate the road ahead like a couple of flashlights. I’m tickled pink at the results. That being said, towards the very end of the polishing I got some very noticeable flashing (read fire) visible through the vents where the brushes are located and a couple of good puffs of smoke. Since it was the very end of the polishing I called it done and then went to thinking about why on of my favorite tools would do this. There wasn’t a lot of dust flying during the sanding and polishing and the 40 minute job presented a duty cycle of about 50%, at most. Any ideas? It now runs just fine, with maybe the normal, mild smell of ozone from the vents. I have two good 18V batteries and replacing the tool itself would be about $50. But still, I’m confused why it would do this at all: act nasty and then recover with nothing done. I do love them DeWALTs. MM ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [September 20, 2013, 1:02am UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/2 "2013-09-20T01:02:04Z")
Sounds like either one of your brush holders slipped, or you need new brushes. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [September 20, 2013, 1:12am UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/3 "2013-09-20T01:12:27Z")
Worn brushes would be my first guess. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [September 20, 2013, 1:25am UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/4 "2013-09-20T01:25:40Z")
Are those things repairable? ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [September 20, 2013, 3:08am UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/5 "2013-09-20T03:08:36Z")
> [@kaylasdad99](#): > > Are those things repairable? yes ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [September 20, 2013, 4:02am UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/6 "2013-09-20T04:02:01Z")
I’m wondering if a small chunk of polycarbonate didn’t get under one of the brushes causing it to make a spotty connection with a lot of arcing. If the chunk was dislodged when you put the tool away that might explain why it works fine now. I would be tempted to open it up and take a look inside. Look for something under the brushes or damage and wear to the brushes, and look for any burn marks on insulation or wires that might indicate a different problem. It may be working fine now but that ozone smell indicates arcing inside. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [September 20, 2013, 1:42pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/7 "2013-09-20T13:42:16Z")
Have you dropped the drill lately? One of my drills was stinky and smoky after a fall. Fortunately, replacement motors are readily available and easy to swap out. In my case, it must have been a rather substantial impact as the brush holder and one of the motor magnets was cracked. ---
**Author:** ![Uber\_the\_Goober](https://avatars.discourse-cdn.com/v4/letter/u/58956e/32.png) [@Uber\_the\_Goober](https://boards.straightdope.com/u/Uber_the_Goober)\ **Post date:** [September 20, 2013, 1:44pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/8 "2013-09-20T13:44:32Z")
I’ve had this happen when dirt/dust/debris gets into the vents. Similar to what **engineer\_comp\_geek** mentioned. Running that baby at full speed, with no load, while shooting (clean) compressed air into the vents cured it. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 20, 2013, 1:56pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/9 "2013-09-20T13:56:02Z")
> [@engineer\_comp\_geek](#): > > It may be working fine now but that ozone smell indicates arcing inside. That’s pretty normal for brushed DC motors. There’s almost always a small degree of arcing between the brushes and the commutators - more if it’s being operated at high load. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [September 20, 2013, 1:59pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/10 "2013-09-20T13:59:19Z")
> [@MonkeyMensch](#): > > I do love them DeWALTs. They are definitely tough. After fixing our gas oven, which involved drilling some holes and using a pop rivet gun, I accidentally left my [12v DeWalt cordless drill](http://www.dewalt.com/tools/cordless-drills-drilldrivers-dcd710s2.aspx) sitting on the broiler rack and forgot about it. Later on, at dinner time, my wife flips the oven on, and after 5 minutes or so, we start smelling burning plastic. I’d basically broiled my drill for 5 minutes on high. I took it out, cooled it off, and to my great surprise, everything still works fine, despite being somewhat melted and burned looking on one side. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [September 20, 2013, 3:11pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/11 "2013-09-20T15:11:17Z")
I thought slight arcing was pretty normal with drills. I certainly notice flashes/sparks through the vent holes when I’m using my cheapo Black & Decker. ---
**Author:** ![MonkeyMensch](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@MonkeyMensch](https://boards.straightdope.com/u/MonkeyMensch)\ **Post date:** [September 20, 2013, 6:55pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/12 "2013-09-20T18:55:24Z")
Yeah, I’m agreeing about the arcing smell. I know that it’s because (I think) of the brushes momentary contact with two poles of the rotor in normal spinning operation. From the responses I think I must have got something lightly coated on the rotor surface and it harmlessly (however showily) burned off. Used it yesterday to mount shelving supports and it ran like a champ. Thanks for all the responses and info. MM ---
**Author:** ![obbn](https://avatars.discourse-cdn.com/v4/letter/o/d6d6ee/32.png) [@obbn](https://boards.straightdope.com/u/obbn)\ **Post date:** [September 21, 2013, 4:26am UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/13 "2013-09-21T04:26:49Z")
> [@Colophon](#): > > I thought slight arcing was pretty normal with drills. I certainly notice flashes/sparks through the vent holes when I’m using my cheapo Black & Decker. Don’t be to quick to discount your Black and Decker. Take a good look and compare it to a DeWalt. Notice the similarities? ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [September 23, 2013, 1:40pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/14 "2013-09-23T13:40:36Z")
> [@obbn](#): > > Don’t be to quick to discount your Black and Decker. Take a good look and compare it to a DeWalt. Notice the similarities? Sure, but plenty of manufacturers make a premium line and a value line; nobody’s really arguing that BF Goodrich tires are the equivalent of Michelin tires, or that Maytag, Admiral and Whirlpool appliances are all the same. Black and Decker is the value brand, while DeWalt is the premium/professional brand. DeWalt power tools are worth getting over B&D for one reason alone- you can get just about any spare part for a DeWalt tool, and B&D are basically disposable. ---
**Author:** ![Muffin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muffin/32/4341_2.png) [@Muffin](https://boards.straightdope.com/u/Muffin)\ **Post date:** [September 23, 2013, 2:21pm UTC](https://boards.straightdope.com/t/cordless-dewalt-spitting-fire-and-recovering/669266/15 "2013-09-23T14:21:16Z")
> [@bump](#): > > They are definitely tough. > > After fixing our gas oven, which involved drilling some holes and using a pop rivet gun, I accidentally left my [12v DeWalt cordless drill](http://www.dewalt.com/tools/cordless-drills-drilldrivers-dcd710s2.aspx) sitting on the broiler rack and forgot about it. > > Later on, at dinner time, my wife flips the oven on, and after 5 minutes or so, we start smelling burning plastic. > > I’d basically broiled my drill for 5 minutes on high. I took it out, cooled it off, and to my great surprise, everything still works fine, despite being somewhat melted and burned looking on one side. How did it taste?