Be careful when sanding metal with belt sander

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Forum topic by RichardDePetris posted 02-25-2014 06:01 PM 3090 views 0 times favorited 8 replies Add to Favorites Watch
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61 posts in 1650 days

02-25-2014 06:01 PM

Topic tags/keywords: safety sander sanding resource

Just experienced a terrifying moment yesterday that I wanted to share with you. Before finishing up for the day, spend some time just hanging out at the shop for a few minutes to catch any potential dangers. In my case, I thought what I was doing was routine and ordinary, but it could have turned very bad and I consider myself fortunate.

I purchased a belt/disc sander a few months back. I normally use it to sand small pieces of wood and occasional metal grinding. The machine is well made in terms of materials, but it can pose a serious hazard.

Yesterday, I was flattening the back of some old plane irons on my belt/disc sander. One of them started sparking which is normal. I thought nothing of it and went on to the other grits of sanding on my bench. I started to smell something like heated plastic. It was sort of like the smell you get when you have a light bulb next to a plastic toy. I thought nothing of it until it started getting stronger and the smell changed into a fragrant burned pine smell. I looked around my shop and lo and behold I saw wisps of smoke coming from the rollers. I immediately unplugged it and carried it outside and started unscrewing it to find the source of the smoke. I saw a red glowing ember affixed to the plastic belt guard after dismantling the belt assembly. I hosed it down to ensure nothing else was burning and left it outside.

Apparently, the sparks from the back of the plane iron and perhaps some iron dust ignited leftover sawdust that was stuck to the plastic guard. This was definitely a check your shorts moment. I could have walked away and it would have caught fire, especially considering that plastic and factory grease. What makes the incident even scarier is that there’s no mention of this potential danger from the manufacturers manuals or online sources. I knew that you shouldn’t run the dust collector when sanding metal, but nothing about this particular scenario. Even Fire Marshall Bill would’ve been stumped!

The only general come away points from this experience is: make sure you just hang out for a few minutes to check everything out before turning out the lights and calling it a day.

8 replies so far

View bigblockyeti's profile


5093 posts in 1686 days

#1 posted 02-25-2014 06:17 PM

Metal working of any kind that creates sparks should never be performed in the vicinity of sawdust (or any other combustible dust for that matter) for the reason you have demonstrated. As the safety officer at the mill work shop I worked in during college, I invited all of the employees to a lengthy meeting after someone was sharpening something on the 12” disc sander (for wood only) and the dust collection wasn’t working correctly. It resulted in what could have been a much more serious fire, fortunately all that was damaged was the drive belt. A fire extinguisher was require to put out the fire and in such a business it resulted in a lot of paperwork for me. The problem was two fold, anyone allowed to used the belt/disc sander has to know how to use it, part of that is checking the dust collection is working correctly (not rocket science). This was not confirmed, that was the first problem, the second was that something other than wood was on the sander specified exclusively for wood. Wood dust suspended in air at the right concentrations changes from combustible to flammable which can in some cases result in an explosion.

View ChuckV's profile


3110 posts in 3492 days

#2 posted 02-25-2014 06:24 PM

I am glad that you caught this before it turned into a disaster.

This story brings up another point that we have discussed before but bears repeating. Be sure to have a fully-charged fire extinguisher handy in your shop. Mine hangs near the shop door.

-- “Big man, pig man, ha ha, charade you are.” ― R. Waters

View crank49's profile


4030 posts in 2936 days

#3 posted 02-25-2014 06:26 PM

I would like to add an additional warning,
Be aware that the dust from sanding/grinding aluminum is explosive when showered with sparks from sanding/grinding of iron or steel. DAMHIKT

View DIYaholic's profile


19597 posts in 2640 days

#4 posted 02-25-2014 06:41 PM

Glad a tragedy was averted!!!

Thanks for the heads up and reminder that we must “police” the shop at the end of the day, for potential issues.

When I was researching sharpening in general, I knew that I did not want to mix wood and metal on the same machines, for just that reason. That is why I went with the WorkSharp 3000 and a slow speed grinder for my sharpening needs. I keep the belt/disk sander and Ridged OSS for wood only.

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procrastination a bad thing?

View Texcaster's profile


1273 posts in 1639 days

#5 posted 02-25-2014 08:34 PM

I kept starting a small grass fire cutting roofing iron with a cutoff wheel in my circular saw. Finally my work area was well soaked and a hose at the ready.

-- Mama calls me Texcaster but my real name is Mr. Earl.

View woodchuckerNJ's profile


1269 posts in 1599 days

#6 posted 02-25-2014 09:13 PM

Why would you be flattening your plane irons with a belt sander, there’s nothing that a belt sander could do to ensure a flat back?

-- Jeff NJ

View SCOTSMAN's profile


5849 posts in 3550 days

#7 posted 02-25-2014 09:23 PM

Wow Lucky nobody was killed. Alistair

-- excuse my typing as I have a form of parkinsons disease

View natenaaron's profile


442 posts in 1762 days

#8 posted 02-25-2014 10:48 PM

When I took over the shop our belt sander was only used with metal. Here is what I learned. If you have sparks you do not have enough lubrication. Tools used with metal should never be used with wood without a thorough cleaning and most importantly, clean your sander of built up debris on a regular basis. I learned the last one when the whole unit burst into flames when the on off switch shorted. Cool thing was the unit survived.

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